Pure motor trigeminal neuropathy in a woman with tegmental pontine infarction.

A 50-year-old woman presented with drowsiness, severe dysarthria, left facial palsy, and left hemiparesis. Diffusion-weighted MRI showed cerebral infarction in the left pontine tegmentum and right cerebellum and angiography revealed basilar artery occlusion. Altered consciousness and hemiparesis fully resolved following successful recananlisation of the basilar artery by emergent intra-arterial thrombolysis. However, about 8 months later, obvious wasting of the left temporal and buccal area without sensory signs was detected. Electrophysiological evaluation revealed a chronic denervation process in the left masseter and temporalis muscles. We suggest that a small infarction in the trigeminal nucleus of the pontine tegmentum can cause an isolated trigeminal motor neuropathy with masticatory muscle atrophy.