Case Studies
Case 12: An elderly lady who suddenly goes blind
A 74-year-old lady wakes up at night and asks her husband to turn on the lights. He informs her that they are already on. She went to bed perfectly fit and well.
Your Answer:
Correct answer: The problem with this lady is she has clearly developed bilateral blindness. This is very unlikely to involve the eyes themselves as it would require a simultaneous bilateral anterior ischaemic optic neuropathy with complete visual loss. Thus it is much more likely that the lesion resides within her occipital lobe and that she has had a bilateral occipital infarct from a lesion at the top of the basilar artery with involvement of both posterior cerebral arteries.
Your Answer:
Correct answer: The cause of the problem is that she either has had an embolus pass up the basilar artery from her heart (or rarely a dissected vertebral artery) or less likely that she has atheromatous disease there and has occluded her vascular system as a consequence of thrombosis in situ.
Your Answer:
Correct answer: The investigations which you organize would be an urgent scan to see the extent to which your diagnosis is right. However in the acute stage infarcts can often be hard to see on CT scan and MRI scan. However if an infarct is confirmed then one would look for the cardiovascular risk factors associated with stroke such as diabetes, high cholesterol, hypertension. One would also look for an embolic source for her stroke and this would involve ECG recordings from the heart, a 24-hour ECG from the heart, and an echocardiogram. If one is confident the stroke is very recent (e.g. less than 4 hours ago), one may consider thrombolytic therapy.