NEURORADIOLOGY

9 month old male child with regression of milestones, motor delay, dystonia, dysarthria and dyskinesia.

Diagnosis

glutaric aciduria type I

Imaging Findings

MR images revealed wide CSF spaces anterior to the temporal lobes with temporal lobe hypoplasia and bilateral frontoparietal subdural effusions.Inversion recovery sequence also revealed widely open opercula and dilated sylvian fissures.

Discussion:

Glutaric aciduria type I is not actually an organic aciduria but rather a disorder of lysine metabolism. It has similarities in clinical presentation and on imaging to organic acidurias. These conditions are autosomal recessive. Oxidative metabolism is often inhibited secondary to metabolic acidosis and leads to cell death.

striking finding on brain imaging is the presence of very wide CSF spaces anterior to the temporal lobes and within the sylvian fissures. Widening of the sylvian fissures is a very characteristic finding in glutaric acidemia type I.he anomaly may range from a complete lack of operculation with gross hypoplasia of the temporal lobes to widening of sylvian fissures in proportion to the prominence of other extra cerebral CSF spaces. It has been suggested that bilateral temporal fluid collections may be caused by arachnoid cysts of the temporal fossa. Extra cerebral fluid collections other than those anterior to the temporal lobes include subdural collection or bilateral frontoparietal subdural hematomas. 

Dr Paresh Desai