Unveiling the Mitochondrial Mystery: A Case of Mitochondrial Encephalopathy With Lactic Acidosis and Stroke-Like Episodes

A 38-year-old female presented with difficulty walking and focal seizures causing non-specific facial and upper limb movements. Examination revealed nystagmus and other peripheral cerebellar signs. Lower limbs were spastic with up-going plantar responses bilaterally. She had been on treatment for epilepsy with multiple anti-seizure medications since the age of 20 and had an episode of status epilepticus when she was 25 years old. An MRI scan of the brain revealed focal gyriform restricted diffusion, and she was followed up with an MR spectroscopy, which revealed lactate peaks involving the affected area as well as the ventricular system in the brain. Her cerebrospinal fluid lactate levels were also elevated. She was also found to have retinitis pigmentosa on dilated fundoscopy. In the absence of genetic studies, due to financial restrictions, she was diagnosed with mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) based on the overall clinical picture. Sodium valproate was discontinued as it had toxic properties against mitochondria, and she was put on co-enzyme Q10, L-arginine, and carnitine. This case highlights the difficulties faced in diagnosing conditions like MELAS in a setting where genetic studies are not feasible.