AMC MCQ Neurology and Mental Health 3 — Questions and Answers
Question 1: A 22-year-old presents with foot drop and weakness of ankle dorsiflexion after sitting cross-legged for a prolonged period. Which nerve is most likely affected?
- Common peroneal (fibular) nerve (Correct answer)
- Tibial nerve
- Femoral nerve
- Sciatic nerve
Correct answer: Common peroneal (fibular) nerve
Compression of the common peroneal nerve at the fibular head causes foot drop and impaired dorsiflexion.
Question 2: A 19-year-old student has had six months of excessive worry about many areas of life, restlessness, muscle tension and difficulty concentrating most days. What is the most likely diagnosis?
- Generalised anxiety disorder (Correct answer)
- Panic disorder
- Obsessive-compulsive disorder
- Adjustment disorder
Correct answer: Generalised anxiety disorder
Persistent, excessive, hard-to-control worry across multiple domains for at least six months defines generalised anxiety disorder.
Question 3: A patient develops a sudden severe headache, neck stiffness, photophobia and a third nerve palsy. What is the most likely underlying cause?
- Ruptured posterior communicating artery aneurysm (Correct answer)
- Migraine with aura
- Tension-type headache
- Cluster headache
Correct answer: Ruptured posterior communicating artery aneurysm
A painful third nerve palsy with meningism strongly suggests a posterior communicating artery aneurysm causing subarachnoid haemorrhage.
Question 4: A 60-year-old with long-standing alcohol use presents confused, with ophthalmoplegia and ataxia. What is the most appropriate immediate treatment?
- Intravenous thiamine before any glucose (Correct answer)
- Intravenous glucose alone
- Oral folic acid
- Benzodiazepine sedation only
Correct answer: Intravenous thiamine before any glucose
Wernicke's encephalopathy requires parenteral thiamine before glucose to avoid precipitating irreversible damage.
Question 5: A 35-year-old man believes he is being followed by government agents, hears voices commenting on his actions, and has shown social withdrawal for the past eight months. What is the most likely diagnosis?
- Schizophrenia (Correct answer)
- Bipolar affective disorder
- Delusional disorder
- Schizoaffective disorder
Correct answer: Schizophrenia
Persistent delusions, third-person auditory hallucinations and functional decline beyond a month indicate schizophrenia.
Question 6: A 28-year-old woman with multiple sclerosis develops acute painful loss of vision in one eye with reduced colour vision. What is the most likely diagnosis?
- Optic neuritis (Correct answer)
- Central retinal artery occlusion
- Acute angle-closure glaucoma
- Retinal detachment
Correct answer: Optic neuritis
Painful monocular visual loss with impaired colour vision in a young patient with MS is typical of optic neuritis.
Question 7: A 75-year-old develops gradual cognitive decline with prominent early memory loss and no focal neurological signs. What is the most likely diagnosis?
- Alzheimer's disease (Correct answer)
- Vascular dementia
- Lewy body dementia
- Frontotemporal dementia
Correct answer: Alzheimer's disease
Insidious progressive memory loss without early focal deficits is most consistent with Alzheimer's disease.
AMC MCQ Neurology and Mental Health 3
A 22-year-old presents with foot drop and weakness of ankle dorsiflexion after sitting cross-legged for a prolonged period.
Which nerve is most likely affected?