Symptoms: stroke-like episodes with focal neurological deficits, short stature, seizures, deafness, recurrent headaches, cognitive regression, diabetes, cardiopathy, gastrointestinal dysmotility, peripheral neuropathy.
Cause: Mitochondrial DNA point mutations: A3243G (most common).
MELAS is a progressive neurodegenerative disorder with typical onset between the ages of 2 and 15, although it may occur in infancy and adulthood. Initial symptoms may include stroke-like episodes, seizures, migraine headaches, and recurrent vomiting.
Stroke-like episodes, often accompanied by seizures, are the hallmark symptom of MELAS and cause partial paralysis, loss of vision, and focal neurological defects. The gradual cumulative effects of these episodes often result in variable combinations of loss of motor skills (speech, movement, and eating), impaired sensation (vision loss and loss of body sensations), and mental impairment (dementia). Lactic acid usually accumulates at high levels in the blood, cerebrospinal fluid, or both.
There is no cure or specific treatment for MELAS. Although no therapeutic trial has proven effective, general treatments may include supplements such as CoQ10, dichloroacetate (DCA), creatine, menadione, and phylloquinone. Seizure medications and insulin may be required for additional symptom management. Some patients with muscle dysfunction may benefit from moderate supervised exercise.
The prognosis for MELAS is poor. Typically, the age of death is between 10 to 35 years, although some patients may live longer. Death may come as a result of general body wasting or to complications from other affected organs, such as heart or kidneys.