Effect of long-term oral treatment with L-arginine and idebenone on the prevention of stroke-like episodes in an adult MELAS patient.

INTRODUCTION Mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a maternally-inherited multisystem disorder. Mitochondrial angiopathy mediated by nitric oxide, a metabolite of L-arginine, is among the proposed pathophysiologic mechanisms of stroke-like episodes (SLEs) in MELAS. There are very few reports on long-term prevention of SLEs with oral L-arginine and idebenone treatment in MELAS adult patients. CASE REPORT A 38-year-old patient with MELAS and SLEs was treated with oral L-arginine and idebenone for 27months. She remained free of attacks throughout the treatment period except when she stopped her treatment on two occasions during which she had recurrent cerebral metabolic attacks. The patient experienced no side effect of treatment with L-arginine and idebenone. CONCLUSION Our observation suggests long-term safety and potential benefit of oral L-arginine and idebenone in the prevention of recurrence of SLEs in adult MELAS patients.