Acute extrapyramidal syndrome in mild ornithine transcarbamylase deficiency: metabolic stroke involving the caudate and putamen without metabolic decompensation.
A 6-year-old male with partial ornithine transcarbamylase (OTC) deficiency had acute and rapidly progressive symmetrical swelling of the head of the caudate nuclei and putamina. Clinical presentation was ataxia and dysarthria progressing to seizures and coma; these symptoms gradually resolved with supportive management. Although he had been recently treated for mild hyperammonemia, there was no evidence of acute metabolic decompensation prior to presentation, and plasma ammonia and amino acids were consistent with good metabolic control. This case is novel in that the neurological insult affected the neostriatum of the basal ganglia and the episode occurred in the absence of an apparent metabolic abnormality, unique observations in a patient with OTC deficiency.


CONCLUSIONS
This case suggests that the pathophysiology of metabolic stroke is complicated. It also argues for an evaluation for metabolic stroke in patients with known inborn errors of metabolism who present with unusual neurological symptoms in the absence of biochemical abnormalities. Similarly, this case suggests that patients presenting with unexplained neurological insults might benefit from an evaluation for an inborn error of metabolism.
Keegan
C E
CE
Department of Pediatrics and Communicable Diseases, Division of Pediatric Genetics, University of Michigan School of Medicine, 3570 MSRB II, P.O. Box 0688, Ann Arbor, MI 48109-0688, USA.
Martin
D M
DM
Quint
D J
DJ
Gorski
J L
JL
D001480:Basal Ganglia Diseases / Q000150:complications*; D002561:Cerebrovascular Disorders / Q000209:etiology* / Q000378:metabolism; D002648:Child; D006801:Humans; D008297:Male; D017072:Neostriatum / Q000473:pathology; D020163:Ornithine Carbamoyltransferase Deficiency Disease / Q000150:complications*