Brain Disorders (Dec 2022)
Characteristic features of electroencephalogram in a pediatric patient with GRIN1 encephalopathy
Abstract
Background: The number of reports on GRIN1 variants associated with neurodevelopmental phenotypes has increased in recent years. However, there are only two detailed reports on electroencephalography findings. Case study: We had a case with severe global developmental delay, and exome sequencing revealed a novel de novo heterozygous variant of GRIN1. The patient's electroencephalography showed unique findings: paroxysmal fast activity—20–30 Hz beta waves, independently in the bilateral occipital regions, sometimes in a continuous manner—and prolonged alpha activity in the bilateral frontal regions, observed mainly during sleep, those findings were observed persistently. Discussion: The electroencephalography findings of our case have not been reported in the past. Receptor hypofunction due to the GRIN1 variant and imbalance in excitatory/inhibitory transmission owing to the dysfunction of the N-methyl-D-aspartate receptors may be the mechanism for the global developmental delay, stereotyped movements, and development of paroxysmal fast activity in our case. Accumulation of additional case reports is needed to confirm the reproducibility of the electroencephalography findings for disease specificity.
