Moyamoya in a Patient with FIRES: A First Case Report

Febrile infection-related epilepsy syndrome (FIRES) is a form of epileptic encephalopathy with severe refractory epilepsy that presents in previously healthy, school-aged children after significant febrile illness with concomitant rise in body temperature. Suspected causes include genetic or acquired channelopathies, as well as mitochondrial disturbances. In FIRES, the EEG shows diffuse slowing, generalized, and/or multifocal discharges. Seizures are present and resistant to treatment. Moyamoya angiopathy (MMA) is characterized by progressive stenosis of cerebral arteries and subsequent development of a network of collateral circulation that is prone to rupture. We present here a case of a 6-year-old patient with a postfebrile illness, acute and explosive bilateral independent seizure onset that was most consistent with FIRES, but also with imaging evidence of right-sided-only MMA. Our patient demonstrated two diseases not described together previously in the literature. It is unknown whether this patient's MMA is related to FIRES. In spite of successful corrective surgery (encephaloduroarteriosynangiosis), the patient continues to suffer from intractable seizures (mostly on the right) and apparent mild encephalopathy. The impact of our interventions (surgery, antiepileptic medication) is unclear. In this article, we describe a case of MMA and FIRES, and the history, physical, laboratory, imaging, and developmental elements of the 6-year-old patient with previously normal development.