The effect of increased intracranial EEG sampling rates in clinical practice.

OBJECTIVE: Recent research suggests that high frequency intracranial EEG (iEEG) may improve localization of epileptic networks. This study aims to determine whether recording macroelectrode iEEG with higher sampling rates improves seizure localization in clinical practice. METHODS: 14 iEEG seizures from 10 patients recorded with >2000 Hz sampling rate were downsampled to four sampling rates: 100, 200, 500, 1000 Hz. In the 56 seizures, seizure onset time and location was marked by 5 independent, blinded EEG experts. RESULTS: When reading iEEG under clinical conditions, there was no consistent difference in time or localization of seizure onset or number of electrodes involved in the seizure onset zone with sampling rates varying from 100 to 1000 Hz. Stratification of patients by outcome did not improve with higher sampling rate. CONCLUSION: When utilizing standard clinical protocols, there was no benefit to acquiring iEEGs with sampling rate >100 Hz. Significant variability was noted in EEG marking both within and between individual expert EEG readers. SIGNIFICANCE: Although commercial equipment is capable of sampling much faster than 100 Hz, tools allowing visualization of subtle high frequency activity such as HFOs will be required to improve patient care. Quantitative methods may decrease reader variability, and potentially improve patient outcomes.

Two patients with a GRIN2A mutation and childhood-onset epilepsy.

BACKGROUND: N-methyl-D-aspartate is a key neurotransmitter within the central nervous system and its dysfunction can play an important role in epilepsy. Mutations of genes involving the N-methyl-D-aspartate receptor have been implicated in a wide variety of neuropsychiatric disorders including epilepsy, specifically, within the glutamate receptor ionotropic N-methyl-D-aspartate 2A (GRIN2A). PATIENTS: We report two patients with a glutamate receptor ionotropic N-methyl-D-aspartate 2A mutation who presented with epilepsy. CONCLUSIONS: Individuals with a glutamate receptor ionotropic N-methyl-D-aspartate 2A mutation exhibit a broad clinical spectrum.

Absolute pitch in a four-year-old boy with autism.

Absolute pitch is the ability to identify the pitch of an isolated tone. We report on a 4-year-old boy with autism and absolute pitch, one of the youngest reported in the literature. Absolute pitch is thought to be attributable to a single gene, transmitted in an autosomal-dominant fashion. The association of absolute pitch with autism raises the speculation that this talent could be linked to a genetically distinct subset of children with autism. Further, the identification of absolute pitch in even young children with autism may lead to a lifelong skill.