The identifying features of BSSS include their typically widespread horizontal dipole distribution that occurs in the absence of any apparent disruption of the ongoing background activities. Often, school staff members are the first to notice the recurrent episodes of absence seizures, and treatment is generally initiated because of the adverse impact on learning.Benign sporadic sleep spikes (BSSS), also referred to as small sharp spikes or benign epileptiform transient of sleep (BETS), are low amplitude (<50 mV), brief (<50 ms), sharply contoured monophasic or biphasic electronegative spikes in theta or alpha frequency range (see figure 1). Affected children need to take precautions to prevent injury during absences and should refrain from activities that would put them at risk if seizures occurred (e.g., climbing heights, swimming unsupervised, or cycling on busy roads).

The episode of unconsciousness may occur at any time, and usually without warning. Absence seizures have a significant impact on quality of life. In other epileptic syndromes, in which absence seizures may coexist with other types of seizure, prognosis is varied, depending on the syndrome. Less than 10% of children develop infrequent generalized tonic-clonic seizures, and it is rare for them to continue having absence seizures. In childhood absence epilepsy, in which typical absence seizures are the only type of seizures affecting the child, seizures generally cease spontaneously by 12 years of age or sooner.

Typical absence seizures should not be confused with atypical absence seizures, which differ markedly in EEG findings and ictal behavior, and are usually present with other seizure types in a child with a background of learning disability and severe epilepsy. However, the abrupt ending of typical absence seizures, without a postictal phase, is the most useful clinical feature in distinguishing the two types. Typical absence seizures are often confused with complex partial seizures, especially in cases of prolonged seizure with automatisms. Typical absence seizures display a characteristic EEG showing regular symmetrical generalized spike and wave complexes with a frequency of 3 Hz, and usually occur in children with normal development and intelligence. Interventions for atypical absence seizures or for absence seizures secondary to structural lesions are not included in this review. atypical seizures is important, as the natural history and response to treatment vary between the two groups. Absence seizures are sudden, frequent episodes of unconsciousness lasting a few seconds, and they are often accompanied by simple automatisms or clonic, atonic, or autonomic components.

Epilepsy eeg vs normal eeg