NEUROSCIENCES – COM MED + BEH SCI

The symptoms described by the patient—persistent sadness, irritability, emptiness, loss of interest in activities, difficulty carrying out daily tasks, and suicidal thoughts—are classic indicators of major depressive disorder (MDD). Depression is characterized by:

1. Core symptoms: Low mood and/or loss of interest or pleasure in most activities (anhedonia).
2. Additional symptoms: Fatigue, irritability, difficulty concentrating, changes in appetite or sleep patterns, and feelings of worthlessness or hopelessness.
3. Duration: Symptoms persisting for at least two weeks or longer.

Her mention of thoughts about taking her life highlights the urgency for immediate intervention to ensure her safety and provide appropriate treatment.

Why not the other options?

1. Schizophrenia: Characterized by psychotic symptoms such as delusions, hallucinations, disorganized thinking, and behavior, which are not present in this case.
2. Bipolar disorder: Involves episodes of both depression and mania/hypomania. There is no evidence of manic or hypomanic symptoms (e.g., elevated mood, increased energy, reduced need for sleep) in this patient.
3. Post-traumatic stress disorder (PTSD): Results from a traumatic event and includes symptoms such as intrusive memories, hyperarousal, and avoidance, none of which are described here.
4. Anxiety: Primarily involves excessive worry and fear without the hallmark depressive symptoms like low mood, loss of interest, and suicidal thoughts.

Nocturnal enuresis (bedwetting) refers to involuntary urination during sleep, not voluntary urination. It is most commonly seen in children but can also occur in adults with underlying medical or neurological conditions.

Since nighttime enuresis is involuntary, the statement “voluntary urination during sleep” is incorrect, making it the best choice.

Analysis of Each Option:

🚫 Incorrect Statement (Correct Answer):
🔹 “Nighttime enuresis – voluntary urination during sleep”
❌ Incorrect – Nocturnal enuresis is involuntary, meaning the person has no control over urination while sleeping.

✅ Correct Statements (Incorrect Choices):

🔹 “Nocturia – waking up multiple times in the night to urinate”
✔️ True – Nocturia is a condition where a person wakes up multiple times at night to urinate. It can be caused by excessive fluid intake, diabetes, bladder dysfunction, or prostate enlargement.

🔹 “Sleep apnea – interrupted breathing while sleeping”
✔️ True – Sleep apnea involves repeated pauses in breathing during sleep, often due to airway obstruction (obstructive sleep apnea) or neurological causes (central sleep apnea).

🔹 “Insomnia – difficulty falling asleep”
✔️ True – Insomnia is a common sleep disorder where a person has trouble falling asleep, staying asleep, or waking up too early.

🔹 “Bed wetting – involuntary urination during sleep”
✔️ True – Bedwetting (nocturnal enuresis) is involuntary urination during sleep, most commonly seen in children but also in some adults with medical conditions.

The frontal lobe is primarily responsible for personality, emotional regulation, social behavior, and executive functions.

• Damage to the prefrontal cortex (especially the orbitofrontal region) can lead to social disinhibition, impulsivity, poor judgment, and emotional instability.
• Patients may exhibit personality changes, such as apathy, aggression, or inappropriate social behavior.
• This type of damage is seen in traumatic brain injuries (TBI), frontotemporal dementia (FTD), and stroke affecting the frontal lobes.

A classic example is Phineas Gage, a railroad worker who had a frontal lobe injury and developed significant personality and emotional changes.

Why the Other Options Are Incorrect:

❌ 1. “Occipital” – Incorrect

• The occipital lobe is mainly responsible for vision.
• Damage results in visual disturbances (e.g., cortical blindness, visual field defects), not social/emotional changes.

❌ 2. “Parietal” – Incorrect

• The parietal lobe is involved in spatial awareness, sensory processing, and attention.
• Damage can lead to hemineglect (if non-dominant hemisphere is affected) or sensory loss, but not direct personality or emotional changes.

❌ 3. “Paracentral lobule” – Incorrect

• The paracentral lobule is part of the frontal and parietal lobes, responsible for motor and sensory control of the lower limbs and bladder control.
• It does not regulate social or emotional behavior.

❌ 4. “Temporal” – Partially Correct but Not the Best Answer

• The temporal lobe (especially the amygdala and hippocampus) plays a role in emotional processing and memory, but social behavior and personality are primarily controlled by the frontal lobe.
• Damage here affects memory and language more than social interactions.

Explanation:

According to the World Health Organization (WHO), a stroke (cerebrovascular accident, CVA) is defined as a neurological deficit due to disrupted cerebral blood flow lasting more than 24 hours or leading to death.

Key Definitions:

• Stroke → Neurological symptoms persist for more than 24 hours due to infarction or hemorrhage.
• Transient Ischemic Attack (TIA) → Neurological symptoms resolve within 24 hours (often within minutes to hours) without permanent damage.

A stroke can be:

1. Ischemic stroke (85%) – Due to a blocked artery (thrombosis or embolism).
2. Hemorrhagic stroke (15%) – Due to a ruptured blood vessel (intracerebral or subarachnoid hemorrhage).

Why the Other Options Are Wrong:

1️⃣ More than 3 minutes ❌

• Ischemic brain damage can begin within minutes, but stroke is not diagnosed unless symptoms persist for more than 24 hours.

2️⃣ At least 3 days ❌

• Stroke is diagnosed at 24 hours, not 3 days. However, symptoms may persist for days to weeks in severe cases.

3️⃣ Less than 1 hour ❌

• Symptoms lasting less than 1 hour are more consistent with a transient ischemic attack (TIA).

4️⃣ More than 1 hour ❌

• Symptoms lasting more than 1 hour but resolving before 24 hours are still considered TIA, not stroke.

The ability of young children to unconsciously absorb and apply language rules without formal instruction suggests implicit learning.

• Implicit learning occurs without conscious effort and involves acquiring grammatical rules, sentence structures, and phonetics simply by exposure to language.
• This type of learning relies on procedural memory and is heavily associated with the basal ganglia and Broca’s area.
• Young children do not explicitly analyze grammar; instead, they internalize language structures automatically through repeated exposure.

Why not the other options?

• Short-term learning → Refers to temporarily holding information, such as repeating a sentence, but does not explain rule-based sentence generation.
• Explicit learning → Requires conscious effort (e.g., studying grammar rules), but young children learn language without direct instruction.
• Working memory → Holds information for a short time for processing (e.g., temporarily remembering a sentence) but does not explain how children form new sentences following rules.
• Long-term learning → Refers to storing knowledge over extended periods, but implicit learning better describes how children acquire language rules unconsciously.

Thus, the correct answer is implicit learning, as it governs the natural acquisition of language rules in early childhood.

The surgeon breached the principle of honesty and truthfulness by persuading the patient to undergo surgery despite a lack of evidence that it is the best treatment option. Ethical medical communication requires providing complete, unbiased, and truthful information so that the patient can make an informed decision.

• Medical ethics emphasize transparency, and a physician must not mislead or withhold critical information to influence a patient’s decision.

Why not the other options?

• Beneficence → Refers to acting in the best interest of the patient. While the surgeon may believe surgery is beneficial, they are not prioritizing the patient’s best interest due to lack of evidence.
• Equity and justice → Concern fairness and equal access to care, but this scenario is more about misleading the patient rather than injustice.
• Active listening → Involves listening to the patient’s concerns, but the ethical violation here is about providing false or misleading information, not a failure to listen.
• Empathy → Involves understanding and sharing the patient’s emotions, but the surgeon’s issue here is lack of honesty, not lack of empathy.

Thus, the correct answer is honesty and truthfulness, as the surgeon has misled the patient by promoting an unproven surgical intervention.

In cases of head trauma or loss of consciousness following a road traffic accident, Computed Tomography (CT) is the radiologic investigation of choice. CT scans provide rapid and detailed images of the brain and are essential for identifying life-threatening conditions like intracranial hemorrhages, fractures, or contusions. Its quick acquisition time and availability in emergency settings make it the preferred modality.

Other Options:

1. X-rays: Useful for skeletal injuries but not ideal for assessing brain injuries.
2. Magnetic Resonance Imaging (MRI): More detailed but not the first-line choice due to longer acquisition times and less availability in emergency settings.
3. Ultrasound: Not suitable for assessing intracranial injuries.
4. Fluoroscopy: Used for real-time imaging in certain procedures but not for initial trauma assessment.

Smoking is the most common cause of stroke in young adults because it significantly increases the risk of ischemic stroke through multiple mechanisms:

• Endothelial damage → Promotes atherosclerosis.
• Increased clot formation → Promotes platelet aggregation and thrombus formation.
• Vasoconstriction → Reduces cerebral blood flow.
• Increased blood viscosity → Higher risk of embolism.

Why the other options are incorrect:

1. Alcohol:
   • Excessive alcohol consumption increases stroke risk but is not the leading cause in young adults.
   • Moderate alcohol intake has variable effects, while binge drinking increases hypertension and atrial fibrillation risk, leading to stroke.
2. Lack of exercise:
   • Sedentary lifestyle is a risk factor for stroke but is not the primary cause in young adults.
   • The effects of inactivity usually contribute to stroke over time, rather than being an immediate cause.
3. Obesity:
   • Obesity contributes to hypertension, diabetes, and metabolic syndrome, increasing the risk of stroke.
   • However, obesity alone is less directly linked to strokes in young adults than smoking.
4. Fatty diet:
   • A diet high in saturated fats and cholesterol contributes to atherosclerosis, but dietary habits take years to develop into stroke risk factors.
   • Smoking has more immediate effects compared to long-term dietary choices.

The Papez circuit is a neural pathway involved in the control of emotions, memory, and learning, and it is a key component of the limbic system.

The circuit consists of the following structures:

1. Hippocampus → Sends output via the fornix
2. Mammillary bodies (hypothalamus) → Relay signals to the anterior thalamic nucleus
3. Anterior nucleus of the thalamus → Projects to the cingulate gyrus
4. Cingulate gyrus → Sends fibers back to the hippocampus via the entorhinal cortex

This closed-loop system is crucial for:

• Memory consolidation (hippocampus)
• Emotional processing (limbic system)
• Behavioral responses

Damage to the Papez circuit, such as in Korsakoff’s syndrome (thiamine deficiency), leads to anterograde amnesia and confabulation.

Why the Other Options Are Wrong:

1. Cerebral Cortex (✗) [Higher Cognitive Functions, Not the Primary Site of the Papez Circuit]
   • The cerebral cortex is involved in higher cognitive functions like reasoning and decision-making.
   • However, the Papez circuit specifically belongs to the limbic system, which interacts with the cortex but is not a part of it.
2. Brainstem (✗) [Involved in Reflexes and Autonomic Control, Not Emotion and Memory]
   • The brainstem (midbrain, pons, medulla) controls basic life functions like breathing, heart rate, and reflexes.
   • It does not play a primary role in memory or emotional processing.
3. Posterior Fossa (✗) [Contains the Cerebellum and Brainstem, Not the Papez Circuit]
   • The posterior fossa houses the cerebellum and parts of the brainstem, which regulate balance and coordination.
   • It is not involved in memory or emotions.
4. Reticular Formation (✗) [Controls Arousal and Wakefulness, Not Memory Processing]
   • The reticular formation is a network in the brainstem that regulates alertness, consciousness, and autonomic functions.
   • It is not part of the Papez circuit.

Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system. It reduces neuronal excitability by increasing chloride ion influx, leading to hyperpolarization of neurons.

• Low GABA levels lead to increased neuronal excitability, which is a major factor in the pathophysiology of epilepsy.
• Seizures occur due to uncontrolled, excessive neuronal firing, which is normally inhibited by GABAergic activity.

GABA and Epilepsy:

✅ Many anti-epileptic drugs (AEDs) work by enhancing GABA activity, such as:

• Benzodiazepines (e.g., diazepam, lorazepam) → Increase GABA-A receptor activity.
• Barbiturates (e.g., phenobarbital) → Prolong GABA-A receptor opening.
• Vigabatrin → Inhibits GABA transaminase, preventing GABA breakdown.

Why not the other options?

• Attention deficit hyperactivity disorder (ADHD) → More related to dopamine and norepinephrine dysregulation, not GABA deficiency.
• Increased pain sensation → More associated with glutamate, substance P, and reduced endorphins, rather than low GABA.
• Cerebral palsy → Primarily caused by brain injury or abnormal development, not directly due to low GABA.
• Anxiety → While GABA is involved in anxiety regulation, it is not the primary cause; serotonin and amygdala dysfunction play a major role.

Thus, epilepsy is the correct answer, as it is strongly associated with low GABA levels and excessive neuronal excitability.

Once a child is diagnosed with paralytic poliomyelitis, the virus has already caused irreversible motor neuron damage, leading to muscle weakness and paralysis. At this stage, the most appropriate intervention is rehabilitation, which aims to maximize functional recovery and improve quality of life.

Key Aspects of Rehabilitation for Poliomyelitis:

✅ Physical therapy → Prevents muscle atrophy and contractures.
✅ Occupational therapy → Helps the child adapt to daily activities.
✅ Orthotic devices and mobility aids → Braces, crutches, or wheelchairs to assist movement.
✅ Surgical interventions (if needed) → For deformities or contractures.

Why not the other options?

• Awareness → Important for prevention, but it does not help an already paralyzed child.
• Vaccination → Prevents poliomyelitis but does not reverse paralysis once the child is infected.
• Nutritional supplementation → May support general health but does not treat paralysis.
• Health education → Useful for prevention and understanding of the disease, but not the primary intervention after diagnosis.

Thus, the most appropriate intervention after poliomyelitis has occurred is rehabilitation, as it helps the child regain function and mobility.

• A disease is classified as endemic when it is constantly present in a particular population, region, or community at a relatively stable rate.
• Examples of endemic diseases include:
  • Malaria in certain parts of Africa
  • Dengue fever in tropical regions
  • Tuberculosis (TB) in some developing countries

Why the Other Options Are Incorrect:

❌ 1. “Epidemic” – Incorrect

• An epidemic refers to a sudden increase in the number of cases of a disease in a specific area beyond the normal expected levels.
• Example: The Ebola outbreak in West Africa (2014-2016) was an epidemic.

❌ 2. “Pandemic” – Incorrect

• A pandemic occurs when a disease spreads across multiple countries or continents, affecting a large number of people.
• Example: COVID-19 (2020-present) is a pandemic.

❌ 4. “None of these” – Incorrect

• Endemic is the correct term, so “None of these” is incorrect.

❌ 5. “Outbreak” – Incorrect

• An outbreak is similar to an epidemic but usually refers to a localized, sudden increase in disease cases.
• Example: A norovirus outbreak in a school or cruise ship.

Understanding Klüver-Bucy Syndrome

• Klüver-Bucy syndrome results from bilateral lesions of the medial temporal lobes, particularly the amygdala.
• It is characterized by:
  ✅ Emotional blunting (lack of fear and emotions, placidity)
  ✅ Hyperphagia (excessive eating)
  ✅ Hypersexuality (inappropriate sexual behavior)
  ✅ Visual agnosia (difficulty recognizing objects visually)
  ✅ Oral fixation (tendency to put objects in the mouth)

Why the Correct Answer is Wrong (Not a Feature of Klüver-Bucy Syndrome)

✅ Bilateral motor paralysis is NOT a feature of Klüver-Bucy syndrome.

• Motor paralysis (inability to move limbs) results from damage to the motor cortex or corticospinal tracts.
• Klüver-Bucy syndrome primarily affects emotional and behavioral functions, not voluntary movement.

Why the Other Options Are Correct (Features of Klüver-Bucy Syndrome)

• Lack of emotions → Correct

  • Due to amygdala damage, patients show emotional blunting and reduced fear responses.

• Placidity → Correct

  • Patients become unusually calm and docile, even in stressful situations.

• Increased sexual drive → Correct

  • Hypersexuality is a hallmark of Klüver-Bucy syndrome, leading to inappropriate sexual behavior.

• Increased hunger → Correct

  • Patients experience hyperphagia, leading to excessive eating and oral fixation.

Poliomyelitis is caused by the poliovirus, which primarily targets the nervous system. The virus infects motor neurons in the spinal cord and brainstem, leading to muscle weakness or paralysis. Severe cases can result in permanent paralysis and respiratory failure if the diaphragm is affected. The poliovirus is transmitted through the fecal-oral route, initially infecting the gastrointestinal tract, but it primarily impacts the nervous system during its viremic phase.

Other Options:

1. Respiratory system: The respiratory muscles may be affected in advanced cases, but the primary infection site is the nervous system.
2. Musculoskeletal system: Paralysis affects muscles indirectly due to damage to motor neurons.
3. Cardiovascular system: Polio does not primarily affect the cardiovascular system.
4. Gastrointestinal system: The virus enters and multiplies in the gastrointestinal tract but primarily targets the nervous system.

The first step in managing a dog bite is immediate wound care, which includes washing and debridement to reduce the risk of infection, including rabies and other bacterial infections (such as Pasteurella, Staphylococcus, and Streptococcus species).

• Wound cleansing: The wound should be washed with soap and running water for at least 15 minutes.
• Debridement: Any devitalized tissue should be removed to lower the risk of infection.
• Antiseptic application: After thorough cleaning, an antiseptic (e.g., povidone-iodine) should be applied.

This step is critical because rabies virus, if present, can enter through open wounds. Proper wound cleansing is the most effective way to reduce the viral load.

Why the Other Options Are Wrong:

1. Testing the dog for rabies ❌

   • While observing the dog for signs of rabies (if available) is important, it is not the first step. Immediate wound care is prioritized before considering rabies status.

2. Administration of anti-rabies immunoglobulin (RIG) ❌

   • Rabies immunoglobulin is given only for Category III bites (deep wounds, mucosal exposure, or bites to high-risk areas like the face or hands).
   • Even if RIG is needed, wound cleansing comes first.

3. Administration of IV saline ❌

   • IV saline is not required unless there is severe bleeding or systemic involvement (e.g., shock). This is not a priority in a stable patient.

4. Administration of anti-rabies vaccine ❌

   • Rabies vaccination is important if indicated, but it is not the first step.
   • Vaccination is given after initial wound management to ensure proper immune response.

The 7th and final stage of the crisis intervention model involves creating a structured follow-up plan and ensuring agreement between the mental health professional and the individual in crisis. This stage is critical for:

1. Ensuring the person has access to support and resources after the initial intervention.
2. Monitoring progress and preventing a recurrence of the crisis.
3. Strengthening coping strategies and reinforcing any action plans made during the intervention.

Why not the other options?

1. Develop and formulate an action plan: This is the 6th stage, where immediate strategies are developed to help resolve the crisis and stabilize the individual.
2. Plan and conduct a crisis intervention: This is the 2nd stage, focused on initiating the intervention after assessing the situation.
3. Generate and explore alternatives: This is the 5th stage, where different coping strategies and solutions are discussed.
4. Deal with feelings and emotions: This is the 4th stage, where the professional helps the individual process their emotional response to the crisis.

Hydrophobia (fear of water) is a pathognomonic feature of rabies, meaning it is highly characteristic of the disease and rarely seen in other conditions.

• It occurs due to spasms of the pharyngeal muscles when the patient attempts to swallow, leading to a panic response.
• This symptom is caused by viral invasion of the brainstem, specifically affecting the medulla oblongata and areas controlling swallowing and breathing.
• Hydrophobia is typically seen in the furious (encephalitic) form of rabies, which is the most common presentation.

Why the Other Options Are Incorrect:

1. Depression ❌
   • Rabies can cause behavioral changes, including agitation and confusion, but depression alone is not pathognomonic.
2. Convulsions ❌
   • Seizures can occur in rabies but are not a hallmark feature of the disease.
   • Seizures are seen in many neurological infections, including meningitis, encephalitis, and metabolic disorders.
3. Agoraphobia ❌
   • Agoraphobia (fear of open spaces) is a psychiatric disorder, not associated with rabies.
4. Irritation ❌
   • Patients may show agitation and restlessness, but irritation alone is not pathognomonic for rabies.

The James-Lange theory of emotion states that physiological arousal occurs first, followed by the experience of emotion. According to this theory, Ali is afraid because he trembled, meaning his body reacts first, and then he interprets the emotion based on his physiological response.

• Example:
  • Event: Ali sees a snake 🐍.
  • Physiological response: His body trembles, heart rate increases, and adrenaline surges.
  • Emotion: Ali feels fear because he perceives his bodily reaction.

Why not the other options?

• Cannon-Bard theory → States that physiological arousal and emotion happen simultaneously, not sequentially. (Ali would feel fear at the same time his body trembles).
• Darwin’s theory → Focuses on evolutionary aspects of emotions (e.g., survival advantages), not the sequence of physiological responses and emotions.
• Two-factor theory (Schachter-Singer theory) → Suggests that physiological arousal is interpreted based on context before experiencing an emotion. (Ali would need to consciously label the trembling as fear).
• Appraisal theory → States that cognitive evaluation of the situation determines the emotional response, rather than bodily reactions leading to emotions.

Thus, the James-Lange theory is the correct answer, as it explains that Ali feels fear because his body trembles first.

The process of creative thinking follows a well-established model in psychology and problem-solving, often referred to as Wallas’ Stages of Creativity, which includes the following steps:

1. Preparation → Gathering knowledge, researching existing literature, and identifying the problem.
2. Incubation → Subconscious processing, where ideas form without active effort.
3. Illumination → The “Aha!” moment when a creative idea or solution emerges.
4. Evaluation → Critically assessing the idea for feasibility and relevance.
5. Implementation → Applying the idea to research, experimentation, or practice.

Why not the other options?

• Preparation, accommodation, assimilation, centration, egocentrism → Includes Piagetian cognitive development terms, not creativity stages.
• Incubation, preparation, revision, accommodation, centration → Does not follow the structured flow of creative thinking.
• Assimilation, centration, egocentrism, incubation, revision → Again, Piagetian cognitive development terms mixed with irrelevant steps.
• Accommodation, centration, egocentrism, incubation, revision → Focuses more on child cognitive development, not creativity.

Thus, the correct answer is preparation, incubation, illumination, evaluation, implementation, as it follows the natural process of creative thinking and research development.

Pre-exposure prophylaxis (PrEP) is recommended for individuals at high risk of exposure to the rabies virus, such as laboratory workers handling rabies-related viruses, veterinarians, and animal handlers. The vaccine consists of:

• Three doses of inactivated rabies vaccine administered on days 0, 7, and 21 (or 28).

PrEP provides immunity and reduces the need for post-exposure prophylaxis (PEP) if the person is exposed to the virus. However, in case of exposure, additional booster doses are still required for optimal protection.

Why not the other options?

1. H-RIG (human rabies immunoglobulin): Used in post-exposure prophylaxis (PEP) for individuals who have already been exposed to the rabies virus and have not received prior vaccination. It is not part of pre-exposure prophylaxis.
2. Post-exposure prophylaxis (PEP): Administered after potential exposure to the rabies virus, combining the rabies vaccine with rabies immunoglobulin (if unvaccinated previously).
3. E-RIG (equine rabies immunoglobulin): Similar to H-RIG, it is used in PEP and not recommended for pre-exposure scenarios.
4. Tetanus: A completely different vaccine, unrelated to rabies prophylaxis.

Response modulation refers to efforts to influence one’s emotional response after the emotional reaction has been fully triggered. In John’s case, he is diverting his attention from disturbing events to manage and suppress overwhelming negative emotions. This falls under the category of response-focused emotion regulation strategies, as it occurs after the emotional response has been activated.

Why not the other options?

1. Cognitive reappraisal: Involves changing the way one interprets or thinks about a situation to alter its emotional impact. This is a cognitive process and occurs earlier in the emotion regulation timeline compared to response modulation.
2. Antecedent-based strategies: Refer to emotion regulation strategies used before an emotional response is fully triggered. Examples include situation selection and cognitive reappraisal.
3. Response-focused strategies: A broader category that includes response modulation, but John’s action is specifically diverting attention to regulate his emotional reaction, making response modulation the best fit.
4. Situation selection: Refers to choosing or avoiding certain situations to influence emotions. John is not altering his environment but modulating his response to it.

An endemic disease is one that is constantly present in a specific population, region, or community at a relatively stable rate. It does not cause large-scale outbreaks but persists over time within a defined area.

Examples of endemic diseases:

• Malaria in parts of Africa and South Asia
• Dengue fever in tropical and subtropical regions
• Common cold in various populations worldwide

Why Are the Other Options Incorrect?

• Pandemic: ❌
  • A pandemic is a global outbreak of a disease affecting multiple countries or continents.
  • Example: COVID-19 pandemic (2020-present).
• Epidemic: ❌
  • An epidemic refers to a sudden increase in disease cases in a particular region or community beyond what is normally expected.
  • Example: Ebola outbreak in West Africa (2014-2016).
• Outbreak: ❌
  • An outbreak is a localized increase in disease cases in a small, defined area.
  • Example: Food poisoning outbreak at a restaurant.
  • It is similar to an epidemic but usually more localized and short-lived.
• None of these: ❌
  • Incorrect, as “endemic” is the correct term for a disease constantly present in a small population.

This disease is caused by a parasite leading to severe brain involvement if untreated. Vector.. Vector.. Vector.. Hector.. Hector Salamanca?

The first and most critical step in managing a potential rabies exposure is thorough wound washing. Washing the wound with soap and water for 10–15 minutes significantly reduces the risk of rabies transmission by physically removing the virus from the site of entry. This initial step is vital before administering post-exposure prophylaxis.

Other Options:

1. Give Rabies Vaccine: Vaccination is essential but comes after wound cleansing.
2. Clean wound with antiseptic: While beneficial, antiseptic use is secondary to wound washing with soap and water.
3. Give Rabies Vaccine and Rabies Immunoglobulin: Post-exposure prophylaxis (PEP) should be started promptly, but it follows initial wound care.
4. Observe the dog: Observing the dog is only relevant for animals that are domesticated and healthy. Since the dog was stray and the bite was unprovoked, immediate treatment is required.

An endemic disease refers to the constant presence and usual frequency of a disease or infectious agent in a particular geographical area or population group. It reflects a steady-state level of the disease within the community, often influenced by local environmental, social, and host factors.

Examples:

• Malaria in certain tropical regions.
• Chickenpox in regions without widespread vaccination.

Why not the other options?

1. Sporadic: Refers to cases that occur infrequently and irregularly, without a predictable pattern (e.g., rabies in humans).
2. Epidemic: Refers to an unexpected increase in the number of cases of a disease in a specific population over a short time (e.g., COVID-19 outbreaks in specific regions).
3. Incidence: Refers to the number of new cases of a disease occurring in a specific population during a specific time period. It is a measurement, not a pattern of disease occurrence.
4. Prevalence: Refers to the total number of cases (new and existing) of a disease in a population at a given time. It is also a measurement, not a pattern.

Schizophrenia is a neuropsychiatric disorder characterized by psychotic symptoms, including hallucinations, delusions, disorganized thought, and cognitive dysfunction. The pathophysiology is complex, but the dopamine hypothesis remains the most widely accepted explanation.

Correct Answer: Increased Dopamine

Why is Increased Dopamine the Correct Answer?

• The dopamine hypothesis suggests that hyperactivity of dopaminergic pathways contributes to schizophrenia, particularly in the mesolimbic system.
• Dopaminergic dysregulation in schizophrenia:
  • Increased dopamine activity in the mesolimbic pathway → Positive symptoms (hallucinations, delusions, paranoia).
  • Decreased dopamine activity in the mesocortical pathway → Negative symptoms (social withdrawal, flat affect, cognitive impairment).
• Antipsychotic medications (e.g., haloperidol, risperidone, clozapine) work by blocking dopamine D2 receptors, reducing excessive dopamine transmission.

Why Are the Other Options Incorrect?

1. Decreased Acetylcholine

   • Acetylcholine is involved in memory and cognition, and while cholinergic dysfunction may play a role in cognitive symptoms, it is not the primary cause of schizophrenia.
   • Incorrect because the main neurotransmitter imbalance is dopamine, not acetylcholine.

2. Increased Glutamate

   • The glutamate hypothesis suggests that hypofunction of NMDA receptors (glutamate receptors) may contribute to schizophrenia.
   • However, decreased glutamate activity, rather than increased, is more commonly implicated in schizophrenia.
   • Incorrect because hypoactivity of glutamate, not hyperactivity, is more likely involved.

3. Decreased Serotonin

   • While serotonin is involved in mood and cognition, schizophrenia is primarily a dopamine-related disorder.
   • Atypical antipsychotics (e.g., clozapine) block both dopamine and serotonin (5-HT2A) receptors, suggesting some involvement, but dopamine is still the primary neurotransmitter.
   • Incorrect because serotonin plays a secondary role compared to dopamine.

4. None of These

   • Since dopamine dysregulation is a well-established cause of schizophrenia, this option is incorrect.

Among the options listed, obesity is the only modifiable risk factor for stroke. Modifiable risk factors are those that can be changed or controlled through lifestyle modifications or medical interventions.

Why is obesity a modifiable risk factor?

• Increases the risk of hypertension, diabetes, and hyperlipidemia, which are all major contributors to stroke.
• Promotes atherosclerosis, leading to ischemic stroke.
• Can be managed through lifestyle changes, such as diet, exercise, and medical therapy.

Why not the other options?

• Genetics → A non-modifiable factor, as inherited predispositions cannot be changed.
• Gender → Men have a higher stroke risk, but this is not modifiable.
• Family history → If close relatives have had strokes, the individual is at increased risk, but this cannot be altered.
• Age → Older age is a major risk factor for stroke, but it cannot be changed.

Thus, the correct answer is obesity, as it is a modifiable risk factor that can be improved through lifestyle and medical interventions.

Corynebacterium diphtheriae is the causative agent of diphtheria, a bacterial infection characterized by the formation of a thick, grayish pseudomembrane over the tonsils, pharynx, or larynx. The pseudomembrane is composed of fibrin, dead cells, and inflammatory exudates. Attempting to remove the membrane may cause bleeding due to the underlying tissue’s vascular damage. This condition is highly infectious and can lead to airway obstruction and systemic complications due to toxin production.

Other Options:

1. Klebsiella: Causes respiratory infections but does not produce a pseudomembrane.
2. Streptococcus: May cause pharyngitis or tonsillitis but does not form a characteristic grayish membrane.
3. Bordetella pertussis: Causes whooping cough, primarily affecting the respiratory tract without forming pseudomembranes.
4. Pseudomonas: Causes opportunistic infections and wound infections but is not associated with pseudomembrane formation in the pharynx.

The principle of autonomy is violated when a patient’s right to make an informed decision about their own healthcare is disregarded. Informed consent is a critical aspect of respecting a patient’s autonomy, ensuring they understand and agree to the risks and benefits of a procedure. Performing a risky procedure without consent disregards the patient’s ability to decide for themselves.

Other Options:

1. Beneficence: Refers to acting in the best interest of the patient. While the surgeon believed their actions were beneficial, they did not respect the patient’s autonomy.
2. Non-maleficence: Refers to avoiding harm. While this principle could be debated if the procedure resulted in harm, it is not the primary issue here.
3. Justice: Refers to fairness and equal treatment, which is not the focus in this scenario.
4. Fidelity: Refers to loyalty and keeping promises, but it is not central to the case of informed consent.

Relationship management is the ability to build and maintain healthy relationships through effective communication and conflict resolution. In this scenario, Alex needs to address his frustrations constructively and foster a positive working relationship with Emily. This requires skills such as active listening, assertive communication, and conflict resolution, which fall under relationship management.

Other Options:

1. Empathy: Important for understanding Emily’s perspective, but the primary issue here is managing the interaction constructively.
2. Self-awareness: Refers to recognizing one’s emotions, which is foundational but not the primary skill needed in this case.
3. Self-regulation: Involves controlling one’s emotional reactions, which is helpful but not the main requirement here.
4. Social awareness: Involves understanding group dynamics and others’ emotions, which is related but secondary to managing the relationship.

• Primary Prevention: This involves preventing the onset of disease before it occurs. In this case, adopting a healthy lifestyle (eating a diet rich in fruits and vegetables, maintaining a healthy weight) is aimed at preventing the development of hypertension and stroke in individuals who do not yet have these conditions.
• Primordial Prevention: This focuses on preventing the risk factors themselves from developing (e.g., preventing obesity or unhealthy diets in a population). While related, the scenario described is more about individual behavior change rather than addressing societal or environmental factors.
• Secondary Prevention: This involves early detection and intervention to prevent the progression of a disease that has already developed (e.g., screening for hypertension and treating it to prevent stroke).
• Tertiary Prevention: This focuses on managing and rehabilitating individuals with established disease to prevent complications or further deterioration (e.g., stroke rehabilitation).
• Quaternary Prevention: This involves avoiding overmedicalization or unnecessary interventions in patients who are already being treated.

Since the scenario is about preventing the onset of hypertension and stroke in healthy individuals, the correct answer is Primary Prevention.

• Memory is a fundamental cognitive function that allows an individual to encode (store), retain, and retrieve information when needed.
• It is a key part of learning, decision-making, and daily functioning.
• The brain structures involved in memory include the hippocampus, amygdala, and cerebral cortex.
• Memory is categorized into different types:
  • Short-term memory (temporary storage).
  • Long-term memory (stored for extended periods).
  • Procedural memory (skills and habits).

Why the Other Options Are Wrong:

1. Skills of learning:
   • Learning is related to memory but is a broader concept involving acquiring new knowledge or modifying behavior. Memory is just one component of learning.
2. Genetic control of brain:
   • Genetics plays a role in brain development and cognitive abilities, but memory itself is not solely controlled by genes; it involves neural circuits and experiences.
3. Ability to rest ourselves:
   • Memory and rest (sleep) are linked, as sleep helps consolidate memory, but resting is not the definition of memory.
4. Forgetting a movie:
   • Forgetting is the opposite of memory and is just one aspect of how memory functions.

Alexia is the inability to read due to damage in the visual and language processing areas of the brain, particularly the left occipitotemporal region, including the angular gyrus. It is often associated with stroke or traumatic brain injury affecting the dominant (usually left) hemisphere.

Why the other options are incorrect:

1. Agraphia:
   • Agraphia is the inability to write, not read.
   • It often occurs alongside alexia when there is damage to the angular gyrus.
2. Prosopagnosia:
   • Prosopagnosia is the inability to recognize faces, caused by damage to the fusiform gyrus in the temporal lobe.
   • It is unrelated to reading difficulties.
3. Aphasia:
   • Aphasia is a broader term for language impairment, affecting speech and comprehension, often due to left hemisphere damage.
   • Specific types like Wernicke’s aphasia can cause difficulties with understanding written and spoken language, but alexia specifically refers to reading impairment.
4. Dysphagia:
   • Dysphagia refers to difficulty swallowing, which is unrelated to reading ability.

The first step in managing a dog bite is thorough wound cleaning and debridement to reduce the risk of infection, including rabies, tetanus, and bacterial infections (e.g., Pasteurella, Staphylococcus, Streptococcus, Capnocytophaga canimorsus). Immediate and vigorous washing with soap and water for at least 15 minutes significantly reduces the risk of rabies virus transmission.

Why the Other Options Are Wrong:

1. Administration of anti-rabies immunoglobulin (RIG) – While rabies immunoglobulin is essential in some cases (e.g., category III bites), it is not the first step. Wound cleaning should be done before administering RIG.
2. Administration of anti-rabies vaccine – The rabies vaccine is crucial but should be given after wound cleansing. The post-exposure prophylaxis (PEP) schedule includes rabies vaccine on days 0, 3, 7, and 14.
3. Administration of IV saline – IV fluids are not the priority unless the patient is in shock or has systemic symptoms. The main concern in a dog bite is infection prevention.
4. Testing the dog for rabies – While important for determining further treatment, waiting for test results is not the priority in an emergency setting. If the dog is available, it should be observed for 10 days for signs of rabies, but immediate wound management takes precedence.

The first step in the management of any animal bite, especially a dog bite, is washing and debridement of the wound. This is crucial for preventing infection and reducing the risk of rabies transmission. Immediate cleaning with soap and water, and possibly using antiseptic solutions, can help minimize the risk of infection. The wound should also be properly examined for any remaining debris or foreign material, which may need to be removed.

Here’s why the other options are incorrect at this stage:

1. Testing the dog for rabies: While testing the dog for rabies may be necessary later if the dog is available for observation, this is not the immediate step in wound management. The first priority is to clean the wound and assess for potential rabies risk.
2. Administration of anti-rabies immunoglobulin: Anti-rabies immunoglobulin is administered if the patient is at high risk of rabies exposure, typically when the dog is not available for observation or is known to have rabies. However, this is not the immediate step unless there are signs of potential rabies exposure.
3. Administration of IV saline: IV saline administration may be necessary for fluid resuscitation in cases of severe bleeding or shock, but this is not the first step unless the patient shows signs of hypovolemia or circulatory compromise.
4. Administration of anti-rabies vaccine: While the rabies vaccine may be indicated in certain situations, especially if the dog is unvaccinated or rabies status is unknown, the first priority is wound cleaning and debridement. The rabies vaccine would typically be administered after the wound is cleaned and when a risk assessment for rabies is performed.

The patient’s symptoms, including persistent sadness, irritability, feelings of emptiness, crying spells, loss of interest in activities, and difficulty performing daily tasks, along with suicidal ideation, strongly suggest major depressive disorder (MDD). Depression often involves significant impairment in social, occupational, or other areas of functioning.

Other Options:

1. Schizophrenia: Involves psychotic symptoms such as delusions and hallucinations, which are not described here.
2. Bipolar disorder: Characterized by episodes of mania or hypomania alternating with depression. No manic or hypomanic symptoms are mentioned.
3. Anxiety: Primarily involves excessive worry or fear without the hallmark depressive features described here.
4. Post-Traumatic Stress Disorder: Occurs following a traumatic event and includes symptoms like intrusive memories, hypervigilance, and avoidance, which are absent in this case.

In Pakistan’s Expanded Program on Immunization (EPI) schedule, the injectable polio vaccine (IPV) is typically administered at 14 weeks of age as part of routine immunization. This dose is given alongside other vaccines such as Pentavalent-3 and OPV-3 (oral polio vaccine). IPV provides systemic immunity by stimulating the production of antibodies in the bloodstream, which helps prevent poliovirus from spreading to the nervous system.

Why not the other options?

1. 10 weeks: OPV-2 (oral polio vaccine) is administered at this age, not IPV.
2. 9 months: At this age, the measles vaccine is given, not IPV.
3. 14 weeks and 9 months: IPV is only given at 14 weeks in the EPI schedule, not at 9 months.
4. 6 weeks: OPV-1 and Pentavalent-1 are given at this age, not IPV.

Procedural memory is a type of long-term memory that involves learning skills and tasks that initially require conscious effort but later become unconscious and automatic with practice. Examples include riding a bike, typing on a keyboard, and playing a musical instrument.

Procedural memory is associated with the basal ganglia, cerebellum, and motor cortex and does not require conscious recall once fully learned.

Why the other options are incorrect:

1. Non-associative learning:
   • This includes habituation and sensitization, which involve changes in response to repeated stimuli but do not specifically involve complex skill learning.
2. Episodic memory:
   • Episodic memory is a type of declarative memory that stores personal experiences and events (e.g., recalling your first day of school).
   • It does not become unconscious or automatic over time.
3. Associative learning:
   • Associative learning involves classical and operant conditioning, where a response is linked to a stimulus (e.g., Pavlov’s dogs salivating to a bell).
   • It is not the same as learning automatic motor tasks.
4. Priming:
   • Priming is a type of implicit memory where exposure to one stimulus influences response to a later stimulus (e.g., recognizing a word faster after seeing it before).
   • It does not involve learning motor skills or automatic behaviors.

Since the 85-year-old male is in a coma, he is unable to provide consent for his medical decisions. In this case, his daughter is making medical decisions on his behalf, which is classified as surrogate consent.

Surrogate Decision-Making:

• A surrogate (proxy) decision-maker is typically a legally authorized family member (such as a spouse, adult child, or designated healthcare proxy) who makes medical decisions when a patient is incapable of doing so.
• The hierarchy of surrogates varies by jurisdiction but generally follows: spouse > adult children > parents > siblings.
• Surrogates should make decisions based on the patient’s previously expressed wishes or best interests.

Why not the other options?

• Expressed consent → Occurs when a patient directly agrees to treatment verbally or in writing, which is not possible in this case.
• Informed consent → Requires a competent patient to understand risks, benefits, and alternatives before agreeing to treatment, which the patient cannot do due to being in a coma.
• Opt-out consent → Used in specific cases like organ donation, where consent is assumed unless the individual explicitly refuses. This scenario does not involve opt-out consent.
• Implied consent → Assumed in emergency situations when the patient is incapacitated, and immediate treatment is necessary to prevent harm. Since the patient’s daughter is actively making decisions, this is a case of surrogate consent, not implied consent.

Thus, the correct answer is surrogate consent, as the daughter is legally making medical decisions for her incapacitated father.

Kluver-Bucy syndrome is a rare neurobehavioral disorder that occurs due to bilateral damage to the temporal lobes, particularly the amygdala. It is characterized by a set of specific symptoms, but bilateral paralysis is not one of them. The classic features of Kluver-Bucy syndrome include:

1. Hyper-sexuality: Increased sexual activity or inappropriate sexual behaviors.
2. Hyper-orality: A tendency to examine objects by putting them in the mouth.
3. Hyperphagia: Excessive eating or consumption of non-food items.
4. Lack of emotions (emotional blunting): Reduced fear, aggression, or emotional responses.

Why the other options are correct:

• Hyper-sexuality, hyper-orality, hyperphagia, and lack of emotions are all well-documented symptoms of Kluver-Bucy syndrome. These behaviors result from damage to the amygdala and surrounding temporal lobe structures, which play a key role in regulating emotions, feeding, and sexual behavior.

Why “bilateral paralysis” is incorrect:

• Bilateral paralysis refers to the loss of muscle function on both sides of the body, which is not associated with Kluver-Bucy syndrome. This condition primarily affects behavior and emotional regulation, not motor function.

The ideal doctor-patient relationship is one where both the doctor and the patient actively participate in decision-making. This is known as the shared decision-making model, where:

• The doctor provides medical expertise, options, and guidance.
• The patient shares their values, preferences, and concerns.
• Both work together as partners to reach the best possible treatment decision.

Why the other options are incorrect:

1. Consumeristic relationship:
   • In this model, the patient is treated as a customer who makes all the decisions, while the doctor acts as a service provider.
   • It undermines the doctor’s professional expertise and may lead to inappropriate medical choices.
2. Mutual relationship:
   • While mutual respect is important, this term is vague and does not emphasize equal participation in decision-making.
3. Default relationship:
   • This occurs when neither the doctor nor the patient takes an active role in decision-making, leading to poor communication and dissatisfaction.
   • It is considered a negative doctor-patient relationship.
4. Paternalistic relationship:
   • In this model, the doctor makes decisions without involving the patient, assuming they know best.
   • It was common in the past but is now discouraged in favor of shared decision-making, except in cases where the patient lacks decision-making capacity.

Why “mutual relationship” is less precise:

• “Mutual relationship” implies a general cooperation, but it does not specifically highlight the equal involvement in decision-making.
• A doctor and patient can have a mutual relationship without active shared decision-making (e.g., if the doctor still makes most decisions, even if the patient agrees).
• Shared decision-making ensures that both the doctor’s expertise and the patient’s preferences are equally considered.

Key Difference:

• Mutual relationship = general cooperation and respect.
• Shared decision-making = active participation by both doctor and patient in medical decisions.

The World Health Organization (WHO) defines a stroke as a sudden loss of cerebral function due to a vascular cause that lasts more than 24 hours or leads to death.

🔹 Key Criteria for Stroke (WHO Definition):

• Neurological deficit of vascular origin
• Lasts more than 24 hours
• Can be ischemic (87%) or hemorrhagic (13%)

If symptoms resolve within 24 hours, it is classified as a transient ischemic attack (TIA) instead of a stroke.

Why Others Are Incorrect?

❌ More than 3 minutes:

• While brain tissue starts to suffer ischemic damage in minutes, a stroke is defined based on symptom duration, not onset speed.

❌ Less than 1 hour:

• Neurological deficits lasting less than 24 hours are categorized as TIA, not a stroke.

❌ More than 1 hour:

• Some strokes last more than an hour, but the official definition requires 24 hours or more.

❌ At least 3 days:

• A stroke does not need to last 3 days to be classified as one. 24 hours is the cutoff.

• The child has been bitten by a dog and is actively bleeding, which suggests a Category III exposure (deep wound, mucosal exposure, or multiple bites).
• Despite having completed the EPI (Expanded Program on Immunization) vaccinations, rabies post-exposure prophylaxis (PEP) is still required, as routine childhood vaccines do not include rabies vaccination.
• Category III dog bites require both:
  1. Rabies vaccine (post-exposure prophylaxis)
     • Given on Day 0, 3, 7, and 14 (sometimes Day 28 if immunocompromised).
  2. Rabies immunoglobulin (HRIG or ERIG)
     • Infiltrated into and around the wound for immediate neutralization of the virus.
  3. Appropriate wound cleaning and antibiotic coverage
     • Thorough washing with soap and water is crucial.
     • Antibiotics (e.g., amoxicillin-clavulanate) to prevent secondary bacterial infections.

Why the Other Options Are Wrong:

1. Anti-rabies vaccine and appropriate antibiotics:
   • Incorrect, because a deep, actively bleeding bite (Category III) requires both vaccine and immunoglobulin, not just antibiotics.
2. Anti-rabies vaccine of both the dog and the child:
   • Incorrect, because vaccinating the dog is irrelevant in post-exposure prophylaxis. The priority is vaccinating the child.
3. Anti-rabies vaccine and cleaning the wound:
   • Incorrect, because cleaning is essential but not sufficient in a high-risk bite. Immunoglobulin must be administered as well.
4. Anti-rabies vaccine infiltration into the wound:
   • Partially correct, but not the best answer since it does not explicitly mention the need for systemic vaccine doses along with immunoglobulin.

In the assessment phase of the ACT (Assessment, Crisis Intervention, Trauma Treatment) Model, the primary focus is to establish a therapeutic alliance and rapport with the individual. This step is crucial for building trust and creating a safe space for the person to communicate their feelings and experiences. Establishing rapport allows the therapist or interventionist to gather critical information and lay the foundation for effective crisis intervention.

Other Options:

1. Implementing relaxation techniques immediately: While helpful in managing anxiety, this is typically addressed after rapport is established.
2. Identifying the root cause of Emily’s trauma: Understanding the trauma is essential, but it is secondary to establishing trust and rapport during the assessment phase.
3. Providing long-term therapy sessions: This is part of the recovery phase, not the immediate crisis assessment phase.
4. Administering medication to alleviate symptoms: Medication may be part of the treatment plan, but it is not the focus of the assessment phase.

Hydrophobia (fear of water) is a pathognomonic feature of rabies, meaning it is highly characteristic of the disease and rarely seen in other conditions.

• It occurs due to spasms of the pharyngeal muscles when the patient attempts to swallow, leading to a panic response.
• This symptom is caused by viral invasion of the brainstem, specifically affecting the medulla oblongata and areas controlling swallowing and breathing.
• Hydrophobia is typically seen in the furious (encephalitic) form of rabies, which is the most common presentation.

Why the Other Options Are Incorrect:

1. Depression ❌
   • Rabies can cause behavioral changes, including agitation and confusion, but depression alone is not pathognomonic.
2. Convulsions ❌
   • Seizures can occur in rabies but are not a hallmark feature of the disease.
   • Seizures are seen in many neurological infections, including meningitis, encephalitis, and metabolic disorders.
3. Agoraphobia ❌
   • Agoraphobia (fear of open spaces) is a psychiatric disorder, not associated with rabies.
4. Irritation ❌
   • Patients may show agitation and restlessness, but irritation alone is not pathognomonic for rabies.

The Hippocratic Oath is the first complete documented set of rules of ancient ethics, attributed to Hippocrates, the father of medicine. It provides ethical guidelines for physicians, emphasizing:

• Patient confidentiality
• Non-maleficence (“Do no harm”)
• Beneficence (acting in the patient’s best interest)
• Professional conduct and integrity

Why the other options are incorrect:

1. Nuremberg Code:
   • The Nuremberg Code (1947) was established after World War II and outlines ethical principles for human experimentation, particularly emphasizing informed consent.
2. Alma Mater:
   • “Alma Mater” refers to a university or school one has attended, not an ethical code.
3. Declaration of Geneva:
   • Adopted by the World Medical Association (WMA) in 1948, the Declaration of Geneva is a modern adaptation of the Hippocratic Oath but is not the first documented ethical code.
4. Helsinki Declaration:
   • The Helsinki Declaration (1964) provides ethical guidelines for medical research involving human subjects, established by the World Medical Association.

The Expanded Program on Immunization (EPI) recommends a five-dose schedule of tetanus toxoid (TT) vaccine for long-term prevention in reproductive-age females (typically 15–49 years) to protect against maternal and neonatal tetanus.

Tetanus Toxoid (TT) Vaccination Schedule for Reproductive-Age Women (EPI Protocol):

• This schedule ensures lifelong immunity against tetanus for future pregnancies and general protection.

Why the Other Options Are Incorrect:

❌ 1. “Two doses” – Incorrect

• Two doses (TT1 and TT2) provide only 3 years of protection, which is not sufficient for long-term prevention.

❌ 2. “Four doses” – Incorrect

• Four doses (TT1 to TT4) provide 10 years of protection, but long-term (lifelong) immunity requires the fifth dose.

❌ 3. “Three doses” – Incorrect

• Three doses (TT1 to TT3) provide only 5 years of protection, which is not enough for long-term immunity.

❌ 5. “Single dose” – Incorrect

• A single TT dose (TT1) provides no protection against tetanus.
• It only initiates the immunization process but does not confer immunity

The symptoms described, such as ptosis (drooping eyelids), diplopia (double vision), dysphagia (difficulty swallowing), and respiratory failure, indicate an effect on the nervous system. Neurotoxins act by disrupting synaptic transmission, either at the neuromuscular junction or central nervous system, leading to paralysis and respiratory arrest. This is characteristic of snakes like cobras and kraits.

Other Options:

1. Cytolytic: Causes local tissue destruction, pain, and swelling, typically not systemic neurological symptoms.
2. Cytotoxic: Damages cells and tissues but does not lead to neurological paralysis.
3. Hemotoxic: Affects blood clotting and vascular integrity, leading to bleeding and organ damage.
4. Hemolytic: Causes destruction of red blood cells but does not affect the nervous system.

In developing countries, older adults are the most likely age group to experience a stroke. This is primarily due to:

• Increased prevalence of hypertension, diabetes, and smoking
• Limited access to preventive healthcare
• Higher rates of untreated cardiovascular disease
• Aging population with cumulative vascular risk factors

While strokes can occur in younger individuals due to conditions like cardioembolic events, sickle cell disease, or vasculitis, the vast majority of strokes still occur in older adults due to atherosclerosis and hypertension.

Other options explained:

❌ Adolescents, young adults, teenagers, and children → While strokes can occur in younger populations due to genetic, hematologic, or congenital factors, they are far less common than in older adults.

MRI is the most sensitive and specific imaging modality for detecting spinal nerve compression. It provides detailed images of soft tissues, including intervertebral discs, nerve roots, and the spinal cord. MRI is particularly useful for diagnosing conditions such as herniated discs, spinal stenosis, and other pathologies that may lead to nerve compression.

Other Options:

1. Computed Tomography (CT): Better for detecting bone abnormalities but less effective in visualizing soft tissues and nerve roots.
2. Radionuclide bone scan: Used for detecting bone metastases, fractures, or infections, but it does not show nerve compression.
3. Tractography: A specialized MRI technique used for visualizing neural tracts, not commonly used for diagnosing nerve compression.
4. Myelography: An invasive technique involving contrast injection into the spinal canal, now largely replaced by MRI for nerve compression.