Peripheral Neuropathy, Neuromuscular Junction, and Myopathies — WACS Viva & Clinical Scenarios (Neurology)

Exam-style peripheral neuropathy, neuromuscular junction, and myopathies viva scenarios with examiner probes and model answers for Internal Medicine candidates.

Scenarios covered

• SCENARIO 1: A 28-year-old man presents to the emergency department with a 4-day history of progressive ascending weakness beginning in the distal lower limbs, associated with tingling paresthesias in the toes and difficulty climbing stairs. Over the past 12 hours, he developed bilateral facial weakness and shortness of breath when lying flat. Two weeks prior, he had a self-limiting diarrheal illness. Examination reveals bilateral lower motor neuron facial palsy, symmetrical flaccid quadriparesis with power grade 3/5 proximally and 2/5 distally, generalized absence of deep tendon reflexes, and reduced sing
• SCENARIO 2: A 34-year-old woman presents with fluctuating bilateral ptosis and diplopia worsening towards the evening, difficulty chewing food, and proximal upper limb weakness. During examination, sustained upward gaze for 60 seconds elicits worsening ptosis. Discuss the diagnostic approach to establish a definitive diagnosis of myasthenia gravis, how you would differentiate a myasthenic crisis from a cholinergic crisis, and the evidence-based management strategy for this patient.
• SCENARIO 3: A 52-year-old woman presents with insidious, progressive, symmetric proximal muscle weakness of the shoulder and pelvic girdles over 3 months, accompanied by difficulty getting up from a low chair and combing her hair. Physical examination reveals violaceous erythema over the upper eyelids with periorbital edema, erythematous flat-topped papules over the dorsum of the metacarpophalangeal joints, and normal deep tendon reflexes. Describe the clinical approach, laboratory investigations, muscle biopsy findings, and treatment protocol for this patient, including recommended cancer screening proto
• SCENARIO 4: A 45-year-old male farmer presents with multiple patchy areas of numbness over the upper and lower extremities, right wrist drop, and left foot drop. Physical examination demonstrates thickened, non-tender greater auricular and common peroneal nerves, along with hypopigmented anesthetic skin plaques over the trunk. Detail the clinical localization, differential diagnosis with specific reference to mononeuropathy multiplex in tropical practice, diagnostic confirmation methods, and the multimodal treatment regimen.
• SCENARIO 5: A 58-year-old man with hyperlipidemia and type 2 diabetes mellitus is brought to the medical emergency room with severe generalized muscle pain, severe proximal weakness, and passage of dark brown tea-colored urine 10 days after starting clarithromycin while continuing his high-dose atorvastatin therapy. Describe your immediate diagnostic assessment, interpretation of biochemical markers, and stepwise emergency management to prevent acute renal shutdown.