Medical Council of Canada Updated MCCQE Exam Questions and Answers by cecily

Wernicke encephalopathy is a medical emergency caused by thiamine (vitamin B1) deficiency, most often seen in chronic alcohol use. The classic triad is:

Confusion

Oculomotor dysfunction (e.g., nystagmus, cranial nerve palsies)

Ataxia

Toronto Notes 2023 – Neurology and Psychiatry, “Wernicke Encephalopathy” Section:

“Wernicke encephalopathy is diagnosed clinically. Symptoms include ophthalmoplegia (e.g., CN VI palsy), horizontal nystagmus, ataxia, and confusion. Immediate parenteral thiamine is indicated before glucose administration.”

MCCQE1 Objectives (Neurology > 75-1: Neurologic Emergencies):

“Candidates must recognize Wernicke encephalopathy in at-risk individuals and initiate urgent thiamine replacement.”

Other choices like cerebellar degeneration (A) and hepatic encephalopathy (D) are more chronic and lack the characteristic eye findings. Subdural hematoma (B) and hemorrhage (E) may mimic confusion but are less likely with these neurologic signs and history.

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Comprehensive and Detailed Explanation:

Epidural analgesia is associated with increased maternal intrapartum fever due to non-infectious(neurogenic) thermoregulation impairment. This is a well-known phenomenon in laboring women.

Toronto Notes 2023 – Obstetrics / Anesthesia:

“Epidural analgesia increases risk of intrapartum fever by up to 20% via non-infectious mechanisms.”

MCCQE1 Objectives (Obstetrics > 80-5: Intrapartum Care):

“Candidates must recognize risk factors for intrapartum complications, including effects of epidural use.”

Multiparity (A), precipitous labor (B), and maternal age (C) are not established risk factors for intrapartum fever.

In cases of blunt testicular trauma with inability to palpate the testicle due to hematoma, scrotal ultrasonography is the first-line investigation to assess for testicular rupture or other injury.

Toronto Notes 2023 – Urology, “Testicular Trauma”:

“Scrotal ultrasound is the investigation of choice to assess for testicular rupture, hematoma, or torsion. Early imaging is critical if testis is non-palpable or if hematoma is significant.”

MCCQE1 Objectives (Surgery > 51-2: Genitourinary Trauma):

“Candidates must investigate testicular trauma using ultrasound to rule out rupture or torsion.”

Exploration (B) is done if ultrasound confirms rupture. Observation or discharge (A, E) without imaging risks missing serious injury.

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The classic description of brief, severe unilateral periorbital pain with autonomic symptoms (tearing), occurring in clusters (same time daily for weeks), is diagnostic of cluster headache.

Toronto Notes 2023 – Neurology, “Headaches”:

“Cluster headaches: severe unilateral periorbital pain, often with lacrimation, nasal congestion, occurring in clusters over weeks. More common in young males.”

MCCQE1 Objectives (Internal Medicine > 35-2: Headache Disorders):

“Candidates must distinguish among headache types based on duration, pattern, and associated symptoms.”

Migraine tends to last hours and has nausea or photophobia. Sinusitis causes dull, pressure-like pain. Tumour-related headache is progressive and worse with Valsalva. Post-concussive headache would have trauma history.

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