Clinical seizure semiology is subtle and identification of seizures by parents unreliable in infants with tuberous sclerosis complex

Abstract

Objective

The objectives of this study were to assess the accuracy of parental seizure detection in infants with antenatally diagnosed tuberous sclerosis complex (TSC), and to document the total seizure burden (clinical and subclinical) in those patients who met criteria for prolonged EEG recording.

Methods

Consecutive infants at a single institution with antenatally diagnosed TSC who met criteria for prolonged video-EEG (vEEG) were recruited to this study. The vEEG data was reviewed and when a seizure was identified on EEG, the video and audio recording was assessed for evidence of clinical seizure and if present whether there was evidence of parent seizure identification.

Results

Nine infants were enrolled, for whom 674 focal seizures were identified in 8/9 patients across 24 prolonged vEEG recordings, with vEEG total duration 634 hours 49 minutes (average seizure frequency of 1 focal seizure/hour). Only 220/674 (32.6%) were clinical seizures, 395/674 (58.6%) were subclinical seizures and 59/674 seizures were unable to be classified. Only 63/220 (28.6%) clinical seizures were identified by parents, with 157/220 (71.4%) not identified. Thirty clusters of epileptic spasms were detected in 1 patient. At least one clinical epileptic spasm occurred in 2/30 (6.7%) clusters, 24/30 (80%) clusters of epileptic spasms were electrographic only, and classification was uncertain for 4/30 (13.3%) clusters. No clinical epileptic spasms were detected by parents. Clinical seizure frequency was significantly under-estimated by parents in all patients.

Significance

This study demonstrates that in TSC infants meeting criteria for prolonged vEEG, that 1) parents significantly under-identify total clinical seizure count, 2) parents fail to identify epileptic spasms and 3) that seizure frequency is high. This highlights that epilepsy treatment decisions should not be solely based on parental clinical seizure identification. Prolonged vEEG monitoring may have an important role in the routine epilepsy care of TSC infants, as demonstrating undetected high clinical seizure frequency may allow improved epilepsy management decisions.

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