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Biomedical subjects

S D Shorvon

Publications and source records attributed to S D Shorvon.

At least 19 recordsLinked to original sources
PubMed1992

National general practice study of epilepsy: the social and psychological effects of a recent diagnosis of epilepsy.

OBJECTIVES: To determine the nature and extent of psychosocial problems in epilepsy and their associations. DESIGN: A postal survey was used drawing data from prospective consecutive cases. Data on demographic, medical, and social backgrounds were collected. A specially designed, validated attitude questionnaire examined 14 areas of psychosocial adjustment to epilepsy. SETTING: 124 primary care general practices. SUBJECTS: Adults (aged over 17) with a recent diagnosis of epilepsy (within previous 36 months). They were registered with the national general practice study of epilepsy and had a confirmed diagnosis according to the usual criteria. 216 subjects were approached for the survey by their general practitioners; 192 returned questionnaires. RESULTS: Problems in at least one area were experienced by 175 (91%) of the 192 subjects. Problems were generally mild, which contrasts strongly with findings in chronic cases. The areas of greatest concern were fear of seizures (80% of cases; 72% moderate or severe) and fear of stigma in employment (69% of cases; 40% moderate or severe). A highly significant relation was found between psychosocial effects and the frequency and recency of seizures. CONCLUSIONS: In the early stages of epilepsy psychosocial effects are closely related to the severity of the medical condition, suggesting that the argument for the stigmatising effect of the diagnosis by itself is less important than previously thought. The findings also suggest that problems may evolve as the condition becomes chronic.

Adaptation, Psychological↗
PubMed1992

The National General Practice Study of Epilepsy. The syndromic classification of the International League Against Epilepsy applied to epilepsy in a general population.

In this prospective, population-based study of 594 cases of newly diagnosed epilepsy, proportions in categories as defined by the International League Against Epilepsy (ILAE) were as follows: (1) localization-related epilepsies: 1.1* idiopathic, 1.2%; 1.2* symptomatic, 16.2%; and 1.3 cryptogenic, 24.6%; (2) generalized epilepsies: 2.1* idiopathic (idiopathic generalized epilepsy) with 3-Hz spike and wave: absence epilepsy, 2.2%; juvenile myoclonic epilepsy, 1.5%; and nonspecific idiopathic generalized epilepsy, 5.6%; 2.3.1* symptomatic generalized epilepsies, 1.5%; 2.3.2* specific syndromes with generalized epilepsy, 0.3%; 3.2 seizures without unequivocal focal or generalized features, 32%; 4.1 situation-related syndromes, isolated seizures, 9.9%; seizures due to acute toxic or metabolic cause,* 4.5%. Only 33.6% were in diagnostic ILAE categories (asterisks) and many rare syndromes were not represented. The remainder (66.4%) were in various nonspecific categories. Only 24% of localization-related epilepsies could be clinically localized to a single ILAE-proposed site of origin and of these best localized cases, 14% had strongly discordant imaging or electroencephalograms. These major problems in applying the ILAE classification to epilepsy in the general population and its underemphasis of modern imaging techniques are discussed.

Cerebral Cortex↗
PubMed1992

Is nocturnal paroxysmal dystonia a form of frontal lobe epilepsy?

The sex ratio, age at onset, and ictal features of nine patients with nocturnal paroxysmal dystonia were compared with those of eight patients with daytime frontal lobe seizures and eight patients with nocturnal motor attacks of known epileptic origin. All patients underwent video electroencephalography telemetry. There were no clinical features that would allow distinction between the groups and no single phenomenon was uniquely seen in nocturnal paroxysmal dystonia. This study provides no evidence that nocturnal paroxysmal dystonia is a separate diagnostic entity.

Adolescent↗
PubMed1992

Open stereotactic selective amygdalo-hippocampectomy for drug resistant epilepsy.

Selective removal of the medio-basal temporal structures has been introduced as an alternative to standard temporal lobectomy in the treatment of intractable temporal lobe epilepsy not related to gross structural lesions. Various approaches have been described for the surgical excision of the amygdalo-hippocampal complex, each of them presenting advantages and limitations. The recently introduced computer-assisted technique of volumetric stereotactic excision of deep-seated intracerebral lesions combines precision of targeting with elimination of unnecessary cortical trauma and may potentially provide an alternative method in the treatment of temporal lobe epilepsy. We present our experience of stereotactic volumetric selective amygdalo-hippocampectomy in six patients with medically intractable temporal lobe epilepsy. The criteria for selection, the pre-operative evaluation and the operative technique are discussed. All patients had a cessation or considerable reduction in seizure frequency while the morbidity was minimal.

Adolescent↗
PubMed1992

Help-seeking strategies for epilepsy by previously untreated patients in northern Ecuador.

Two hundred and fifteen patients with epilepsy and 125 controls were given questions designed to elicit their help-seeking strategies for the condition. This was part of a large-scale medical intervention study in a rural area of a developing country (the provinces of El Carchi and Imbaburra, northern Ecuador). Local medical personnel were also surveyed. One hundred and forty-four patients and 98 controls were questioned again 12 months after they had been enrolled in the intervention programme to see if their attitudes and practices had changed. Over the study period, belief in medical remedies, particularly those offered by the study, rose significantly among both controls and patients. Control readiness to consult local healers for help and belief in their effectiveness also rose, whereas patient belief in healer help, already significantly less at baseline because of previous negative experiences, had declined still further. Though no patients treated were on antiepileptic treatment at baseline, 71% claimed to have sought the help of allopathic practitioners at some point in the past, 35% 'many times'. Of these only 21% had ever been given antiepileptic drugs; some consultations were not at local health facilities. Thirty-two per cent of patients also claimed to have consulted traditional healers. The high number of patients claiming to visit doctors was not entirely confirmed in the medical evidence. Even this source, however, suggested more consulted doctors than expected from the observation that only 10% were on any kind of treatment at the start of the study (none on antiepileptic drugs).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Epileptic seizures in an Andean region of Ecuador. Incidence and prevalence and regional variation.

A large-scale neuro-epidemiological study was carried out in a population of 72,121 inhabitants of a region of Northern Ecuadorian Andean Sierra, to identify prevalence and incidence rates of epileptic seizures and to identify demographic and geographic variations in these rates. Calculations were made using three datasets. First, rates were calculated from all cases identified in the field (raw dataset); secondly, lower rates were calculated based on a further diagnostic and reclassification procedure (minimum estimated dataset); thirdly, higher rates were derived by calculating false negative rates from the screening procedures, and adding these to the cases actually identified (maximum estimated dataset). Lifetime point-prevalence rates between 12.2/1000 and 19.5/1000 were recorded (minimum and maximum estimated rates), and the prevalence of active epileptic seizures was between 6.7/1000 and 8.0/1000 (minimum estimated and raw datasets). Incidence rate ranging between 122/100,000/year and 190/100,000/year were found (minimum, estimated and raw datasets). A marked difference in prevalence rates was found in two subregions of the survey area, and also in urban and rural areas. The reasons for these differences were not identified.

Adolescent↗
PubMed1992

Validation of a screening questionnaire for the detection of epileptic seizures in epidemiological studies.

A large-scale clinico-epidemiological study of epileptic seizures has been carried out in a highland area in northern Ecuador, South America. This paper describes the design and the two-staged validation procedures undertaken to authenticate the screening questionnaire, which was used to detect epileptic seizures in the community during this project. An initial questionnaire consisting of 20 questions was devised and then validated in a group of healthy subjects and a group of patients with known epileptic seizures. This questionnaire was found to have a sensitivity of 100% and a specificity of 50.8%. A cluster analysis of the responses rates was undertaken and a set of nine questions which presented a specificity of 92% and sensitivity of 98% were chosen to be used during the survey. The validation of this nine-question instrument was then undertaken by direct application to a general population of 72,121 persons. Positive, negative, false positive and false negative rates were derived. The screening instrument was found to have a sensitivity of 79.3%, a specificity of 92.9%, a positive predictive value of 18.3%, a negative predictive value of 99.6% and a Youden's index of 0.79. The methodology of the study and the instruments developed are recommended for future neuro-epidemiological work in epilepsy. The problems of validation are discussed, and previous epidemiological studies of epilepsy reviewed with special emphasis on the handling of questions of validation.

Adolescent↗
PubMed1992

Hippocampal volumetric and morphometric studies in frontal and temporal lobe epilepsy.

The most common temporal lobe pathology is Ammons Horn sclerosis (AHS), and several different imaging techniques have been utilized to detect this with varying success. We describe the clinical application of magnetic resonance imaging (MRI) using a three-dimensional volume technique which allows total hippocampal volume to be measured and symmetry evaluated. Hippocampal surface area was calculated in sequential 1.5 mm thick contiguous images, using a GE IC workstation. Total volumes and surface areas were calculated. The cross-sectional surface area at 1.5 mm intervals was displayed graphically, permitting morphometric analysis of the hippocampus throughout its length. Focal atrophy within any part of the hippocampal formation (HF) and its extent could thus be assessed. Patients with well-lateralized temporal lobe epilepsy (TLE) (n = 20) and well-defined frontal lobe epilepsy (FLE) (n = 20) were studied, and volumes compared with normal values derived from 10 neurologically normal controls. Asymmetric hippocampal volume loss was demonstrated in all 20 patients with clinically typed TLE, but not in normal controls or patients with FLE. Volume loss distribution was anterior in 12 patients, posterior in one patient and widespread in seven patients. Secondarily generalized seizures were strongly associated with widespread loss. This method of surface area and volumetric analysis of the hippocampus in TLE can demonstrate asymmetry and focal involvement, and help distinguish between hippocampal and frontal pathologies.

Adult↗
PubMed1992

Prolonged sensory or visceral symptoms: an under-diagnosed form of non-convulsive focal (simple partial) status epilepticus.

Four patients had prolonged, sensory, simple partial seizures (SPS), lasting up to several days, without associated behavioural impairment. In three patients, the SPS often occurred as a prolonged "aura" before a more overt seizure. Descriptions included: "butterflies", rising epigastric sensation; "a thought in the stomach", and an olfactory sensation. Seizure localisation was frontal in one case, temporal in two cases and uncertain in one case. These sensations may represent an under-reported form of continuous, focal seizure activity, which arises from various cerebral regions.

Adult↗
PubMed1992

A large-scale study of epilepsy in Ecuador: methodological aspects.

The methodology is presented of a large-scale study of epilepsy carried out in a highland area in northern Ecuador, South America, covering a population of 72,121 people; The study was carried out in two phases, the first, a cross-sectional phase, consisted of a house-to-house survey of all persons in this population, screening for epileptic seizures using a specially designed questionnaire. Possible cases identified in screening were assessed in a cascade diagnostic procedure applied by general doctors and neurologists. Its objectives were: to establish a comprehensive epidemiological profile of epileptic seizures; to describe the clinical phenomenology of this condition in the community; to validate methods for diagnosis and classification of epileptic seizures by a non-specialised team; and to ascertain the community's knowledge, attitudes and practices regarding epilepsy. A sample was selected in this phase in order to study the social aspects of epilepsy in this community. The second phase, which was longitudinal, assessed the ability of non-specialist care in the treatment of epilepsy. It consisted of a prospective clinical trial of antiepileptic therapy in untreated patients using two standard anti-epileptic drugs. Patients were followed for 12 months by a multidisciplinary team consisting of a primary health worker, rural doctor, neurologist, anthropologist, and psychologist. Standardised, reproducible instruments and methods were used. This study was carried out through co-operation between the medical profession, political agencies and the pharmaceutical industry, at an international level. We consider this a model for further large-scale studies of this type.

Adolescent↗
PubMed1992

Effects of epilepsy on daily functioning in northern Ecuador: summary of findings of a population-based research project.

215 patients with epilepsy and 125 healthy controls were questioned on the effects of epilepsy on social functioning as part of a population-based study of epilepsy in Northern Ecuador. 144 of these patients and 98 of the controls were followed, over a period of 1 year during an intervention study and their response to treatment assessed. Economic, intellectual and social functioning were examined. In the patient group, function was affected in important areas, most clearly, work. The low opinion the community had of the intellectual and physical abilities of patients might affect a patient's own view of themselves and sometimes diminish their opportunity for development. At 12 months, as a result of treatment, a significantly lower level of patients reported effects on function in some areas, though control individuals' views of their functional impairment had not shifted to any extent. Moreover, despite improvement, more patients at 12 months acknowledged fear of seizures, especially their unpredictability, as a handicapping factor, particularly in working outside or away from home. This seems to indicate that even when seizures are controlled, for many patients, the uncertainties of the condition remain and continue to affect their view of their capabilities.

Activities of Daily Living↗
PubMed1992

National General Practice Study of Epilepsy (NGPSE): partial seizure patterns in a general population.

The National General Practice Study of Epilepsy (NGPSE) is a prospective community-based study of newly diagnosed epileptic seizures. Of 594 patients with definite epileptic seizures, 160 (26.9%) had seizures with a clinically localizable onset: 36 (22.5%) frontal, 52 (32.5%) central sensorimotor, 43 (27%) temporal, nine (5.6%) frontotemporal, and 10 each (6.3%) parietal and other posterior cortex. There was no difference among these groups in seizure frequency or remission rate; 46.5% were seizure free and 6.9% had severe epilepsy. Etiology was identifiable in 41% and focal CT and EEG abnormalities in 33% and 19%, with results discordant with the clinical seizure localization in 21% and 20%. Temporal lobe epilepsy may be underreported, as it may be more difficult to localize clinically. Extratemporal seizures are extremely common in the general population, especially frontal and central sensorimotor, in relation to cerebrovascular disease. Prognoses are similar for partial epilepsies with different clinical patterns and regions of onset and are much better than suggested in hospital-based studies. The clinical, EEG, and CT localizations may frequently be discordant in this nonrefractory group.

Electroencephalography↗
PubMed1991

Comprehensive primary health care antiepileptic drug treatment programme in rural and semi-urban Kenya. ICBERG (International Community-based Epilepsy Research Group)

A programme of antiepileptic treatment in a rural and semi-urban region in Kenya was assessed. Patients with generalised tonic-clonic seizures were treated according to one of two simple drug protocols. Health workers screened cases reported by key informants in the community. From the 529 patients identified by health workers as having active seizures 302 patients aged 6-65 years were recruited by a psychiatrist for therapy with carbamazepine or phenobarbitone. Treatment was supervised largely by primary health workers, and the programme was monitored by a research team, which assessed the effectiveness of treatment. Of the 249 patients who completed the study, 53% became seizure-free in the second 6 months of therapy, and another 26% had substantially (50% or more reduction) fewer seizures than in the 6 months before therapy. The similarity of these findings to those obtained in newly diagnosed patients in the developed world, the low drop-out rate, the low rate of withdrawal due to adverse effects, and the acceptable compliance with therapy indicate that health workers can monitor therapy adequately. Most patients had had several years of delay before starting therapy for their epilepsy, yet they responded well--a finding that does not support the suggestion that the disorder becomes intractable if not treated early.

Adolescent↗
PubMed1991

A comprehensive community epilepsy programme: the Nakuru project.

The methodology of a programme of investigation of epilepsy carried out at a community health level in Nakuru district, Kenya, East Africa, and the characteristics of patients with tonic-clonic epilepsy in this community, are presented. The study identified a group of 302 patients with untreated generalised tonic-clonic seizures (with or without other seizure types) from the general population. Case finding was carried out using the key informant method over a 12-month period. The clinical characteristics of this cohort of patients, the majority of whom had never had previous contact with a formal medical system, is described. Most were young, living in a rural area, with a mean age of seizure onset of 14 years and a mean duration of seizures of 7 years. Thirty-eight per cent had a clinically evident focal disturbance associated with the tonic-clonic seizures. In 77% of the cases, no aetiology was established. Most cases had had a substantial number of seizures during the course of their condition and only about a third of the patients had less than 1 seizure a month in the previous year. Only 26% had ever had previous anti-epileptic drug treatment. In addition to the medical inquiry, psychological and sociological studies were also conducted and a prospective treatment programme was carried out. Throughout the study, strict definitions and standardised instruments were used, and the study was the result of a collaboration between local investigators, an international neurological team, the Kenyan Government agencies and the pharmaceutical industry. We consider this a model for community-based investigations for the management of epilepsy in developing countries.

Adolescent↗
PubMed1991

The effect of intravenous flumazenil on interictal electroencephalographic epileptic activity: results of a placebo-controlled study.

The effect on interictal electroencephalographic epileptic activity of intravenous flumazenil (Ro 15-1788), a benzodiazepine antagonist and potential antiepileptic drug, was studied in 10 patients. Comparison was made with intravenous diazepam (10 mg) and placebo using a single-blind, single-dose, cross-over design. A dose of 3 mg flumazenil was well tolerated and produced a significantly greater reduction in the number of epileptic transients during the first 40 minutes after injection than did placebo (p less than 0.05). This effect was similar to that of diazepam in magnitude and duration. When flumazenil (3 mg) was administered immediately after intravenous diazepam (10 mg), the reduction in interictal epileptic activity was not significantly different from that produced by diazepam alone. The results suggest that either flumazenil has intrinsic antiepileptic activity and in this respect acts as a partial agonist at the benzodiazepine receptor, or that it is antagonising an endogenous proconvulsant ligand in these patients.

Adult↗
PubMed1991

Vigabatrin and psychosis.

We report a series of 14 cases of psychosis occurring in patients with severe intractable epilepsy, following the prescription of vigabatrin, a new antiepileptic drug. Nine patients had no previous history of psychosis. In eight patients the psychosis occurred following a change in the habitual pattern of seizure activity; in four it developed after a period of seizure freedom followed by a cluster of seizures, and in the other four patients an alternating psychosis was observed. In five patients there was no clear relationship to seizure pattern. Another patient developed psychosis after taking an overdose of between eight and 12 g of vigabatrin. A further three patients, who developed psychosis following vigabatrin withdrawal, were not included in this series. The mean dose at onset of the psychosis (excluding the patient who took an overdose) was 2580 mg, and the period from initiation of therapy to the onset of psychosis varied from five days to 32 weeks (and occurred 24 hours after the overdose of vigabatrin). In all cases the psychosis resolved, but necessitated the withdrawal of vigabatrin, except in the single patient who took the overdose. The mechanism of this behaviour change is unclear, but in some instances may reflect vigabatrin's powerful anti-epileptic action. This is clearly not the case for all patients. Vigabatrin should be started with caution in patients with severe epilepsy, particularly in the presence of a previous history of psychosis, and such patients should be carefully monitored.

4-Aminobutyrate Transaminase↗
PubMed1979

Reduction in polypharmacy for epilepsy.

A two-year prospective study of 40 adult outpatients with chronic epilepsy was carried out in which blood drug concentrations were monitored, and anticonvulsant polypharmacy was reduced to treatment with a single drug in 29 patients (72%). In the year after the reduction of treatment the control of seizures was improved in 16 patients (55%), unchanged in eight(28%), and worse in five (17%). Mental function was improved in 16 (55%). The main reason for failure to reduce to or maintain treatment with a single drug was exacerbation of seizures during the difficult withdrawal period, especially in patients with frequent seizures, taking several drugs, or with additional neuropsychological handicaps. It is more difficult to reduce polypharmacy than to avoid it in the first place. Polypharmacy may sometimes aggravate control of seizures.

Adolescent↗