Variations of Patterns of Electroencephalogram in West syndrom

Abstract

Background: West syndrome (WS) or Infantile epileptic spasms syndrome (IESS) is a potentially devastating form of developmental and epileptic encephalopathy of early childhood. Early diagnosis and initiation of prompt treatment are very important for better outcome. But it has many differential diagnoses, especially in atypical or subtle cases. EEG is essential to diagnose it. Initially, hypsarrhythmia was described as the prototypical EEG pattern associated with WS. However, other EEG patterns were also found to be associated with WS in subsequent studies. Recognition of those patterns is important for appropriate diagnosis and prompt initiation of specific anti-seizure medications. Moreover, some of the EEG patterns were reported to be related to specific underlying aetiologies.

Objective: This study was undertaken to identify various interictal EEG patterns in WS and to examine their relationship with etiology.

Methodology: It was a cross-sectional observational study done at the Paediatric Neurology unit of, Bangabandhu Sheikh Mujib Medical University, Dhaka from January 2013 to June 2015, Clinically, WS was diagnosed by epileptic spasms with psychomotor delay or regression. Those were elicited by detailed history and thorough physical examination. EEG, neuroimaging and other diagnostic tests were performed. Those findings were analyzed.

Results: Among 57 children with WS, EEG showed multifocal epileptiform discharges in 22(38.5%), burst suppression pattern in 18(31.5%), asymmetrical hypsarrhythmia in 9(15.7%), classic hypsarrhythmia in 5(8.7%) and increased interhemispheric synchronization in 3(5.2%) cases. However, no significant association was found between a particular EEG pattern and underlying aetiology.

Conclusion: This study reveals that interictal EEG of children with WS may show various EEG patterns other than classic hypsarrhythmia.

Journal of National Institute of Neurosciences Bangladesh, July 2025;11(2):104-109