| Summary points: | A 34-year-old Saudi woman presents with clinical symptoms suggestive of mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). At age 24, she started to have generalised tonic-clonic seizures; at age 27, she lost her vision and hearing; and at age 32, she developed right-sided weakness. Medical history, brain imaging, and histochemical analysis are described. The authors discuss the case of a patient with typical clinical features of MELAS, but without an obvious genetic cause. |