MSRA Clinical Problem Solving 1 — Questions and Answers
Question 1: A 45-year-old woman presents with sudden onset severe headache she describes as 'the worst headache of her life.' A CT head is normal. What is the most appropriate next investigation?
- MRI brain with gadolinium
- Lumbar puncture for xanthochromia (Correct answer)
- CT angiography of the brain
- Blood cultures and CRP
Correct answer: Lumbar puncture for xanthochromia
A normal CT does not exclude subarachnoid hemorrhage; lumbar puncture looking for xanthochromia is required when clinical suspicion remains high.
Question 2: A 68-year-old man with COPD has an ABG showing pH 7.32, PaCO2 58 mmHg, PaO2 52 mmHg, and HCO3 28 mEq/L. What is the correct interpretation?
- Acute metabolic acidosis
- Type I respiratory failure
- Type II respiratory failure with compensatory metabolic alkalosis (Correct answer)
- Respiratory alkalosis with renal compensation
Correct answer: Type II respiratory failure with compensatory metabolic alkalosis
Elevated PaCO2 with low PaO2 defines Type II respiratory failure, and the raised bicarbonate reflects chronic renal compensation for the respiratory acidosis.
Question 3: A 25-year-old woman reports 3 months of fatigue, unintentional weight loss, heat intolerance, and palpitations. Lab results show an undetectable TSH and elevated free T4. What is the most likely diagnosis?
- Primary hypothyroidism
- Hyperthyroidism (Graves' disease) (Correct answer)
- Thyroid carcinoma
- Subacute (De Quervain's) thyroiditis
Correct answer: Hyperthyroidism (Graves' disease)
Suppressed TSH with elevated free T4 is consistent with primary hyperthyroidism, and Graves' disease is the most common cause in young women.
Question 4: A 55-year-old man reports chest pain radiating to the jaw on exertion that resolves with rest. His resting ECG is normal. What is the most appropriate next investigation?
- Transthoracic echocardiogram
- Exercise tolerance test (ETT) (Correct answer)
- 24-hour Holter monitor
- Chest X-ray
Correct answer: Exercise tolerance test (ETT)
Classic exertional angina with a normal resting ECG warrants an exercise tolerance test to provoke ischemic changes under stress.
Question 5: A 30-year-old woman at 32 weeks gestation presents with a blood pressure of 158/104 mmHg, 2+ proteinuria on dipstick, and a severe headache. What is the most likely diagnosis?
- Gestational hypertension
- Chronic essential hypertension
- Pre-eclampsia (Correct answer)
- HELLP syndrome
Correct answer: Pre-eclampsia
New hypertension after 20 weeks with significant proteinuria and symptoms such as headache defines pre-eclampsia.
Question 6: A 70-year-old man develops sudden painless loss of vision in his right eye, describing it as a 'curtain coming down.' Fundoscopy reveals a pale retina with a cherry-red spot at the macula. What is the diagnosis?
- Vitreous hemorrhage
- Rhegmatogenous retinal detachment
- Central retinal artery occlusion (Correct answer)
- Central retinal vein occlusion
Correct answer: Central retinal artery occlusion
Sudden painless monocular visual loss with a pale infarcted retina and cherry-red spot at the fovea is the classic presentation of central retinal artery occlusion.
Question 7: A 40-year-old woman has recurrent episodes of palpitations. ECG during an episode shows a regular narrow complex tachycardia at 180 bpm with P waves visible just after the QRS complexes. What is the most likely diagnosis?
- Atrial fibrillation
- Atrial flutter with 2:1 block
- AV nodal re-entrant tachycardia (AVNRT) (Correct answer)
- Ventricular tachycardia
Correct answer: AV nodal re-entrant tachycardia (AVNRT)
Regular narrow complex tachycardia with retrograde P waves immediately after the QRS is the hallmark of AVNRT, the most common paroxysmal supraventricular tachycardia.
MSRA Clinical Problem Solving 1
A 45-year-old woman presents with sudden onset severe headache she describes as 'the worst headache of her life.' A CT head is normal.
What is the most appropriate next investigation?