Medial medullary infarction identified by diffusion-weighted magnetic resonance imaging.
OBJECTIVE
To elucidate the frequency and clinical profiles of patients with medial medullary infarction (MMI) identified by diffusion-weighted MRI (DWI).


METHODS
We assessed the frequency, radiological findings, etiology and clinical features of MMI detected by DWI from our single-center registry of acute ischemic patients.


RESULTS
Thirty patients (1.5% of 2,014 with ischemic stroke) had MMI, including isolated unilateral MMI in 26 patients. Lesions were located by DWI in the rostral medulla of 25 patients (83%). Culprit infarcts that were undetectable by DWI in 6 (38%) of 16 patients who were assessed within 24 h after onset were later confirmed as MMI. The major etiological mechanism was small artery occlusion (SAO; 19 patients) and the median initial National Institutes of Health Stroke Scale score was 4 (interquartile range: 3-4.75). The most frequent symptom was contralateral hemiparesis (27 patients). None of the patients fulfilled the classical Dejerine Triad. Twenty-two patients (73%) had a modified Rankin Scale score of ≤2 at 3 months. A patient developed transient ischemic attack within 3 months; none developed recurrent stroke.


CONCLUSIONS
Rostral medullary infarction with mild neurological deficits resulting from SAO is relatively frequent. Because emergency DWI within 24 h could not detect MMI in one third of the patients, this type of infarction could be misdiagnosed as capsular/pontine lacunae or other neurological disorders.
Shono
Yuji
Y
Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka, Japan.
Koga
Masatoshi
M
Toyoda
Kazunori
K
Matsuoka
Hideki
H
Yokota
Chiaki
C
Uehara
Toshiyuki
T
Yamamoto
Haruko
H
Minematsu
Kazuo
K
D000368:Aged; D000369:Aged, 80 and over; D020526:Brain Stem Infarctions / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*; D048909:Diabetes Complications / Q000150:complications; D038524:Diffusion Magnetic Resonance Imaging; D050171:Dyslipidemias / Q000150:complications; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects