[Left-sided extremity myorhythmia and rightward slow eye movement caused by a hemorrhage in the right pontine tegmentum].

A sixty-year-old man was admitted to our hospital on January, 1989. He had suffered a hemorrhage in the right side of pontine tegmentum on April, 1988. He had been in deep coma for about a week, and then he had showed diplopia, mild right deafness, right facial palsy, left hemiparesis, dysarthria, dysphagia, and urinary disturbance. He showed slight improvement of these symptoms and signs, but had developed thereafter extremity myorhythmia on the left side. On admission, rightward slow eye movement (absence of saccadic eye movement and preservation of pursuit eye movement of both eyes) was present. MRI revealed a hypointensity lesion with a hyperintensity spot on T2-weighted images showing an old hemorrhage in the right pontine tegmentum and a hyperintensity lesion on T2-weighted images showing an olivary pseudohypertrophy on the right. We concluded that the extremity myorhythmia in this patient was caused by the damage of the right central tegmental tract followed by right olivary pseudohypertrophy. The rightward slow eye movement was considered to be due to the damage of the right paramedian pontine reticular formation and/or its afferent fibers in the pontine tegmentum.