四肢麻痺をきたした両側橋下部延髄内側梗塞の1例

A Case of Bilateral Lower Pons-Medial Medullary Infarction Presenting Quadriparesis

要旨　四肢麻痺をきたした橋下部延髄内側梗塞の1例について報告する。症例は63歳女性。左片麻痺にて発症。発症5日目で四肢麻痺となった。発症9日目のMRI検査にて両側橋下部上部延髄内側の梗塞巣を認めた。延髄内側症候群は稀な疾患で，なかでも両側錐体路を含む延髄内側症候群により四肢麻痺をきたしたのは過去に18例の報告があるのみである。それらの多くの症例は呼吸障害を併発し，予後不良であったが，われわれの症例では呼吸障害を認めず，生命予後は良好であった。

A 63-year-old woman was admitted to our hospital because of moderate left hemiparesis. Hyperreflexia in left limbs and positive Babinski's reflex in left foot was observed. Sensory disturbance was mild left hemihypesthesia （in light touch, postural sense and vibration） without facial involvement. She also had lateral gaze nystagmus, dysarthria, and bilateral decreased gag reflex. Respiratory failure was not observed. A conservative therapy for cerebral infarction was performed. But the hemiparesis was deteriorated and progressed to complete quadriparesis on the 5th day.

The brain MRI （T2-weighted image and FLAIR ） demonstrated bilateral lower pons-medial medullary infarction on the 9th day. Cerebral angiography and 3D-CT angiography revealed no stenosis or occlusions in the major cerebral arteries. The anterior spinal artery was not evaluated enough because of the arteriosclerosis.

The prognosis of this patient was favorable except for the quadriparesis. The severe quadriparesis has not been improved for about 2 years.

The bilateral medial medullary infarction was quite rare in the literature. The prognoses of these cases were unfavorable for the respiratory failure. Our case was not fatal because of no respiratory paralysis.