Impairment of Consciousness During Epileptic Seizures with Special Reference to Neuronal Mechanisms

Summary: Two neuronal structures, i.e., the cerebral cortex and the subcortical structures, were shown by clinical observations to be involved in maintaining consciousness. The alteration of consciousness during epileptic seizures is discussed with respect to these findings: Alterations of consciousness during epileptic seizures may be produced by subcortical, i.e., reticular formation, and/or cortical dysfunction followed by excessive, hypersynchronous neuronal discharges. An impairment of consciousness during absence seizures may be due mainly to cortical dysfunction; during complex partial seizures (CPS), it may be due to dysfunctional subcortical neuronal structures. The mechanisms underlying an alteration of consciousness are defined as causing "irritative" functional disturbances and/or as having "inhibitory" effects on consciousness-related structures.     

Aggravation of Focal Epileptic Seizures by Antiepileptic Drugs

Summary: Aggravation of focal epileptic seizures in adults is common after the antiepileptic drug (AED) therapy is initiated. Sometimes aggravation is mimicked by clustering of the seizures. Therefore, it is always necessary to analyze the patient's history and therapy carefully before drawing any conclusions. It is likely that a paradoxical aggravation of epileptic seizures can be attributed to the given AED and is sometimes, but only rarely, due to drug interactions.     

Epileptic Seizures in Elderly Patients with Dementia

All inpatients aged greater than 55 years with dementia in the Dundee Psychiatric Service were surveyed for seizure occurrence by interviewing staff and reviewing records. Of 208 patients, 19 (9.1%) were recorded as having seizures. The seizures were major in 92% and occurred at a rate of approximately 2.3 seizures per patient per year. Patients with epilepsy were significantly younger than a control group of dementia inpatients and were significantly more cognitively impaired on the survey Clifton Assessment Procedure for the Elderly (CAPE), but not on the Mini Mental State Examination. Of 111 reported accidents, only 5 appeared to be associated with epilepsy. Although epileptic seizures are relatively common in patients with severe dementia, they rarely caused severe problems.     

Correlates of Generalized Tonic-Clonic Seizures with Intellectual, Neuropsychological, Emotional, and Social Function in Patients with Epilepsy

Relationships between generalized tonic-clonic seizures and indicators of psychological functioning were evaluated in 94 adults with epilepsy who had exceptionally clear seizure histories. Patients were divided according to lifetime numbers of attacks and the presence or absence of a history of major motor status epilepticus. History of status epilepticus or history of more than 100 individual convulsions was associated with decreased functioning in all areas. Abilities were poorest for the group with a history of status, whereas emotional and psychosocial adjustment were worst in persons having large numbers of single convulsions. Possible reasons for the decreased test scores other than seizures were explored in great detail, but none could account for the differences in performance across the groups.     

The Mortality Associated with Epilepsy, with Particular Reference to Sudden Unexpected Death: A Review

Summary: Recent studies indicate that the overall mortality rate for persons with epilepsy is elevated two- or threefold compared with the general population. The standardized mortality ratio (SMR) is greatest in the first few years after diagnosis and in symptomatic epilepsies. Idiopathic epilepsies also have a small increase in SMR. The sudden unexpected death rate in those with epilepsy (SUDEP) depends on the population examined. In the general population of persons with epilepsy, the risk is between 1:500 and 1:1,000 person-years. For those with severe epilepsy or other neurologic impairments, the risk appears to be 1:200 person-years. The risk in children remains uncertain. Estimates of mortality should be borne in mind when patients are counseled about the risks and benefits of various treatment strategies.     

Remission of Seizures in a Population-Based Adult Cohort with a Newly Diagnosed Unprovoked Epileptic Seizure

PURPOSE: To investigate the probability of achieving remission of seizures after a newly diagnosed unprovoked epileptic seizure in an adult population-based cohort. METHODS: 107 patients aged 17 years or older with a newly diagnosed unprovoked epileptic seizure (index seizure) in 1985 through 1987 were followed up until the date of death or to the end of 1996. The proportion of cases during follow-up that attained a 1-year, 3-year, 5-year remission was calculated by actuarial analyses. Variables for stratification were age at diagnosis, seizure type, etiology, EEG, and the occurrence of seizures within 1 year of initiation of antiepileptic drug (AED) therapy. RESULTS: Cumulative 1-, 3- and 5-year remission rates were 68, 64, and 58%. There was no statistically significant difference regarding time points of achieving a 1-year remission after epilepsy diagnosis and the subsequent probability during follow-up of attaining a 5-year remission. Having seizures within 1 year after beginning with an AED was a statistically significant predictor of never achieving 1-year remission of seizures during follow-up (refractory seizures). Other stratified variables were not statistically significant predictors. CONCLUSIONS: Seizure prognosis for the majority of patients with newly diagnosed epilepsy is good. The time required after epilepsy diagnosis to achieve a 1-year remission of seizures does not affect the probability of additionally achieving a 5-year remission. Patients with refractory seizures can be identified within a few years from diagnosis of epilepsy. These patients must be targeted early for optimization of pharmacologic treatment, possible surgery, and psychosocial intervention.     

Developmental Aspects of Epilepsy with Special Reference to Age-Dependent Epileptic Encephalopathy

Abstract: The specificity of childhood epilepsy was characterized by investigating the evolutional changes with age and prognoses of age-dependent epileptic encephalopathy from the developmental aspect through a long-term follow-up.
Three types of age-dependent epileptic encephalopathy showed mutual evolutional changes at certain ages. This indicated an important role of the brain development in the clinicoelectroencephalographical manifestations of age-dependent epileptic encephalopathy. Furthermore, the evolutional changes demonstrated an association with organic brain damage and etiology in addition to the age factors. The evolutional changes occurred more frequently in the cases with overt organic brain pathology. The prognosis was poorer in cases which underwent an evolutional change.     

Effects of a Broad-Spectrum Behavior Modification Treatment Program on Children with Refractory Epileptic Seizures

A group of 18 children with refractory epileptic seizures was divided into three groups--behavior modification treatment, attention control, and control groups--with the purpose of investigating the effects of a learning-based broad-spectrum treatment program superimposed on a regular medical treatment program. The design consisted of a 10-week baseline, 6-week intervention, and 10-week and 1-year follow-ups. A combination of number of seizures and seizure duration--termed "seizure index"--was used as a dependent measure. There was a significant reduction in seizure index only for those children receiving the behavior modification treatment, at both follow-ups. The results indicate that this behavioral treatment program may be of substantial help to children with epilepsy who are resistant to conventional drug therapy.     

Experience with the International League Against Epilepsy Proposals for Classification of Epileptic Seizures and the Epilepsies and Epileptic Syndromes in a Pediatric Outpatient Epilepsy Clinic

The International League Against Epilepsy proposals for classification of epileptic seizures (1981) and of the epilepsies and epileptic syndromes (1985) have been used in daily practice in a pediatric epilepsy clinic in Bogota, Colombia. Most patients can be classified by these schemes, and the classifications are useful in everyday diagnosis and management. However, there are some drawbacks and difficulties with the classifications. Some syndromes are unnecessarily separated as different entities, artificially contributing to the complexity of the Classification.     

Remission of Seizures and Relapse in Patients with Epilepsy

In a longitudinal study of patients with epilepsy in Rochester, Minnesota, we found that the probability of being in remission (at least 5 consecutive years seizure-free, and continuing) at 20 years after diagnosis was 70%. The rates for remission we encountered were generally higher than those previously reported. We believe that the better prognosis in our series results from inclusion of all incidence cases in a defined population, beginning at the initial diagnosis of epilepsy. Prognosis for remission of epilepsy is poor in patients with associated neurologic dysfunction identified from birth. Patients with idiopathic seizures and survivors of postnatally acquired epilepsy have better prospects for eventual remission. The probability of remission is highest in patients with generalized-onset seizures diagnosed before 10 years of age. Prognosis is less favorable for those with partial complex seizures and adult-onset epilepsy.     

Symptomatology of Epileptic Seizures in the First Three Years of Life

PURPOSE: Few data are available concerning symptomatology of epileptic seizures in infants. METHODS: We reviewed 296 videotaped seizures from 76 patients aged 1-35 months (mean, 15.1 months) who underwent video-EEG monitoring at our institution from 1988 to 1998. Seizure symptomatology was first classified based on observable behavioral and motor manifestations and then correlated with ictal EEG. RESULTS: Four seizure types accounted for 81% of all seizures seen in this group: epileptic spasms (24%), clonic seizures (20%), tonic seizures (17%), and hypomotor seizures (20%; characterized by arrest or significant decrease of behavioral motor activity with indeterminate level of consciousness). The remaining seizures included small numbers of myoclonic, atonic, and versive seizures. All 12 focal motor seizures and all five versive seizures were associated with focal EEG seizure patterns, seen in the contralateral hemisphere in all but one patient with versive seizures. Generalized motor seizures (clinically generalized at onset) were accompanied either by focal (19 of 51; 37%) or generalized (32 of 51; 63%) EEG seizures. Hypomotor seizures also were associated with focal (14 of 20; 70%) or generalized (six of 20; 30%) EEG seizures. Four patients with generalized epileptic spasms had generalized EEG seizures in the setting of focal epilepsy based on neuroimaging, interictal EEG, and in two cases also on postresection seizure freedom. Seizure types not seen in this age group included auras, seizures with prominent automatisms (except in one case), and classic generalized tonic-clonic seizures. CONCLUSIONS: The repertoire of seizure manifestation in the first 3 years of life appears to be limited. In infants, focal motor seizures are reliably associated with focal EEG seizures in the contralateral hemisphere, whereas generalized motor and hypomotor clinical seizures may be either focal or generalized on EEG. Epileptic spasms may be seen in focal as well as generalized epilepsies. Video-EEG monitoring and neuroimaging may be critical for clarifying the focal or generalized nature of the epilepsy in infants.     

It Is Not Harmful for Patients with Epilepsy to View Their Own Seizures

Summary: Having a seizure in public is a concern to people with epilepsy and can represent a barrier to psychosocial adjustment. Seeing his or her own seizures might help the patient deal with seizures more realistically, but also could be emotionally detrimental. We therefore showed patients videos of their own seizures before their discharge from our inpatient epilepsy monitoring unit. One of the investigators was present to answer questions. The Spielberger State Trait Anxiety Scale (SSTAS) was administered before and after viewing and 1 month later together with a questionnaire related to the patients' feelings and attitudes about viewing their own seizures. Results using one-way repeated-measures multivariate analysis of variance (MANOVA) showed no differences for the items in the pre- and posttest questionnaire. For the SSTAS, no significant differences were detected among the pretest and the two posttests by one-way repeated ANOVA (p = 0.10). These results suggest that it is not harmful to view one's own seizures in a controlled setting.     

Patients with Epileptic Seizures and Cerebral Lesions Who Underwent Lesionectomy Restricted to or Associated with the Adjacent Irritative Area

PURPOSE: To analyze the best surgical procedure for patients with epileptic seizures and cerebral lesions-i.e., resection restricted to the lesion or resection associated with the adjacent irritative area-based on the clinical evolution of patients' seizure outcome and electroencephalographic (EEG) and electrocorticographic (ECoG) findings. METHODS: This study comprised 37 patients with epileptic seizures and cerebral lesions, ranging in age from 9 to 66 years. Patients were divided into two groups: Group 1 consisted of 21 patients with medically intractable epilepsy, Group 2 of 16 patients with medically controlled epilepsy. Eleven of the 21 patients in Group 1 (Subgroup A) underwent surgical resection of the cerebral lesion and adjacent irritative area as shown by ECoG. For the remaining 10 patients in Group 1 (Subgroup B), the resection was restricted to the lesion. The 16 patients in Group 2 all underwent lesionectomies. RESULTS: Of the 11 patients in group 1 who underwent resection of the cerebral lesion and adjacent irritative area, 91% became seizure free. Sixty percent of the remaining patients in group I whose resections were restricted to the lesion also became seizure free, as did all the patients in group 2. An overall analysis of the EEGs for all patients showed a statistically significant decrease in paroxysmal activity. CONCLUSIONS: In patients with uncontrolled seizures, resection of the cerebral lesion associated with the irritative area shows a tendency to obtain better seizure-outcome results than restricted lesionectomy.     

Vocational and Educational Problems of Epileptic Patients

The results of a study to elicit factors which are associated with an epileptic patient's gaining and keeping employment are presented. Eighty-seven employed patients were compared with 90 unemployed patients on a wide variety of variables. It was found that the employed patients had higher intelligence, less impairment on neuro-psychological tests, less neurological and electroencephalographic abnormalities, and their work history was considerably better than that of the unemployed group. A step-wise discriminant function analysis revealed that the most powerful predictors for employment success were: high motivation for work, good verbal IQ, a self confidence item, and the patient's present level of socialization. A review of the type of employment held by our patients, when compared against the total labor force and the minority labor force (Negro citizens) of the Detroit Metropolitan area, showed that the epileptic patients tend to be similar to the minority labor force, clustering in the lower socio-economic brackets. It was felt that discrimination against both groups is probably only one common denominator. Another, possibly a more important one, is inadequate schooling which results in failure to acquire the skills needed for living successfully in a highly technological, complex, competitive society. It is pointed out that although the majority of epileptic children attend regular schools, their grades tend to be below average and that they are not being prepared for entering the competitive job market. Suggestions how to improve this situation through rehabilitation efforts during the school years and how to more effectively remove the stigma from the illness are also presented.     

Characteristics of Seizures in a Population-Based Series of Mentally Retarded Children with Active Epilepsy

Summary: Purpose: The characteristics of seizures were analysed in a population-based study of active epilepsy in 6-to 13-year-old mentally retarded children. Methods: The search procedure included diagnostic registers, EEG registers, and registers of the Education of the Subnormal. Medical files were scrutinized, and clinical examinations and interviews with parents or caretakers or both were performed. Results: The median age of seizure onset was 1·3 years, 3·1 for children with mild retardation and 0·8 for children with severe retardation. Among the 98 children identified, current seizure groups were partial in 20, generalized in 59, and mixed in 19. The prevailing seizure types were tonic-clonic, myoclonic, atypical absences, and partial complex seizures, present in 42, 33, 23, and 23 children, respectively. A total of 46 children had more than one seizure type. Seizures every day/week occurred in 44 children. There was a constancy between seizure type at onset and later seizure type. Neonatal seizures (n = 25), infantile spasms (n = 12), and status epilepticus (n = 37) occurred independent of one another. Prognostic factors for poor neurologic outcome were early onset of epilepsy, infantile spasms as onset type, and prior neonatal seizures. Children with only partial seizures less frequently had severe mental retardation, cerebral palsy, and visual impairment than those with only generalized seizures. Conclusions: Epilepsies in children with mental retardation are characterized by severe seizure manifestations. The brain damage giving rise to mental retardation and epilepsy is probably the main factor in terms of seizure outcome.