Biomedical subjects

E L So

Publications and source records attributed to E L So.

At least 55 records · Page 3Linked to original sources

PubMed1997

Factors associated with work outcome after anterior temporal lobectomy for intractable epilepsy.

PURPOSE: Whereas the effect of anterior temporal lobectomy on seizure frequency is well recognized, less is known about its impact on work status. METHODS: One hundred thirty-four of 190 consecutive patients with temporal lobectomy participated in this study. Eligibility criteria were developed to ensure that only patients with the potential of achieving specific outcomes were included in the corresponding analyses. RESULTS: After surgery, significantly more patients were independent in activities of daily living (p < 0.001) or able to drive (p < 0.001). Income from work also increased (p < 0.01). Nearly one fifth of the patients who were eligible for analysis had either a gain (8%) or a loss (11%) of full- or of part-time work. Univariate analyses revealed the following factors to be associated with full-time work after surgery: student or full-time work within a year before surgery, full-time work experience before surgery, full- or part-time employment experience before surgery, no disability benefits before surgery, low postsurgical seizure frequency, improved postsurgical seizure control, excellent postsurgical seizure control, driving after surgery, and further education after surgery (p < 0.05). Significant factors on multivariate analysis were being a student or having full-time work within a year before surgery [odds ratio, 16.2 (95% CI, 4.3-60.5)], driving after surgery [15.2 (3.2-72.0)], and obtaining further education after surgery [9.2 (2.2-53.0)]. CONCLUSIONS: Anterior temporal lobectomy for intractable epilepsy improves activities of daily living and the ability to drive. Work outcome of this surgery is influenced by presurgical work experience, successful postsurgical seizure control especially to allow driving, and obtaining further education after surgery.

Activities of Daily Living↗

PubMed1996

The ictal bradycardia syndrome.

PURPOSE: Episodic loss of consciousness presents a diagnostic challenge to the neurologist. A perhaps underrecognized cause of episodic loss of consciousness, which we call the ictal bradycardia syndrome, occurs when epileptic discharges profoundly disrupt normal cardiac rhythm, resulting in cardiogenic syncope during the ictal event. We attempt to determine whether the presence of the ictal bradycardia syndrome provides localizing information regarding the site of seizure onset and to describe the demographics of patients with this syndrome. We also discuss difficulties in diagnosis and treatment. METHODS: We review 23 cases of the ictal bradycardia syndrome from the literature and present four additional cases. Brief histories are provided for the four previously unreported cases. Where data are available, cases are analyzed with respect to age, sex, and site of seizure onset. RESULTS: Patients with the ictal bradycardia syndrome ranged from 4 months to 72 years (mean 39 years). There was an approximately 5:1 ratio of males to females. Twenty of the 23 patients (87%) whose site of ictal onset could be localized had temporal lobe epilepsy, although no clear lateralizing predominance was apparent. CONCLUSIONS: The ictal bradycardia syndrome should be considered in patients with unusual or refractory episodes of syncope, or in patients with a history suggestive of both epilepsy and syncope. It suggests seizure onset in temporal lobe, and is more commonly diagnosed in males. Diagnosis may be aided by ambulatory EEG/ECG monitoring. Cardiac pacemaker implantation along with antiepileptic drug therapy may be necessary to minimize the possibility of death.

Adolescent↗

PubMed1996

Movement disorders associated with the use of gabapentin.

PURPOSE: We report two cases of unusual movement disorders associated with the use of gabapentin (GBP) in patients being treated for epilepsy who were otherwise neurologically intact. METHODS: We describe two cases of unusual movement disorders associated with the use of GBP. RESULTS: There were significant differences in the clinical findings between the two cases. In the first case, movements were very pronounced and the patient was in oculogyric crisis. Movements in the second case were quite subtle but nonetheless problematic for the patient. In each case, discontinuation of GBP led to rapid resolution of the movements, although a single dose of lorazepam was used in the first case. CONCLUSIONS: Although formal electrophysiologic studies have not been performed, the movements associated with GBP use appear to be dystonic or myoclonic. Discontinuation of GBP led to rapid resolution of the movements. In severe cases, as in patients with oculogyric crisis, small doses of a benzodiazepine (BZD) appear to be efficacious and safe.

Acetates↗

PubMed1996

Bilateral magnetic resonance imaging-determined hippocampal atrophy and verbal memory before and after temporal lobectomy.

We investigated pre- and postoperative verbal memory in temporal lobectomy patients who had volumetrically symmetric hippocampi. Pre- and postoperative verbal memory data based on the Logical Memory subtest of the Wechsler Memory Scale-Revised (WMS-R) were obtained from 15 left and 18 right temporal lobectomy patients. The difference between hippocampal volumes (R/L) was between -0.1 and 0.3 cm3, which is indeterminate for lateralizing hippocampal atrophy. Patients were divided into four groups based on side of operation and combined hippocampal volume expressed as a function of total intracranial volume (R + L volume/total intracranial volume). Patients with a combined hippocampal volume that was smaller than any combined hippocampal value of a normal control group were defined as bilaterally atrophic. Left temporal lobectomy patients demonstrated the expected decrease in verbal memory postoperatively regardless of whether the volumetrically symmetric hippocampi were nonatrophic or atrophic. Left temporal lobectomy patients with bilaterally atrophic hippocampi, however, had the poorest verbal memory before and after operation. Right temporal lobectomy patients tended to have improved verbal memory after operation whether or not the volumetrically symmetric hippocampi were atrophic. We conclude that side of operation is a more potent predictor of verbal memory outcome than is hippocampal atrophy when hippocampi are bilaterally symmetric and that left temporal lobectomy patients with bilateral atrophy may be at risk for greater functional deficits after operation.

Adult↗

PubMed1996

Routine EEG and temporal lobe epilepsy: relation to long-term EEG monitoring, quantitative MRI, and operative outcome.

PURPOSE: To investigate the relation among routine EEG, long-term EEG monitoring (LTM), quantitative magnetic resonance imaging (MRI), and surgical outcome in temporal lobe epilepsy (TLE). METHODS: We evaluated 159 patients with intractable TLE who underwent an anterior temporal lobectomy between 1988 and 1993. The epileptogenic temporal lobe was determined by ictal LTM. A single awake-sleep outpatient EEG with standard activating procedures was performed before LTM. EEGs were analyzed by a blinded investigator. RESULTS: MRI scans showed unilateral medial temporal atrophy (109 patients) or symmetrical hippocampal volumes (50 patients). The surgically excised epileptogenic brain tissue revealed mesial temporal sclerosis, gliosis, or no histopathologic alteration. Routine EEG revealed temporal lobe epileptiform discharges in 123 patients. Routine EEG findings correlated with the temporal lobe of seizure origin (p < 0.0001) and the results of MRI volumetric studies (p < 0.0001). Interictal epileptiform discharges were seen only during LTM in 24 patients. Routine EEG was disconcordant with interictal LTM in another 20 patients. MRI-identified unilateral medial temporal lobe atrophy was a strong predictor of operative success (p < 0.0001). There was no significant relation between the routine EEG findings and operative outcome (p > 0.20). CONCLUSIONS: Results of this study modified our approach in patients with TLE. Interictal epileptiform discharges localized to one temporal lobe on serial routine EEGs or during LTM may be adequate to identify the epileptogenic zone in patients with MRI-identified unilateral medial temporal lobe atrophy.

Adolescent↗

PubMed1996

Population-based study of seizure disorders after cerebral infarction.

We performed the first population-based study that determined the magnitude of the risk and identified the factors predictive of developing seizure disorders after cerebral infarction. Five hundred thirty-five consecutive persons without prior unprovoked seizures were followed from their first cerebral infarctions until death or migration out of Rochester, Minnesota. Thirty-three patients (6%) developed early seizures (within 1 week), 78% of which occurred within the first 24 hours after infarction. Using multivariate analysis, the only factor predictive of early seizure occurrence was anterior hemisphere location of infarct (odds ratio 4.0; 95% CI 1.2 to 13.7). Twenty-seven patients developed an initial late seizure (past 1 week), whereas 18 developed epilepsy (recurrent late seizures). Compared with the population in the community, the risk during the first year was 23 times higher for initial late seizures and 17 times higher for epilepsy. The cumulative probability of developing initial late seizures was 3.0% by 1 year, 4.7% by 2 years, 7.4% by 5 years, and 8.9% by 10 years. Independent predictive factors on multivariate analysis for initial late seizures were early seizure occurrence (hazard ratio of 7.8 [95% CI 2.8 to 21.7]) and stroke recurrence (3.1 [1.2 to 8.3]). Both early seizure occurrence (16.4 [5.5 to 49.2]) and stroke recurrence (3.5 [1.2 to 10.5]) independently predicted the development of epilepsy as well. We also found that early seizure occurrence predisposed those with initial late seizures to develop epilepsy.

Adolescent↗

PubMed1996

A clinical approach to the classification of seizures and epileptic syndromes.

Seizures and epilepsies are heterogeneous. Their classifications are essential for clinicians to achieve a common understanding of the disorders. The diagnosis, treatment, and prognosis of seizure disorders depend on the correct identification of the types of seizures and epilepsy. The two currently accepted classifications are the International Classification of Epileptic Seizures and the International Classification of Epilepsies and Epileptic Syndromes. Both are based on clinical and electrophysiologic data, and both maintain a basic dichotomy between partial (focal, localization-related) and generalized epileptic disorders. Partial seizures are further classified into those that are simple partial, complex partial, and partial with secondary generalization. Generalized seizures are classified predominantly on the basis of their motor manifestations. Epilepsies are divided into idiopathic, cryptogenic, and symptomatic types. The utility and the limitations of these two classifications are discussed. A simplified system that encompasses neuroradiologic advances is offered to enhance the clinical usefulness of classifying epileptic disorders.

Epilepsy↗

PubMed1996

Psychogenic nonepileptic seizures.

Psychogenic nonepileptic seizures (NES) are commonly encountered in clinical practice, and they may pose difficult diagnostic problems. For appropriate evaluation and treatment of NES, a multidisciplinary team approach is needed; typically, a neurologist with expertise in epilepsy, a psychologist or psychiatrist, and a support staff should be involved. Psychogenic NES have no single initial clinical manifestation, and various etiologic factors may contribute to their development. Of importance, psychogenic NES are "real" seizures that may be as disabling as epileptic seizures. Most often, they occur on a subconscious level, and the patient may have no control over their occurrence. Precipitation or termination of a habitual seizure during video-electroencephalographic monitoring has often been used to distinguish NES from epileptic seizures, but the results can sometimes be misleading. Numerous additional diagnostic techniques can be used to assist in making the diagnosis. Treatment is based on the type of psychiatric disorder present. Favorable prognostic factors include being female and having an independent lifestyle, normal electroencephalographic findings, higher intelligence, and no prior psychotherapy.

Conversion Disorder↗

PubMed1996

Selection of antiepileptic drugs: a practical approach.

The selection of antiepileptic drugs (AEDs) is increasingly more complex as new agents become available. We discuss an individualized approach to selection of an AED that is tailored to each patient's needs by considering the following six factors: effectiveness of the drug in controlling seizures, adverse effects profile, pharmacokinetic properties, special or unique patient situations, drug interactions, and cost of treatment. When these factors are considered, treatment complications and failure can be minimized by anticipating incompatibilities among drugs or between the drugs and the patient's condition. We emphasize the concept that the best AED therapy is dependent on optimal seizure control and absence of unacceptable side effects. In the current environment of medical practice, the cost of treatment has also become a major concern. With rare exceptions, no single factor dictates the choice of an AED. In the long term, the most cost-effective treatment will be the one that provides the most therapeutic benefit with the fewest complications and maximal patient satisfaction.

Anticonvulsants↗

PubMed1995

Pharmacokinetics of tiagabine as add-on therapy in patients taking enzyme-inducing antiepilepsy drugs.

The effect of hepatic enzyme-inducing antiepilepsy drugs (AEDs) on the clinical pharmacokinetics of tiagabine, a new AED, was studied in the steady-state condition. Patients with epilepsy entered this two-day study on a previously stable regimen of one to three enzyme-inducing drugs (phenytoin, phenobarbital, carbamazepine, and/or primidone) and tiagabine.HCl (24, 40, 56, or 80 mg daily). Patients were confined on both days, and serial blood samples were collected. Plasma tiagabine concentrations were determined by high-performance liquid chromatography; pharmacokinetic parameters were calculated using noncompartmental methods. Tiagabine pharmacokinetics were linear at all doses, as substantiated by the lack of significant differences among groups for dose-adjusted Cmax, Cmin, and AUC0-6. Some diurnal variation occurred, as evidenced by a statistically significant time effect for dose-adjusted AUC0-6. The effect was small, however, and possibly not clinically relevant. The harmonic mean half-lives of 3.8 to 4.9 h were remarkably constant across dosages and shorter than those of historical control subjects not taking enzyme-inducing AEDs suggesting that epilepsy patients not taking enzyme-inducing AEDs may require lower tiagabine.HCl doses to achieve the plasma levels observed in patients taking these drugs.

Adolescent↗

PubMed1995

Depth electrode studies in temporal lobe epilepsy: relation to quantitative magnetic resonance imaging and operative outcome.

We performed a retrospective study of 30 patients with presumed intractable temporal lobe epilepsy (TLE) who underwent chronic intracranial EEG monitoring (CIEM). Multicontact depth electrodes were stereotactically implanted through the medial occipital lobe into amygdala and hippocampus. All patients had previously undergone extracranial ictal EEG monitoring that proved inadequate to localize the epileptogenic zone. No morbidity was associated with CIEM in the 30 patients. Twenty-five patients were shown to have exclusively or predominantly unilateral temporal lobe seizures, and 5 patients had bitemporal seizures without unilateral predominance; 24 patients subsequently underwent an anterotemporal lobe cortical resection. Twenty-one patients have been followed a minimum of 1 year postoperatively. Nine patients (43%) had a class I outcome (seizure-free, auras only, or provoked seizures), 3 patients (14%) had a class II outcome (> or = 95% seizure reduction), 4 patients (19%) had a class III outcome (> or = 50% seizure reduction); and 5 patients (24%) had a class IV outcome (< 50% seizure reduction or no change). A prolonged interhemispheric propagation time (p < 0.01) and magnetic resonance imaging (MRI)-identified hippocampal atrophy (p < 0.01) correlated with a favorable surgical outcome. Results of this study may prove useful in counseling patients who undergo CIEM before temporal lobe surgery.

Adolescent↗

PubMed1995

Electrocorticography and temporal lobe epilepsy: relationship to quantitative MRI and operative outcome.

We investigated the relationship between electrocorticography (ECoG), quantitative magnetic resonance imaging (MRI), and surgical outcome in 165 patients with intractable nonlesional temporal lobe epilepsy (NLTLE). A standard mesial temporal resection was performed in all patients. Patients with an operative follow-up < 1 year were excluded from the study. The extent of the lateral temporal neocortex resection (LCR) was guided by ECoG and the side of surgery. The extent of the LCR was not predictive of seizure outcome in patients with or without hippocampal formation atrophy (p > 0.5). Patients undergoing a right anterior temporal lobectomy had a larger LCR (p < 0.0001), but the side of surgery was not of predictive value in determining seizure outcome (p > 0.1). The topography of the acute intracranial spikes did not correlate with operative outcome (p > 0.5) and was independent of hippocampal volumetric studies (p > 0.5). The postexcision ECoG was also shown not to be of prognostic importance (p > 0.5). Our results indicates that the extent of the lateral temporal cortical resection and the ECoG findings are not important determinants of surgical outcome in patients with NLTLE.

Adolescent↗

PubMed1995

Bilaterally symmetric hippocampi and surgical outcome.

This study investigates the relationship between hippocampal volume and seizure control following temporal lobectomy in patients with volumetrically symmetric hippocampi. Forty-six patients who underwent temporal lobectomy for nonlesional temporal-lobe-onset seizures, and in whom the volumes of the two hippocampi were roughly equal (ie, the difference of the right minus the left hippocampal volume fell between -0.1 and 0.3 cm3), were included. We graded postoperative seizure control on a four-point scale according to criteria defined by Engel. We found no relationship between the hippocampal sum (sum of the right plus left hippocampal volumes normalized for cranial size) and operative outcome. A satisfactory operative outcome is possible in patients with bilaterally symmetric mesial temporal sclerosis by MRI criteria.

Adult↗

PubMed1995

Nimodipine as an add-on therapy for intractable epilepsy.

OBJECTIVE: To analyze the effect of nimodipine in patients with intractable epilepsy. DESIGN: We conducted a double-blind placebo-controlled crossover study in 95 patients. MATERIAL AND METHODS: The dihydropyridine calcium antagonist nimodipine was used as add-on therapy (60 mg four times a day) in a 1-year placebo-controlled crossover study in 71 patients with localization-related epilepsy and 24 with generalized seizure disorders. Of the 95 patients, 81 were receiving two or more antiepileptic drugs. Patients diaries were used to record the number of seizures and any side effects. RESULTS: Nimodipine seemed to be well tolerated during the study; only two patients were unable to complete the study because of probable adverse effects. The trial demonstrated no significant crossover effect and no significant effect of nimodipine on either the mean or the median number of seizures or seizure days. The peak median serum nimodipine level was less than 5 ng/mL in the 78 patients who completed the study. CONCLUSION: This clinical trial found no beneficial effect with use of nimodipine as add-on therapy for intractable epilepsy. Potential reasons for the absence of efficacy of nimodipine may be the inclusion of patients with very refractory seizure disorders or the relatively low serum nimodipine concentrations related to the pharmacokinetic effect of concurrent antiepileptic medication.

Adult↗

PubMed1995

Classifications and epidemiologic considerations of epileptic seizures and epilepsy.

The manifestations of epileptic disorders are widely known to be extremely protean. Classifying the disorders is a way of achieving a common understanding of the terminology used in identifying seizure disorders in the clinical or research settings. Two International Classifications have been developed, namely the International Classification of Epileptic Seizures and the International Classification of Epilepsy and Epileptic Syndromes. The first divides epileptic seizures into two major categories: partial and generalized. Partial epileptic seizures are further classified according to the impairment or the preservation of consciousness into simple partial and complex partial seizures. Either condition may secondarily generalize into tonic-clonic seizures. Under the International Classification, epilepsy and epileptic syndromes are initially classified according to their corresponding types of seizures into localization-related and generalized disorders. Each disorder is further classified according to the relationship to etiologic or predisposing factors into symptomatic, cryptogenic, or idiopathic types. The classifications undoubtedly will be further revised as more is learned about epileptic disorders with advances in electrophysiology, neuroimaging techniques, and molecular genetics. An overview of the epidemiology of epileptic disorders shows that, contrary to the popular belief, they are primarily disorders of childhood; age-specific incidence rates of first unprovoked seizure and of epilepsy are highest in the elderly. An appreciation of the epidemiology of seizure disorders is essential in their clinical and laboratory evaluation.

Adolescent↗

PubMed1994

Seizure exacerbation and status epilepticus related to carbamazepine-10,11-epoxide.

Over a 3-year period, we encountered 6 adults whose seizure control unexpectedly deteriorated with the occurrence of partial status epilepticus and daily multiple seizures. Analysis of the case histories and subsequent clinical follow-up for 1 1/2 to 3 years disclosed the following evidence that demonstrates the role of carbamazepine-epoxide in the development of the seizure exacerbation: (1) There were high serum carbamazepine-epoxide concentrations while serum carbamazepine concentrations were lower than or the same as baseline levels; (2) all patients were taking drugs that are known to increase serum carbamazepine-epoxide concentrations; (3) status epilepticus failed to respond to intravenous phenytoin loading; (4) seizure exacerbation in all patients was corrected by withholding carbamazepine dose; (5) seizure exacerbation recurred in 1 patient who resumed the same dose of carbamazepine; and (6) there were no prior status epilepticus or daily multiple seizures despite previous toxicities with other antiepileptic drugs in 3 patients. Our experience shows that inconspicuous elevation of carbamazepine-epoxide levels during polytherapy may precipitate a distinct state of drug toxicity characterized by severe exacerbation of seizures. Mental retardation may be a predisposition to this condition.

Adult↗

PubMed1994

Yield of sphenoidal recording in sleep-deprived outpatients.

We retrospectively reviewed the results of sphenoidal recordings performed after sleep deprivation in 101 consecutive outpatients whose prior scalp EEGs failed to show epileptiform discharges (EDs). These patients were suspected of having seizures of temporal lobe origin. Blinded reviews of the recordings by two electroencephalographers showed a tendency for sphenoidal recording to detect EDs at a higher rate than scalp recording, but the difference did not reach statistical significance (p = 0.06). However, EDs appeared exclusively at sphenoidal electrodes in 11 patients and exclusively at scalp electrodes in 3. The probability of detecting EDs with combined scalp and sphenoidal recordings was greater when spells were characterized by focal symptoms or signs. Except in three patients, initial EDs occurred during the first 30 min of recording. We recommend that post-sleep-deprivation recording be performed initially with scalp and other noninvasive electrodes (such as anterior temporal, ear, or cheek electrodes). If no EDs occur after 30 min, sphenoidal electrode insertion and recording may then be considered, especially in patients with spells characterized by focal signs or symptoms.

Adolescent↗

PubMed1993

Update on epilepsy.

Increasing knowledge of prognostic factors and of treatment outcomes has led to major changes in the treatment of epileptic seizures. The management of first seizures can now be individualized, based on the probability of seizure recurrence and its expected repercussions. When a decision is made to treat initial or recurrent seizures, monotherapy with nonsedating AEDs is recommended. Therapy should also be optimized to achieve seizure control as early as possible. During AED therapy, clinical monitoring of drug reaction symptoms is preferred over routine laboratory testing. Laboratory monitoring is not cost-effective, and there is no proof that it can forecast drug reactions. The risk of congenital malformations in newborns prenatally exposed to AEDs is around 5%, which is 2 to 2.5 times that of the general population. Valproate and carbamazepine have recently been associated with a 1% risk of spina bifida. There are measures that can be used to reduce the risk of teratogenicity, the most important of which is using the least amount of AEDs necessary to control seizures during pregnancy. Although AEDs to reduce the efficacy of oral contraceptives, oral contraceptives are still reliable with certain precautions. For patients with intractable epilepsy, surgery should be considered to improve seizure control. Proper selection of candidates increases the probability of an excellent outcome in these patients, who otherwise have no hope of leading a normal life. Postsurgical outcome largely depends on the location, the extent, and the pathology of the epileptogenic tissues in the brain.

Abnormalities, Drug-Induced↗