Atypical Presentation of a Progressive and Treatable Encephalopathy in an Older Child With Gelastic and Dacrystic Seizures.

We discuss an unusual case of a teenage boy who presented with waxing and waning cognitive decline and gelastic-dacrystic seizures, evolving later into a rapidly progressive encephalopathy with status epilepticus. Extensive genetic and metabolic testing did not lead to a specific diagnosis. Cerebrospinal fluid studies performed during admission to the intensive care unit provided the information needed to establish a diagnosis. After implementation of specific treatment, his seizures stopped and his background electroencephalogram returned to normal. He has remained largely seizure-free experiencing a significant cognitive recovery. This case illustrates the importance of performing cerebrospinal fluid analysis in patient with refractory seizures and cognitive decline of unknown etiology.