Characterizing Clinical and Electrophysiological Features of Seizures in Familial Cortical Myoclonic Tremor with Epilepsy Type 1
Abstract number :
1.192
Submission category :
4. Clinical Epilepsy / 4A. Classification and Syndromes
Year :
2023
Submission ID :
401
Source :
www.aesnet.org
Presentation date :
12/2/2023 12:00:00 AM
Published date :
Authors :
Presenting Author: Yao Ding, PhD – Department of Neurology, Zhejiang University School of Medicine Second Affiliated Hospital, Hangzhou, China
Rationale:
This study aims to investigate and characterize epileptic seizures and electrophysiological features of familial cortical myoclonic tremor with epilepsy (FCMTE) type 1 patients in a large Chinese cohort.
Methods:
We systematically evaluated 125 FCMTE-1 patients carrying the pentanucleotide (TTTCA) repeat expansion in the SAMD12 gene in China. Seizure-related features were characterized. Routine and/or overnight electroencephalography (EEG) was conducted.
Results:
Among the 28 probands, epileptic seizures (96.4%, 27/28) were the most common reason for an initial clinic visit. Ninety-seven (77.6%, 97/125) patients had experienced seizures, all manifesting as bilateral tonic-clonic seizures, often initiated alongside myoclonic jerks. The seizures onset age was 36.5±9.0 years, which was 6.9 years later than cortical tremors. Over 95% of patients experienced seizures after 24 years of age. The seizures were largely rare (< 1/year, 58.8%) and occasional (1–6/year, 37.1%). Prolonged prodromes were reported in 57.7% (56/97) of those experiencing seizures. Thirty-one patients (24.8%, 31/125) reported photosensitivity history, and 79.5% (31/39) of patients exposed to intermittent photic simulation had a photoparoxysmal response. Interictal epileptiform discharges (IEDs) were recorded in 69.1% (56/81) of patients. Thirty-three patients showed generalized IEDs and 72.7% (24/33) were occipitally dominant, while 23 patients presented with focal IEDs with 65.2% (15/23) taking place over the occipital lobe. Overnight EEG of FCMTE patients displayed paradoxical sleep-wake fluctuation, with a higher average IED index of 0.82 ± 0.88/min during wakefulness and a lower IED index of 0.04 ± 0.06/min during non-rapid eye movement sleep stages I–II.
Clinical Epilepsy