Psychiatric and behavioral side effects of the newer antiepileptic drugs in adults with epilepsy.

OBJECTIVE: Psychiatric/behavioral side effects (PSEs) are common in patients taking antiepileptic drugs (AEDs). The objective of the study described here was to compare the PSE profiles of the newer AEDs. METHODS: We examined the charts of 1394 adult outpatients seen at the Columbia Comprehensive Epilepsy Center who had taken one of the newer AEDs. We compared the rate of AED-related PSEs in patients newly started on the newer AEDs both before and after controlling for non-AED predictors of PSEs. RESULTS: Overall, 221 of 1394 (16%) patients experienced PSEs. The average rate of AED-related PSEs for a single AED was 8.4%, with 6.1% resulting in dosage change and 4.3% resulting in AED discontinuation. Significantly fewer PSEs were attributed to gabapentin (n=160, 0.6% incidence, P<0.001) and lamotrigine (n=547, 4.8% incidence, P<0.001), and significantly more PSEs were attributed to levetiracetam (n=521, 15.7% incidence, P<0.001; 8.8% discontinued LEV because of PSEs). Vigabatrin, felbamate, and oxcarbazepine were associated with similarly low rates of PSEs in many analyses but with fewer of patients. Tiagabine was associated with high PSE rates (similar to those for levetiracetam), but was used much less commonly at our center. Intermediate rates of PSEs were attributed to topiramate and zonisamide (both nonsignificant). Psychiatric history was the most significant nondrug predictor of AED-related PSEs (PSEs occurred in 23% of patients with a psychiatric history vs 12% of patients without such a history, P<0.001). The relative rates of AED-related PSEs were similar when controlling for non-AED predictors and when analyzing only patients on monotherapy. CONCLUSIONS: There are significant differences between the newer AEDs in terms of their PSE profiles. Patients taking levetiracetan experience significantly more PSEs than average, and patients taking gabapentin and lamotrigine experience significantly fewer PSEs. Even with the medication with the highest rate of PSEs (levetiracetam), less than 10% of patients discontinued it because of PSEs. A past psychiatric condition is the most significant nondrug predictor of AED-related PSEs.

Anticonvulsant and antidepressant properties of electroconvulsive therapy: a proposed mechanism of action.

The efficacy of electroconvulsive therapy (ECT) in the treatment of affective disorders is well established. Despite its clinical utility, there is no generally accepted theory regarding its mode of action. Several lines of evidence indicate that ECT has significant anticonvulsant properties and results in decreased neural metabolic activity. We suggest that these effects are due to enhanced gamma-aminobutyric acid (GABA) transmission and that localized suppression of neural metabolic activity is associated with therapeutic response to ECT. An implication of this view is that ECT may be a useful adjunctive treatment in intractable epilepsy.

Chronic acetazolamide monotherapy in the treatment of juvenile myoclonic epilepsy.

We reviewed the charts of 84 patients with juvenile myoclonic epilepsy (JME) whom we had followed over the past 12 years, and identified 51 treated with acetazolamide (AZM) either because of a poor response to conventional antiepileptic drugs or to avoid valproate-associated adverse effects. Among the 51 we could isolate the effect of AZM on the generalized tonic-clonic seizures (GTCS) of JME in thirty-one. Chronic AZM monotherapy controlled GTCS in 14 of 31 patients. Most tolerated AZM very well; 5, however, developed renal calculi. Chronic AZM monotherapy controls GTCS in some patients with JME, but the development of renal calculi may limit its usefulness.

Somnambulism in adults.

We evaluated with clinical interviews and polysomnographic examinations 10 adults with the complaint of sleepwalking, often accompanied by violent behavior or self-injury. During the polysomnographic studies, 8 patients had 47 distinct somnambulistic episodes. All episodes occurred in non-REM sleep, with 91% occurring in slow-wave sleep. Contrary to previous reports, episodes were not confined to the 1st 3rd of the night. Clinical EEGs were normal in 5 of 6 patients. In the 7 patients tried on 1 or more treatment regimens, clonazepam effectively suppressed the somnambulism in 5 of 6 patients in whom it was tried, carbamazepine in 1 of 3, flurazepam in 2 of 2, and a combination of clonazepam and phenytoin in one.

No evidence for a major susceptibility locus for juvenile myoclonic epilepsy on chromosome 15q.

Juvenile myoclonic epilepsy (JME) is a distinct epileptic syndrome with a complex mode of inheritance. Several studies found evidence for a locus involved in JME on chromosome 6 near the HLA region. Recently, Elmslie et al. [1997] reported evidence of linkage in JME to chromosome 15q14 assuming a recessive mode of inheritance with 50% penetrance and 65% linked families. The area on chromosome 15q14 encompasses the location of the gene for the alpha-7 subunit of the nicotinic acetylcholine receptor. This could fit the hypothesis that there are two interacting loci, one on chromosome 6 and on chromosome 15 or that there is genetic heterogeneity in JME. In an independent dataset of JME families, we tested for linkage to chromosome 15 but found little evidence for linkage. Moreover, families with more than one family member affected with JME provide a lodscore of 3.4 for the HLA-DR/DQ haplotype on chromosome 6. The lodscore for these same families on chromosome 15q14 is <-2 assuming homogeneity and the maximum lodscore is 0.2 assuming alpha =.25. Only one of these families has a negative lodscore on chromosome 6 and a positive lodscore of 0.5 on chromosome 15q14. Our results indicate that this possible gene on chromosome 15 plays at most a minor role in our JME families. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:49-52, 2000.

Functional magnetic resonance imaging localization of ictal onset to a dysplastic cleft with simultaneous sensorimotor mapping: intraoperative electrophysiological confirmation and postoperative follow-up: technical note.

INTRODUCTION: Although technically challenging to obtain, ictal functional magnetic resonance imaging has been used to localize ictal onset zones in a small number of patients. We used this technique to demonstrate the inherent epileptogenicity of dysplastic cortex. METHODS: We present a 16-year-old female patient with intractable left-sided sensorimotor seizures and a congenital dysplastic cleft lying along the right rolandic fissure. Preoperative functional magnetic resonance imaging (blood oxygen level-dependent sequence, 1.5 T) localized the motor and sensory cortices to the anterior border of the cleft. During a speech activation run, the patient experienced a 20-second seizure. Initial activation was seen within the dysplastic cortex along the deep posterior margin of the cleft. Intraoperative median nerve stimulation produced a distinct N20/P20 wave inversion over the dysplastic cleft. Stimulation mapping performed with the patient awake confirmed the location of the sensorimotor cortex on the anterior border of the cleft, and preresection electrocorticography identified abundant interictal spikes along the posterior border after opening the cleft. RESULTS: After surgical resection of the dysplastic cortex, the patient exhibited transient minimal weakness and mild neglect, which resolved within 1 week. Two years after surgery, she was neurologically intact and seizure-free. CONCLUSION: This study used functional magnetic resonance imaging to demonstrate the inherent epileptogenicity of dysplastic cortex and to simultaneously map ictal and functional cortex. The N20 wave inversion can be a useful intraoperative tool for identifying the central sulcus (or its equivalent), even in the presence of abnormal cortical architecture.

The medical treatment of head and neck pain.

Head and neck pain are extremely common and in any year, four of five people will experience a headache. In one out of two the headache will be severe enough to interfere with daily activity. In this article the multiple clinical syndromes of head and neck pain are presented and the current medical therapies reviewed.

Cross-sensitivity of skin rashes with antiepileptic drug use.

OBJECTIVE: To determine rates of cross-sensitivity of rash among commonly used antiepileptic drugs (AEDs) in patients with epilepsy. METHODS: The incidence of AED-related rash was determined in 1875 outpatients (> or =12 years), taking carbamazepine (CBZ), clobazam (CLB), felbamate (FBM), gabapentin (GBP), levetiracetam (LEV), lamotrigine (LTG), oxcarbazepine (OXC), phenobarbital (PB), phenytoin (PHT), primidone (PRM), tiagabine (TGB), topiramate (TPM), vigabatrin (VGB), valproic acid (VPA), or zonisamide (ZNS). We compared rates of rash for each AED in patients with vs those without a rash to 1) another specific AED; 2) any other AED; 3) any two other AEDs; and 4) any non-epilepsy medication. RESULTS: A total of 14.3% (269/1,875) of patients had a rash attributed to at least one AED; 2.8% had a rash to two or more AEDs. Of patients who had a rash to CBZ and were also prescribed PHT (n = 59), 57.6% had a rash to PHT (abbreviated as CBZ --> PHT: 57.6%); of patients who had a rash to PHT and were also prescribed CBZ (n = 81), rate of rash was 42% (i.e., PHT --> CBZ: 42%). Other results: CBZ --> LTG: 20% (n = 50); LTG --> CBZ: 26.3% (n = 38); CBZ --> OXC: 33% (n = 15); OXC --> CBZ: 71.4% (n = 7); CBZ --> PB: 26.7% (n = 30); PB --> CBZ: 66.7% (n = 12); LTG --> PHT: 38.9% (n = 36); PHT --> LTG: 18.9% (n = 74); PB --> PHT: 53.3% (n = 15); PHT --> PB: 19.5% (n = 41); OXC --> LTG: 37.5% (n = 8); LTG --> OXC: 20% (n = 15). There was evidence of specific cross-sensitivity between CBZ and PHT, and between CBZ and PB. CONCLUSION: Cross-sensitivity rates between certain antiepileptic drugs (AEDs) are high, especially when involving carbamazepine and phenytoin. Specific cross-sensitivity rates provided here may be useful for AED selection and counseling in individual patients.

Comparison and predictors of rash associated with 15 antiepileptic drugs.

OBJECTIVE: To determine predictors and relative incidence of antiepileptic drug (AED)-related rash in patients taking all common AEDs. METHODS: We reviewed 1,890 outpatients. Eighty-one variables were tested as potential predictors of rash. We compared the rate of rash attributed to each AED (AED rash) with the average rate of rash attributed to the other AEDs in all adults (aged > or =16 years; n = 1,649) when taking carbamazepine (CBZ), clobazam (CLB), felbamate (FBM), gabapentin (GBP), lamotrigine (LTG), levetiracetam (LEV), oxcarbazepine (OXC), phenobarbital (PB), phenytoin (PHT), primidone (PRM), tiagabine (TGB), topiramate (TPM), vigabatrin (VGB), valproate (VPA), or zonisamide (ZNS). We repeated this analysis for patients with and without the identified nondrug predictors of AED rash. RESULTS: The average rate of AED rash was 2.8%. The only nondrug predictor significant in multivariate analysis was occurrence of another AED rash (odds ratio 3.1, 95% CI 1.8 to 5.1; p < 0.0001); the rate of rash in this subgroup was 8.8%, vs 1.7% in those without another AED rash. Higher AED rash rates were seen with PHT (5.9% overall, p = 0.0008; 25.0% in those with another AED rash, p = 0.001), LTG (4.8%, p = 0.00095; 14.4%, p = 0.025), and CBZ (3.7%, not significant; 16.5%, p = 0.01). Lower rates were seen with LEV (0.6% overall; p = 0.00042), GBP (0.3%, p = 0.00035), and VPA (0.7%, p = 0.01). Rash rates were also low (<1% overall) with FBM, PRM, TPM, and VGB (not significant). These AED differences remained similar in patients with and without other AED rashes. There were four cases of Stevens-Johnson syndrome involving four AEDs. CONCLUSIONS: The rate of an antiepileptic drug (AED) rash is approximately five times greater in patients with another AED rash (8.8%) vs those without (1.7%). Rash rates were highest with phenytoin, lamotrigine, and carbamazepine and low (<1%) with several AEDs.

ECT in the treatment of status epilepticus.

INTRODUCTION: Owing to its potent anticonvulsant actions, electroconvulsive therapy (ECT) has been proposed as an intervention for treatment-resistant seizure disorders. METHOD: We review the literature on the use of ECT in treatment-resistant epilepsy and status epilepticus (SE) and present a case of a patient who was in nonconvulsive SE for 26 days and then treated with ECT after all standard pharmacological strategies were exhausted. Because of skull defects, a novel electrode placement was used. RESULTS: Owing to massively elevated seizure threshold attributable to concomitant anticonvulsant medications, extraordinarily high electrical dosage was needed for ECT to elicit generalized seizures. Status was terminated after three successful ECT-induced seizures. However, the long-term functional outcome of the patient was poor. DISCUSSION: The role of ECT in the treatment algorithm for SE is discussed.

Correlating lamotrigine serum concentrations with tolerability in patients with epilepsy.

OBJECTIVE: To correlate lamotrigine (LTG) serum concentrations (levels) with tolerability in patients with epilepsy. METHODS: The charts of 811 outpatients with epilepsy who had received LTG and were seen at the Columbia Comprehensive Epilepsy Center after January 1, 2000, were reviewed. Data gathered included levels, dosage, duration of use, concomitant antiepileptic drugs (AEDs), clinical toxicity, specific side effects, and efficacy. Rates of toxicity, specific side effects, and efficacy were calculated and correlated with serum levels. RESULTS: In total, 3,731 LTG levels were recorded. A regimen was categorized as toxic if the patient experienced side effects that led to a dosage change or discontinuation of LTG. Of 3,919 AED regimens, 9.4% were toxic and 30.7% of patients had at least one toxic regimen. Toxicity increased with increasing LTG levels (p < 0.0001): With levels <5.0 microg/mL, 7% of patients were toxic; with levels of 5 to 10 microg/mL, 14%; with 10 to 15 microg/mL, 24%; with 15 to 20 microg/mL, 34%; and with >20 microg/mL, 59%. The correlation between levels and tolerability was independent of concurrent medication. Increasing efficacy, as measured by seizure freedom for a 6-month period, occurred up to levels of >20 microg/mL. CONCLUSIONS: There is a correlation between LTG serum level and tolerability, independent of the use of other AEDs. Adverse effects requiring a dose change are uncommon with the most frequently encountered LTG concentrations (<10 microg/mL) and occur in only 7.4% of patients at levels obtained during the majority of clinical trials (<5 microg/mL). An initial target range of 1.5 to 10 microg/mL is suggested, though higher levels, up to >20 microg/mL, are often tolerated and can lead to additional efficacy in refractory patients.

Human serum teratogenicity studied by rat embryo culture: epilepsy, anticonvulsant drugs, and nutrition.

Epileptic women have a greater risk for spontaneous abortions and children with birth defects than do nonepileptics. In a unique approach to identifying causes of these problems, we have cultured whole rat embryos for 48 h on blood sera from epileptics. In the first part of the study, three embryos were cultured on each serum sample from 128 different epileptics being treated with either single anticonvulsants or no drug to compare the teratogenicity of these drugs. Sera from subjects receiving either phenobarbital or no drug had comparable frequencies of cultured embryo abnormalities, which were lower than those from subjects taking phenytoin, valproic acid, or carbamazepine. In the second phase of the study, attempts to identify causes for serum teratogenicity led to the finding that the abnormalities and reduced embryo growth produced by many serum samples could be completely overcome by adding vitamins and/or amino acids to the serum. Of 53 samples tested, 32 (60%) were corrected by supplementation (17 of 23 phenytoin, seven of nine phenobarbital, six of 12 carbamazepine, none of six valproic acid, and two of three no drug). Although the results of this study provided a general assessment of drug teratogenicity that agreed with other studies and emphasized the role of nutrition in fetal defects, the importance of individual differences in causes of teratogenicity was also noted.

Reproducibility and complications in gene searches: linkage on chromosome 6, heterogeneity, association, and maternal inheritance in juvenile myoclonic epilepsy.

Evidence for genetic influences in epilepsy is strong, but reports identifying specific chromosomal origins of those influences conflict. One early study reported that human leukocyte antigen (HLA) markers were genetically linked to juvenile myoclonic epilepsy (JME); this was confirmed in a later study. Other reports did not find linkage to HLA markers. One found evidence of linkage to markers on chromosome 15, another to markers on chromosome 6, centromeric to HLA. We identified families through a patient with JME and genotyped markers throughout chromosome 6. Linkage analysis assuming equal male-female recombination probabilities showed evidence for linkage (LOD score 2.5), but at a high recombination fraction (theta), suggesting heterogeneity. When linkage analysis was redone to allow independent male-female thetas, the LOD score was significantly higher (4.2) at a male-female theta of.5,.01. Although the overall pattern of LOD scores with respect to male-female theta could not be explained solely by heterogeneity, the presence of heterogeneity and predominantly maternal inheritance of JME might explain it. By analyzing loci between HLA-DP and HLA-DR and stratifying the families on the basis of evidence for or against linkage, we were able to show evidence of heterogeneity within JME and to propose a marker associated with the linked form. These data also suggest that JME may be predominantly maternally inherited and that the HLA-linked form is more likely to occur in families of European origin.

Evidence for linkage of adolescent-onset idiopathic generalized epilepsies to chromosome 8-and genetic heterogeneity.

Several loci and candidate genes for epilepsies or epileptic syndromes map or have been suggested to map to chromosome 8. We investigated families with adolescent-onset idiopathic generalized epilepsy (IGE), for linkage to markers spanning chromosome 8. The IGEs that we studied included juvenile myoclonic epilepsy (JME), epilepsy with only generalized tonic-clonic seizures occurring either randomly during the day (random grand mal) or on awakening (awakening grand mal), and juvenile absence epilepsy (JAE). We looked for a gene common to all these IGEs, but we also investigated linkage to specific subforms of IGE. We found evidence for linkage to chromosome 8 in adolescent-onset IGE families in which JME was not present. The maximum multipoint LOD score was 3.24 when family members with IGE or generalized spike-and-waves (SW) were considered affected. The LOD score remained very similar (3.18) when clinically normal family members with SW were not considered to be affected. Families with either pure grand mal epilepsy or absence epilepsy contributed equally to the positive LOD score. The area where the LOD score reaches the maximum encompasses the location of the gene for the beta3-subunit of the nicotinic acetylcholine receptor (CHRNB3), thus making this gene a possible candidate for these specific forms of adolescent-onset IGE. The data excluded linkage of JME to this region. These results indicate genetic heterogeneity within IGE and provide no evidence, on chromosome 8, for a gene common to all IGEs.

Genome scan of idiopathic generalized epilepsy: evidence for major susceptibility gene and modifying genes influencing the seizure type.

Idiopathic generalized epilepsy (IGE) is a common, complex disease with an almost exclusively genetic etiology but with variable phenotypes. Clinically, IGE can be divided into different syndromes. Varying lines of evidence point to the involvement of several interacting genes in the etiology of IGE. We performed a genome scan in 91 families ascertained through a proband with adolescent-onset IGE. The IGEs included juvenile myoclonic epilepsy (JME), juvenile absence epilepsy (JAE), and epilepsy with generalized tonic clonic seizures (EGTCS). Our linkage results support an oligogenic model for IGE, with strong evidence for a locus common to most IGEs on chromosome 18 (lod score 4.4/5.2 multipoint/two-point) and other loci that may influence specific seizure phenotypes for different IGEs: a previously identified locus on chromosome 6 for JME (lod score 2.5/4.2), a locus on chromosome 8 influencing non-JME forms of IGE (lod score 3.8/2.5), and, more tentatively, two newly discovered loci for absence seizures on chromosome 5 (lod scores 3.8/2.8 and 3.4/1.9). Our data also suggest that the genetic classification of different forms of IGE is likely to cut across the clinical classification of these subforms of IGE. We hypothesize that interactions of different combinations of these loci produce the related heterogeneous phenotypes seen in IGE families.