Transient Postictal Hyperglycemia as a Diagnostic Clue of Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like Episodes.

PURPOSE: To propose that transient postictal hyperglycemia as a diagnostic clue of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS).

CASE REPORT: We reported two non-diabetic patients presenting with generalized seizure and transient postictal hyperglycemia. At the acute stage, both patients had hyperglycemia with serum glucose levels more than 400 mg/dl, normal glycated hemoglobin (HbA1C) levels, normal ketone body levels, and absence of infection signs. Within three days of the seizure event, both patients were euglycemic and did not require any diabetes treatment. Brain MRI examination revealed gyriform restricted diffusion at bilateral superior temporal gyrus in one patient, and diffuse cerebral and cerebellar atrophy without restricted diffusion lesions in another patient. Polymerase chain reaction and restriction fragment length polymorphism (RFLP) analysis confirmed that both patients harbored the m.3243A more than G mutation.

CONCLUSION

Seizure-induced stress hyperglycemia is uncommon in normal individuals, but such kind of energy crisis may be pronounced in patients with mitochondrial dysfunction. Early diagnosis of mitochondrial diseases-related epilepsy and hyperglycemia is crucial since certain antiepileptic drugs (ex. Valproic acid) and antihyperglycemic agents (ex. Metformin) are contraindicated in patients with mitochondrial diseases. Our findings support that transient postictal hyperglycemia may be a red flag to consider the diagnosis of MELAS.