Neuro-ophthalmology: Case five |
This 46 year old man developed an acute confusional state. He was agitated and complained of visual problem. He was able to see the letters on the Snellen Chart but was unable to read them. Visual field examination was difficult as he could not maintain his fixation. Neurological examination showed he had a right/left disorientation. An urgent CT scan was requested.The following signs may be present:
a. What does the CT scan show?
The CT scan was performed with contrast and shows a hyperdense area in the left parietal lobe.
The appearance is that of a left parietal lobe haemorrhage.Haemorrhagic cerebrovascular accident accounts for about 10% of all cerebrovascular
accidents.
Mental status fluctuation is a common feature. The sources of haemorrhage can arise from
ruptured intracerebral haemorrhage, arterial venous malformation or congophilic angiopathy.
b. What clinical signs may be present on further physical examination?
- intracerebral haemorrahge can give rise to hypertension and bradycardiac (Cushing's reflex) due to raised intracranial pressure.
- Gerstmann's syndrome caused by involvement of the dominant angular gyrus. It is characterized by alcalculia (difficulty in calculation), agraphia (difficulty in writing), right/left disorientation and finger agnosia (difficulty in identifying the fingers and naming them). Dyslexia which is the loss of ability to recognize words or letters is also seen in this syndrome.
- right inferior homonymous quadrantonopia
- asymmetry of opticokinetic nystagmus (OKN). The OKN response is decreased when the OK drum is rotated to the left.
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