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Biomedical subjects

O Devinsky

Publications and source records attributed to O Devinsky.

At least 73 records · Page 4Linked to original sources
PubMed1994

Decreased seizure frequency after withdrawal and reinstitution of antiepileptic drug therapy.

We reviewed the seizure frequencies of 38 patients with medically refractory epilepsy 6 weeks before (baseline) and 3 weeks after withdrawing their antiepileptic drugs (AEDs) for video-EEG monitoring. Seizure frequency during the first 3 weeks after restarting AEDs was diminished compared with baseline (P < 0.05). We found no correlation between seizure frequency and patient age, specific antiepileptic drugs, number of seizures during the video-EEG monitoring, number of days without AEDs, or partial vs total withdrawal of AEDs. Medication tachyphylaxis, functional tolerance, or long term post-ictal depression of the seizure threshold is hypothesized. The diminished seizure frequency after reinstitution of medications in four of five patients who did not have seizures during their hospitalization suggests that drug tachyphylaxis is a relevant mechanism.

Adolescent↗
PubMed1994

Multiple subpial transections in the language cortex.

Multiple subpial transections (MST) were made in language cortex in three patients with medically refractory partial epilepsy. All patients were mapped with extra-operative stimulation using subdural grids over the dominant temporal, frontal and parietal convexity. Two patients had anterior temporal lobectomy and MST in posterior language cortex. One patient who had undergone a previous frontal tumour resection had only MST over the frontoparietal convexity, including frontal and parietal language areas. Both patients with MST in the posterior language cortex had postoperative language dysfunction, which had improved significantly by 9 months after surgery. The patient with MST in frontoparietal language areas had improved language functions immediately postoperatively. The two men with anterior temporal lobectomies and MST are seizure-free at 1 year follow-up and the woman with frontoparietal MST has had a > 70% reduction in seizure frequency at 1 year follow-up.

Adult↗
PubMed1994

Anatomic and physiological considerations in pallidotomy for Parkinson's disease.

Our ongoing study of central pallidotomy for the control of Parkison's disease in selected patients has provided the opportunity to explore the topographical and somatotopic organization of the human globus pallidus. Utilizing microelectrode techniques we have obtained recordings which were correlated with data from MPTP-parkinsonian primates. In addition, we performed pre- and postoperative FDG/PET scans in these patients. Our studies reveal similarities between the MPTP-parkisonian primate model and human Parkinson's disease in terms of physiological recordings and responses. However, we have encountered significant differences between dominant and nondominant hemisphere representations, particularly for the hand, in the human. In addition, our PET studies confirmed, as in previous parkinsonian primate models, glucose hypermetabolism in the lenticular area of Parkinson's disease patients. This hypermetabolism is dramatically altered by creation of a lesion in the globus pallidus medialis. This is demonstrated by follow-up PET scans which reveal not only a decrease in metabolism of the operated lenticular region, but also in the frontal cortical projections. These combined observations of the cellular activity in globus pallidus and the observed changes in PET metabolism support the selection of the pallidum for lesioning and control of Parkinson's disease, and offer insight into the underlying physiology of this disorder. The above physiological and PET data will be clinically correlated with our ongoing series of 35+ patients.

Brain Mapping↗
PubMed1994

Invasive intracranial monitoring, cortical resection and multiple subpial transection for the control of intractable complex partial seizure of cortical onset.

Invasive intracranial monitoring with subdural grids has led to a greater appreciation of cortical function and the discovery of ictal onset either independently or in conjunction with deep structures. With the description of multiple subpial transections the armamentarium for surgical control of intractable seizures has been expanded. Utilizing invasive intracranial monitoring with subdural grids and strips, a large series of patients with intractable complex partial seizures originating in exquisite cortex, and in some cases additionally in deep structures, have undergone surgery. These patients would previously have been judged not to be candidates for surgical control of seizures. We will present 9-month or greater follow-up in an ongoing series of patients undergoing cortical resection and subpial transections in whom there has been a statistical improvement in control or alleviation of their seizure disorder. The report will specifically discuss outcomes as related to exquisite cortex, motor, sensory and language functions, as well as clinical results and EEG.

Adult↗
PubMed1994

New antiepileptic drugs for children: felbamate, gabapentin, lamotrigine, and vigabatrin.

After a 15-year hiatus, several new antiepileptic drugs have been approved or are under Food and Drug Administration investigation for use in the United States. This article reviews four of these new drugs--felbamate, gabapentin, lamotrigine, and vigabatrin. Although these drugs have been primarily developed for use in adults with partial seizures, they will also likely be used in children with partial epilepsy. Pediatric experience with several of these drugs has demonstrated safety and efficacy in other seizure types and epilepsy syndromes. These drugs will be an important addition to the therapeutic armamentarium for pediatric epilepsy. Additional studies are needed to fully explore the safety and efficacy of these drugs in a variety of pediatric epilepsies and to compare them to existing antiepileptic drugs.

Acetates↗
PubMed1994

Left temporal neocortex mediation of verbal memory: evidence from functional mapping with cortical stimulation.

We examined the contribution of the temporal neocortex to short-term memory (STM) in 15 patients with left hemisphere language dominance during intraoperative or extraoperative cortical mapping prior to left anterior temporal lobectomy. Recall errors were examined following stimulation during the acquisition, consolidation, and retrieval stages of a verbal STM task. Ten patients showed stimulation-induced recall errors, and five patients showed no significant memory errors. More patients showed errors following stimulation during consolidation than during acquisition or retrieval, possibly because of disrupted transfer of information from the temporal neocortex to the hippocampus. Patients with stimulation-induced recall errors did not differ significantly from patients without memory errors in terms of seizure, demographic, or neuropsychological variables. Patients with resection of sites showing stimulation-induced recall errors had greater postoperative decline in verbal memory than did patients with resection sparing these sites. We suggest that the left temporal neocortex contributes to verbal memory consolidation in patients with chronic epilepsy.

Adult↗
PubMed1994

Epilepsy and sleep apnea syndrome.

We identified seven patients with refractory partial epilepsy and sleep apnea. Treatment of the sleep apnea with nasal continuous positive airway pressure (CPAP), protriptyline, trazodone, acetazolamide, or tracheostomy reduced seizure frequency and severity in six patients. Success with CPAP depended largely on compliance. Four of five patients had a clear reduction in seizure frequency with the use of CPAP. Sleep apnea may exacerbate epilepsy by causing sleep disruption and deprivation, hypoxemia, and decreased cerebral blood flow. In epilepsy patients with risk factors (eg, obesity) or markers (eg, habitual snoring, daytime somnolence) for sleep apnea, a careful sleep history should be elicited and a polysomnogram obtained when indicated. Treatment of the sleep disorder can improve seizure control.

Adult↗
PubMed1994

Clozapine-related seizures: experience with 5,629 patients.

We reviewed the incidence, clinical features, and management of all clozapine-related seizures in 5,629 patients monitored by the Clozaril Patient Management System, during the first 6 months after marketing. Seventy-one patients had generalized tonic-clonic seizures yielding a frequency of 1.3%. One patient had myoclonic seizures prior to generalization. Seizures tended to occur at low doses (< 300 mg/d) during the titration phase, and at high doses (> or = 600 mg/d) during the maintenance phase. Patients with a history of seizures or epilepsy were more likely to have seizures soon after initiation of therapy, on low doses. Twenty-nine of 37 patients (78%) who had seizures and were rechallenged with clozapine were able to continue the medication with dose reduction and more-gradual dose titration, or with the addition of an antiepileptic medication.

Adolescent↗
PubMed1994

The secondarily generalized tonic-clonic seizure: a videotape analysis.

We studied 120 generalized tonic-clonic seizures (GTCSs) in 47 patients with video-EEG telemetry. GTCSs were preceded by antecedent seizures, including 13 simple partial, 70 complex partial, 17 simple partial leading to complex partial, seven tonic, seven clonic, and one typical absence. We divided GTCSs into the following phases: onset of generalization, pretonic clonic, tonic, tremulousness, and clonic. The mean GTCS duration was 62 seconds. There was a non-significant trend toward longer duration on reduced antiepileptic drug doses. Marked heterogeneity in GTCS phenomenology was present; only 27% of seizures included all five phases. Individual phase duration and clinical expression, including tonic and clonic phases, was highly variable. The clinical phenomena suggest that multiple cortical and subcortical routes of spread may exist. When GTCSs last longer than 2 minutes, intravenous antiepileptic drug treatment should be initiated.

Adolescent↗
PubMed1994

The prolonged QT syndrome presenting as epilepsy: a report of two cases and literature review.

The prolonged QT syndrome is associated with ventricular tachyarrhythmias and sudden death. We report two patients and review eight previously reported cases of this syndrome, presenting as epilepsy. The average age at the time of the first convulsion was 4.7 years. Episodes were often infrequent, and the time to correct diagnosis ranged from 1 to 28 years. Only one-half the patients had histories suggestive of a familial syndrome. Presyncopal complaints and "lifelessness" prior to seizure activity were common findings in retrospect. Beta-blockade was effective in preventing recurrences in all patients who received treatment.

Adult↗
PubMed1994

Seizures during clozapine therapy.

Seizures are an important adverse effect of clozapine therapy; a cumulative 10% risk of tonic-clonic seizures is estimated after 3.8 years of treatment. Although the risk of seizures may be increased by rapid upward titration and higher doses, recent data do not clearly confirm the dose-dependent effect. The vast majority of clozapine-related seizures are tonic-clonic, although myoclonic seizures also occur. The role of the EEG in predicting the occurrence of clozapine-induced seizures remains uncertain. In patients with clozapine-related seizures, either reducing the dose or adding an antiepileptic medication usually allows continuation of therapy.

Anticonvulsants↗
PubMed1994

Women with epilepsy. Reproduction and effects of pregnancy on epilepsy.

Conventional wisdom and prevailing medical practice strongly support the belief that medication should be avoided during pregnancy. For the nearly one million women of childbearing age with epilepsy in the United States this is often difficult, if not impossible, and for many of these women becoming pregnant raises many conflicting issues. Women with epilepsy may face a possible increase in the frequency and severity of seizures, and in generalized tonic-clonic seizures there is a small but increased risk of miscarriage.

Abnormalities, Drug-Induced↗
PubMed1994

Legal aspects of epilepsy.

Legal issues must be considered in caring for patients with epilepsy. Doctors caring for people with epilepsy may be legally involved in three primary ways: as the agent of social control, as patient advocate, and as the target of liability or malpractice suits. This article examines these factors and the implications for patients and their caregivers.

Accidents, Traffic↗
PubMed1993

Nonepileptic seizures during apparent sleep.

We report 12 patients with nonepileptic seizures (NESs) documented with video-electroencephalographic monitoring during apparent sleep. There were 7 females and 5 males, ages 11 to 67 years (mean, 33 yr). In all patients there was a well-organized posterior alpha rhythm present immediately before onset of clinical changes despite the appearance of sleep. Patients later "confirmed" that these attacks occurred during sleep. Features of these episodes were typical of NESs and none were associated with ictal or postictal electroencephalographic changes other than muscle and movement artifact. Provocative testing with suggestion confirmed the nonepileptic nature of these episodes in 9 patients. Three patients had epileptiform discharges during prolonged interictal recordings and 1 had a documented complex partial seizure. Our findings indicate that reports of seizures during sleep are not uncommon among patients with NESs.

Adolescent↗
PubMed1993

Anterior temporal language areas in patients with early onset of temporal lobe epilepsy.

Eighteen consecutive patients undergoing dominant temporal lobectomy underwent preoperative cortical stimulation for language localization. Patients with naming deficits on anterior (4.5 cm from the temporal pole) temporal lobe stimulation had earlier seizure onset vs those without such deficits (5.8 yr vs 12.9 yr; p < 0.04). There was a similar trend for reading errors (6.3 yr vs 12.4 yr; p < 0.052). Resections always spared at least 1 cm anterior to any language area. There was no significant difference in postoperative neuropsychological tests between patients with and without anterior language representation. Early onset of dominant temporal lobe seizure foci leads to a more widespread or atypical distribution of language areas. Individual variability should be considered in epilepsy surgery to reduce postoperative language deficits.

Adolescent↗