COUPLING OF FOCAL ELECTRICAL SEIZURE DISCHARGES WITH INFANTILE SPASMS- INCIDENCE DURING LONG-TERM MONITORING IN NEWLY-DIAGNOSED PATIENTS

To investigate the coupling of focal electrical seizure discharges (FS ) and infantile spasms, we analyzed the video/polygraphic monitoring s tudies performed on 96 consecutive patients newly diagnosed with infan tile spasms and hypsarrhythmic EEGs. A FS was considered to be coupled with infantile spasms if it occurred during a cluster of spasms (a se ries of individual spasms separated by < 1 min) or within 10 s of spas m onset or cessation. Ten patients demonstrated FS. In five patients ( 5% of the entire population) an apparent coupling of some FS with infa ntile spasms was observed during the baseline monitoring study. Howeve r, in three patients (only 3% of the entire population) was the observ ed coupling of FS and infantile spasms significant (p < 0.05). These r esults indicate that coupling of FS and infantile spasms occurs rarely , and that, in some instances, apparent couplings of FS and infantile spasms are best explained by chance coincidence. These findings do not support the hypothesis that the generation of infantile spasms at a s ubcortical level is dependent on a focal cortical discharge.