A case report of sequential seizure semiology as a sign of genetic etiology

Objective: To demonstrate the importance of recognizing genetic etiology for “sequential” seizure semiology. The case demonstrates that genetic etiology must be considered, particularly when structural abnormalities are not aligning with EEG findings. Methods: We present the case of a 6-week-old boy who develop intractable epilepsy, with seizures consisting of a tonic-hypermotor-spasms “sequence”. Results: His MRI demonstrated a thick left frontal gyrus and PET scan showed decreased uptake in the left frontal gyrus. A structural etiology behind his epilepsy was initially considered pending further testing. Nevertheless, his long-term video EEG was non-localizable and genetic testing demonstrated a pathogenic variant on the CDKL5 gene. Conclusions: This case demonstrates the importance in recognizing “sequential” seizure semiology, as potential manifestation of an underlying genetic etiology and importance of considering genetic testing before proceeding with surgical evaluation. The case also proves that the order of sequence or number of seizures in the sequence is not a gene specific phenomena.
Keywords: epilepsy, semiology, sequential, genetic, sequence