Stroke involving the midbrain and thalamus and causing 'nonfocal' coma.

We have described two patients who had coma without focal findings and who were found to have an ischemic stroke involving the midbrain and the thalamus. In both cases metabolic encephalopathy or drug overdose was initially suspected, but recognition of abnormal vertical eye movements led to the proper diagnosis. Examination of vertical eye movements in drowsy or comatose patients may be helpful in arriving at the correct diagnosis early and may prevent unnecessary investigations.