Bulent Unay
Ankara University School of Medicine, Turkey
Title: Clinical importance of occipital intermittent rhythmic delta activity in children
Biography
Biography: Bulent Unay
Abstract
Occipital intermittent rhythmic delta activity (OIRDA) may be present either in physiological or pathological conditions. Absence seizures present as brief episodes of staring and unresponsiveness and are characterized by an abrupt cessation of activity and impairment of consciousness. Generalized 2.5–4 Hz spike and wave discharges are electrographic pattern of absence epilepsy. OIRDA occurs usually in children. OIRDA was described in patients with epilepsy, particularly with generalized syndromes, such as absence epilepsy. In this report we present a patient with absence epilepsy who have OIRDA findings in their EEG recording and discussed the clinical importance of OIRDA in children. Posterior slow activity on EEG was initially described in children with behavior problems. Throughout the years, the range of clinical interpretation of this pattern by researchers varied to suggesting non-specific, metabolic, epileptic and structural. 7-year old boy who met the diagnostic criteria for absence epilepsy admitted to epilepsy center of university hospital. Absence was defined based on ILAE classification. OIRDA was defined as intermittent monomorphic rhythmic delta activity with maximal amplitude over the occipital regions ranging from 1-4 Hz. He had one record of awaken EEG where OIRDA was reported and sleep EEG was normal. OIRDA ranged from 1-2 Hz to 2-3 Hz in same record. In previous studies, OIRDA was found in 3-4 % of children. OIRDA may not be associated to structural lesions and was described in patients with absence seizures by Cobb in 1945. Recently (2003) Gullapali and Fountain reported a series of 77 patients with OIRDA and found seizures to be more frequent than in the control group. Some authors consider OIRDA as a good prognosis factor in patients with absences.
