Mitochondrial Encephalopathy With Lactic Acidosis and Stroke-like Episodes (MELAS) May Respond to Adjunctive Ketogenic Diet

BACKGROUND: Mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome can present management challenges. Refractory seizures and stroke-like episodes leading to disability are common. PATIENT: We analyzed the clinical, electrophysiologic, and radiologic data of a 22-year-old woman with multiple episodes of generalized and focal status epilepticus and migratory cortical stroke-like lesions who underwent muscle biopsy for mitochondrial genome sequencing. RESULTS: Although initial mitochondrial genetic testing was negative, muscle biopsy demonstrated a mitochondrial DNA disease-causing mutation (m.3260A > G). New antiepileptic medications were added with each episode of focal status epilepticus with only temporary improvement, until a modified ketogenic diet and magnesium were introduced, leading to seizure freedom despite development of a new stroke-like lesion, and subsequent decrease in frequency of stroke-like episodes. We propose a metabolic model in which the ketogenic diet may lead to improvement of the function of respiratory chain complexes. CONCLUSIONS: The ketogenic diet may lead to improvement of mitochondrial dysfunction in MELAS, which in turn may promote better seizure control and less frequent stroke-like episodes.