Scalp-recorded high-frequency oscillations in atypical benign partial epilepsy.

OBJECTIVE

To investigate how high-frequency oscillations (HFOs) were affected by methylprednisolone treatment and the clinical significance of HFOs in patients with atypical benign partial epilepsy (ABPE).

METHODS

In 14 ABPE patients with methylprednisolone treatment, we measured interictal HFOs and spikes during sleep in pre- and post-methylprednisolone scalp electroencephalography (EEG). Patients with benign childhood epilepsy with centrotemporal spikes (BECTS) were taken as control.

RESULTS

Before methylprednisolone treatment, 10/14 ABPE patients had HFOs, with a mean value of 85.79 per 60s per patient, while 2/14 BECTS patients had HFOs with a mean value of 1.86 per 60s per patient (p=0.006). The 10 ABPE patients with HFOs tended to have more frequent epileptic negative myoclonus/atypical absences than the other 4 ABPE patients without HFOs. Rates reduced by methylprednisolone treatment were statistically significant for both spikes (p=0.027) and HFOs (p=0.005). The percentage of reduction was 41.8% (4653/11,133) and 95% (1141/1202) for spikes and HFOs, respectively.

CONCLUSION

Proportion and rates of HFOs in ABPE were more prevalent than in BECTS. HFO rates reduced by methylprednisolone treatment might be more significant than spike rates.

SIGNIFICANCE

Prevalence of HFOs reflected at least some aspect of epileptic severity of ABPE. HFOs were more sensitive to methylprednisolone treatment than spikes.