Medial medullary infarction: clinical, radiological findings and long-term prognosis.

Abstract

Medial medullary infarction (MMI) is a rare type of posterior circulation stroke. We aim to examine the clinical and radiological features, etiology, and prognosis of patients with MMI. MMI patients registered consecutively in the stroke databank of the Istanbul Medical Faculty between January 1999 and April 2022 were included in the study. Medullary lesions were rostrocaudally classified as rostral, middle, and caudal, and ventrodorsally as ventral, middle, and dorsal. The etiological classification was performed, and functional outcome was assessed based on the modified Rankin Scale (mRS). Overall survival was estimated using the Kaplan-Meier technique. We examined 48 cases of MMI including 9 with bilateral MMI. There were 34 men (70%), and mean age was 62.9 (± 12.8) years. The median NIHSS score was 7 (IQR; 4.5-10.5). The most common symptom was motor dysfunction. The medullary lesions were located caudally in 4 patients, rostrally in 30, rostromedially in 10, and rostro-medio-caudally in 2 patients. On ventro-dorsal classification; unilateral lesions were found ventrally in 19, ventromedially in 11, and ventro-medio-dorsally in 4 patients. The median follow-up duration was 20months (interquartile range (IQR); 1-60). According to the third-month mRS, 39% of the patients were considered to have a good prognosis. The most common etiology was distal vertebral artery atherosclerosis. More than 50% of the patients could walk unassisted in the long-term follow-up, and stroke recurrence was infrequent. Patients with bilateral MMI had poor outcomes.