Metabolic Strokes in Propionic Acidemia: Transient Hemiplegic Events Without Encephalopathy

Metabolic strokes are a notable feature associated with acute catabolic crises in patients with propionic acidemia. Despite their importance, these events are not well characterized. Here, we present the clinical history of a patient with propionic acidemia who developed 5 episodes of acute hemiparesis between 3 and 11 years of age. The clinical finding of hemiparesis associated with 4 of these 5 events were shorted lived (2-5 days). Neuroimaging showed signal changes in the basal ganglia manifesting many years following the initial episode. Two of the episodes were accompanied by definite seizures. Based on these factors, the hemiparetic events were most consistent with metabolic strokes, though what is distinctive is that most of the events occurred without evidence of metabolic decompensation; brain magnetic resonance imaging findings were not suggestive in the acute setting. We present a framework for evaluating suspected metabolic stroke in propionic acidemia, in light of the sometimes perplexing clinical heterogeneity underlining these events.