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Deep white matter pathologic features in watershed regions: a novel pattern of central nervous system involvement in
Liana G Apostolova1, Matthew White, Steven A Moore
1Department of Neurology, University of California, Los Angeles, USA. lapostolova@mednet.ucla.edu
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.
Insights
Myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome, typically seen in younger adults, can occur in older individuals. This case highlights MELAS presenting with stroke-like lesions in a rare watershed pattern.
Area of Science:
- Neurology
- Mitochondrial Diseases
- Genetics
Background:
- Myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a mitochondrial disorder.
- It typically presents in individuals under 40 with encephalopathy, stroke-like episodes, and lactic acidosis.
- Characteristic MRI findings involve cortical gray and adjacent subcortical white matter.
Observation:
- This report details a 58-year-old woman diagnosed with MELAS.
- Her initial presentation included acute myopathy, cardiac ischemia, psychosis, and MRI abnormalities.
- MRI revealed characteristic parieto-occipital gray matter lesions and later, deep white matter involvement in a watershed distribution.
Findings:
- Muscle biopsy showed ragged red and cytochrome-c oxidase-negative fibers.
- Mitochondrial DNA analysis confirmed the A3243G mutation.
- Cerebral angiogram and hypercoagulable workup were normal, while electromyography indicated acute denervation and myopathy.
Implications:
- MELAS should be considered in older patients presenting with myopathy, cardiomyopathy, encephalopathy, and unexplained MRI findings.
- Cerebral involvement in a watershed distribution is an uncommon presentation of MELAS.
- This case expands the known clinical and radiological spectrum of MELAS syndrome.
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