Cognitive effects of topiramate, gabapentin, and lamotrigine in healthy young adults

Comparative retention rates and long-term tolerability of new antiepileptic drugs

OBJECTIVE

Retention rates of five new anti-epileptic medications (AEDs) were compared in order to evaluate their long-term tolerability and efficacy.

METHOD

We acquired the retention data on levetiracetam (LEV), lamotrigine (LTG), oxcarbazepine (OXC), topiramate (TPM), and zonisamide (ZNS) from the electronic database. The data included patient's age, gender, seizure type, current and previous medications, dosage, main reasons for discontinuation, and duration of therapy. The retention rates of these AEDs were evaluated at 4, 12, 24, 52, and 104 weeks.

RESULTS

A total of 828 new AED exposures were obtained (LEV=196, LTG=251, OXC=97, TPM=156, ZNS=128) from patients with partial or generalized epilepsy. At 2 years, retention rate was highest with LTG (74.1%), followed by ZNS (60.2%), OXC (58.8%), LEV (53.6%), and TPM (44.2%). When these AEDs were discontinued, it was mainly due to inefficacy (29.5%) and sedating side-effects (20.5%), and commonly within 6 months into therapy. Several important AED specific side-effects leading to discontinuation were identified, including behavioral or irritability from LEV, rash from LTG and OXC, nausea from OXC and ZNS, hyponatremia from OXC, and kidney stones from TPM and ZNS.

CONCLUSION

Comparing retention rates of new AEDs can provide useful insight into their tolerability and efficacy. This study showed highest retention rate with LTG, which was significantly different from ZNS (p=0.0025), LEV (p<0.0001), OXC (p=0.0024), and TPM (p<0.0001). Beside ineffectiveness, other leading causes of discontinuation were adverse behavioral effects with LEV, rash with LTG and OXC, and sedation for TPM and ZNS.

Topiramate effects on the EEG and alertness in healthy volunteers: a different profile of antiepileptic drug neurotoxicity

OBJECTIVE

Previous quantitative EEG (QEEG) studies of carbamazepine (CBZ), oxcarbazepine (OXC), and phenytoin (PHT) revealed a pattern of EEG slowing and an increase in drowsiness on the awake maintenance task (AMT). EEG slowing has been shown to correlate with negative effects on cognitive tests. Topiramate (TPM) is a novel AED with relatively large negative effects on cognitive function. We tested the hypothesis that TPM would induce significant slowing of EEG background rhythms and an increase in AMT drowsiness.

METHODS

Forty healthy volunteers were randomized to TPM, gabapentin (GBP), or placebo. Doses were escalated as tolerated to a maximum of 400mg/day for TPM or 3600 mg/day for GBP, over a 10-week period, followed by a minimum 2-week plateau period. Volunteers underwent an EEG, cognitive tests, and the AMT prior to starting an AED and again 12 weeks later. The EEG was captured using a structured recording protocol and quantified using the fast Fourier transform. Four target measures were derived from the averaged occipital electrodes (peak frequency of the dominant posterior rhythm, median frequency, percentage theta, and percentage delta). Test-retest changes for all measures were scored against similar test-retest distributions previously obtained from untreated healthy volunteers.

RESULTS

TPM produced no significant change in any of the four target EEG measures or on the AMT, even though several target cognitive tests revealed moderate or greater negative effects. There were also no significant changes in the placebo group. GBP slowed the peak and median frequency EEG measures and increased the percentage of theta and delta activity. Neither TPM, GBP, nor placebo caused a significant increase in drowsiness on the AMT.

CONCLUSIONS

TPM has a unique neurotoxicity profile. It has no effect on EEG background measures or on the AMT, but induces moderate to large negative changes in many cognitive test scores. This profile differs from those of CBZ, OXC, PHT, and GBP.

Comparison of cognitive effects of lamotrigine and oxcarbazepine in epilepsy patients

BACKGROUND AND PURPOSE

This study compared the cognitive effects of 1 year of treatment with lamotrigine (LTG) and oxcarbazepine (OXC) in epilepsy patients.

METHODS

This retrospective study investigated 60 epilepsy patients undergoing neuropsychological tests who were either newly diagnosed or untreated in the preceding 6 months. The cognitive function in 30 patients receiving LTG monotherapy and 30 age-matched patients receiving OXC monotherapy was compared after 1 year. The neuropsychological scores at baseline and all of the epilepsy-relevant variables except seizure type did not differ between the groups. The mean daily dosages of LTG and OXC at 1 year were 93 mg and 825 mg, respectively.

RESULTS

The posttreatment list-learning performance was better in the LTG group than in the OXC group (p<0.05). The incidence of cognitive complaints did not differ between the two groups. The list-learning performance and Trail Making Test scores were better in each group after treatment.

CONCLUSIONS

LTG and OXC monotherapies have similar, slightly beneficial effects on cognitive function, and are probably not harmful.

Effects of antiepileptic drugs on learning as assessed by a repeated acquisition of response sequences task in rats

Patients with epilepsy can have impaired cognitive abilities. Antiepileptic drugs (AEDs) may contribute to the cognitive deficits observed in patients with epilepsy, and have been shown to induce cognitive impairments in healthy individuals. However, there are few systematic data on the effects of AEDs on specific cognitive domains. We have previously demonstrated that a number of AEDs can impair working memory and attention. The purpose of the present study was to evaluate the effects of AEDs on learning as measured by a repeated acquisition of response sequences task in nonepileptic rats. The GABA-related AEDs phenobarbital and chlordiazepoxide significantly disrupted performance by shifting the learning curve to the right and increasing errors, whereas tiagabine and valproate did not. The sodium channel blockers carbamazepine and phenytoin suppressed responding at higher doses, whereas lamotrigine shifted the learning curve to the right and increased errors, and topiramate was without significant effect. Levetiracetam also shifted the learning curve to the right and increased errors. The disruptions produced by triazolam, chlordiazepoxide, lamotrigine, and levetiracetam were qualitatively similar to the effects of the muscarinic cholinergic receptor antagonist scopolamine. The present results indicate that AEDs can impair learning, but there are differences among AEDs in the magnitude of the disruption in nonepileptic rats, with drugs that enhance GABA receptor function and some that block sodium channels producing the most consistent impairment of learning.

Differential effects of low and high doses of topiramate on consolidation and retrieval of novel object recognition memory in rats

Topiramate is a new antiepileptic drug proposed to facilitate synaptic inhibition and block excitatory receptors. However, little is known about the effects of topiramate on memory. In the first experiment, intraperitoneal injection of topiramate at doses of 10.0 and 100.0 mg/kg, immediately after training, induced a deficit in short-term memory (STM) of a novel object recognition (NOR) task tested 1.5 hours after training in rats. In a long-term memory (LTM) test given to the same rats 24 hours after training, topiramate 0.1mg/kg enhanced, whereas 10.0 and 100.0 mg/kg impaired, NOR retention. In the second experiment, administration of topiramate 0.01 and 0.10 mg/kg 1 hour prior to the LTM retention test improved NOR retention, whereas 10.0 and 100.0 mg/kg produced retrieval deficits. The results indicate that low doses of topiramate improve, whereas high doses impair, consolidation and retrieval of recognition memory in rats.

Novel anticonvulsant drugs

Principles of complex mechanisms of action of anticonvulsants including latest reports concerning new antiepileptic drugs (AED) are considered. Different aspects of new anticonvulsant drugs (2nd generation) from preclinical and clinical testing, pharmacokinetics, and mono or combination therapy in children and adults are summarized. In the following condensed synopsis pharmacological and clinical characteristics of gabapentin (GBP), lamotrigine (LTG), levetiracetam (LEV), oxcarbazepine (OXC), pregabalin (PGB) and tiagabine (TGB) as well as topiramate (TPM) and zonisamide (ZNS) are discussed. In addition to the mechanisms of action, pharmacokinetics, interactions, indications and dosages as well as side effects are considered. Important data concerning the effect and tolerability of anticonvulsant drugs can be obtained from controlled studies. In comparison to drugs of the first generation (phenobarbital [PB], primidon [PRD], phenytoin [PHT], carbamazepine [CBZ] and valproic acid [VPA]) the potential for interactions and side effects due to enzyme induction or inhibition is reduced by most of the anticonvulsant drugs of the second generation. New anticonvulsant drugs increase the spectrum of treatment and represent further steps with regard to the optimization of an individual therapy of the epilepsies.

Negative Effects of Antiepileptic Drugs on Mood in Patients with Epilepsy

With the introduction of several new antiepileptic drugs into clinical practice, renewed attention has been focussed on treatment-emergent adverse effects, including mood disorders. There are several possible causes of psychiatric disorders in patients with epilepsy, including antiepileptic drugs, and it is often difficult to determine whether psychopathological manifestations, especially depressive symptoms, are due to drug therapy or to multiple other factors. Assessment of the negative effects of antiepileptic drugs on mood should always consider all potential factors. Case series, audits and open observational studies can identify psychopathological features, case-control studies are useful for identifying the endophenotypes of patients at risk of adverse effects on mood, and controlled clinical trials give good estimates of incidence of such effects, adjusted for the spontaneous occurrence of symptoms. The barbiturates, vigabatrin and topiramate show greater associations with the occurrence of depressive symptoms than other antiepileptic drugs, presenting in up to 10% of all patients, but even more so in susceptible patients. Data on zonisamide are scarce but it seems that mood disorders may occur in approximately 7% of patients who are receiving high dosages of this drug. In most cases, the use of monotherapy, with slow titration schedules, can significantly reduce the incidence of mood disorders. Tiagabine, levetiracetam and felbamate present an intermediate risk, with prevalence of depression of about 4% or lower. Phenytoin, ethosuximide, carbamazepine, oxcarbazepine, gabapentin, sodium valproate, pregabalin and lamotrigine are all associated with low risks for depression (<1%), and several of these antiepileptic drugs seem to have a positive effect on mood. Antiepileptic drugs can negatively affect mood and behaviour by different mechanisms: potentiation of GABA neurotransmission, folate deficiency, pharmacodynamic interactions with other antiepileptic drugs in polytherapy regimens, forced normalisation. Individuals with a personal or family history of depression should be carefully followed after initiation of therapy with a new antiepileptic drug, especially if structural brain abnormalities such as hippocampal sclerosis are present.

Psychopharmacology of topiramate: from epilepsy to bipolar disorder

Topiramate (TPM) is one of the novel antiepileptic drugs and exhibits a wide range of mechanisms of action. Efficacy of TPM has been demonstrated in partial-onset seizures and primary generalized seizures in adults and children, as both monotherapy and adjunctive therapy. More recently, TPM has been proposed as an add-on treatment for patients with lithium-resistant bipolar disorder, especially those displaying rapid-cycling and mixed states. This paper reviews the multiple mechanisms of action and the tolerability profile of TPM in the light of its therapeutic potential in affective disorders. Studies of TPM in bipolar disorder are evaluated, and the efficacy and tolerability issues as a mood stabilizing agent are discussed.

Pharmacokinetics, toxicology and safety of lamotrigine in epilepsy

Optimisation of pharmacotherapy for epilepsy requires consideration of the impact of drug metabolism and toxicology on the therapeutic profiles and clinical use of antiepileptic drugs (AEDs). This review discusses the pharmacokinetics and toxicology of the AED lamotrigine, and considers the implications of these data for optimising its use in the management of epilepsy. Lamotrigine has good absorption, minimal plasma protein binding and linear pharmacokinetics. Partly because of these properties, frequent dosing adjustments are generally unnecessary, and therapeutic monitoring is not required under most circumstances. Lamotrigine is not associated with clinically significant neurological, cognitive, metabolic, hepatic or reproductive endocrine toxicity. Like other AEDs, including carbamazepine and phenytoin, lamotrigine has been associated with serious rash. With some exceptions, lamotrigine has relatively few clinically relevant drug interactions, a characteristic important in reducing safety risks, especially among patients who require polytherapy. The clinical impact of pharmacokinetic interactions between lamotrigine and enzyme-inducing AEDs or valproate can be minimised by adhering to recommended dose-escalation schedules with demonstrated reliability in clinical trials and clinical practice. Likewise, adhering to recommended dosing guidelines can minimise the risk of lamotrigine-associated rash. The pharmacokinetic, toxicology and safety profiles of lamotrigine make the drug suitable for use across a spectrum of patients with epilepsy.

The Neuropsychology of Recurrent Headache

Headache is recognized as one of the most prevalent neurological disorders, and is the most frequently reported symptom following injury to the head, brain, or neck. Although studies of central nervous system abnormalities in headache sufferers have emerged in recent years, less is known about the associated functional impairments. The research literature addressing neuropsychological consequences of headache has been far from conclusive. Migraine has been most extensively studied, with some consistent evidence of subtle but potentially significant changes in cognition occurring during and between migraine episodes. It also appears likely that migraine patients with aura experience more neuropsychological deficits than those without aura. While the literature devoted to understanding the neurocognitive profile of migraine sufferers is growing, much less research has addressed the neuropsychology of tension-type headache and posttraumatic headache (PTHA). There is some suggestion of poorer neuropsychological function in tension-type headache than controls, but the evidence is inconclusive. The PTHA population is highly varied in degree and location of trauma, preexisting headache condition, and other injury-related variables, allowing little generalization across studies. This paper summarizes research regarding the cognitive symptoms associated with migraine, tension-type headache, and PTHA, provides an overview of the cognitive side effects of headache medications, and addresses clinical implications and priorities for future research.

The role of hippocampal sclerosis in antiepileptic drug-related depression in patients with epilepsy: A study on levetiracetam

OBJECTIVE

Hippocampal sclerosis (HS) has been described as a relevant factor for the development of topiramate-related depression and cognitive deficits. The aim of our study was to clarify whether patients with temporal lobe epilepsy (TLE) and HS were also at risk during therapy with levetiracetam (LEV).

METHODS

Data of 156 patients was analysed: 78 with TLE and HS and 78 with TLE and normal MRI matched for age, starting dose and titration schedule of LEV. Patients were selected from a population of consecutive patients started on LEV between 2000 and 2002.

RESULTS

No differences were observed in prevalence of cognitive adverse events and depression between the two groups.

CONCLUSIONS

LEV treatment is not associated with cognitive adverse events and depression in patients with hippocampal sclerosis.

Functional MRI reveals declined prefrontal cortex activation in patients with epilepsy on topiramate therapy

Functional magnetic resonance imaging of covert word generation was used to examine brain activation abnormalities associated with topiramate-induced cognitive language impairment in patients with epilepsy. Compared with a control epilepsy group, in the topiramate-treated group, there was significantly less activation in the language-mediating regions of the prefrontal cortex; the topiramate group also had significantly lower neuropsychological language scores. These findings suggest that topiramate has a critical effect on the cerebral neural systems that mediate expressive language.

Topiramate and its clinical applications in epilepsy

Topiramate, a derivative of the monosaccharide d-fructose, has shown a wide spectrum of antiepileptic efficacy in both animal models and clinical trials. Multiple putative mechanisms of action include voltage-sensitive sodium channel blockade, calcium channel inhibition, increase of potassium conductance, GABA-mediated chloride current increment, glutamate-mediated neurotransmission inhibition and carbonic anhydrase isoenzyme inhibition. In general, the clinical response is maintained in the long-term. The most common side effects include somnolence, fatigue, headache, psychomotor slowing, confusion, difficulty with memory, impaired concentration and attention, speech and language problems and weight loss. If slowly titrated and used at a low-to-medium dosage, it is well tolerated and offers a valid therapeutic option, the relevance of which is comparable to that of the most widely used 'old' antiepileptic drugs. As it is not yet wholly clear which specific epilepsy syndromes may benefit most from topiramate with respect to other drugs, more accurate indications for initial monotherapy would require syndrome-oriented trials and more clinical experience.

Cognitive side effects of anti-epileptic drugs

In recent years several new anti-epileptic drugs have been introduced, also for the treatment of childhood epilepsy. A major concern is their effect on learning and cognitive development. Testing the genuine effects on cognition of the anti-epileptic drugs is methodologically not easy. At this moment there are very few controlled trials that systematically examine the cognitive side effects of anti-epileptic drugs in childhood epilepsy. The available data indicate that the newer anti-epileptic drugs have a safe cognitive profile when prescribed correctly at the right dose and in monotherapy. Possible negative effects are mainly found for speed of processing and attention processes. As these processes are important instruments in every day learning and cognition, it is necessary to test these newer anti-epileptic drugs in well designed studies and in specific childhood epilepsy syndromes.

Cognitive functioning in bipolar patients receiving lamotrigine: preliminary results

Despite the increasing use of lamotrigine (LTG) in bipolar disorder, little is known about its impact on cognition in bipolar patients. Therefore, we have evaluated 33 bipolar I and II patients on cognitive measures (verbal memory, attention, executive functions) while receiving either LTG (n = 15) or another anticonvulsant (carbamazepine or valproate; n = 18). Patients receiving LTG were generally diagnosed as having bipolar II disorder, had experienced more depressive episodes but a lesser number of hospitalizations, and had better performance than the patients receiving carbamazepine or valproate on the verbal fluency task. A moderate effect size also suggests that both groups may differ on the immediate verbal memory test (California Verbal Learning Test). These preliminary results suggest a safer neurocognitive profile of LTG on bipolar patients, as compared with other anticonvulsants.

Subjective preference for lamotrigine or topiramate in healthy volunteers: relationship to cognitive and behavioral functioning

OBJECTIVE

Outcomes research emphasizes patient self-assessment and preferences in optimizing treatment. We previously showed that lamotrigine produces significantly less cognitive and behavioral impairment compared with topiramate. In the current study we extend these observations to subject self-report of preference for lamotrigine or topiramate independent of potentially confounding effects of seizures or seizure control. Additionally, drug preference was related to effects of lamotrigine and topiramate on objective neuropsychological tests as well as self-perception on behavioral instruments.

METHODS

Thirty-seven healthy volunteers completed a double-blind, randomized crossover design incorporating two 12-week treatment periods of lamotrigine and topiramate each titrated to a dose of 300 mg/day. Evaluation of 23 objective neuropsychological and 15 subjective behavioral measures occurred at four times: pretreatment baseline, first treatment, second treatment, and posttreatment baseline. Preference for lamotrigine or topiramate was assessed, while blinding was maintained, at the final study visit when each subject was asked which drug he or she would prefer to take.

RESULTS

A large majority (70%) preferred lamotrigine, 16% stated preference for topiramate, and 14% had no preference (drugs equivalent). Consistent with preference, those preferring lamotrigine performed better on 19 of 23 objective and 13 of 15 subjective behavioral measurements while on lamotrigine. Inconsistent with preference, subjects preferring topiramate performed better on 19 of 23 objective and 9 of 15 subjective behavioral measures while on lamotrigine. Topiramate preference also did not correlate with IQ, serum concentration, body mass index, age, or gender. Topiramate preference did relate to responses on the Profile of Mood States.

CONCLUSION

Lamotrigine was preferred by the majority of subjects, congruent with objective neuropsychological and subjective behavioral measures. In contrast, for those stating a preference for topiramate the results on objective neuropsychological measures were impaired while fewer complaints were noted on the Profile of Mood States. This suggests that preference for topiramate may be determined by an effect on mood.

Older adults with epilepsy demonstrate cognitive impairments compared with patients with amnestic mild cognitive impairment

Little is known about the cognitive effects of chronic epilepsy in older adults. To better characterize cognitive impairment in seniors with epilepsy, we compared cognitive performance of 26 seniors with epilepsy with that of 26 well-matched patients with mild cognitive impairment (MCI) and 26 well-matched healthy older adults. Participants completed neuropsychological testing with the Dementia Rating Scale (DRS), Logical Memory, and CFL Word Fluency. There were no significant demographic group differences, although seniors with epilepsy had higher self-reported depression. Seniors with epilepsy performed below controls on virtually all neuropsychological tests, and performed below patients with MCI on DRS Total score, Initiation/Perseveration, and CFL Fluency. Seniors with epilepsy on antiepileptic drug (AED) polytherapy had the most severe cognitive deficits, whereas seniors with epilepsy on AED monotherapy were comparable to cholinesterase inhibitor-naïve patients with MCI. This study emphasizes the clinical importance of cognitive impairment in seniors with epilepsy and highlights the need for future studies addressing causes and treatment of cognitive impairment.

Is there any correlation between severity of epilepsy and cognitive abilities in patients with temporal lobe epilepsy?

Frequent refractory seizures may cause cognitive deterioration when they present at an early age, especially in infants. The findings of previous studies designed to examine the impact of repetitive seizures on cognition in adolescents and adults, however, have shown wide variation. We analyzed the data of neuropsychological evaluations of patients before they underwent temporal lobe resection because of refractory seizure disorder in our institution from 1998 to 2001. Forty-four consecutive patients aged 12-48 years underwent a comprehensive neuropsychological evaluation that included a battery of selected visual and verbal memory tests. Statistical analysis revealed no significant correlation between disease-related parameters, such as age of onset, duration of active disease, estimated cumulative number of complex partial seizures and secondarily generalized seizures, and the results of neuropsychological tests. These findings support the hypothesis that factors other than repetitive seizures are responsible for cognitive dysfunction among adolescents and adults.

Cognitive and behavioral effects of lamotrigine and topiramate in healthy volunteers

BACKGROUND

The relative cognitive and behavioral effects of lamotrigine (LTG) and topiramate (TPM) are unclear.

METHODS

The authors directly compared the cognitive and behavioral effects of LTG and TPM in 47 healthy adults using a double-blind, randomized crossover design with two 12-week treatment periods. During each treatment condition, subjects were titrated to receive either LTG or TPM at a target dose of 300 mg/day for each. Neuropsychological evaluation included 17 measures yielding 41 variables of cognitive function and subjective behavioral effects. Subjects were tested at the end of each antiepileptic drug (AED) treatment period and during two drug-free conditions (pretreatment baseline and 1 month following final AED withdrawal).

RESULTS

Direct comparison of the two AEDs revealed significantly better performance on 33 (80%) variables for LTG, but none for TPM. Even after adjustment for blood levels, performance was better on 19 (46%) variables for LTG, but none for TPM. Differences spanned both objective cognitive and subjective behavioral measures. Comparison of TPM to the non-drug average revealed significantly better performance for non-drug average on 36 (88%) variables, but none for TPM. Comparison of LTG to non-drug average revealed better performance on 7 (17%) variables for non-drug average and 4 (10%) variables for LTG.

CONCLUSIONS

Lamotrigine produces significantly fewer untoward cognitive and behavioral effects compared to topiramate (TPM) at the dosages, titrations, and timeframes employed in this study. The dosages employed may not have been equivalent in efficacy. Future studies are needed to delineate the cognitive and behavioral effects of TPM at lower dosages.

Effects of Lamotrigine on field potentials, propagation, and long-term potentiation in rat prefrontal cortex in multi-electrode recording

Lamotrigine (LTG) is an anti-epileptic drug that is widely used clinically in various neuropsychiatric disorders. Although consensus is found on the general mode of action by LTG on voltage-gated sodium current, its effect on field potential, neuropropagation, and long-term potentiation, especially in prefrontal cortex (PFC), is still not understood completely. We investigated LTG effects on synaptic response in rat prefrontal cortical slice with the aid of a novel multi-electrode dish (MED64) system. The amplitude and propagation of field excitatory postsynaptic potentials (fEPSP), presynaptic fiber volleys (PrV) were expressed dimensionally in the MED64 system. Lamotrigine (3-100 microM) inhibited the amplitude and propagation of fEPSP and PrV in a concentration dependent manner. It exerted a predominant presynaptic action, as indicated by the increment in paired-pulse facilitation. Stimulating dependency with reduction fEPSP was seen in the presence of LTG at clinically relevant concentrations as well as with PrV, both in amplitude and propagation. In addition, the depression of PrV amplitudes in the presence of LTG showed a use-dependent fashion. As to LTP in PFC, it was not fEPSP amplitude but propagation reduced by LTG. In PFC, LTG exerts its use- and concentration-dependent inhibitory effect on presynaptic action and depresses fEPSP amplitude and propagation in a clinically relevant concentration. LTP was preserved in its fEPSP amplitude but not propagation in PFC in the presence of LTG.

Effects of antiepileptic drugs on attention as assessed by a five-choice serial reaction time task in rats

Patients with epilepsy can have impaired cognitive abilities. Antiepileptic drugs (AEDs) may contribute to the cognitive deficits observed in patients with epilepsy, and have been shown to induce cognitive impairments in healthy individuals. However, there are few systematic data on the effects of AEDs on specific cognitive domains. We have previously evaluated a number of AEDs with respect to their effects on working memory. The purpose of the present study was to evaluate the effects of AEDs on attention as measured by five-choice serial reaction time behavior in nonepileptic rats. The GABA-related AEDs triazolam, phenobarbital, and chlordiazepoxide significantly disrupted performance by increasing errors of omission, whereas tiagabine, valproate, and gabapentin did not. The sodium channel blocker carbamazepine increased errors of omission at relatively high doses, whereas the sodium channel blockers phenytoin, topiramate, and lamotrigine were without significant effect. Levetiracetam had no effect on attention. The disruptions produced by triazolam, phenobarbital, chlordiazepoxide, and carbamazepine were similar in magnitude to the effects of the muscarinic cholinergic receptor antagonist scopolamine. The present results indicate that AEDs can disrupt attention, but there are differences among AEDs in the magnitude of the disruption in nonepileptic rats, with drugs that enhance GABA receptor function producing the most consistent disruption of attention.

Ultimate success in epilepsy - the patient's perspective

Most people with epilepsy can live outwardly normal lives, but fear about impending seizures, driving restrictions, lack of independence, employment and social problems, medication-related adverse effects and the presence of cognitive or psychiatric complications are all concerns readily identified by affected individuals. While seizure control is the overriding goal of treatment, it is essential to realize the importance that patients place on other aspects of daily functioning. While many of the concerns identified by patients can only be managed by improved social support, others (e.g. neuropsychological impairment, medication-related adverse events, cognitive impairment, sleep disturbance) may be amenable to therapy (if available) or to the selection of a more appropriate antiepileptic drug. Each antiepileptic drug has a unique pharmacodynamic and tolerability profile. Awareness by the treating clinician of the pharmacological profile of each drug may help to minimize unwanted treatment-related effects and possibly improve the outcome of treatment from an epilepsy patient's perspective. Therefore, in order to achieve true treatment success, clinicians need to understand how individuals perceive their disorder and, where possible, address those factors that adversely affect patient quality of life. For the person with epilepsy, successful treatment involves beneficial effects on social, vocational and psychological function. This extends beyond seizure control to freedom from the fear associated with seizures, confidence in pharmacological therapy and improvements in health-related quality of life.

The use of monotherapy in patients with epilepsy: an appraisal of the new antiepileptic drugs

The use of antiepileptic drugs (AEDs) in monotherapy is always preferred to a polytherapy regimen because monotherapy facilitates drug compliance, is associated with a lower risk of toxicity, and is less costly. In addition, the yield of polytherapy to render a patient seizure-free when monotherapy regimens did not is relatively low. The available data derived from randomized controlled trials suggest that standard and new AEDs appear to display comparable antiepileptic efficacy but they differ with respect to tolerability and toxicity, which may be related to their pharmacodynamic and pharmacokinetic properties. New AEDs appear to be better tolerated than standard AEDs and to have fewer pharmacokinetic interactions than standard AEDs. In this article, we review the advantages of using AEDs in monotherapy in patients with newly diagnosed and refractory epilepsies, focusing on the individual properties of the drugs that may make them more appropriate in various patient groups.

Motor performance and behavior of immature rats are not compromised by a high dose of topiramate

The first step in a study of possible cognitive side effects of topiramate in immature rats is to determine if and how topiramate (TPM) influences motor ability and spontaneous behavior. We therefore studied the effects of TPM on motor performance of 12- and 25-day-old rats using age-appropriate tests. Spontaneous behavior in the open field was studied in 25-day-old animals only. TPM was administered intraperitoneally at 80 and/or 160 mg/kg; control rats were injected with solvent (dimethylsulfoxide). A battery of motor tests was conducted before and 1, 3, and 24 hours after administration; behavior in the open field was recorded 2 and 24 hours after TPM administration. The effects of TPM on motor performance were similar to those of solvent. A few differences were found only at the 3-hour interval in 12-day-old rats. Behavior in the open field was not impaired by TPM; on the contrary, an apparent anxiolytic effect was observed. Habituation (a decrease in locomotor activity during the 5-minute observation period), a form of simple nonassociative learning, was also not compromised by TPM. A single high dose of TPM resulted only in transient changes in motor performance. A possible anxiolytic effect observed in 25-day-old rats should be studied.

Safety and tolerability of emerging pharmacological treatments for bipolar disorder

OBJECTIVES

Over the past few years numerous new agents have been examined for their efficacy in bipolar disorder (BPD). New antiepileptic agents and atypical antipsychotics currently form the bulk of these emerging agents. As the armamentarium for treating BPD increases, it allows for the possibility of choosing drugs on the basis of their tolerability as well as their efficacy, rather than on efficacy alone.

METHODS

Efficacy data for newer antiepileptic drugs (lamotrigine, topiramate, gabapentin, oxcarbazepine) and atypical antipsychotics (olanzapine, clozapine, risperidone, quetiapine, ziprasidone, aripiprazole) are briefly reviewed. The article focuses on relative safety and tolerability of these agents.

RESULTS

In general, most of these newer agents have better side effect and tolerability profiles than older agents commonly used to treat BPD (lithium, valproate, carbamazepine); however, these must be weighed against efficacy demonstrated to date in randomized, controlled trials. Cognitive impairment is a concern with topiramate, weight gain and risk of diabetes with some of the atypical antipsychotic agents, and rash with lamotrigine.

CONCLUSIONS

Side effects of newer emerging agents for the treatment of BPD can be effectively managed and the risks reduced by instituting practical strategies early in management.

Antiepileptic Drugs and the Regulation of Mood and Quality of Life (QOL): The Evidence from Epilepsy

We review the literature on the influence of antiepileptic drugs (AEDs) on mood and quality of life in patients with epilepsy. Although many anecdotal reports cover a spectrum of AEDs, most of the controlled data have come from studies of carbamazepine and lamotrigine. Both of these compounds appear to have positive effects on mood, and these data parallel the effects noted in nonepilepsy populations. AEDs that are gamma-aminobutyric acid (GABA)ergic tend to have negative effects on mood, and an affective disorder is often noted as a treatment-emergent effect. It is speculated that the amygdala is an important anatomic structure in the cerebral circuits that regulate mood in affective disorders but also in epilepsy, and an effect of AEDs on such circuits aids mood stability in both populations of patients.

Effect of topiramate on cognitive function and activity level following neonatal seizures

Topiramate, an antiepileptic drug with a number of mechanisms of action including blockade of AMPA/KA receptor subtypes, was assessed as a neuroprotective agent following seizures. We administered topiramate or saline chronically during and following a series of 25 neonatal seizures. After completion of the topiramate treatment, animals were tested in the water maze for spatial learning and the open field for activity level. Brains were then examined for cell loss and sprouting of mossy fibers. Rats treated with topiramate performed significantly better in the water maze than rats treated with saline. Topiramate treatment also reduced the amount of seizure-induced sprouting in the supragranular region. There were no differences between topiramate- and saline-treated rats in activity level in the open field, swimming speed, or weight gain. These findings show that long-term treatment with topiramate after neonatal seizures changes the long-term consequences of seizures and improves cognitive function.

Time Course of Adverse Events in Patients with Localization-related Epilepsy Receiving Topiramate Added to Carbamazepine

PURPOSE

To explore the time course of treatment-emergent adverse events (AEs) during topiramate (TPM) adjunctive therapy.

METHODS

Post hoc analyses were performed by using data from a large (264 subjects) multicenter, double-blind, placebo-controlled trial in which 200 mg/day TPM was added to carbamazepine (CBZ) with or without another antiepileptic drug (AED) in adults with treatment-resistant partial-onset seizures. The daily incidence and mean duration of the most common (> or =5% incidence) AEs were calculated for patients completing the 12-week study.

RESULTS

The daily incidence of somnolence, headache, loss of appetite, nervousness, fatigue, dizziness, upper respiratory tract infection, and vertigo peaked during titration and declined to rates similar to that of placebo after the target TPM dose had been reached. In contrast, the daily incidence of paresthesia increased during titration and was maintained for the study duration. Relatively few patients had cognitive symptoms (9% with TPM, 5% with placebo), but these were the most common AEs associated with treatment discontinuation. Patient/investigator reports of weight loss increased gradually over the course of the trial, corresponding with the pattern of change in weight measured at study visits.

CONCLUSIONS

This study demonstrates that most of the more common AEs with TPM adjunctive therapy are transient. Patients can be counseled that most AEs emerging when TPM is initially added to CBZ can be expected to diminish with continued therapy.

Efficacy and cognitive side effects of tiagabine and topiramate in patients with epilepsy

OBJECTIVE

Whereas the efficacy of the newer antiepileptic drugs (AEDs) is well established, there remain questions regarding their cognitive side effects. Therefore, we performed a comparative open randomized trial with TPM and TGB as add-on therapy, with particular consideration of cognition, mood, and health-related quality of life (HRQOL).

METHODS

Forty-one patients with refractory epilepsy were randomly assigned to one of the two treatment groups (TPM vs TGB) and received neuropsychological testing at baseline (T1), after titration (3 months, T2), and during the maintenance phase (another 3 months, T3). Tests included measures of intelligence, attention, working memory, episodic memory, language, and self-report questionnaires regarding mood and HRQOL. Twenty patients (8 TPM, 12 TGB) discontinued the trial for different reasons (no group difference).

RESULTS

Seizure outcome (intention-to-treat analysis) was comparably good in both groups (8.1% seizure free, 29.7% seizure reduction>50%). From baseline to after the titration paired sample t tests revealed significant deterioration in verbal fluency, language comprehension, working memory, and visual block tapping under TPM and a deterioration in verbal memory (delayed free recall) in the TGB group. These functions remained stable in the maintenance phase. Self-report measures initially indicated concerns about AED side effects in both groups and concerns about worse cognitive functioning and depression under TPM. In the maintenance phase the TGB group reported feeling a lack of energy, whereas patients on TPM demonstrated improvement on all QOLIE scales on a descriptive level.

CONCLUSION

This study demonstrates the comparable efficacy of TPM and TGB. Consistent with previous reports, TPM but not TGB appears to be associated with persistent negative cognitive side effects on frontal lobe-associated functions, the degree of which may be estimated by the fact that this effect was observed with a very small sample size. In contrast, in patients taking TPM, initially negatively affected HRQOL returns to baseline in the long run on a descriptive level. The latter finding may be interpreted in accordance with the observation that objective performance and subjective self-report under TPM can be dissociated.

Clinical experience with Topiramate to counteract neuroleptic induced weight gain in 10 individuals with autistic spectrum disorders

Children and adolescents with autistic spectrum disorders are treated with neuroleptics to limit behavioral disturbances such as aggression, hyperactivity and self-injury. They may experience substantial weight gain when undergoing treatment with atypical antipsychotics actually employed. Topiramate (TPM) is an antiepileptic medication that is being progressively demonstrating a wider spectrum of action, mainly as an agent for weight control and as a mood stabilizer. It was administered to a group of children and adolescents with autistic spectrum disorders with the aim of reversing weight gain. This is an open study over an observation period of 18 months of 10 children and adolescents, eight males and two females, mean age 13 years, SD+/-3.6, range 8-19 years with a diagnosis of autistic disorder or pervasive developmental disorder not otherwise specified according to DSM-IV. Starting dosage of TPM was 0.5 mg/kg followed by titration of 0.5 mg/kg on a weekly basis, up to 1-3 mg/kg/day as the maintenance dosage. Eight subjects were undergoing long-term treatment with risperidone, one with pimozide and one was temporarily not on antipsychotics. Six patients took TPM on a regular basis and four dropped out. Variable degrees of weight reduction were observed in four patients, two subjects showed weight increase. Behavioral adverse effects were observed in three patients causing rapid withdrawal of the medication. TPM should be used with caution in autistic spectrum disorders because this population has a high risk of behavioral disruption.

Reduced anesthetization during the intracarotid amobarbital (Wada) test in patients taking carbonic anhydrase-inhibiting medications

PURPOSE

Failure to show adequate anesthetization during the intracarotid amobarbital procedure (IAP or "Wada test") is a rare complication. After an unusually high rate of recent anesthetization failures, we sought to determine the frequency of reduced anesthetization and any common factors underlying these failures.

METHODS

We reviewed the records of all patients who underwent IAP tests through the UCLA Seizure Disorder Center between September 1999 and May 2002. Age, date, epileptogenic focus, radiologist, and current medications were all considered.

RESULTS

Of a total of 56 patients who underwent our intracarotid amobarbital examination, 11 (19.6%) showed either very rapid recovery (<or=1 min) or anesthetization failure. Of these, 10 (91%) of 11 were taking a medication with some carbonic anhydrase-inhibiting (CAI) properties (topiramate (TPM), n=7; zonisamide (ZNS), n=2; hydrochlorothiazide and furosemide, n=1 each). The only patient of 40 (2.5%) who was not taking any CAI drugs and showed an early IAP recovery (55 s) had recently discontinued TPM. IAPs performed on patients after weaning from TPM showed a correlation between length of drug discontinuation and duration of anesthesia effect.

CONCLUSIONS

Our data strongly suggest that recent failures of anesthetization during the IAP are associated with a possible interaction between amobarbital and medications possessing CAI properties. We suggest that the IAP be performed only after >/=8 weeks after discontinuation of such medications.

Pharmacological strategies in relieving neuropathic pain

The pharmacological treatment of neuropathic pain relies, to a large extent, on drugs belonging to a small number of defined classes. Opioids, tricyclic antidepressants, antiepileptic drugs and membrane stabilisers form the current basis of treatment. Varying levels of evidence support the use of individual members of these classes and overall show no indication that one class of drug, or individual drug has universal effectiveness. More refined knowledge of the modes of action of these agents used to treat neuropathic pain should lead to a more logical approach to the management of this difficult series of conditions. A number of drugs currently licensed for a different indication have recently had an analgesic effect in neuropathic pain attributed to them. In addition, a number of novel compounds are undergoing investigation and provide hope of dicovering more efficacious treatment options in the future.

Twenty Years of Pharmacology

During the past 20 years in pharmacology, a number of innovations have appeared that have resulted in significant changes in the drugs available for people with traumatic brain injury. Among the anticonvulsants, antidepressants, and antipsychotics, new drugs have appeared with fewer cognitive side effects. In these classes of drugs, as well as among central nervous system stimulants, once-daily or other sustained-release preparations have been introduced that make it considerably more likely that the patient will take his or her medication, with smaller fluctuations in drug levels as well. New drugs have also resulted in a greater number of medications for the clinician to choose from. The overall effect has been a dramatic change in pharmacology that has benefited people with traumatic brain injury.

Attention deficit disorder and epilepsy

Countless studies have demonstrated that patients with epilepsy have a significant increase in behavioral disturbances of all kinds, including hyperactivity and inattention. This finding has been demonstrated in studies utilizing observer questionnaires and behavior rating scales, neuropsychological test batteries, and standardized tests of attention such as continuous performance tests. Multiple factors must be considered in the evaluation of a child with epilepsy and hyperactivity or inattention. For instance, inattention could be due to subclinical seizures, undiagnosed learning disabilities, disturbed sleep as a result of a side effect of antiepileptic medication, or due to an attention deficit disorder. Electroencephalographic monitoring is helpful to distinguish between behavioral inattention and partial complex or absence seizures. Electroencephalographic monitoring can also assess subclinical spike frequency, which may affect attention and other aspects of cognitive functioning in various ways, even in the absence of clinical seizures. Most antiepileptic drugs do not adversely affect attention and behavior in therapeutic doses, with the exception of phenobarbital, gabapentin, and topiramate. Some antiepileptic drugs, such as lamotrigine and carbamazepine, may even have beneficial effects. The preponderance of evidence suggests that stimulants other than bupropion are safe and effective in the treatment of attention deficit disorder in children with epilepsy, although controlled studies of dextroamphetamine in this population are lacking. So far, atomoxetine has not been demonstrated to have any adverse effect in children with epilepsy.

Effects of antiepileptic drugs on working memory as assessed by spatial alternation performance in rats

Patients with epilepsy can have impaired cognitive abilities. Many factors contribute to this impairment, including the adverse effects of antiepileptic drugs (AEDs). However, there are few systematic data on the effects of AEDs on specific cognitive domains, such as working memory. The purpose of the present study was to evaluate the effects of AEDs on working memory as measured by delayed spatial alternation behavior in nonepileptic rats. The GABA-related AEDs triazolam and phenobarbital significantly disrupted performance, whereas tiagabine, valproate, and gabapentin did not. The sodium channel blockers carbamazepine and topiramate produced modest but significant disruption of performance, whereas the effects of lamotrigine were not significant and phenytoin produced a modest but significant improvement in performance but at doses that abolished responding in some animals. Levetiracetam had no effect on working memory. In contrast, ethosuximide significantly disrupted working memory. The disruptions produced by triazolam and phenobarbital were similar in magnitude to the effects of the muscarinic antagonist scopolamine. The present results indicate that AEDs can disrupt working memory, but there are differences among AEDs in the magnitude of the disruption that do not appear to be correlated with mechanism of action.

Effects of oxcarbazepine and phenytoin on the EEG and cognition in healthy volunteers

We studied the EEG and cognitive effects of oxcarbazepine (OXC) and phenytoin (PHT) using a double-blind, randomized, parallel-group design. Thirty-two healthy volunteers received a maximum of 1200 mg of OXC or 360 mg of PHT. EEG and cognitive testing were performed at baseline and after 12 weeks of treatment. For each subject and measure, test-retest Z scores were calculated from regression equations derived from 73 healthy controls. Twenty-six subjects completed the study. Both the OXC and PHT groups had significant slowing of the EEG peak frequency and increased relative theta and delta power. Differences between AEDs (antiepileptic drugs) were not significant. Significant cognitive effects were seen on 5 of 20 measures, primarily measures of motor speed and reaction time. Again, there were no significant differences between AEDs. The only significant difference between AEDs was for the POMS-Vigor scale, favoring OXC. The small sample size may have contributed to the lack of significant differences between AEDs.

Clinical, Cognitive, and Neurophysiologic Correlates of Short-Term Treatment with Carbamazepine, Oxcarbazepine, and Levetiracetam in Healthy Volunteers

BACKGROUND

The adverse effects of the antiepileptic drugs (AEDs) originally developed are well known, while those of the newer AEDs remain unclear.

OBJECTIVE

To investigate clinical, cognitive, and neurophysiologic effects of carbamazepine, oxcarbazepine, and levetiracetam in healthy volunteers.

METHODS

A double-blind crossover study was conducted in 10 volunteers. Eight-day treatment with carbamazepine, oxcarbazepine, levetiracetam, or placebo was administered in random order. Drug doses were titrated gradually to the daily target doses on day 7: carbamazepine 800 mg, oxcarbazepine 1200 mg, and levetiracetam 1500 mg. At baseline and at the end of each treatment period, participants underwent cognitive and neurophysiologic assessment. A washout period of 14 days between treatment periods was conducted.

RESULTS

More adverse events were self-reported with carbamazepine (63%) than the other treatments (oxcarbazepine 12%, levetiracetam 20%, placebo 5%; p < 0.001 between the 4 groups). Carbamazepine induced the greatest motor slowing (p = 0.002), followed by oxcarbazepine (p = 0.01). Levetiracetam left baseline motor speed unchanged. All AEDs increased attention span from baseline values as shown on the Stroop test. Quantitative electroencephalogram (EEG) analysis showed that carbamazepine significantly increased the delta–theta power and reduced the frequency of alpha rhythm; oxcarbazepine induced smaller changes than carbamazepine. Levetiracetam did not change any EEG measurements. On color visually evoked potential (VEP) tests, carbamazepine induced a constant slowing of P1 latency, while oxcarbazepine induced changes only after the blue–black pattern. All color VEP measures for volunteers receiving levetiracetam were almost unchanged.

CONCLUSIONS

After short-term treatment in healthy volunteers, carbamazepine induced major clinical and neurophysiologic changes. Oxcarbazepine was better tolerated than carbamazepine. Levetiracetam interfered least with clinical and neurophysiologic test results.

Cognitive profile of topiramate as compared with lamotrigine in epilepsy patients on antiepileptic drug polytherapy: relationships to blood serum levels and comedication

RATIONALE

This retrospective study was conducted to identify cognitive domains affected by topiramate (TPM), and to evaluate the role of blood serum levels of TPM and comedication in the etiology of TPM-induced cognitive impairment.

METHODS

Forty-two patients on AED polytherapy containing topiramate and a random sample of 42 patients with lamotrigine as the corresponding agent underwent extensive neuropsychological testing. Current blood serum levels of TPM were correlated with test scores.

RESULTS

Patients on TPM scored significantly worse in phonematic verbal fluency, memory spans, and working memory; language and memory function were not affected per se. In few cognitive domains, serum levels of TPM and performance were correlated before correction for multiple testing. Drug load of additional medication did not account for differences between or within groups.

DISCUSSION

Consistent with previous reports, patients on AED polytherapy including TPM display a cognitive pattern with specific impairment in executive functions. The severity of the cognitive side effects of TPM may be related to dosing to a certain extent, but this relationship may be disclosed only with larger sample sizes. Accordingly, TPM dosage does not appear to be a good indicator of TPM-related cognitive side effects in the individual patient.

Differential diagnosis and treatment of psychiatric disorders in children and adolescents with epilepsy

Behavioral problems, such as the inattentive form of attention-deficit hyperactivity disorder (ADHD), anxiety, and depression, are common in children and adolescents with epilepsy and especially associated with central nervous system damage, family dysfunction, and severe seizures. This article discusses the risk factors to be considered when focusing on the prevalence of behavioral problems, the family factors that influence their incidence, as well as the differential diagnosis of behavioral disorders commonly associated with epilepsy. It also considers the assessment of these behavioral disorders and their treatment with psychotherapy, education, and a variety of psychopharmacological agents.

Determining the effects of antiepileptic drugs on cognitive function in pediatric patients with epilepsy

The majority of children with epilepsy are of normal intelligence; however, a significant subset suffers from temporary or permanent cognitive impairment. Factors that affect cognitive function are myriad and include the neuropathology underlying the epilepsy, seizures, epileptiform activity, psychosocial problems, and antiepileptic drug side effects. Although cognitive impairment is often wrongly attributed to the effects of antiepileptic drugs, antiepileptic drugs do impair cognition in some children. Clinicians should be aware of the differential cognitive effects of antiepileptic drugs and should monitor cognitive function closely when adding or changing therapy. Based on published data from prospective, chronic dosing studies, phenobarbital and topiramate have the highest potential for causing cognitive dysfunction.

Comprehensive Care of the Epilepsy Patient-Control, Comorbidity, and Cost

Traditionally, control of seizures in patients with epilepsy is viewed as the most important clinical outcome. Yet, current antiepileptic drugs (AEDs) do not always achieve this. Around 30-40% of patients remain uncontrolled despite pharmacological intervention. Poor tolerability of AEDs is a large part of the problem and contributes as much to the overall effectiveness of therapy as efficacy. Comorbid conditions are present in many patients, and appropriate management of these can further improve seizure control and quality of life. Patients with epilepsy often experience--among other disorders--neuropsychological effects, migraines, and psychological problems (especially anxiety and depression). Sleep disturbances are also common and have been shown to contribute to the intractability of seizures in some patients. Many anticonvulsant treatments have the potential to improve--or in some cases worsen--these concurrent conditions, and these properties should therefore be considered in the total care of the patient. Finally, the costs of uncontrolled epilepsy are measured not only in terms of direct healthcare-related costs, but also in terms of lost productivity and opportunity. The indirect costs of epilepsy are substantial and account for 70-85% of total disease-related costs. Patients with uncontrolled seizures contribute disproportionately to healthcare costs, reinforcing the need for the development of newer AEDs with improved profiles of efficacy and tolerability, but with minimal adverse effects on behavior, cognition, and sleep.

Antiepileptic drugs and memory

Impaired memory is among the most common complaints of patients with epilepsy. Multiple factors contribute to memory impairment in patients with epilepsy. Thus, delineation of the effects of antiepileptic drugs (AEDs) on memory in clinical populations faces methodological difficulties. Further, subjective perception of memory problems by patients is influenced by mood. However, there is evidence from animal and healthy volunteer studies supporting an independent potential for AEDs to impair memory. Differential AED effects on memory have been observed, and AED effects may interact with focal brain lesions. Memory impairment from AEDs is a greater concern at the age extremes, although the effects of AEDs, especially the newer agents, have not been thoroughly studied in these populations. Well-controlled studies are needed to understand the underlying mechanisms and to further delineate the magnitude and relative effects of AEDs on memory.

Therapy for neurobehavioral disorders in epilepsy

Neurobehavioral disorders commonly affect patients with epilepsy. In addition to the behavioral changes during and immediately after seizures, the epileptogenic disorder of function often extends further into the postictal and interictal period. Cognitive impairments commonly affect attention, memory, mental speed, and language, as well as executive and social functions. Reducing seizure frequency and the antiepileptic drug burden can reduce these problems. Attentional deficits may respond to therapies for attention-deficit/hyperactivity disorder, but apart from patients with this comorbid disorder, their efficacy is unproven in other epilepsy patients. No effective therapies are established for other cognitive problems, but pragmatic, compensatory strategies can be helpful. Behavioral disorders include fatigue, depression, anxiety, and psychosis. Many of these disorders usually respond well to pharmacotherapy, which can be supplemented by psychotherapy. Cognitive and behavioral disorders can be the greatest cause of morbidity and impaired quality of life, often overshadowing seizures. Yet these problems often go unrecognized and, even when identified, are often undertreated or untreated.

SSRIs versus non-SSRIs in post-traumatic stress disorder: an update with recommendations

Post-traumatic stress disorder (PTSD) is a highly prevalent (7.8% lifetime rate) anxiety disorder with impairment in daily functioning, frequent suicidal behaviour and high rates of co-morbidity. Fortunately, PTSD is responsive to pharmacotherapy and psychotherapy. The selective serotonin reuptake inhibitors (SSRIs) are the most studied medications for PTSD, with the largest number of double-blind, placebo-controlled trials. Of the SSRIs, sertraline, paroxetine and fluoxetine have been the most extensively studied, with sertraline and paroxetine being US FDA-approved for PTSD. These studies have demonstrated that SSRIs are effective in short-term trials (6-12 weeks). Furthermore, continuation and maintenance treatment for 6-12 months decrease relapse rates. Besides being the most studied and effective drugs for PTSD, SSRIs have a favourable adverse effect profile, making them the first-line treatment for PTSD. If SSRIs are not tolerated or are ineffective, non-SSRIs should be considered. Serotonin-potentiating non-SSRIs, such as venlafaxine, nefazodone, trazodone and mirtazapine, have been evaluated in PTSD only in open-label and case studies. Because of their promising results and relatively good safety profile, they should be considered as second-line treatment. Monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants (TCAs) have both been evaluated in a small number of double-blind, placebo-controlled studies. The results have been inconsistent but promising. In the limited comparative studies, MAOIs appeared superior to TCAs but patients continued to have residual symptoms. These drugs have significant adverse effects, such as cardiovascular complications, and safety issues, such as ease of overdose. Therefore, TCAs and MAOIs should be considered as third-line treatment. Anticonvulsants have been evaluated in PTSD in open-label studies and results have been positive for carbamazepine, valproic acid, topiramate and gabapentin. A small double-blind, placebo-controlled study demonstrated efficacy of lamotrigine for PTSD. Anticonvulsants should be considered where co-morbidity of bipolar disorder exists, and where impulsivity and anger predominate. Bupropion (amfebutamone), a predominantly noradrenergic reuptake inhibitor, was ineffective in PTSD in an open-label study. Benzodiazepines were ineffective in a double-blind, placebo-controlled study despite encouraging case reports. They should be avoided or used only short term because of potential depressogenic effects, and the possibility that they may promote or worsen PTSD. Buspirone, a non-benzodiazepine anxiolytic, was found to be effective in PTSD only in open-label studies. Recently, atypical antipsychotics were as effective as monotherapy and as an augmenter to SSRIs in open-label/case studies and small double-blind, placebo-controlled trials; atypical antipsychotics should be considered in PTSD where paranoia or flashbacks are prominent and in potentiating SSRIs in refractory cases.

Efficacy and safety of levetiracetam in pediatric migraine

BACKGROUND

Headache is a frequent occurrence among children and adolescents. Chronic headaches can be severe and disabling, and require prophylactic treatment; however, additional data on the use of prophylactic medications for migraine in children are needed.

OBJECTIVE

To review the efficacy and safety of levetiracetam (Keppra) in pediatric patients with a history of recurrent headache.

DESIGN/METHODS

Data from 19 pediatric patients were retrospectively reviewed. The initial dose of levetiracetam was usually 125 or 250 mg twice daily, but varied depending upon clinical judgment.

RESULTS

Charts of 9 girls and 10 boys (mean age, 11.9 years) were reviewed. A variety of medications, including triptans, had been used before initiating treatment with levetiracetam. Mean headache frequency before treatment was 6.3 per month (standard deviation [SD], 3.8; confidence interval [CI], 4.4 to 8.1). Duration of headaches ranged from 0.25 to 8 years. Migraine (63.2%) and migraine with aura (15.8%) were the most common types of headache reported. Most patients (89.5%) had headaches that were severe. After treatment, the mean headache frequency decreased to 1.7 per month (SD, 2.7; CI, 0.4 to 3.0), representing a reduction compared with baseline (P <.0001). Levetiracetam eliminated headaches in 10 patients (52.6%), and 7 patients (36.8%) had less severe and less frequent headaches. Levetiracetam did not have an effect on headaches in 2 patients (10.5%). Mean duration of treatment with levetiracetam was 4.1 months. Doses ranged from 125 to 750 mg twice daily. Sixteen patients (84.2%) reported no side effects on levetiracetam. One patient experienced asthenia/somnolence and dizziness, and irritable, hyperactive, and hostile behavior led to discontinuation of levetiracetam in another patient. A third patient experienced irritability and moodiness that attenuated after 1 month of treatment and did not require discontinuation.

CONCLUSIONS

In this small retrospective review, levetiracetam was found to be generally well tolerated and appears to be a promising candidate for additional evaluation in well-controlled clinical trials of pediatric patients with migraine.

Daytime Sleepiness in Epilepsy Patients Receiving Topiramate Monotherapy

PURPOSE

Limited research has focused to date on objective neurophysiological evaluation of daytime sleepiness in patients treated with newer antiepileptic drugs (AEDs), especially when used as monotherapy. This study was aimed at assessing occurrence of daytime sleepiness in newly diagnosed, drug-naïve patients with partial epilepsy receiving initial topiramate (TPM) monotherapy.

METHODS

Daytime vigilance was assessed in 14 consecutive, newly diagnosed and never medicated adult patients with focal epilepsy, receiving monotherapy with TPM. At baseline and 2 months after slowly titrated therapy with TPM, 200 mg/day, patients underwent the Multiple Sleep Latency Test (MSLT), visual simple and choice reaction times (VRT), and self-rated their own degree of sleepiness with the Epworth Sleepiness Scale. A group of 14 age- and gender-matched healthy volunteers served as controls.

RESULTS

At baseline, mean daytime sleep latencies on the MSLT were comparable in patients and in controls. Two months after TPM monotherapy, MSLT scores did not significantly change in patients as compared with pretreatment values. Accordingly, subjective daytime sleepiness and VRTs, which were comparable in controls and in untreated patients at baseline, did not change in patients after TPM monotherapy.

CONCLUSIONS

Study results suggest that an initial short-course monotherapy with TPM, 200 mg/day, does not impair daytime vigilance in newly diagnosed adult patients with partial seizures.

Effects of topiramate on memory performance on the intracarotid amobarbital (Wada) test

We evaluated the effects of topiramate (TPM) on memory function in the intracarotid amobarbital (Wada) test in nine patients with mesial temporal lobe epilepsy (MTLE) whose antiepileptic drugs (AEDs) included TPM and compared their scores with those of 16 patients with MTLE on AEDs not including TPM. Sodium amobarbital was injected first into the hemisphere ipsilateral to the seizure focus and then into a contralateral site, and the patients were tested for naming and memorization. There was no statistical difference in percentage memory scores between the two patient groups following the contralateral injection. After the ipsilateral injection, however, TPM patients had significantly lower percentage memory scores compared with non-TPM patients (P < 0.02). We conclude that a possible adverse effect of TPM on memory performance should be considered when evaluating the Wada test memory scores of patients on TPM therapy.

Improvement in alertness and behavior in children treated with combination topiramate and vagus nerve stimulation

It has been reported that vagus nerve stimulation (VNS) improves behavior in children, whereas topiramate has a less clear effect. Three boys, aged 5-12 years, with generalized slow spike-wave discharges and refractory epilepsy, were treated with combination therapy of topiramate and VNS. All three had a significant reduction in seizures, but even more dramatic improvement in aggression, social interaction, and ambulation. The Cyberonics Patient Outcome Registry was subsequently queried and a beneficial effect of this combination therapy on behavior (specifically alertness) beyond that of VNS and other anticonvulsants was noted. This did not appear to be due solely to seizure reduction, which was observed only differentially at 12 months.