An Extraordinary EEG Phenomenon Misdiagnosed as Nonconvulsive Status Epilepticus: Frequent Subclinical Periodic Discharges Terminated by Sudden Auditory Stimuli.
{"title":"An Extraordinary EEG Phenomenon Misdiagnosed as Nonconvulsive Status Epilepticus: Frequent Subclinical Periodic Discharges Terminated by Sudden Auditory Stimuli.","authors":"Emel Oguz-Akarsu, Barıs Salman, Sibel Ugur-Iseri, Betul Baykan","doi":"10.1177/15500594221129965","DOIUrl":null,"url":null,"abstract":"<p><p>Triggering or modulation of seizures and rhythmic EEG patterns by external stimuli are well-known with the most common clinical appearance of stimulus induced periodic discharges (SI- PDs) patterns which are elicited by physical or auditory stimulation. However, stimulus terminated periodic discharges (ST-PDs), in other words, the periodic discharges stopped by external stimuli is an extremely rare electroencephalographic (EEG) finding. We report a 20-year-old woman with a marked psychomotor developmental delay of unknown cause, with frequent EEG patterns of long-lasting (10-60 s) bilateral paroxysmal high-voltage slow waves with occasional spikes, misdiagnosed as non-convulsive status epilepticus. However, no apparent clinical change was noted by the technician, physician, and her mother during these subclinical ictal EEG recordings. Interestingly, however, these epileptic discharges were abruptly interrupted by sudden verbal stimuli on the EEG, repeatedly. Whole exome sequencing and genotyping were performed to investigate possible genetic etiology that revealed two sequence variants, a frameshift variant of <i>CACNA1H</i> NM_021098.3:c.1701del;p.Asp568ThrfsTer15 and a missense variant of <i>GRIN2D</i> NM_000836.4:c.1783A>T;p.Thr595Ser as well as a copy number variant part deletion of <i>ATP6V1A</i> gene arr [hg19]3q13.31(113,499,698_113,543,081)x1 as possible pathogenic candidates. The subclinical periodic discharges terminated by verbal stimuli, is a very rare manifestation and needs particular attention. External modulation of ictal-appearing EEG patterns is important to identify stimulus terminated EEG patterns.</p>","PeriodicalId":10682,"journal":{"name":"Clinical EEG and Neuroscience","volume":"54 2","pages":"160-163"},"PeriodicalIF":1.6000,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Clinical EEG and Neuroscience","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1177/15500594221129965","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CLINICAL NEUROLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Triggering or modulation of seizures and rhythmic EEG patterns by external stimuli are well-known with the most common clinical appearance of stimulus induced periodic discharges (SI- PDs) patterns which are elicited by physical or auditory stimulation. However, stimulus terminated periodic discharges (ST-PDs), in other words, the periodic discharges stopped by external stimuli is an extremely rare electroencephalographic (EEG) finding. We report a 20-year-old woman with a marked psychomotor developmental delay of unknown cause, with frequent EEG patterns of long-lasting (10-60 s) bilateral paroxysmal high-voltage slow waves with occasional spikes, misdiagnosed as non-convulsive status epilepticus. However, no apparent clinical change was noted by the technician, physician, and her mother during these subclinical ictal EEG recordings. Interestingly, however, these epileptic discharges were abruptly interrupted by sudden verbal stimuli on the EEG, repeatedly. Whole exome sequencing and genotyping were performed to investigate possible genetic etiology that revealed two sequence variants, a frameshift variant of CACNA1H NM_021098.3:c.1701del;p.Asp568ThrfsTer15 and a missense variant of GRIN2D NM_000836.4:c.1783A>T;p.Thr595Ser as well as a copy number variant part deletion of ATP6V1A gene arr [hg19]3q13.31(113,499,698_113,543,081)x1 as possible pathogenic candidates. The subclinical periodic discharges terminated by verbal stimuli, is a very rare manifestation and needs particular attention. External modulation of ictal-appearing EEG patterns is important to identify stimulus terminated EEG patterns.
期刊介绍:
Clinical EEG and Neuroscience conveys clinically relevant research and development in electroencephalography and neuroscience. Original articles on any aspect of clinical neurophysiology or related work in allied fields are invited for publication.