Efficacy and safety of topiramate in refractory epilepsy: a long-term prospective trial

The effects of topiramate in 15 patients with drug refractory partial epilepsy or Lennox-Gastaut syndrome were assessed in an open, add-on prospective study. After a follow-up of 14–21 months, six patients are still on topiramate (mean dosage 583 mg/day, range 400–800 mg/day), and nine have discontinued treatment because of adverse events (n=6), inefficacy (n=2) or poor compliance (n=1). Nine patients (69%) continued to have a 50% reduction in seizure frequency during the last two months of treatment, and one has been seizure-free for the last 19 months. The most common adverse events were somnolence, weight loss, mental slowing, fatigue, ataxia and irritability. Most of these events were reversible, but withdrawal of treatment was required in six cases as a result of ataxia (two patients), somnolence, metabolic acidosis, irritability or psychotic symptoms (one patient each). It is concluded that topiramate is a valuable agent for the long-term management of refractory epilepsy.

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Sommario Gli effetti di topiramato utilizzato in aggiunta alla terapia preesistente sono stati valutati nell'ambito di uno studio prospettico in aperto in 15 pazienti farmacoresistenti affetti da epilessia parziale o sindrome Lennox-Gastaut. Dopo un follow-up di 14–21 mesi, 6 pazienti sono tuttora in trattamento (posologia media di topiramato 583 mg/die, range 400–800 mg/die), mentre 9 hanno sospeso il farmaco a causa di eventi avversi (n=6), inefficacia (n=2) o scarsa compliance (n=1). Nove pazienti (69%) continuavano a presentare una riduzione di almeno il 50% della frequenza delle crisi durante gli ultimi 2 mesi di trattamento e un paziente è libero da crisi da 19 mesi. Gli eventi avversi più frequenti erano costituiti da sonnolenza, calo ponderale, rallentamento mentale, astenia, atassia e irritabilità. La maggior parte di questi eventi è risultata reversibile, ma in 6 pazienti si è resa necessaria la sospensione del trattamento a causa di atassia (2 casi), sonnolenza, acidosi metabolica, irritabilità e sintomi psicotici (1 caso ciascuno). Sulla base di questi dati, il topiramato può essere ritenuto un utile presidio nel trattamento a lungo termine dell'epilessia farmacoresistente.

     

Efficacy and safety of topiramate in refractory epilepsy of childhood: long-term follow-up study

This study aimed to evaluate the long-term efficacy and safety of topiramate in treating children with drug-resistant epilepsy. A multicentric, retrospective, open-label, add-on study was undertaken of 277 children (mean age 8.4 years; range 12 months to 16 years) affected by drug-resistant epilepsy. The efficacy was rated according to the seizure types and epilepsy syndrome. After a mean period of 27.5 months of treatment (range 24-61 months), 11 patients (4%) were seizure free and 56 (20%) had more than 50% reduction in seizure frequency. The efficacy of topiramate treatment was noted in localization-related epilepsy and in generalized epilepsy. In addition, in a group of 114 patients, we compared the initial efficacy (evaluated after a mean of 9 months of follow-up) and the retention at a mean of 30 months of topiramate with regard to loss of efficacy (defined as the return to the baseline seizure frequency). Fifty-five (48%) of 114 patients were initial responders. The retention at a mean of 30 months was 23 of 114 patients (20%), 4 of whom (3.5%) were still seizure free. A loss of efficacy occurred in 32 of the 55 initial responders (58%). It was prominent in patients with generalized epilepsy, such as symptomatic infantile spasms and Lennox-Gastaut syndrome, as well as in those with Dravet syndrome. By contrast, a well-sustained topiramate efficacy was noted among patients with localization-related epilepsy. Globally, adverse events were observed in 161 patients (58%) and were mainly represented by weight loss, hyperthermia, sedation, and nervousness, which, in most cases, disappeared after slowing titration or reducing the dosage of the drug. In conclusion, the present long-term study confirms that topiramate represents a useful drug effective in a wide range of seizures and epilepsy syndromes. Moreover, preliminary data seem to suggest that the efficacy of topiramate, when evaluated in the long-term perspective, is more sustained in localization-related epilepsy than in generalized epilepsy.     

The efficacy and side effects of topiramate on refractory epilepsy in infants and young children: a multi-center clinical trial.

OBJECTIVES: This study has been conducted to assess the efficacy and safety of topiramate in refractory epilepsies in infants and young children. METHODS: A prospective clinical trial was performed in three tertiary care hospitals, on 47 children aged 6-60 months with refractory epilepsy. Topiramate was added to at least two baseline anti-epileptic drugs. The efficacy was rated according to seizure type, frequency and duration. RESULTS: Children with refractory epilepsy were classified according to their clinical, neuro-imaging, and neurophysiological profile into infantile spasms (IS) (9 cases, 19%), Lennox-Gastaut syndrome (LGS) (25 cases, 53%) and other epilepsies (13 cases, 28%). Children were also classified into cryptogenic and symptomatic epilepsy. Topiramate was introduced as add-on therapy in a daily dose of 1 mg/kg/day for 2 weeks, followed by increments of 1-3 mg/kg/day at 2-week intervals, up to a maximum of 10 mg/kg/day. After a minimum treatment period of 6 months, 28 (60%) of the children had a satisfactory response (completely seizure free, or more than a 50% seizure reduction). The remaining 19 children (40%) had an unsatisfactory response (50% or less reduction in seizure frequency, no change or increased seizure frequency). Topiramate appeared to be equally effective in infantile spasms, Lennox-Gastaut syndrome and children with other types of epilepsy, with no significant difference between those with a satisfactory and an unsatisfactory response (p=0.089). There was also no significant difference in response between patients with cryptogenic and symptomatic epilepsy (p=0.360). Mild to moderate adverse effects, mainly somnolence, anorexia and nervousness, were present in 25 (53%) of children. One of the children developed hypothyroidism. CONCLUSION: Although the long term safety and possible adverse effects of topiramate have not been fully established in infants and young children, this study has shown that it is a useful option for children with frequent seizures unresponsive to standard anti-epileptic drugs.     

Heart rate variability in children with refractory generalized epilepsy.

OBJECTIVE: Repetitive seizures can alter the regulation of cardiac activity by the autonomic nervous system (ANS), and ANS dysregulation is thought to be associated with higher morbidity and mortality in epileptic patients, especially from sudden unexpected death. Few studies of interictal dysregulation of cardiac activity in children with epilepsy have been performed. In this study we characterize heart rate variability (HRV) in children with refractory generalized epilepsy. METHODS: Fifteen male and 15 female children, average age = 10.9+/-0.6 years, all with refractory generalized epilepsy were enrolled into the study group. A control group consisted of 15 males and 15 females with average age = 10.6+/-0.6 years. A lead I ECG was recorded for 5 min in the interictal period during daylight hours from each subject while awake. Frequency-domain analysis of HRV was performed using a non-parametric method of fast Fourier transformation. Changes of HRV were categorized into high frequency power (HF; 0.15-0.45 Hz), which represented vagal regulation, and low frequency power (LF; 0.04-0.15 Hz). LF/(HF+LF) expressed in normalized units (LF%) was considered to mirror sympathetic regulation. RESULTS: There were significant reductions in RR, LF, and HF in the study group when compared to controls. There was no significant difference in LF% between the two groups. CONCLUSIONS: We postulate that the lower HRV in our patients results from parasympathetic or vagal reduction. This suggests that decreased HRV in epileptic children occurs by a different mechanism than in adults with epilepsy.     

Long-term efficacy and tolerability of topiramate as add-on therapy in refractory partial epilepsy: An observational study

Purpose:   To evaluate the long-term efficacy and tolerability of topiramate (TPM) as add-on therapy in patients with refractory partial epilepsy.
Methods:   This is a retrospective, single-center, long-term observational study. Patients fulfilling the criteria of medical intractability proposed by Berg et al. were entered into the study if they were newly prescribed TPM as add-on therapy between January 2000 and June 2002. The usual starting dosage of TPM was 50 mg/day and optimal-dose adjustments were made according to individual clinical responses. Efficacy and tolerability were analyzed every year during 5-year follow-up in the "intention-to-treat (ITT) population." Retention rate was estimated by Kaplan-Meyer analysis.
Results:   A total of 125 patients were included in the study and 107 patients (85.6%) were followed for 5 years. Retention rate was 87.2% at 1 year and 64% at 5 years. At the end of 5 years, the median seizure frequency reduction rate was 69.0% and responder rate was 43.2% in the ITT population. Cumulative seizure-free rate (SFR) was 30.4% and the terminal 1-year SFR was 12.8% in the ITT population (20.0% in completers) at 5-year follow-up. Adverse events (AEs) occurred in 39.2% of patients, including significant AEs leading to antiepileptic drug (AED) withdrawal in 14.4%. The most common AEs were anorexia (16.0%), weight loss (10.4%), and gastrointestinal symptoms (8.8%). Concomitant AEDs were reduced in 25.0% of the completers.
Discussion:   Low-dose and slow-dose escalation of TPM in add-on therapy for patients with refractory partial epilepsy is effective and well tolerated in long-term, individualized clinical practice.     

A pooled analysis of adjunctive topiramate in refractory partial epilepsy

OBJECTIVES: To evaluate the impact of different dosages of topiramate (TPM) add-on to stable antiepileptic therapy for refractory partial epilepsy in adults. MATERIAL AND METHODS: Pooled intention-to-treat analysis of six similarly designed double-blind, placebo-controlled trials, including 481 patients treated with doses of TPM 200, 400, 600 and 800 mg/day, and 265 patients receiving placebo. RESULTS: Seizures were reduced by >/=50% from baseline in 41% of TPM-treated patients and 15% of placebo-treated patients (P < 0.001); 5 and 0.8%, respectively, were seizure-free (P < 0.003). TPM was significantly better than placebo regardless of gender, age, baseline seizure rate as well as number and type of concomitant antiepileptic drugs. Efficacy was statistically significant in favour of TPM at all dose levels: at least 50% seizure reduction was achieved in 40% of patients with 200 mg, 41% with 400 mg, 44% with 600 mg and 41% with 800 mg TPM when compared with 15% with placebo (P 相似文献   

Use of topiramate in localization-related epilepsy in children

Topiramate has been shown to be safe and effective in refractory partial epilepsy in children. Pharmacokinetic studies show that the clearance of topiramate is greater in children than in adults; therefore, higher doses may be needed in children than adults. It is generally well tolerated, except for cognitive dysfunction. Weight loss and the risk of renal stones can be significant in some cases. However, when compared with other anticonvulsant medications, topiramate has few serious idiosyncratic reactions such as rash, hematologic reactions, and hepatotoxicity.     

Treatment of refractory primary generalized epilepsy

Although complete seizure control is achievable in 54% to 82% of patients with primary (idiopathic) generalized epilepsy syndromes, there remains a substantial group with inadequate control. Valproate has been considered the drug of choice but is not always effective and might produce unacceptable adverse effects. Several newer drugs have emerged as potential alternatives to valproate, including lamotrigine, levetiracetam, topiramate, and zonisamide. Sedation and tolerance limit the utility of benzodiazepines. For severely refractory patients, drug combinations, vagal nerve stimulation, or felbamate might be considered. Only a few controlled clinical trials have been conducted for these syndromes; more are needed.     

The long-term use of felbamate in children with severe refractory epilepsy.

The aim of the study was to assess the efficacy and safety of felbamate (FBM) as add-on therapy in pediatric patients with severe uncontrolled seizures during a 3-year follow-up. Thirty-six patients were enrolled between February 1994 and February 1997. Patients suffered from partial epilepsy (n=13), Lennox-Gastaut syndrome (LGS) (n=9), infantile spasms (IS) n=8 or other forms of generalized epilepsy (n=6). FBM was titrated weekly from 15 up to 45 mg/kg. By February 1995, all patients had hematological and biochemical monitoring prior to FBM therapy and every 15 days during the study. The results achieved at different treatment durations were analyzed. Overall efficacy measured as > or =50% reduction in seizure frequency varied during follow-up: 69% at 3 months, progressively decreasing to 66% at 6 months, to 47% at 1 year and 41% of the initial cohort at the end of the study. Most frequent side effects were anorexia, weight loss, urinary retention, somnolence, nervousness and insomnia. FBM controlled a broad spectrum of otherwise refractory seizures. Best results were obtained against simple partial seizures with or without secondary generalization, tonic and atonic seizures. A substantial improvement in seizure control was maintained in one-third of the patients for at least 3 years.     

Corpus callosotomy in refractory idiopathic generalized epilepsy

RATIONALE: A small percentage of patients with idiopathic generalized epilepsy (IGE) do not respond to medical therapy. Generalized tonic-clonic (GTC) seizures are especially debilitating and can be associated with severe injuries. The benefit, safety and effect of corpus callosotomy (CC) in patients with IGE have not been studied. METHODS: We reviewed patients with presumed IGE who underwent CC between 1991 and 2000. Criteria for selection included history, examination, brain imagining, interictal and ictal EEG. All patients had refractory and debilitating tonic-clonic seizures (GTCS) and had failed four or more antiepileptic drugs. Seizure frequency was calculated per month over the last year and pre-operative baseline was compared to last follow-up using paired t-tests. IQ, executive function, language and verbal, non-verbal memory and quality of life (QOL) was compared before and after surgery. Serial EEGs after surgery were reviewed. RESULTS: There were nine patients (seven men), mean age 37.9 (range: 22-49), mean IQ 87.3 (range: 75-107). All had anterior CC. Mean follow-up time was 5.4 years (range: 0.6-10.3 years). One patient died from sudden death in epilepsy 9 months after surgery. There was a significant reduction of GTC seizures from 6.3 to 1.1 (p<0.005). Four patients had more than 80% and eight more than 50% reduction. Of five patients with absence seizures, two became seizure free and one had more than 80% reduction and two worsened slightly, and of three with myoclonic seizures one had more than 90% reduction. One patient had completion of the CC with improvement of myoclonus and absence seizures, but not of GTC seizures and suffered a disconnection syndrome. Another had right frontal focal resection without improvement after new seizures of focal onset. Cognitive testing showed a good outcome (improved or no change) in all cognitive domains. Post-surgical EEG showed new focal slowing and sharp waves. There was no change in QOL. CONCLUSION: CC can be effective in reducing GTC, absence and myoclonic seizures in patients with refractory IGE. These findings suggest that interhemispheric communication of the cerebral cortices plays an important role in the generation of seizures in IGE. Anterior CC appears safe while complete callosotomy has a risk of disconnection syndrome.     

托吡酯添加治疗难治性癫痫的临床研究

目的观察托吡酯作为添加药物治疗难治性癫痫的疗效、用药方法、剂量及副作用.方法采用开放性试验的方法对50例难治性癫痫患者(其中成人30例,小儿20例)进行添加托吡酯治疗,观察其疗效.结果托吡酯作为添加药物治疗难治性癫痫,总有效率达58%,22%的患者发作停止.对复杂部分性发作有效率达69%,对其他发作类型亦有一定疗效.本组中成人的疗效好于儿童.平均有效剂量成人为(123.9±47.9)mg/d,小儿为(3.6±1.2)mg·kg     

Efficacy of topiramate in children with refractory status epilepticus

PURPOSE: Status epilepticus (SE) is a life-threatening medical condition associated with significant morbidity and mortality that requires urgent medical intervention. Although several agents are available to treat SE, they occasionally fail to abort seizure activity. Topiramate (TPM) was anecdotally reported to be effective in adult patients with refractory SE. In this study, we evaluated the efficacy of TPM administered to children with this condition. METHODS: We retrospectively reviewed the pediatric SE database at the University of Michigan Medical Center and identified three children with refractory SE who were treated with TPM. Those children failed to respond to treatment with benzodiazepines, phenytoin, phenobarbital, midazolam, or pentobarbital. Additional treatment with TPM was administered by nasogastric tube. All patients were continuously monitored by 21-channel digital EEG machines, and the diagnosis of SE was made by a board-certified neurophysiologist. RESULTS: The ages of the three children were 4.5 months, 34 months, and 11 years. TPM was initiated at 2 mg/kg/day in two children and at 3 mg/kg/day in the third. The status was terminated in all three children within 24 h of maintenance therapy with TPM at 5-6 mg/kg/day. CONCLUSIONS: These results support the potential efficacy of TPM for children with refractory SE. Larger prospective series are needed to confirm those results.     

Amantadine hydrochloride for refractory generalized epilepsy in adults

Amantadine hydrochloride has been shown in several open studies to benefit children with refractory generalized epilepsy. We used amantadine as adjunctive therapy in 10 adolescents and adults with generalized tonic-clonic, myoclonic, or absence seizures refractory to therapeutic levels of valproate, carbamazepine, phenytoin, and benzodiazepines. Seven patients were men and 3 were women aged 18-29 years, and 8 of 10 patients were mentally retarded. All patients had generalized epileptiform paroxysms on EEG, with generalized or absence seizure recorded in 9. Five patients had both absence and tonic-clonic seizures, and 2 had all three seizure types. Amantadine was added to the existing regimens in weekly increments to 400 mg/day. Two patients had greater than 90 per cent seizure reduction, both with vomiting and somnolence. Two patients had seizure reduction between 50 and 90 per cent, 1 with anorexia and sleepiness. Three patients had no change in seizures, and 3 had worse tonic-clonic seizures. Amantadine may have some antiepileptic efficacy of unknown mechanism, but it may worsen generalized tonic-clonic seizures and is likely to be of limited value in adults.     

Lacosamide use in refractory idiopathic primary generalized epilepsy

Treatment of refractory idiopathic primary generalized epilepsy can be very challenging, with limited drug options, especially in young women of childbearing age. Here we describe the cases of two young women with refractory idiopathic primary generalized epilepsy refractory to multiple antiepileptic drugs in monotherapy or combination before achieving a long-term remission with adjunctive lacosamide (LCS) treatment. Larger, randomized prospective studies are necessary to establish the effectiveness of lacosamide in these patients.     

Clinical characteristics and long-term outcome of surgery for hypothalamic hamartoma in children with refractory epilepsy

Context:

Hypothalamic hamartomas (HH) are ectopic masses of neuronal and glial tissue most commonly presenting with medically refractory gelastic seizures with evolution to other seizure types. They are also associated with cognitive and behavioral problems to varying extent. Surgery has been found to improve quality of life in more than 50% of patients.

Aim:

To evaluate the clinical characteristics and long-term outcome of surgery in children with HH and refractory epilepsy.

Materials and Methods:

A retrospective analysis of presurgical, surgical, and postsurgical data of six children who underwent surgery for HH and had at least 3 years follow-up was performed.

Results:

Six children (male: female = 5:1) aged 3-16 years (at the time of surgery) underwent surgical resection of HH for refractory epilepsy. At last follow-up (range 3-9 years), three children were in Engel''s class I, two in Class II, and one in class III outcome. Significant improvement in behavior, quality of life was noted in four children; while the change in intelligence quotient (IQ) was marginal.

Conclusions:

Medically refractory epilepsy associated with behavioral and cognitive dysfunction is the most common presentation of HH. Open surgical resection is safe with favorable outcome of epilepsy in 50% with significant improvement in behavior and marginal change in cognitive functions.     

妥泰加用治疗成人难治性部分性癫痫的疗效观察

目的：观察妥泰（TPM）加用治疗成人难治性部分性伴或不伴随继发身性发作（GTCS）的疗效,安全性及耐受性。方法：56例在不动原用抗癫痫药（AEDs)的基础上加用TPM治疗20周、前8周为加量期,后12周为维持治疗的稳定期,治疗前（基础期）记录好作频率,用药情况。体重等作为自身对照。TPM自25mg/d开始,逐渐加量,目标剂量为200mg/d,治疗及治疗结束各查基础AEDs血药浓度进行比较,治疗结束行全面疗效分析。结果：TPM加用治疗20周后,与基础期发作频率比较,64．29％患者发作频率降低≥50％;25．00％,患者发生频率降低≥75％＜100％;16．07％完全不发。不良反应轻至中度,但与合AEDs的多少有关。50％患者体重可有不同程度的下降。TPM对止痛民西平及丙戊酸钠血药浓度影响不大。结论：TMP是治疗难治性部分性伴或不伴继发GTCS的表效的药物。     

A study of topiramate pharmacokinetics and tolerability in children with epilepsy

The pharmacokinetic and safety profile of topiramate as adjunctive therapy was assessed in pediatric patients with epilepsy in an open-label, 4-week, single-center study. Six children from each of the following age groups were enrolled: 4-7 years, 8-11 years, and 12-17 years. Patients received topiramate 1 mg/kg/day for 1 week, with subsequent progressive weekly increases in dosage to 3, 6, and then 9 mg/kg/day or 800 mg/day, whichever was less. Topiramate oral plasma clearance (CL/F) was independent of dose, and steady-state plasma concentrations increased in proportion to dose. Weight-normalized topiramate CL/F was higher (P = 0.003) in pediatric patients receiving enzyme-inducing concomitant antiepileptic drugs (AEDs) (mean = 70.1 mL/minute/70 kg) than in those not receiving enzyme-inducing AEDs (mean = 33.1 mL/minute/kg). Topiramate CL/F in children was approximately 50% greater than that observed in adults regardless of the type of concomitant AED therapy. Thus steady-state plasma topiramate concentrations for the same mg/kg dose will be approximately 33% lower in pediatric patients than in adult patients. The most frequently reported treatment-emergent adverse events considered related to topiramate therapy included anorexia, fatigue, and nervousness, and no patient discontinued therapy. This study indicates that, in children 4-17 years of age, topiramate has linear pharmacokinetics, 50% higher clearance than in adults, and is generally well tolerated.