Pregabalin in patients with primary brain tumors and seizures: A preliminary observation

Clinical Diagnosis and Perioperative Management of Glioma-Related Epilepsy

Gliomas account for more than half of all adult primary brain tumors. Epilepsy is the most common initial clinical presentation in gliomas. Glioma related epilepsy (GRE) is defined as symptomatic epileptic seizures secondary to gliomas, occurring in nearly 50% in high-grade glioma (HGG) patients and up to 90% in patients with low-grade glioma (LGG). Uncontrolled seizures, which have major impact on patients’ quality of life, are caused by multiple factors. Although the anti-seizure medications (ASMs), chemotherapy and radiation therapy are also beneficial for seizure treatment, the overall seizure control for GRE continue to be unsatisfactory. Due to the close relationship between GRE and glioma, surgical resection is often the treatment of choice not only for the tumor treatment, but also for the seizure control. Despite aggressive surgical treatment, there are about 30% of patients continue to have poor seizure control postoperatively. Furthermore, the diagnostic criteria for GRE is not well established. In this review, we propose an algorithm for the diagnosis and perioperative management for GRE.

Efficacy of clobazam as add-on therapy in brain tumor-related epilepsy

PURPOSE

Brain tumor-related epilepsy (TRE) is often resistant to currently available antiepileptic medications (AEDs). Clobazam was initially approved as adjunctive AED for patients with Lennox Gastaut syndrome but has been used in TRE, despite limited evidence in this context. This observational study aims to examine the effect of clobazam on seizure frequency on patients who have a primary CNS tumor and continued seizures despite their current AEDs.

METHODS

A retrospective review of patients with histologically-confirmed primary brain tumors seen in the neuro-oncology interdisciplinary clinic from April 2016-2019 was completed, and patients on clobazam were identified. Response to clobazam was defined as a greater than 50% reduction in seizure frequency. Additional data including patient and tumor characteristics, treatment course, tolerability, AEDs used prior to addition of clobazam, and AEDs concomitantly used with clobazam were collected.

RESULTS

A total of 35 patients with TRE on clobazam were identified, with 2 patients unable to tolerate the medication due to side effects. Of the 33 remaining patients, a total of 31 (93.9%) of patients were deemed responders. Ten patients (30.3%) were seizure free within 6 months of clobazam initiation and 21 (63.6%) reported a significant reduction in seizure frequency. This reduction also allowed several patients to modify concurrent AEDs.

CONCLUSIONS

Clobazam is an effective agent to use as add-on AED in TRE, with 94% of patients showing a significant response within 6 months. Furthermore, the addition of clobazam may yield a reduction in polypharmacy, as concomitant AEDs can be reduced and potentially withdrawn.

Management of epilepsy in brain tumors

Epilepsy in brain tumors (BTE) may require medical attention for a variety of unique concerns: epileptic seizures, possible serious adverse effects of antineoplastic and antiepileptic drugs (AEDs), physical disability, and/or neurocognitive disturbances correlated to tumor site. Guidelines for the management of tumor-related epilepsies are lacking. Treatment is not standardized, and overall management might differ according to different specialists. The aim of this document was to provide directives on the procedures to be adopted for a correct diagnostic-therapeutic path of the patient with BTE, evaluating indications, risks, and benefits. A board comprising neurologists, epileptologists, neurophysiologists, neuroradiologists, neurosurgeons, neuro-oncologists, neuropsychologists, and patients' representatives was formed. The board converted diagnostic and therapeutic problems into seventeen questions. A literature search was performed in September-October 2017, and a total of 7827 unique records were retrieved, of which 148 constituted the core literature. There is no evidence that histological type or localization of the brain tumor affects the response to an AED. The board recommended to avoid enzyme-inducing antiepileptic drugs because of their interference with antitumoral drugs and consider as first-choice newer generation drugs (among them, levetiracetam, lamotrigine, and topiramate). Valproic acid should also be considered. Both short-term and long-term prophylaxes are not recommended in primary and metastatic brain tumors. Management of seizures in patients with BTE should be multidisciplinary. The panel evidenced conflicting or lacking data regarding the role of EEG, the choice of therapeutic strategy, and timing to withdraw AEDs and recommended high-quality long-term studies to standardize BTE care.

Tumor-related epilepsy: epidemiology, pathogenesis and management

INTRODUCTION

Seizure is a common comorbidity in patients with brain tumor. It may be the presenting symptom or develop after the tumor diagnosis. The underlying pathophysiology of brain tumor-related epilepsy remains poorly understood.

METHODS

A comprehensive literature review of Pubmed English articles from 1980-2017 was performed to summarize current knowledge and treatment options of brain tumor-related epilepsy.

RESULTS

Multiple factors have been found to contribute to tumor-related epilepsy, including tumor type, speed of tumor growth, location, and tumor burden. The underlying pathogenesis of epilepsy is not clear but perturbations in the peri-tumoral regions, both structural and cellular communications, have been implicated.

CONCLUSIONS

Surgical and medical treatments of tumor-related epilepsy remain challenging as additional factors such as the extent of surgical resection, interactions with tumor-related oncological treatments and anti-epileptic medication related side effects need to be considered.

Clinical Management of Seizures in Patients With Low-Grade Glioma

Seizures, transient disruptions of normal brain electrical activity, are common for patients with low-grade glioma (LGG) and significantly affect quality of life. Up to 75% of patients with a LGG will have seizures in the course of their disease (compared with 1%-2% of the general population). Depending on the type of abnormal electrical activity, the functional implications of seizure can impact any domain, including mental status, sensation or strength. In most cases, either the seizure or the medications used to treat the seizure may contribute to cognitive and psychosocial difficulties of various degrees of severity. Hence, effective management of seizures is a major priority for patients with LGG. Evidence-based guidelines suggest that levetiracetam is the best first-line agent for treatment of seizures in this population due to both its efficacy and tolerability. An important consideration in the field of neuro-oncology is that levetiracetam has very few drug interactions. Unfortunately, approximately one-third of patients with LGG have refractory epilepsy where additional agents such as valproic acid, or lacosamide, lamotrigine and nonpharmacologic therapies such as diet-based interventions, epilepsy surgery, and devices are considered.

Visible-light-induced synthesis of pH-responsive composite hydrogels for controlled delivery of the anticonvulsant drug pregabalin

We report here a novel method for the synthesis of a pH-responsive composite using visible light. Formation of the pH-responsive layer is based on poly(methacrylic acid-g-ethylene glycol) as the macromer, eosin Y as the photoinitiator and triethanolamine as the co-initiator. The hydrogel was functionalized with hydrophobic domains through incorporation of crosslinked styrene-butadiene-styrene (SBS) copolymer into the pH-responsive prepolymer. Swelling ratios were decreased with the addition of SBS, and resulted in high hydrogel crosslink density. The composite allowed for controlled release of an anticonvulsant model drug, pregabalin, under neutral pH condition and the release was analyzed to describe the mode of transport through the network. In vitro human fibroblast survival assay and in vivo rabbit implantation experiments demonstrated that this hybrid network is not toxic and has desirable biocompatibility properties. This is the first report about the synthesis of a pH-responsive network incorporating crosslinked SBS synthesized under visible light. The approach for multifunctional membranes could allow the incorporation of molecules with specific functionalities so that sequential molecule delivery in response to specific stimuli could be achieved.

Time to focus on brain tumor-related epilepsy trials

Brain tumor-related epilepsy (BTRE) is a common complication of cerebral glioma. It has a serious impact on the patient's confidence and quality of life and can be life threatening. There are significant differences in the management of BTRE and nontumoral epilepsy in adults. Surgery is performed early in management, and resection can be curative. Radiotherapy can also improve seizure frequency. Antiepileptic drugs (AEDs) are started after first seizure but are only effective at stopping attacks in 50% of cases. There are no satisfactory randomized controlled clinical trials, or even good prospective series, to support using one AED over another with respect to efficacy. Guidelines are therefore based on poor levels of evidence. In general, the choice of AED may depend on risk of early side effect (rash, biochemical, or hematological effects) and whether drug interactions with chemotherapy are likely. In patients with suspected low-grade glioma, where use of chemotherapy early in the management is not standard practice and survival in measured in many years, the drug interactions are less relevant, and rational seizure management should focus on drugs with the fewest long-term effects on neurocognition, personality, mood, and fatigue. While intriguing and potentially very important, there is no good evidence that any specific AED has a clinical antitumor effect or improves survival. Development of special interest groups in BTRE within countries, or between countries, may be a model for promoting better BTRE trials in the future.

Treatment of epileptic seizures in brain tumors: a critical review

Epileptic seizures represent a common signal of intracranial tumors, frequently the presenting symptom and the main factor influencing quality of life. Treatment of tumors concentrates on survival; antiepileptic drug (AED) treatment frequently is prescribed in a stereotyped way. A differentiated approach according to epileptic syndromes can improve seizure control and minimize unwarranted AED effects. Prophylactic use of AEDs is to be discouraged in patients without seizures. Acutely provoked seizures do not need long-term medication except for patients with high recurrence risk indicated by distinct EEG patterns, auras, and several other parameters. With chronically repeated seizures (epilepsies), long-term AED treatment is indicated. Non-enzyme-inducing AEDs might be preferred. Valproic acid exerts effects against progression of gliomatous tumors. In low-grade astrocytomas with epilepsy, a comprehensive presurgical epilepsy work-up including EEG-video monitoring is advisable; in static non-progressive tumors, it is mandatory. In these cases, the neurosurgical approach has to include the removal of the seizure-onset zone frequently located outside the lesion.

Levetiracetam and pregabalin for antiepileptic monotherapy in patients with primary brain tumors. A phase II randomized study

BACKGROUND

In patients with brain tumors, the choice of antiepileptic medication is guided by tolerability and pharmacokinetic interactions. This study investigated the effectiveness of levetiracetam (LEV) and pregabalin (PGB), 2 non-enzyme-inducing agents, in this setting.

METHODS

In this pragmatic, randomized, unblinded phase II trial (NCT00629889), patients with primary brain tumors and epilepsy were titrated to a monotherapy of LEV or PGB. Efficacy and tolerability were assessed using structured questionnaires. The primary composite endpoint was the need to discontinue the study drug, add-on of a further antiepileptic treatment, or occurrence of at least 2 seizures with impaired consciousness during 1 year follow-up.

RESULTS

Over 40 months, 25 patients were randomized to LEV, and 27 to PGB. Most were middle-aged men, with a high-grade tumor and at least one generalized convulsion. Mean daily doses were 1125 mg (LEV) and 294 mg (PGB). Retention rates were 59% in the LEV group, and 41% in the PGB group. The composite endpoint was reached in 9 LEV and 12 PGB patients-need to discontinue: side effects, 6 LEV, 3 PGB; lack of efficacy, 1 and 2; impaired oral administration, 0 and 2; add-on of another agent: 1 LEV, 4 PGB; and seizures impairing consciousness: 1 in each. Seven LEV and 5 PGB subjects died of tumor progression.

CONCLUSIONS

This study shows that LEV and PGB represent valuable monotherapy options in this setting, with very good antiepileptic efficacy and an acceptable tolerability profile, and provides important data for the design of a phase III trial.

Epilepsy in glioblastoma patients: basic mechanisms and current problems in treatment

Glioblastoma-related epilepsy requires paying careful attention to a combination of factors with an integrated approach. Major interrelated issues must be considered in the seizure care of glioblastoma patients. Seizure control frequently requires the administration of antiepileptic drugs simultaneously with other treatments, including surgery, radiotherapy and chemotherapy, with complete seizure relief often being difficult to achieve. The pharmacological interactions between antiepileptic drugs and antineoplastic agents can modify the activity of both treatments, compromising their efficacy and increasing the probability of developing adverse events related to both therapies. This review summarizes the new pathophysiological pathways involved in the epileptogenesis of glioblastoma-related seizures and the interactions between antiepileptic drugs and oncological treatment, paying special attention to its impact on survival and the current evidence of the antiepileptic treatment efficacy, including the potential usefulness of new third-generation compounds.

Decreased inhibitory neuronal activity in patients with frontal lobe brain tumors with seizure presentation: Preliminary study using magnetoencephalography

BACKGROUND

Although 30-50 % of patients with brain tumors experience epileptic seizure as the presenting clinical symptom, and another 10-30 % are at risk for developing epilepsy in the later stages of the disease, the mechanisms of tumor-related epileptogenesis are poorly understood. We used magnetoencephalography (MEG) to investigate sensory evoked fields (SEFs) in patients with frontal lobe brain tumors as a means of evaluating the neuronal activity of peri-tumoral cortex.

METHODS

Twelve patients with frontal lobe brain tumors underwent MEG. We calculated the equivalent current dipole strength of two components of the primary sensory cortical response (N20m and P35m) and compared the P35m/N20m ratio in the tumor hemisphere vs. the normal hemisphere. There were two subsets of patients: group I, in which P35m/N20m was higher in the tumor hemisphere (n= 7), and group II, in which P35m/N20m was higher in the normal hemisphere (n=5). We looked for associations between clinical factors and P35m/N20m within each group.

RESULTS

All patients with seizure presentation were in group I, whereas only two patients without seizure presentation were in group I (Fisher exact test, p=0.028). No other clinical factors were related to P35m/N20m. The mean ratio of P35m/N20m equivalent current dipole strength in patients with seizure presentation was 4.07 ± 2.38 in the tumor hemisphere and 2.00 ± 0.55 in the normal hemisphere. This difference was statistically significant (Mann-Whitney test, p=0.030).

CONCLUSION

The paradoxical increase in P35m/N20m in patients with seizure presentation suggests that decreased inhibitory neuronal activity is a potential cause of tumorrelated epilepsy.

Seizures in low-grade gliomas: natural history, pathogenesis, and outcome after treatments

Seizures represent a common symptom in low-grade gliomas; when uncontrolled, they significantly contribute to patient morbidity and negatively impact quality of life. Tumor location and histology influence the risk for epilepsy. The pathogenesis of tumor-related epilepsy is multifactorial and may differ among tumor histologies (glioneuronal tumors vs diffuse grade II gliomas). Gross total resection is the strongest predictor of seizure freedom in addition to clinical factors, such as preoperative seizure duration, type, and control with antiepileptic drugs (AEDs). Epilepsy surgery may improve seizure control. Radiotherapy and chemotherapy with alkylating agents (procarbazine + CCNU+ vincristine, temozolomide) are effective in reducing the frequency of seizures in patients with pharmacoresistant epilepsy. Newer AEDs (levetiracetam, topiramate, lacosamide) seem to be better tolerated than the old AEDs (phenobarbital, phenytoin, carbamazepine), but there is lack of evidence regarding their superiority in terms of efficacy.

[Glioma-associated epilepsy]

BACKGROUND

Epileptic seizures are a common symptom in patients with primary brain tumours of the glioma type. The paper presents a discussion of epileptogenesis, choice of medication and follow-up of these patients.

METHOD

The article is based on a search in PubMed and selection of articles based on the authors' discretionary judgement and clinical experience with this patient group.

RESULTS

Epileptic seizures are a common symptom of glioma, particularly the low-grade types. The background to glioma-associated epilepsy is multifactorial, and the molecular biological characteristics of the tumour probably play a central part in the epileptogenesis. Effective treatment of epileptic seizures is of great importance to the quality of life of the glioma patient. Seizure frequency and the effectiveness of anti-epileptic treatment vary, and some patients require treatment with several anti-epileptic drugs. Surgical and oncological treatment of the tumour will also often reduce the frequency of seizures.

CONCLUSION

As a general rule, antiepileptics without enzyme-inducing properties and with low protein-binding should be preferred for glioma patients. This will reduce the risk of interactions with chemotherapy or steroid therapy. Patients with brain tumours are particularly vulnerable to the effects on wakefulness, moods and cognition, and this should be borne in mind in the choice of medication and in follow-up. Haematological status should be monitored particularly closely when there is concomitant use of chemotherapy and antiepileptic drugs that may affect the bone marrow function.

Brain tumor-related epilepsy

In patients with brain tumor (BT), seizures are the onset symptom in 20-40% of patients, while a further 20-45% of patients will present them during the course of the disease. These patients present a complex therapeutic profile and require a unique and multidisciplinary approach. The choice of antiepileptic drugs is challenging for this particular patient population because brain tumor-related epilepsy (BTRE) is often drug-resistant, has a strong impact on the quality of life and weighs heavily on public health expenditures.In BT patients, the presence of epilepsy is considered the most important risk factor for long-term disability. For this reason, the problem of the proper administration of medications and their potential side effects is of great importance, because good seizure control can significantly improve the patient's psychological and relational sphere. In these patients, new generation drugs such as gabapentin, lacosamide, levetiracetam, oxcarbazepine, pregabalin, topiramate, zonisamide are preferred because they have fewer drug interactions and cause fewer side effects. Among the recently marketed drugs, lacosamide has demonstrated promising results and should be considered a possible treatment option. Therefore, it is necessary to develop a customized treatment plan for each individual patient with BTRE. This requires a vision of patient management concerned not only with medical therapies (pharmacological, surgical, radiological, etc.) but also with emotional and psychological support for the individual as well as his or her family throughout all stages of the illness.

Lecture: profile of risks and benefits of new antiepileptic drugs in brain tumor-related epilepsy

In patients with brain tumor, seizures are the onset symptom in 20-40% of the patients, while a further 20-45% of the patients will present them during the course of the disease. These data are important when considering the choice of antiepileptic drugs for this particular patient population, because brain tumor-related epilepsy (BTRE) is often drug resistant, has a strong impact on the quality of life and weighs heavily on public health expenditures. In brain tumor patients, the presence of epilepsy is considered as the most important risk factor for long-term disability. For this reason, the problem of the proper administration of medications and their potential side effects is of great importance, because good seizure control can significantly improve the patient's psychological and relational sphere. In these patients, new generation drugs such as gabapentin, lamotrigine, levetiracetam, oxcarbazepine, pregabalin, topiramate, and zonisamide are preferred, because they have fewer drug interactions and cause fewer side effects. Among the recently marketed drugs, lacosamide has demonstrated promising results and should be considered as a possible treatment option. Therefore, it is necessary to develop a customized treatment plan for each patient with BTRE, whose goals are complete seizure control, minimal or no side effects, and elimination of cognitive impairment and/or psychosocial problems.

A review of the use of antiepileptic drugs in high-grade central nervous system tumors

BACKGROUND

Seizures are a common complication in patients with central nervous system (CNS) tumors. Optimal management is unclear with no defined guidelines and pharmacological management poses many controversies. Due to a hypothesized lack of consistency, we aimed to retrospectively review seizure management in patients with high-grade CNS tumors in our institution.

METHODS

The medical records of patients with high-grade CNS tumors referred to the specialist palliative medicine service in our institution from January-June 2008 were retrospectively reviewed. Seizure incidence, antiepileptic drug (AED) choice, neurology input, medication interactions, and appropriate drug level monitoring were assessed.

RESULTS

Twenty-seven patients were included for analysis. Fifteen (56%) were female. The mean age was 58.8 years (range 31-82 years). Three (11%) patients presented with seizures and 8 (30%) developed seizures subsequently. Eight (73% of those with seizures) were on monotherapy AED. Six different agents were used as first-line agents. Phenytoin was the most common AED used (n = 4). Three (27%) patients were on combination AEDs. Five (45.5%) patients had been seen by neurology and 6 (54.5%) had appropriate drug level monitoring performed. Six (55%) patients had potential AED-non-AED interactions. None of the patients had instructions documented in the clinical notes against driving.

CONCLUSION

Seizure management in patients with CNS tumors is not consistent and remains very much a neglected area. Appropriate choice of AED is crucial. Physicians should be aware of potential drug interactions. Ownership and regular follow-up of this group is required to ensure optimum patient management.

Antiepileptic drugs for treating seizures in adults with brain tumours

BACKGROUND

Seizures are a common symptom of brain tumours. The mainstay of treatment for seizures is medical therapy with antiepileptic drugs.

OBJECTIVES

To evaluate the relative effectiveness and tolerability of antiepileptic drugs commonly used to treat seizures in adults with brain tumours.

SEARCH STRATEGY

We searched CENTRAL (Issue 2 of 4, The Cochrane Library 2011), MEDLINE (1948 to May week 3, 2011) and EMBASE (1980 to 31 May 2011) databases. In addition, we handsearched articles published since 2000 in the following journals selected by the authors: Epilepsia; The Lancet Neurology and Neuro-Oncology.

SELECTION CRITERIA

Controlled clinical trials with random allocation of the use of antiepileptic drugs to treat seizures in adults with brain tumours.

DATA COLLECTION AND ANALYSIS

Both review authors screened the search results and reviewed the abstracts of potentially relevant articles before retrieving the full text of eligible articles.

MAIN RESULTS

Only one trial met the inclusion criteria for this review which was a small, open-label, unblinded, randomised trial of the safety and feasibility of switching from phenytoin to levetiracetam monotherapy or continuing phenytoin for glioma-related seizure control following craniotomy (Lim 2009). Levetiracetam (a non enzyme-inducing antiepileptic drug) appears to have been at least as well tolerated and as effective as phenytoin (an enzyme-inducing antiepileptic drug) for the treatment of seizures in people with brain tumours. Eighty-seven per cent of participants treated with levetiracetam were free of seizures at six months compared with 75% of participants treated with phenytoin. There is one ongoing study of levetiracetam versus pregabalin for the treatment of seizures in adults undergoing chemotherapy, radiotherapy,or both for primary brain tumours. No data from this study were available at the time of preparing this review.

AUTHORS' CONCLUSIONS

There is a lack of robust, randomised, controlled evidence to support the choice of antiepileptic drug for the treatment of seizures in adults with brain tumours. While some authors support the use of non enzyme-inducing antiepileptic drugs, reliable, comparative evidence to provide clinical justification for this is limited. There is a need for further large, randomised, controlled trials in this area.

Lacosamide as add-on in brain tumor-related epilepsy: preliminary report on efficacy and tolerability

Lacosamide (LCM) is an antiepileptic drug (AED) that has demonstrated a good efficacy in controlling seizures as an add-on in adult epilepsy. To date, there have been no studies on LCM in patients with brain tumor-related epilepsy (BTRE). To evaluate efficacy and tolerability of LCM as an add-on in BTRE, we followed 14 patients suffering from BTRE who had already been treated with other AEDs and who had not experienced adequate seizure control. Eleven patients underwent chemotherapy while being treated with LCM. Mean duration of follow up was 5.4 months (min < 1 max 10 months). Mean seizure number in the last month prior to the introduction of LCM had been 15.4. At last follow-up, the mean seizure number was reduced to 1.9/month. Lacosamide mean dosage was of 332.1 mg/day (min 100 max 400 mg/day). Responder rate was 78.6%. One patient discontinued LCM because of side-effects. There were no other reported side-effects. Preliminary data on the use of LCM in add-on in patients with BTRE indicate that this drug may represent a valid alternative as an add-on in this particular patient population. However, larger samples are necessary in order to draw definitive conclusions.

Postoperative seizures following the resection of convexity meningiomas: are prophylactic anticonvulsants indicated?

Object

Seizures in the perioperative period are a well-recognized clinical entity in the setting of brain tumor surgery. At present, the suitability of antiepileptic prophylaxis in patients following brain tumor surgery is unclear, especially in those without prior seizures. Given the paucity of tumor-type and site-specific data, the authors evaluated the incidence of postoperative seizures in patients with convexity meningiomas and no prior seizures.

Methods

The authors identified 180 patients with no preoperative history of seizures who underwent resection of a convexity meningioma. Some patients received antiepileptic prophylaxis for 7 days postoperatively while others did not, based on the practice patterns of different attendings. The rates of clinically evident seizures in the first 3–4 weeks after surgery were compared.

Results

Patients who received antiepilepsy drugs (129 patients) did not significantly differ from those who did not (51 patients) in terms of age, sex, WHO tumor grade, extent of resection, rate of previous cranial surgery or radiation therapies, or use of preoperative embolization. There was a single new postoperative seizure in the entire cohort, yielding a new seizure rate of 1.9% in patients not on antiepileptic prophylaxis compared with 0% in patients on antiepileptics (p = not significant).

Conclusions

While it is thought that the routine use of prophylactic antiepileptics may prevent new seizures in patients undergoing surgery for a convexity meningioma, the rate of new seizures in untreated patients is probably very low. Data in this study call into question whether the cost and side effects of these medications are worth the small benefit their administration may confer.

Epilepsy in the cancer patient

PURPOSE

Epileptic seizures in patients with malignancies usually occur as a consequence of brain metastases from systemic cancer or the presence of a primary brain tumor. Other less-frequent causes include metabolic disorders such as electrolyte abnormalities, hypoglycemia, hypoxia and liver failure, paraneoplastic encephalitis, leptomeningeal carcinomatosis, side effects of certain chemotherapeutic agents, central nervous system infections, and pre-existing epilepsy.

METHODS

We reviewed all published literature in the English language regarding the use of antiepileptic drugs in patients with cancer.

RESULTS

In patients with brain metastases or primary brain tumors that had never experienced seizures, prophylactic anticonvulsant treatment is justified only for a period up to 6 months postoperatively after surgical excision of a cerebral tumor, since approximately half of the patients will never develop seizures and the anti-epileptic drugs may cause toxicity and interactions with antineoplastic therapies. For brief prophylaxis, newer antiepileptic drugs such as levetiracetam and oxcarbazepine are superior to older agents like phenytoin. In patients with a malignancy and seizures, certain antiepileptic drugs that express tumor inhibitory properties should be used such as valproic acid and levetiracetam, followed by oxcarbazepine and topiramate that exhibit good tolerance, efficient seizure control and absence of significant interactions with the chemotherapy.

CONCLUSIONS

Future clinical trials in patients with cancer and epilepsy should focus on combinations of chemotherapeutic interventions with antiepileptic drugs that demonstrate antineoplastic activities.

Epilepsy and brain tumors

PURPOSE OF REVIEW

To present an overview of the recent findings in pathophysiology and management of epileptic seizures in patients with brain tumors.

RECENT FINDINGS

Low-grade gliomas are the most epileptogenic brain tumors. Regarding pathophysiology, the role of peritumoral changes [hypoxia and acidosis, blood-brain barrier (BBB) disruption, increase or decrease of neurotransmitters and receptors] are of increasing importance. Tumor-associated epilepsy and tumor growth could have some common molecular pathways. Total/subtotal surgical resection (with or without epilepsy surgery) allows a seizure control in a high percentage of patients. Radiotherapy and chemotherapy as well have a role. New antiepileptic drugs are promising, both in terms of efficacy and tolerability. The resistance to antiepileptic drugs is still a major problem: new insights into pathogenesis are needed to develop strategies to manipulate the pharmakoresistance.

SUMMARY

Epileptic seizures in brain tumors have been definitely recognized as one of the major problems in patients with brain tumors, and need specific and multidisciplinary approaches.

Levetiracetam monotherapy in patients with brain tumor-related epilepsy: seizure control, safety, and quality of life

We performed a case series analysis to evaluate the effects of levetiracetam (LEV) monotherapy on seizures, adverse events, cognitive functioning and quality of life (QoL) in patients with brain tumor-related epilepsy (BTRE). We also explored the possible effects of systemic therapies on the efficacy of LEV. Twenty-nine patients were followed (13 female, 16 male; age 24-75 years) with 12 months of follow-up. Patients were evaluated by QoL and neuropsychological tests. At final follow-up, mean LEV dosage was 1991.4 mg/day. Among patients who reached the final follow-up of 12 months (n = 15), 1 patient had ≥50% reduction of seizure frequency (SF), and 14/15 were seizure free. The difference in presence/absence of seizures between baseline and final follow-up was significant (p < 0.001). Responder rate was 100%. We observed five side-effects: four mild (reversible) and one severe. Logistic regression revealed that chemotherapy and radiotherapy did not affect the efficacy of LEV in seizure outcome (p = 0.999). The following statistically significant observations emerged by tests' evaluation: less worry about seizures, effects of antiepileptic, and ability to maintain social functions. Our data suggest that seizure occurrence can be an important warning sign that the clinician should heed throughout the duration of the illness. Patients with BTRE represent a unique patient population that presents difficulties regarding management of two very different pathologies: epilepsy on the one hand, and brain tumor on the other. Our data indicate that LEV, in patients with BTRE, is safe and efficacious, with positive impact on QoL.

Epilepsy and insular Grade II gliomas: an interdisciplinary point of view from a retrospective monocentric series of 46 cases

OBJECT

There are few data in the literature concerning a multimodal approach to insular WHO Grade II gliomas (GIIGs) and the control of epilepsy after treatment. In this paper, the authors describe a monocentric series of 46 cases in which patients underwent various sequential treatments for insular GIIGs. On the basis of global results with regard to epilepsy, the respective interests in the various treatments are discussed.

METHODS

Available data on 46 patients harboring insular GIIGs were extracted from a local database of 288 GIIGs. The various therapeutic sequences were analyzed in parallel with the course of seizure frequency.

RESULTS

Despite the usual difficulties with seizure quantification in retrospective studies, the authors showed that 1) the negative course of seizure frequency was mostly connected to tumor progression, 2) surgery almost always had a favorable effect on epilepsy, and 3) chemotherapy had a mostly favorable effect with acceptable tolerance. The authors were unable to draw conclusions about the role of radiotherapy given the too few cases.

CONCLUSIONS

This extensive experience with insular GIIGs tends to confirm interest in their surgical removal and supports interest in chemotherapy from an epileptological point of view.

Efficacy and tolerability of zonisamide as add-on in brain tumor-related epilepsy: preliminary report

BACKGROUND

Zonisamide (ZNS) is an antiepileptic drug (AED) with broad spectrum action that demonstrated a good efficacy in controlling seizures as add-on in adult and pediatric epilepsy. To date there have been no studies on ZNS in patients with brain tumor-related epilepsy (BTRE).

AIM OF THE STUDY

To evaluate efficacy and tolerability of ZNS as add-on in BTRE.

METHODS

We followed six patients suffering from BTRE who had already been treated with other AEDs and who had had not experienced adequate seizure control. Three patients underwent chemotherapy while being treated with ZNS. Mean duration of follow-up was 8 months.

RESULTS

Mean seizure number in the last month prior to the introduction of ZNS had been 27.7/month. ZNS mean dosage was of 283.3 mg/day. At last follow-up, the mean seizure number was reduced to 8.8/month. Responder rate was 83.3%.Two patients discontinued the drug because of side effects. There were no other reported side effects.

CONCLUSIONS

Preliminary data on the use of ZNS in add-on in patients with BTRE indicate that this drug may represent a valid alternative as add-on in this particular patient population. However, larger samples are necessary to draw definitive conclusions.