PLAB 2 Clinical Examination 2 — Questions and Answers
Question 1: During a peripheral vascular examination, you find a pulseless, pale, cold, painful leg with absent dorsalis pedis and posterior tibial pulses. The patient has paraesthesia. What is the clinical classification of this presentation?
- Chronic peripheral arterial disease
- Acute limb ischaemia — the 6 P's: Pain, Pallor, Pulselessness, Paraesthesia, Paralysis, Perishingly cold (Correct answer)
- Deep vein thrombosis
- Chronic venous insufficiency
Correct answer: Acute limb ischaemia — the 6 P's: Pain, Pallor, Pulselessness, Paraesthesia, Paralysis, Perishingly cold
The 6 P's of acute limb ischaemia are Pain, Pallor, Pulselessness, Paraesthesia, Paralysis, and Perishingly cold. This is a vascular emergency requiring urgent revascularisation within 6 hours to prevent irreversible tissue loss. Common causes include embolism (AF) and thrombosis in situ.
Question 2: You are asked to perform a neurological examination of the upper limbs. You find wasting of the small muscles of the hand, claw hand deformity, and loss of sensation over the medial one and a half fingers. Which nerve is affected?
- Median nerve
- Ulnar nerve (Correct answer)
- Radial nerve
- Musculocutaneous nerve
Correct answer: Ulnar nerve
The ulnar nerve supplies the small muscles of the hand (except LOAF — Lateral 2 lumbricals, Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis), and provides sensation to the medial one and a half fingers. Claw hand deformity results from loss of lumbrical and interosseous muscle function.
Question 3: During an abdominal examination station, you identify shifting dullness. What does this sign indicate?
- Hepatomegaly
- Ascites — free fluid in the peritoneal cavity (Correct answer)
- Bowel obstruction
- Splenomegaly
Correct answer: Ascites — free fluid in the peritoneal cavity
Shifting dullness is a clinical sign for detecting ascites (free fluid in the peritoneal cavity). When the patient rolls to one side, fluid shifts to the dependent area, changing the border between dullness and resonance. At least 500 mL of fluid is needed to detect shifting dullness. A fluid thrill confirms larger volumes.
Question 4: In a PLAB 2 examination station, you assess a patient's visual fields by confrontation. You find a left homonymous hemianopia. Where is the most likely site of the lesion?
- Left optic nerve
- Right optic tract or right occipital cortex (Correct answer)
- Optic chiasm
- Left retina
Correct answer: Right optic tract or right occipital cortex
A left homonymous hemianopia (loss of the left visual field in both eyes) indicates a lesion posterior to the optic chiasm on the right side — either the right optic tract, right lateral geniculate nucleus, right optic radiation, or right occipital cortex. The most common cause is a right-sided stroke.
Question 5: You examine a patient's hands and find Heberden's nodes at the distal interphalangeal joints and Bouchard's nodes at the proximal interphalangeal joints. What is the most likely diagnosis?
- Rheumatoid arthritis
- Osteoarthritis (Correct answer)
- Psoriatic arthritis
- Gout
Correct answer: Osteoarthritis
Heberden's nodes (DIP joints) and Bouchard's nodes (PIP joints) are bony enlargements characteristic of osteoarthritis. Rheumatoid arthritis typically affects the MCP and PIP joints (sparing the DIP joints) and causes soft tissue swelling, ulnar deviation, and swan neck or boutonniere deformities.
Question 6: During a cerebellar examination, you ask the patient to walk heel-to-toe and they are unable to maintain balance. You also find intention tremor, past-pointing, and dysdiadochokinesia. Which mnemonic summarises cerebellar signs?
- SOCRATES
- DANISH — Dysdiadochokinesia, Ataxia, Nystagmus, Intention tremor, Slurred speech, Hypotonia (Correct answer)
- ABCDE
- CURB-65
Correct answer: DANISH — Dysdiadochokinesia, Ataxia, Nystagmus, Intention tremor, Slurred speech, Hypotonia
DANISH summarises the key cerebellar signs: Dysdiadochokinesia (inability to perform rapid alternating movements), Ataxia (broad-based gait, heel-toe walking difficulty), Nystagmus, Intention tremor (tremor worse on reaching for a target), Slurred/scanning speech, and Hypotonia. Past-pointing is part of the dysmetria spectrum.
PLAB 2 Clinical Examination 2
During a peripheral vascular examination, you find a pulseless, pale, cold, painful leg with absent dorsalis pedis and posterior tibial pulses.
The patient has paraesthesia.
What is the clinical classification of this presentation?