On this page
Study tools
Write your answer
Saved on this device. No marking — you are the marker.
Stem
A 68-year-old male smoker presents with a 15-minute episode of right arm weakness and difficulty speaking that resolved completely. On examination, a left carotid bruit is audible. Carotid duplex shows 82% stenosis of the left internal carotid artery (NASCET method). CT brain shows no infarct.
Questions
a) What is the diagnosis and what is the most appropriate management? (3 marks)
Diagnosis: Symptomatic left carotid stenosis (82% by NASCET) presenting as a TIA in the left carotid territory (right hemiparesis + aphasia = left/dominant hemisphere).
Management: Carotid endarterectomy (CEA) within 2 weeks (NASCET trial: symptomatic stenosis over 70% benefits from CEA with ARR 17% at 2 years). Plus best medical therapy: aspirin, statin, smoking cessation, BP control.
b) What is amaurosis fugax and what does it indicate? (2 marks)
Amaurosis fugax is transient, painless monocular visual loss (described as a "curtain descending") lasting seconds to minutes, caused by a cholesterol embolus (Hollenhorst plaque) from the carotid bifurcation lodging transiently in the central retinal artery. It indicates ipsilateral carotid stenosis until proven otherwise. Urgent carotid ultrasound is required.
c) Describe the NASCET method for measuring carotid stenosis. (2 marks)
(Normal ICA diameter - Minimal residual lumen diameter) / Normal ICA diameter x 100 = percent stenosis.
The "normal" diameter is measured in the distal internal carotid artery (where the walls are parallel, beyond the bulb). This method is used in all major guidelines to classify stenosis severity.
d) List three complications of carotid endarterectomy. (3 marks)
- Perioperative stroke or death (the main risk; must be under 6% for symptomatic, under 3% for asymptomatic).
- Cranial nerve injury (hypoglossal XII commonest - tongue deviation; vagus X - hoarseness; marginal mandibular VII - mouth droop).
- Wound haematoma (can cause airway compromise - surgical emergency).
- Cerebral hyperperfusion syndrome (headache, seizures, haemorrhage from BP surge after revascularisation).
- Myocardial infarction (commonest cause of perioperative death).