Radiologic Findings:
7/5/95
An MRI was obtained at this time. The MRI demonstrated abnormal
signal in the left middle cerebral artery and bilateral posterior
cerebral artery distribution. Volume loss was present in the
right middle cerebral artery distribution.
8/17/95
MRI revealed abnormal increased signal in
the middle cerebral distribution on the right without
enhancement.
A biopsy at this time revealed gliosis. Recently the patient was re-admitted with increasing blurred vision and the presence of flashing lights. The patient subsequently became confused.
Diagnosis: Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes. (MELAS).
Discussion: Melas presents with stroke-like episodes with focal neurological deficits, lactic acidosis, and at least two of the following: 1) focal or generalized seizures, 2) dementia, 3) recurrent headaches. Muscle biopsy demonstrates ragged red fibers. Biopsy of the brain demonstrates necrosis with reactive astrocytosis thought to represent infarcts. Affected ages from 4 to 46 years of age. 80% present at age 5-15 years.
References:
Rosen L: Magnetic Resonance Imaging in Melas Syndrome.
Neuroradiology 1990;32:168-171.
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