Deep white matter pathologic features in watershed regions: a novel pattern of central nervous system involvement in MELAS.
BACKGROUND
Myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome typically manifests in adults younger than 40 years with encephalopathy, stroke-like episodes, and lactic acidosis. Magnetic resonance imaging (MRI) abnormalities typically involve the cortical gray and the adjacent subcortical white matter.


OBJECTIVE
To describe a 58-year-old woman diagnosed with MELAS who was initially seen with acute myopathy, cardiac ischemia, psychosis, and MRI changes in a watershed distribution.


RESULTS
Initial MRI of the brain showed the characteristic parieto-occipital gray matter lesions involving the adjacent white matter. Follow-up MRI revealed striking deep white matter involvement in a watershed distribution. A cerebral angiogram and thorough hypercoagulable workup results were normal. Electromyography showed acute denervation and myopathy. A muscle biopsy specimen revealed ragged red and cytochrome-c oxidase-negative fibers. Mitochondrial DNA analysis revealed an A3243G mutation.


CONCLUSIONS
Myopathy, encephalopathy, lactic acidosis, and stroke-like episodes should be considered in older patients with myopathy, cardiomyopathy, encephalopathy, and unaccountable MRI findings. Watershed pathologic features are a rare pattern of cerebral involvement in MELAS.
Apostolova
Liana G
LG
Department of Neurology, University of California, Los Angeles, USA. lapostolova@mednet.ucla.edu
White
Matthew
M
Moore
Steven A
SA
Davis
Patricia H
PH
D000208:Acute Disease; D002540:Cerebral Cortex / Q000473:pathology*; D005260:Female; D006801:Humans; D017241:MELAS Syndrome / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology; D009135:Muscular Diseases / Q000209:etiology; D017202:Myocardial Ischemia / Q000209:etiology; D011618:Psychotic Disorders / Q000209:etiology; D020521:Stroke / Q000209:etiology