[A case of bilateral lower pons-medial medullary infarction presenting quadriparesis].

Bilateral medial medullary infarction is rare. Only 18 cases have been reported previously. We experienced a case of the bilateral lower pons-medullary infarction. 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.