The Periodically Recurring Focal Discharge

Abstract

SUMMARY A rare electrographic pattern of periodically recurring focal discharges, mainly in the parieto‐occipital area, has been described. The constancy of the rate of discharges under various conditions has been noted. In some patients, the discharge seems to occur at preferential time intervals after the heart beat. Most of the patients were adults with histories of a seizure disorder, especially with a focal aspect, and also with neurological symptoms, mainly motor deficits, and psychiatric signs, but the seizures of the majority of patients temporarily lessened with anticonvulsant medication. The most common etiological factor was cerebrovascular disease; the possibility that prolonged hypoxia or anoxia may be responsible for the discharges is discussed. A phenomenon, possibly related to the recurring focal discharge in the human, has also been noted in the monkey. RÉASUMÉA Les auteurs deAcrivent un type rare de deAcharges focaliseAes qui se reApeGtent de facLon peAriodique et surviennent principalement dans la reAgion parieAto‐occipitale. La peAriodiciteA du pheAnomeGne est constante dans des conditions varieAes et, chez quelques patients, il semble que les deAcharges surviennent preAfeArentiellement un certain temps apreGs les pulsatiAons cardiaques. Laplupart des patients eAtaient des adultes preAsentantdes crises aG seAmeAiologie focale ainsi que des symptoCmes neurologiques, principalement deAficitaires, et des manifestations psychiatriques; les crises de la plupart de ces sujets furent atteAnueAes par une theArapeutique anti‐convulsive. Le facteur eAtiologique le plus commun eAtait repreAsenteA par une affection vasculare ceAreAbrale; le roCle d'une hypoxie prolongeAe ou d'une anoxie peut done eCtre envisageA a l'origine de ces deAcharges. Un pheAnomeGne qu'il est possible derattacher aG ces deAcharges focaliseAes reAcurrentes de l'homme a eAteA noteA chez les singes.

Clinical Significance of Focal Periodic Discharges in Neonates

“…The incidence rate of 0.3% of our records with PLEDs was below the reported range of 0.6% to 8.5% of records in older patients. 3,17,19,30 There are no comparable incidence rates for focal periodic discharges of shorter duration than PLEDs in our age group. The incidence of 5% of our neonatal records with focal periodic discharges was more than 16 times the incidence rate of PLEDs in this population.…”

Reassessment of the Clinical Significance of Periodic Lateralized Epileptiform Discharges in Pediatric Patients

“…From these results, it was concluded that PLEDs carried a different clinical significance for pediatric patients, but this conclusion may have been premature owing to certain limitations of the study. The study sample was small, involving only 7 patients, and the cited adult data were actually derived from mixed-age studies with mean ages in the adult range but with inclusion of children as young as 3 years of age (Chatrian et al, 1964;Hughes and Schlagenhauff, 1965;Schwartz et al, 1973). We examined this early pediatric study against a better defined adult population and our larger series of pediatric patients.…”

Regional Cerebral Perfusion in PLEDs: A Case Report

“…Periodic lateralized epileptiform discharges (PLEDs), a term coined by Chatrian et al (1964), are an electroencephalographic (EEG) phenomenon consisting of unilateral or focal spikes or sharp wave complexes occurring in a pseudoperiodic fashion, usually at a rate of 1-2 s. The most common etiology of PLEDs is an acute or subacute hemispheric or focal cerebral lesion, but PLEDs also occur in patients with a chronic static cerebral lesion or chronic epilepsy (Chatrian et al, 1964;Hughes and Schlagenhauff, 1965;Markand and Daly, 1971;Schwartz et al, 1973;Dauben and Adams, 1977;Erkulvrawatr, 1977;Porecha and Reilly, 1977;PeBenito and Cracco, 1979;Schraeder and Singh, 1980;de la Paz and Brenner, 1981;Westmoreland et al, 1986). Investigation of regional cerebral blood flow (rCBF) and local cerebral metabolic ratio (LCMR) by using positron emission computed tomography (PET) or single-photon-emission computed tomography (SPECT) provides valuable information about the pathophysiology of epilepsy, which is complementary to the findings of electrophysiologic studies (Kuhl et al, 1980;Engel et al, 1982;Mazziottaand Engel, 1984).…”