Recognition Impairment Correlated with Short Bisynchronous Epileptic Discharges

Abstract

The occurrence of transitory cognitive impairment during diffuse subclinical electroencephalographic (EEG) discharges has been widely documented but the role of the parameters influencing the cognitive performance and the involvement of motor or verbal response in the tasks used is still under debate. Fifteen patients suffering from primary generalized epilepsy with frequent bisynchronous EEG epileptic bursts underwent a shape recognition task during EEG monitoring. The test sequence was as follows: memorandum, pause, and multiple choice set. After pressing the response button, the patient was asked to confirm the choice verbally. The following parameters were considered: geometrical complexity of the shape, chronological position of the burst occurring during the single test, and the duration of discharge ranging from 1 to 3 s. Results showed a significant increase in incorrect responses during the test when discharges occurred, with more errors occurring for difficult than for easy shapes. Neither the discharge position nor the duration of the epileptic burst influenced the performance. Diffuse epileptic activity of short duration produced selective effects on the cognitive process regardless of the motor component of the response.

The Electroencephalogram in Attention Deficit–Hyperactivity Disorder: Emphasis on Epileptiform Discharges

“…On the other hand, in most of these same patients the generalized discharges appeared only rarely in the records, still leaving open the possibility that the bilateral spike and wave complexes could contribute to deficits in attention. This possibility exists especially since published data have shown frequent abnormal responsiveness during these complexes of only 1 second in duration (16). The focal discharges, seen in nearly one-quarter of patients, represent a major finding and these spikes likely represent an example of the clinical significance of the interictal discharge, which can affect nearly all cerebral functions (9).…”

Learning and Memory Impairment in Patients with Temporal Lobe Epilepsy: Relation to the Presence, Type, and Location of Brain Lesion

“…We believe that the learning and memory disturbances observed in our patients with lesional TLE are mainly the result of the epileptiform activity induced by the lesion rather than of the destructive effect of the lesion itself. There is evidence, in fact, that temporal lobe seizures (33) and bisynchronous epileptic discharges (34) are related to transient memory impairment. It is clear, however, that epileptic discharges may be associated with pathologic alterations not revealed by neuroradiologic investigations, and the presence of a lesion cannot be excluded in all patients with cryptogenic TLE.…”

Distúrbio cognitivo transitório associado a atividade epileptiforme generalizada ou difusa durante o eletrencefalograma

“…Por vezes, essas descargas apareceram entre uma resposta e o estímulo seguinte, o u seja, em momento inadequado para a análise. Provavelmente houve inibição das descargas nas atividades cognitivas, fato também relatado em outras séries de pacientes com AE generalizada 21,23 . É possível que a utilização, em cada paciente, de testes mais variados e de diferentes níveis de dificuldade, pudesse identificar os que ocasionassem menor redução de AE 2 5 .…”