Biomedical subjects

O Devinsky

Publications and source records attributed to O Devinsky.

At least 55 records · Page 3Linked to original sources

PubMed1995

Stereotactic ventral pallidotomy for Parkinson's disease.

Eighteen patients with medically intractable Parkinson's disease that was characterized by bradykinesia, rigidity, and marked "on-off" fluctuations underwent stereotactic ventral pallidotomy under local anesthesia. Targeting was aided by anatomic coordinates derived from the MRI, intraoperative cell recordings, and electrical stimulation prior to lesioning. A nonsurgically treated group of seven similarly affected individuals was also followed. Assessment of motor function was made at baseline and at 3-month intervals for 1 year. Following the lesioning, patients improved in bradykinesia, rigidity, resting tremor, and balance with resolution of medication-induced contralateral dyskinesia. When compared with preoperative baseline, all quantifiable test scores after surgery improved significantly with the patients off medications for 12 hours: UPDRS by 65%, and CAPIT subtest scores on the contralateral limb by 38.2% and the ipsilateral limb by 24.2%. Walk scores improved by 45%. Medication requirements were unchanged, but the patients who had had surgery were able to tolerate larger doses because of reduced dyskinesia. Ventral pallidotomy produces statistically significant reduction in parkinsonism and contralateral "on" dyskinesia without morbidity or mortality and with a short hospitalization in Parkinson's disease patients for whom medical therapy has failed.

Adult↗

PubMed1995

Ictus emeticus: further evidence of nondominant temporal involvement.

We report two cases of ictal vomiting in patients who had left temporal lobe epilepsy. In one patient, vomiting developed when the discharge spread to the right temporal lobe as seen during depth electrode recording. In the second patient, ictal vomiting occurred with a restricted left temporal discharge, but the patient was left-handed and had right-hemisphere language dominance. These cases provide additional evidence of the involvement of the nondominant temporal lobe in ictus emeticus.

Adolescent↗

PubMed1995

Psychogenic basilar migraine: report of four cases.

We discuss four patients with the clinical diagnosis of basilar migraine and suspected coexisting epilepsy who were referred to our epilepsy center. Their symptoms suggested episodic dysfunction in the distribution of the basilar artery, followed by pulsating headache with nausea. Verbal unresponsiveness and sensory symptoms occurred in all four patients; two also had focal paresis or jerking movements. Diagnostic studies excluded other disorders with similar symptoms. None of the patients improved with antimigraine or antiepileptic drugs. Provocation tests with suggestion elicited typical events in three patients and aura and headache in one patient. There were no EEG or ECG abnormalities during spontaneous or provoked episodes. Two patients improved with psychiatric treatment. Conversion disorder or malingering should be considered in patients whose symptoms of basilar migraine are atypical or refractory to treatment.

Adult↗

PubMed1995

Nonepileptic seizures.

The widespread use of video-electroencephalogram monitoring has dramatically increased our recognition of the high prevalence and diversity of nonepileptic seizures. Nonepileptic seizures stand squarely in the interface between psychiatry and neurology, an area that has been both claimed and denied by both sides. Collaborative exploration of this border zone has provided new insights into a disorder that may be as ancient as epilepsy.

Adult↗

PubMed1995

Open-label trial of venlafaxine in adults with attention deficit disorder.

Antidepressants or stimulants are commonly used to treat attention deficit disorder (ADD). We report the results of an open-label trial of the recently marketed antidepressant venlafaxine in 16 adult patients with ADD. Patients were treated with venlafaxine (25 to 225 mg/day) for 8 weeks. Four patients discontinued treatment within the first week because of sedation, agitation, or nausea. In the remaining 12 patients, venlafaxine treatment decreased ADD ratings by almost half.

Adult↗

PubMed1994

Postictal behavior. A clinical and subdural electroencephalographic study.

OBJECTIVE: To examine postictal behaviors after temporal lobe complex partial seizures (CPSs) and to correlate these behavioral phenomena with side of origin and ictal spread pattern. DESIGN: Review language and other behavioral phenomena after seizures defined by subdural electroencephalography. SETTINGS: A surgical epilepsy center. PATIENTS: We studied postictal behavior following 65 CPSs in 18 patients with left hemisphere language dominance using subdural electrode recordings. INTERVENTION: Subdural electrodes. MAIN OUTCOME MEASURES: Language function, affect, orientation, and postictal automatisms. RESULTS: Following the CPS ictal discharge, the mean interval for initial nonreflexive response to an environmental stimulus was 43 seconds (left foci, 57 seconds; right foci, 29 seconds; not significantly) and for first correct verbal response was 219 seconds (left foci, 275 seconds; right foci, 167 seconds; not significant). Impaired comprehension with fluent but unintelligible speech, as well as anomia, occurred after seizures arising from either temporal lobe. All nine seizures followed by global or nonfluent aphasia originated on the left side. Paraphasic errors were significantly more common after left temporal CPSs. Prolonged disorientation for place and flat affect were significantly more common after right temporal CPS. Postictal automatisms were frequent and included rubbing of the face, fumbling and picking hand movements, and repetitive oral movements. CONCLUSIONS: Postictal paraphasias, disorientation for place, and flat affect most likely reflect the functions of the area from which seizures arise but not the areas involved by spread.

Adolescent↗

PubMed1994

Neurophysiological properties of pallidal neurons in Parkinson's disease.

Neuronal properties of the human globus pallidus (GP) are not known. Since GP is the major output of the basal ganglia, it may be involved in the pathophysiology of Parkinson's disease. We studied 12 patients with medically resistant Parkinson's disease by using single cell recording of the GP during stereotaxic pallidotomy to define neuronal firing rate and its modulation during active and passive movements. Different frequency and pattern of single cell activity was found in globus pallidus externus compared with globus pallidus internus. Discharge rates of 19% of GP cells were modulated by passive contralateral movements. Pallidal units were most often related solely to single joint movement. Different patterns of activity in relation to the two different movements of the same joint were often observed. We identified somatotopically arranged cell clusters that alter discharge rate with related movements. These findings suggest at least a partial somatotopic organization of the human GP and similarity with experimental results in both healthy and MPTP monkeys, providing a rationale for surgical or pharmacological targeting of GP for treating Parkinson's disease.

Brain Mapping↗

PubMed1994

Changes in glutamate receptor and proenkephalin gene expression after kindled seizures.

Changes in gene expression after kindled seizures were examined using microdissection of discrete brain areas and Northern and slot blot analyses. Experimental animals were kindled with either of two protocols: (1) a paradigm in which 50 Hz/10 s stimulus trains were delivered every 30 min through hippocampal electrodes (12 stimulations every other day for 4 days) and (2) a traditional approach in which 50 Hz/10 s stimulus trains were given to the hippocampus three times daily for 16 days. Rats were sacrificed 24 h or 30 days after the last kindled seizure. We first examined the possibility that kindling may affect transcription of mRNA for neurotransmitter receptors. We found significant decreases (22-58%) in AMPA/kainate activated glutamate receptor mRNAs (GluR1, -2, -3 mRNAs) in hippocampus, amygdala/entorhinal cortex and in frontoparietal cortex 24 h but not 30 days after rapidly kindled seizures. However, changes in GABA receptor alpha 1, alpha 2, alpha 4 or beta 1 mRNAs were not observed in any brain region 30 days after traditional kindling or 24 h after rapidly kindled seizures. In addition, we tested whether changes in the expression of proenkephalin could be detected after kindling. We found significant increases (1.7-10 fold) in proenkephalin mRNA in the frontoparietal cortex, hippocampus and in the amygdala/entorhinal cortex 24 h but not 30 days after rapidly kindled seizures. Our findings suggest that changes in glutamate receptor and proenkephalin gene expression are robust, acute sequelae to kindled seizures and may be involved in kindling.

Amygdala↗

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↗