Co‐existence of Focal and Bilateral Diffuse Paroxysmal Discharges in Epileptics: Clinical‐electro graphic study

Abstract

SUMMARY Thirty‐five epileptic patients with co‐existent focal and bilaterally synchronous, diffuse paroxysmal electrographic discharges are evaluated and their electrographic features are correlated with clinico‐pathological data. The findings are compared with information derived from a control group of 67 patients with clearly defined and uncomplicated focal epileptiform discharges. Statistically significant differences were found between the control and study groups in regard to the following variables. The mean age of onset of seizures and age at the time of EEG recording of the study group was lower and the mean interval of time between the two events was shorter. The age distributions within the two groups were different in a similar manner. A greater number of patients with frontal foci and fewer with temporal foci were found in the study group. Excessively slow background rhythms occurred more frequently in the study group. Partial, complex seizures with or without secondary generalization were more common in the control group. Focal or lateralizing neurologic signs were more common in the study group. Non‐electrographic evidence of cerebral abnormality extending beyond the temporal lobe in patients with temporal foci was more common in the study group. When the effect of age was minimized by age matching the differences of the variables outlined above remained significant. Patients with electrographic foci consistent with the clinical seizure pattern, abnormal findings on neurological examination and contrast radiography had electro‐graphic evidence suggesting a lesion in areas other than the frontal region. The localizing value of foci in the frontal regions, when associated with bilaterally synchronous discharges, would appear to be questionable: such foci were generally not supported and, in some cases, were actually contradicted by the various clinical data. RÉSUMÉ Trente‐cinq malades épileptiques qui présentent des paroxysmes EEGraphiques focalisés aussi bien que généralisés (bilatéraux synchrones et diffuses) sont étudiés, les données de l'EEG étant corrélées avec le tableau clinico‐pathologique. Les résultats sont comparés avec ceux obtenus dans un groupe (contrôle) de soixante‐sept épileptiques dont l'EEG présente seulement des décharges épileptiformes focales. Des différences statistiquement significatives entre les deux groupes ont été trouvées pour les facteurs suivants. L'âge moyen du début des crises et l'âge moyen au moment du premier enregistrement EEG sont plus bas et l'intervalle de temps moyen entre ces deux événements est plus court dans le groupe étudié que dans le groupe contrôle. Les distributions d'âge dans les deux groupes montrent une différence semblable. Dans le groupe étudié on trouve un plus grand nombre de malades avec un foyer frontal et moins de cas avec un foyer temporal. Les rythmes de base anormalement lents sont observés plus fréquemment dans le groupe étudié. Les crises partielles à séméiologie élaborée sont plus communes dans le groupe de contrôle. ...

Symptomatic Partial Epilepsies with Secondary Bilateral Synchrony: Differentiation from Symptomatic Generalized Epilepsies of the Lennox-Gastaut Type

“…Thus, 24% of these patients had complex partial seizures, 18% had hemiclonic and 10% adversive seizures with or without secondary generalization. This proportion is similar to those found by Gabor and Ajmone-Marsan (1969), who noted 14% with complex partial seizures and 25% with simple partial seizures with sensorimotor symptoms; and by Niedermeyer (1972), who found 23% with psychomotor seizures and 23% with focal motor, hemiconvulsive, or adversive seizures.…”

“…Mental retardation was found in 36%. Gabor and Ajmone-Marsan (1969) and Niedermeyer (1972) found 20% and 12% respectively with hemiplegia, and 17% and 12% respectively with mental retardation.…”

“…SBS is thus contrasted with primary bilateral synchrony, which is manifested by more rapid symmetric and bilaterally synchronous spike-and-wave discharges over both hemispheres, due to a generalized epileptogenic process independent of any focal hemispheric lesion. Since then, SBS has been discussed by Gastaut et al (1968), Niedermeyer (1968Niedermeyer ( , 1972, Gabor and Ajmone-Marsan (1969), Blume and Pillay (1985), and Spencer et al (1985).…”

Prognostic Factors for Childhood and Juvenile Absence Epilepsies

“…As has long been known [24], interictal focal abnormalities were frequent in our series (22% in CAE and 33% in JAE). Recently several studies have pointed out that focal and/or asymmetric abnormalities can be noted in patients with JME, another form of 1GE.…”

Indices of Resective Surgery Effectiveness for Intractable Nonlesional Focal Epilepsy

“…In contrast to the current study, Williamson et al (41) found contralateral seizure onsets in 13% of nonlesional, postoperatively SF temporal lobe patients. The appearance of multiple interictal spike foci or generalized spike-waves augur an unfavorable surgical outcome likely by representing multifocal epileptogenesis (55)(56)(57)(58).…”