Abstracts

Rationale: Generalized periodic discharges (GPDs) pattern is characterized by a repetition of a waveform with relatively uniform morphology and duration with a quantifiable inter-discharge interval between consecutive waveforms and recurrence of the waveform at nearly regular intervals.1 It typically arises from a diffusely slow or attenuated background.1 Although GPDs have been recognized for over half a century, their underlying pathophysiology and clinical significance remain unclear.2,3 Reports have correlated GPDs with obtunded patients, typically after anoxia, metabolic insults, central nervous system infectious, recent overt seizures, degenerative diseases, or in the late stages of status epileptic.1,3 GPDs tend to persist even with aggressive therapy, and it is not known whether patients benefit from treatment of these EEG findings.4 GPDs are associated with poor outcome, independent of age, etiology, and level of consciousness.1,4,5Methods: In this study, we evaluated the epidemiological and etiological profiles of 23 patients with GPDs pattern at the Hospital das Clinicas, Faculty of Medicine, University of São Paulo over a one-year period (2014) by retrospective analysis of EEG laboratory data.Results: The age of the study population ranged from 4.4 years to 90.6 years, with a mean of 63 years and three months. There were 13 women (56.5%) and 10 men (43.5%). The most common etiology was Acute Cerebral Injury, found in 11 patients (47.8%), subdivided into 4 cases of Traumatic brain injury, two of encephalitis, one of Ischemic Stroke, one of Subarachnoid hemorrhage, one of Subdural hemorrhage, one of Central Nervous System Tumor and one of hydrocephalus shunt Ventriculoperitoneal. Other etiologies included Systemic Disease Acute in 7 patients (30.4%), subdivided into 4 of toxicmetabolic cause and 3 for sepsis, Epilepsy in 3 patients (13%) and neurodegenerative disease in two patients (8.8%).Conclusions: The GPDs standard has no predisposition for sex and was found predominantly in older patients. The Acute Cerebral Injury was the main cause of GPDS found in the group of patients studied. These results are consistent with the current literature.2 1- Schomer, DL, Lopes da Silva, FH. Niedermeyer’s Electroencephalography. Basic principles, clinical applications and related fields. Sexta edição, 2011. Philadelphia, PA. Chapter 23: 437. 2- Foreman B, Claassen J, Abou Khaled K, Jirsch J, Alschuler D, Wittman J, Emerson R, Hirsch L. Generalized periodic discharges in the critically ill: A case-control study of 200 patients. Neurology 2012; 79: 1951–1960. 3- Yemisci M, Gurer G, Saygi S, Ciger A. Generalised periodic epileptiform discharges: clinical features, neuroradiological evaluation and prognosis in 37 adult patients. Seizure 2003;7: 465–472. 4- Jette N, Moseley BD. Generalized periodic discharges: more light shed on the old ""GPEDs"". Neurology 2012;19:1940-1. 5- Van Putten MJAM, Hofmeijer J. Generalized periodic discharges: Pathophysiology and clinical considerations. Epilepsy Behav 2015.