Incidence of epilepsy in a racially diverse, community-dwelling, elderly cohort: results from the Einstein aging study.

OBJECTIVE: To determine age-specific incidence and cumulative incidence of epilepsy in a well-defined cohort of elderly people, and to examine how rates of epilepsy are modified by sex, race, stroke, dementia, head injury, and depression. METHODS: The authors examined data from a reconstructed cohort based on 1919 community-dwelling volunteers, followed as part of a large ongoing prospective aging study. RESULTS: Age-specific incidence was 10.6 (per 100,000 person-years) between ages 45 and 59, 25.8 between ages 60 and 74, and 101.1 between ages 75 and 89. Cumulative incidence was 0.15% from age 45 to age 60, 0.38% to age 70, 1.01% to age 80, and 1.47% to age 90. In addition, the difference in cumulative incidence among African-American subjects approached statistical significance (57.6/100,000 person-years versus 26.1 in Caucasian, p=0.10), and the difference in incidence among subjects reporting a history of stroke was significantly elevated (p=0.029). Incidence of epilepsy was not statistically elevated among males, those with dementia, or individuals reporting a history of head injury or treatment for depression. Among "healthy" subjects without history of stroke, head injury, or dementia, we observed a cumulative risk of epilepsy with onset after age 60 of only 1.1%. CONCLUSIONS: The incidence of epilepsy was low in this relatively healthy cohort of elderly people, especially among subjects without known risk factors. In this study we identified African-American race as a risk factor in the elderly for epilepsy independent of stroke.

Identifying seizure clusters in patients with epilepsy.

Clinicians often encounter patients whose neurologic attacks appear to cluster. In a daily diary study, the authors explored whether clustering is a true phenomenon in epilepsy and can be identified in the clinical setting. Nearly half the subjects experienced at least one episode of three or more seizures in 24 hours; 20% also met a statistical clustering criterion. Utilizing the clinical definition of clustering should identify all seizure clusterers, and false positives can be determined with diary data.

The association between seizure clustering and convulsive status epilepticus in patients with intractable complex partial seizures.

PURPOSE: We examined the association between seizure clustering and convulsive status epilepticus (SE) in patients with intractable complex partial seizures, to identify whether patients whose seizures typically cluster are at high risk for convulsive SE (CSE). METHODS: Seventy-six patients with intractable complex partial epilepsy who underwent presurgical evaluation in the Montefiore Epilepsy Management Unit from 1993 to 1997 were contacted and interviewed about typical seizure frequency and distribution and history of CSE. Seizure clustering was defined as three or more complex partial seizures within a 24-h period, with return to baseline between seizures. RESULTS: Of the 76 patients contacted, 21 (28%) had experienced at least one episode of CSE, and 36 (47%) typically experienced clustered seizures. SE occurred in 16 (44%) of 36 patients with clustered seizures, and in five (12.5%) of 40 patients with nonclustered seizures (p < 0.002). Of 53 patients with temporal lobe epilepsy, CSE occurred in 13 (50%) of 26 patients with clustered seizures, and four (14.8%) of 27 patients with nonclustered seizures (p < 0.006). CONCLUSIONS: Patients with intractable complex partial or localization-related epilepsy who typically experience seizure clustering are at a significantly higher risk for CSE than are patients with nonclustered seizures.

Angiographic criteria reliably predict when carotid endarterectomy can be safely performed without a shunt.

BACKGROUND: Selective shunting during carotid endarterectomy is widely performed, but the optimal approach for predicting when a shunt is unnecessary remains uncertain. We evaluated the ability of preoperative cerebral angiography to predict when carotid endarterectomy could be safely performed without a shunt. STUDY DESIGN: Eighty-seven patients undergoing carotid endarterectomy between August 1991 and December 1997 had preoperative cerebral angiograms. The angiograms were evaluated for the presence of collateral flow from the contralateral carotid through the anterior communicating artery and from the posterior circulation through the posterior communicating artery. Patients then underwent endarterectomy and were selectively shunted based on somatosensory evoked potential changes. Internal carotid artery stump pressure was routinely measured in all patients. RESULTS: Nine patients (10%) had a shunt placed based on somatosensory evoked potential changes and none of the 87 patients had a perioperative (30 days) stroke. Angiography revealed that 36 patients (41%) had no cross-filling from the contralateral carotid through the anterior communicating artery. Nine of these patients (25%) required a shunt; none of the 51 patients with adequate cross-filling (p < 0.001) did. Furthermore, 94% of the patients without cross-filling but with a patent ipsilateral posterior communicating artery did not require a shunt using somatosensory evoked potential changes as the standard for shunt insertion. Stump pressure measurements (> or = 25 mmHg) or (> or = 50 mmHg) did not reliably exclude the need for a shunt. Only 2 of 15 patients with contralateral carotid occlusion and 1 of 16 patients with a prior ipsilateral stroke required shunts. CONCLUSIONS: In the presence of cross-filling from the contralateral carotid artery, shunt insertion was uniformly unnecessary. In addition, routine shunting of patients with previous ipsilateral strokes or contralateral carotid occlusion was not always necessary. Stump pressures were less sensitive than angiographic criteria in determining when a shunt was unnecessary. Evaluation of cross-filling from the contralateral carotid artery on preoperative angiography can predict with certainty which patients will not require a shunt.

Seizure lateralization during EEG monitoring in patients with bilateral foci: the cluster effect.

PURPOSE: To determine whether seizures that occur in clusters are more likely to reflect activity of the same focus than are seizures that are widely separated in time. METHODS: EEG monitoring data from 14 patients with bilateral independent seizure onsets were analyzed. Twelve of the 14 patients had surface recordings only, and two had implanted electrodes. Interseizure intervals (ISIs) for 151 seizure pairs were measured. Seizure onsets were classified as right hemispheric, left hemispheric, or indeterminate. Seizure pairs were classified as concordant for hemisphere of onset, discordant, or indeterminate. The relation between seizure-pair concordance and ISI was examined by using univariate analysis and analysis of variance (ANOVA). RESULTS: Both seizures originated from the same hemisphere in 61 (75%) of 81 seizure pairs with ISIs <8 h, compared with 28 (55%) of 51 seizure pairs with ISIs >8 h (p < 0.015). The cluster effect was not more pronounced for ISIs <2 h. ANOVA demonstrated that the relation between ISI and seizure concordance was not a result of the variability in seizure rates among patients. In three patients, the presence of bilateral foci was not demonstrated until more than five seizures were recorded. CONCLUSIONS: Seizures that occur after an ISI of <8 h are more likely to come from the same side as the previous seizure than are those with longer ISIs. Thus clustered seizures should not be given the same weight as seizures widely separated in time. In addition, more than five seizures may sometimes be needed to adequately assess patients being evaluated for epilepsy surgery.

Neurotoxic reaction to lindane in an HIV-seropositive patient. An old medication's new problem.

Scabies is a common infestation for patients of all ages throughout the world. One of the standard therapies for scabies is 1% lindane lotion. Lindane has been associated with neurotoxic reactions, specifically seizures. We describe a case of a middle-aged adult man with human immunodeficiency virus (HIV) infection who was found to have typical scabies and was treated with a single topical application of lindane. Two hours after the application, the patient experienced a new-onset generalized seizure. We believe that the triad of HIV infection, medications that reduce seizure thresholds, and percutaneous absorption factors, in the aggregate, induced the seizure. We believe that lindane should not be prescribed for patients with HIV infection.

Molecular evolution of the telomere-associated MAL loci of Saccharomyces.

The MAL gene family of Saccharomyces consists of five multigene complexes (MAL1, MAL2, MAL3, MAL4, and MAL6) each of which encodes maltose permease (GENE 1), maltase (GENE 2) and the trans-acting MAL-activator (GENE 3). Four of these loci have been mapped and each is located at or near the telomere of a different chromosome. We compare the physical structure of the MAL loci and their flanking sequences. The MAL loci were shown to be both structurally and functionally homologous throughout an approximately 9.0-kb region. The orientation of the MAL loci was determined to be: CENTROMERE . . . GENE 3-GENE 1-GENE 2 . . . TELOMERE. Telomere-adjacent sequences were found flanking GENE 2 of the MAL1, MAL3 and MAL6 loci. No common repeated elements were found on the centromere-proximal side of all the MAL1, loci. These results suggest that, during the evolution of this polygenic family, the MAL loci translocated to different chromosomes via a mechanism that involved the rearrangement(s) of chromosome termini.

Constitutive expression of the maltose fermentative enzymes in Saccharomyces carlsbergensis is dependent upon the mutational activation of a nonessential homolog of MAL63.

Maltose fermentation in Saccharomyces carlsbergensis is dependent upon the MAL6 locus. This complex locus is composed of the MAL61 and MAL62 genes, which encode maltose permease and maltase, respectively, and a third gene, MAL63, which codes for a trans-acting positive regulatory product. In wild-type strains, expression of the MAL61 and MAL62 mRNAs and proteins is induced by maltose and induction is dependent upon the MAL63 gene. Mutants constitutively expressing the MAL61 and MAL62 gene products have been isolated in mal63 backgrounds, and the mutations which have been analyzed map to a fourth MAL6-linked gene, MAL64. Cloning and characterization of this new gene are described in this report. The results revealed that the MAL64-C alleles present in constitutive strains encode a trans-acting positive function required for constitutive expression of the MAL61 and MAL62 gene products. In inducible strains, the MAL64 gene is dispensable, as deletion of the gene had no effect on maltose fermentation or maltose-regulated induction. MAL64 encoded transcripts of 2.0 and 1.4 kilobase pairs. While both MAL64 mRNAs were constitutively expressed in constitutive strains, they were maltose inducible in wild-type strains and induction was dependent upon the MAL63 gene. The MAL63 and MAL64 genes are at least partially structurally homologous, suggesting that they control MAL61 and MAL62 transcript accumulation by similar mechanisms.