[Unilateral multiple cranial nerve palsies mimicking Garcin syndrome as an atypical symptom of brainstem encephalitis: a case report].

We report a 56-year-old Japanese man who was admitted because of dysphagia and left side facial dysesthesia. On admission, his general conditions were unremarkable. Neurological examination revealed that he was alert and well oriented. He exhibited left-side cranial nerve involvement such as the trigeminal(sensory and motor), glossopharyngeal and potential vagal nerve palsy. He exhibited neither long-tract signs, such as motor weakness, sensory disturbance in his exremities and pathological reflex, nor ataxia. By a few days after admission, his symptoms had worsened. Vertigo and diplopia appeared, and his consciousness level became drowsy. Bilateral third and sixth nerves, left fourth, fifth, eighth, ninth and tenth nerves were involved. Results of laboratory tests and CSF studies were within normal. Results of examination of the skull base X-ray and MRIs of the brain were normal. Administration of corticosteroid and intravenous administration of a high dose of gamma-globulin were not effective. His symptoms gradually recovered three months after admission. Based on clinical symptoms and results of physiological examination, i.e., an involvement of his consciousness and abnormal findings in blink reflex test that suggest involvement of the brainstem, he was diagnosed as having brainstem encephalitis. Although the exact pathophysiological mechanisms were unclear, it is clinically important to note that an atypical brainstem encephalitis may present a subacute progressive appearance of unilateral multiple cranial nerve palsies mimicking Garcin syndrome.