[The clinical, radiological and prognostic factor analysis of medullary infarction]

To investigate the clinical and radiological features of medullary infarction (MI), and to compare the clinical characteristics of lateral medullary infarction (LMI) and medial medullary infarction (MMI).

Patients diagnosed as acute MI who were treated from January 2009 to December 2014 in Department of Neurology, Peking University Third Hospital, were retrospectively enrolled in the study and data were analyzed including risk factors, clinical features, laboratory findings, radiological characteristics, etiology and outcomes.

A total of 62 cases of MI were enrolled with 48 cases of LMI and 14 cases of MMI , including 2 cases of bilateral MMI. The mean onset age of LMI and MMI was 60.2±12.3 and 56.9±14.2, respectively. The frequently affected location of LMI was the middle and upper part of medulla [40 cases (83.3%)]. The common symptoms and signs of LMI were dizzy (38 cases , 79.2%), sensory disturbance (33 cases , 68.8%), dysarthria ( 32 cases , 66.7%), dysphagia (30 cases , 62.5%), diminished pharyngeal reflex (30 cases, 62.5%), Horner's sign (29 cases, 60.4%), ataxia (26 cases, 54.2%) and nausea or vomiting (25 cases, 52.1%). The frequently affected location of MMI was the upper part of medulla (13 cases, 92.9%). The common symptoms and signs of MMI were motor dysfunction (12 cases, 85.7%), sensory disturbances (11 cases, 78.6%), dizzy (10 cases, 71.4%) and dysarthria (10 cases, 71.4%). Infarctions caused by atherosclerosis were found in 35 cases of LMI (72.9%) and 12 cases of MMI (85.7%). Five cases (10.4%) of LMI died in hospital, while 1 case (7.1%) of MMI died in hospital. No lesion was found in 16 cases (25.8%) by MRI-DWI within the first 24 hours of onset.

Our study showes that the mean onset age of LMI is older than that of MMI. The lesion of LMI is frequently located in the upper and middle medulla, whereas the lesion of MMI is mostly in the upper medulla. The prognosis of LMI is worse than that of MMI. Atherosclerosis of the vertebral arteries is the predominant vascular pathology in MI.