A case of neuro-Behçet's encephalitis with pleds as distinct from herpes simplex encephalitis: a differential diagnosis.

We report a male patient with neuro-Behçet's disease who had somnolence, mild motor aphasia and periodic lateralized epileptiform discharge. SPECT study showed decreased cerebral blood flow in the left frontal and temporal lobes. An MRI scan of the head showed only mild brain stem atrophy. His clinical signs were markedly improved after administration of prednisolone. We propose that some cases of neuro-Beh,cet's disease may have very similar clinical features to herpes simplex encephalitis and that SPECT and MRI examinations can be very useful in distinguishing the ischemic lesion of neuro-Behçet's from the inflammatory lesion of herpes simplex encephalitis.