Mitochondrial disease in a heteroplasmic MT DNA mutation causing mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) and leigh syndrome phenotypes

Case presentation: A six year-old female child presented in a tertiary hospital with an acute stroke-like event after a week of cerebelar, bulbar and pyramidal syndromes. She had past history of failure to thrive, since young age, and another three stroke-like events since she was 2 years old. The course of the disease was chronic with acute exacerbation with some recovery in between. Milestones of motor development were adequate, but she present speech delay and learning disabilities. She is the third child of a non-consanguineous healthy couple. Mother's second gestation the child had unique multicystic kidney disease and died within five hours after being born. No family history of neurologic disease was reported. During investigation she was submitted to neuroimage with identification of stroke-like acute and past events, compared with previous images, and showed symmetrical hyperintense T2/FLAIR in striatum and putamen. Spectroscopy was normal. Cardiologic, auditory and visual investigations showed no additional findings. The cerebrospinal fluid showed slightly high lactate and cellularity and isolated herpes VI and VII-PCR. It was presumed that the infection was a trigger to the acute event, and therefore treated such, with ganciclovir. The acute event was treated with arginine and she had improvement mainly in bulbar symptoms.