Absolute spike frequency and different comorbidities in temporal lobe epilepsy

Abstract

ObjectiveThe objective of this study was to examine if the absolute number of interictal epileptiform discharges (IED) is related to the presence of different comorbidities and refractivity in patients with temporal lobe epilepsy. MethodsAnalysis with scalp EEG of the IED of 30 patients with temporal epilepsy. The analysis was performed in three selected periods of the record during N2–N3 sleep. We analyzed the number of IED and the sum of the values obtained in the three selected segments to determine the absolute interictal spike frequency. ResultsThe number of IED for patients varied from 11 to 450. The absolute interictal spike frequency showed a statistically significant relation with the presence of refractivity (p < 0.05), and neurological and/or psychiatric comorbidity (p < 0.05). Patients with an absolute interictal spike frequency ≤ 60 showed little refractoriness and no comorbidity. Patients with an absolute interictal spike frequency > 60 were mostly refractory and with neurological and/or psychiatric comorbidity. No significant relation was found of absolute interictal spike frequency with age at the onset of epilepsy, number of anticonvulsant drugs used, or base pathology (MRI). ConclusionsThe absolute interictal spike frequency is capable of differentiating patients with temporal lobe epilepsy, identifying those with temporal lobe epilepsy according to the severity of the condition. Only those patients with non-frequent spikes (≤60 over the affected temporal lobe) have a low percentage of refractoriness with little or no presence of comorbidity.