[A case of jaw opening phenomenon associated with basilar artery thrombosis].

We describe a 74 year old man who showed the jaw opening phenomenon by painful stimuli from two months after the onset of basilar artery thrombosis. He was admitted to our hospital because of consciousness disturbance and paralysis of all extremities. Soon after admission, he was in a state of impending herniation but with conservative therapy he recovered slightly, and then fell into an akinetic and mute state. Two months after the onset of the stroke, he began to open his mouth in response to painful stimuli, and five months after the stroke palatal myoclonus also appeared. Neurological signs and symptoms five months after admission were as follows; he was akinetic, mute and always kept his eyes closed because of complete blepharoptosis due to oculomotor nerve palsy. Pupils were dilated and adducted. Bilateral light reflexes were absent and the oculocepharic reflex could not adduct the eyes inwardly. Bilateral corneal reflexes were present, facial reflexes were exaggerated and jaw reflexes were also active. All limbs were spastic and paralyzed, and no voluntary movement was observed. Deep tendon reflexes were active in all extremities, and bilateral plantar responses were extensor. Palatal myoclonus was recognized in his soft palate, lips, sternocleidomastoid and diaphragm. Its frequency was about 150 cycles per minute. CT scan revealed severe low density areas in the midbrain and bilateral posterior lobes. In cerebral angiography, the upper part of the basilar artery was completely occluded.(ABSTRACT TRUNCATED AT 250 WORDS)