Although this effect also can be observed in normal individuals, it is, however, more prevalent and pronounced in patients with epilepsy ( 1). Hyperventilation (HV) constitutes a classic activation procedure of the electroencephalogram (EEG) that usually provokes physiological slowing of the brain rhythms, more intense and abrupt in children from 8 to 12 years old ( 1–4). This observation is clinically relevant and suggests the effectiveness and the potential of HV in shortening the presurgical evaluation, especially of temporal lobe epilepsy patients, consequently reducing its costs and increasing the number of candidates for epilepsy surgery. It does not modify any of the characteristics of the seizures and allows the obtaining of valuable ictal SPECTs. Spontaneous and activated seizures did not differ in terms of their clinical characteristics, and the activation did not affect the performance of ictal single-photon emission computed tomography (SPECT).Ĭonclusions: HV is a safe and effective method of seizure activation during monitoring. Temporal lobe epilepsies were significantly more activated than frontal lobe epilepsies. No differences were found between groups regarding sex, age, age at epilepsy onset, duration of epilepsy, frequency of seizures, and etiology. Results: We analyzed 97 patients 24 had positive seizure activation (PSA), and 73 had negative seizure activation (NSA). We excluded children younger than 10 years, mentally retarded patients, and individuals with frequent seizures. Methods: We analyzed the effects of hyperventilation (HV) during video-EEG monitoring (video-EEG) of patients with medically intractable focal epilepsies. In this study we assessed its effectiveness in inducing focal seizures during video-EEG monitoring. Summary: Purpose: Hyperventilation is an activation method that provokes physiological slowing of brain rhythms, interictal discharges, and seizures, especially in generalized idiopathic epilepsies.

Normal vs abnormal eeg