NAC OSCE Clinical Reasoning

Question 1

A 55-year-old male presents with sudden-onset severe headache described as 'the worst headache of my life.' What is the MOST important diagnosis to rule out?

Accepted Answer

Subarachnoid hemorrhage — a life-threatening emergency requiring urgent CT head and, if negative, lumbar puncture

Answer

Tension headache

Answer

Migraine with aura

Answer

Sinusitis

Question 2

A 30-year-old woman presents with a unilateral, throbbing headache with nausea and photophobia. She reports seeing zigzag lines before the headache started. What is the MOST likely diagnosis?

Accepted Answer

Migraine with aura — the visual symptoms (scintillating scotoma) preceding the headache are characteristic

Answer

Tension-type headache

Answer

Cluster headache

Answer

Meningitis

Question 3

A patient presents with acute right lower quadrant pain, fever, and rebound tenderness. The initial blood work shows elevated WBC. What is the MOST likely diagnosis and next step?

Accepted Answer

Acute appendicitis — urgent surgical consultation and consider CT abdomen/pelvis for confirmation

Answer

Gastroenteritis — prescribe anti-emetics and fluids

Answer

Irritable bowel syndrome — reassure and discharge

Answer

Renal colic — order renal ultrasound

Question 4

A 70-year-old man presents with acute onset of left-sided weakness and slurred speech that began 1 hour ago. What is the time-critical management priority?

Accepted Answer

Rapid assessment for stroke using a validated scale, urgent non-contrast CT head to exclude hemorrhage, and consideration of thrombolysis (tPA) within the 4.5-hour window

Answer

Order a full blood panel and wait for results

Answer

Start antibiotics for possible meningitis

Answer

Schedule an outpatient MRI for next week

Question 5

When developing a differential diagnosis, what does the mnemonic 'VINDICATE' stand for?

Accepted Answer

Vascular, Infectious, Neoplastic, Degenerative, Iatrogenic, Congenital, Autoimmune, Trauma, Endocrine/metabolic

Answer

Viral, Inflammatory, Neoplastic, Degenerative, Idiopathic, Congenital, Autoimmune, Trauma, Endocrine

Answer

Various, Important, Notable, Diagnostic, Imaging, Clinical, Assessment, Treatment, Evaluation

Answer

Vascular, Immune, Neurological, Digestive, Inflammatory, Cardiac, Allergic, Toxic, Environmental

Question 6

A 25-year-old woman presents with fatigue, weight gain, cold intolerance, and constipation. Her TSH is elevated and free T4 is low. What is the diagnosis and most common cause in Canada?

Accepted Answer

Hypothyroidism — most commonly Hashimoto's thyroiditis (autoimmune thyroiditis) in Canada

Answer

Hyperthyroidism — likely Graves' disease

Answer

Cushing's syndrome

Answer

Adrenal insufficiency