A 7-month-old boy with glutaric aciduria type 1 (GA1) presented with 1 week of clustered flexor spasms. Examination revealed mild axial hypotonia without encephalopathy. Video-EEG monitoring revealed hypsarrhythmia and infantile spasms (figure, A). MRI showed acute basal ganglia injury (figure, B). After 3 weeks of prednisolone treatment, 5-month follow-up showed continued resolution of hypsarrhythmia and spasms.