Persistence of EEG abnormalities in <i>KCNT1</i>‐related DEE in an adult patient

The KCNT1 gene encodes a sodium-activated potassium channel, with variants causing developmental/epileptic encephalopathies (DEEs) and intractable epilepsies.1, 2 EEGs characteristically reveal multi-focal interictal discharges migrating through contiguous cortical regions.3 We demonstrate multi-focal interictal discharges (left parietal, left frontal, right centroparietal, and right parieto-occipital) amidst a disorganized, slow background in a 20-year-old female with a heterozygous likely pathogenic KCNT1 variant (p.L281I; c.841C>A) and DEE (Figures 1 and 2). EEG available at https://hub.eegtalk.com/go/KCNT1. Seizures developed at age 6, followed by developmental regression, precocious puberty, and behavioral/psychiatric disturbances. Cardiac arrhythmias and pulmonary hemorrhage have also been reported.4 Presently, she experiences five to six focal seizures without impaired awareness weekly on lacosamide. Quinidine, thought to control seizures and slow developmental regression in KCNT1-related epilepsies, is no longer recommended and was discontinued.5, 6 A recent trial has not proven its efficacy despite carrying significant risks of arrhythmia.7 Although well-described in children, we demonstrate these EEG findings' persistence into adulthood. Irfan S. Sheikh is the assistant program leader for the Epileptic Disorders Journal Internship Program, is an Associate Editor for the journal, and has collaboration with EEGHub. Doyle Yuan has collaboration with EEGHub. Other authors report no disclosures. The data that support the findings of this study are openly available in EEGHub at https://hub.eegtalk.com/go/KCNT1. Data S1 Data S2 Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. The KCNT1 gene encodes EEG characteristically shows Which of these can be seen in KCNT1-related epilepsy Answers may be found in the Supporting information.