Optimal seizure management in brain tumor patients

Impact of seizures and antiseizure medication on survival in patients with glioma

PURPOSE

Seizures are a common presenting symptom among patients with low- and high-grade glioma. However, the impact and inter-relationship between the presence of seizures, anti-seizure medication (ASM) and survival are unclear. We retrospectively analyzed the incidence of seizures and identified the pattern and relationship of anti-seizure medication on survival in our cohort of patients with glioma.

METHODS

We evaluated all glioma patients who underwent treatment at the University of Malaya Medical Centre (UMMC) between 2008 and 2020. Demographic and clinical data of seizures and pattern of ASM administration in comparison to overall survival were analyzed.

RESULTS

A total of 235 patients were studied, with a minimum of one year clinical follow-up post-treatment. The median survival for low-grade glioma was 38 months whereas high-grade glioma was 15 months. One-third of our glioma patients (n = 74) presented with seizures. All patients with seizures and a further 31% of patients without seizures were started on anti-seizure medication preoperatively. Seizure and Levetiracetam (LEV) were significantly associated with OS on univariate analysis. However, only LEV (HR 0.49; 95% CI 0.23-0.87; p=0.02) was significantly associated with improving overall survival (OS) on multivariate analysis. Once ASM was adjusted for relevant factors and each other, LEV was associated with improved survival in all grade gliomas (HR 0.52; 95% CI 0.31-0.88; p=0.02) and specifically high-grade gliomas (HR 0.53; 95% CI 0.30-0.94; p=0.03).

CONCLUSIONS

Pre-operative seizures among patients with glioma indicated a better overall prognosis. The administration of ASM, specifically LEV was associated with a  significant survival advantage in our retrospective cohort of patients.

Anatomical features of primary brain tumors affect seizure risk and semiology

Objective

An epileptic seizure is the most common clinical manifestation of a primary brain tumor. Due to modern neuroimaging, detailed anatomical information on a brain tumor is available early in the diagnostic process and therefore carries considerable potential in clinical decision making. The goal of this study was to gain a better understanding of the relevance of anatomical tumor characteristics on seizure prevalence and semiology.

Methods

We reviewed prospectively collected clinical and imaging data of all patients operated on a supratentorial intraparenchymal primary brain tumor at our department between January 2009 and December 2016. The effect of tumor histology, anatomical location and white matter infiltration on seizure prevalence and semiology were assessed using uni- and multivariate analyses.

Results

Of 678 included patients, 311 (45.9%) presented with epileptic seizures. Tumor location within the central lobe was associated with higher seizure prevalence (OR 4.67, 95% CI: 1.90–13.3, p = .002), especially within the precentral gyrus or paracentral lobule (100%). Bilateral extension, location within subcortical structures and invasion of deeper white matter sectors were associated with a lower risk (OR 0.45, 95% CI: 0.25–0.78; OR 0.10, 95% CI: 0.04–0.21 and OR 0.39, 95% CI: 0.14–0.96, respectively). Multivariate analysis revealed the impact of a location within the central lobe on seizure risk to be highly significant and more relevant than histopathology (OR: 4.79, 95% CI: 1.82–14.52, p = .003). Seizures due to tumors within the central lobe differed from those of other locations by lower risk of secondary generalization (p < .001).

Conclusions

Topographical lobar and gyral location, as well as extent of white matter infiltration impact seizure risk and semiology. This finding may have a high therapeutic potential, for example regarding the use of prophylactic antiepileptic therapy.

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Brain tumor location affects seizure prevalence and semiology.

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Central lobe location is the strongest independent pro-epileptogenic factor.

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The precentral gyrus and paracentral lobule are most epileptogenic.

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Central lobe tumors rarely cause bilateral tonic-clonic seizures.

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Tumor location and white matter infiltration may guide antiepileptic therapy.

Efficacy and safety of prophylactic levetiracetam in supratentorial brain tumour surgery: a systematic review and meta-analysis

AIMS

The aim of this study was to perform an up-to-date systematic review and meta-analysis on the efficacy and safety of prophylactic administration of levetiracetam in brain tumour patients.

METHOD

A systematic review of studies published until April 2015 was conducted using Scopus/Elsevier, EMBASE and MEDLINE. The search was limited to articles reporting results from adult patients, suffering from brain tumour, undergoing supratentorial craniotomy for tumour resection or biopsy and administered levetiracetam in the perioperative period for seizure prophylaxis. Outcomes included the efficacy and safety of levetiracetam, as well as the tolerability of the specific regimen, defined by the discontinuation of the treatment due to side effects.

RESULTS

The systematic review included 1148 patients from 12 studies comparing levetiracetam with no treatment, phenytoin and valproate, while only 243 patients from three studies, comparing levetiracetam vs phenytoin efficacy and safety, were included in the meta-analysis. The combined results from the meta-analysis showed that levetiracetam administration was followed by significantly fewer seizures than treatment with phenytoin (OR = 0.12 [0.03-0.42]: χ(2) = 1.76: I(2) = 0%). Analysis also showed significantly fewer side effects in patients receiving levetiracetam, compared to other groups (P < 0.05). The combined results showed fewer side effects in the levetiracetam group compared to the phenytoin group (OR = 0.65 [0.14-2.99]: χ(2) = 8.79: I(2) = 77%).

CONCLUSIONS

The efficacy of prophylaxis with levetiracetam seems to be superior to that with phenytoin and valproate administration. Moreover, levetiracetam use demonstrates fewer side effects in brain tumour patients. Nevertheless, high risk of bias and moderate methodological quality must be taken into account when considering these results.

Tumour associated epilepsy and glutamate excitotoxicity in patients with gliomas

Tumour associated epilepsy (TAE) is common, debilitating and often not successfully controlled by surgical resection of the tumour and administration of multiple anti-epileptic drugs. It represents a cause of significant lost quality of life in an incurable disease and is therefore an important subject for ongoing research. The pathogenesis of TAE is likely to be multifactorial and involve, on the microscopic level, the interaction of genetic factors, changes in the peritumoural microenvironment, alterations in synaptic neurotransmitter release and re-uptake, and the excitotoxic effects of glutamate. On a macroscopic level, the occurrence of TAE is likely to be influenced by tumour size, location and interaction with environmental factors. The optimal treatment of TAE requires a multi-disciplinary approach with input from neurosurgeons, neurologists, radiologists, pathologists and basic scientists. This article reviews the current literature regarding the incidence, treatment, and aetiology of TAE.

The role of levetiracetam in treatment of seizures in brain tumor patients

Levetiracetam, trade name Keppra, is a new second generation antiepileptic drug that is being increasingly used in brain tumor patients. In patients suffering with brain tumors, seizures are one of the leading neurologic complications being seen in more than 30% of patients. Unlike other antiepileptic drugs, levetiracetam is proposed to bind to a synaptic vesicle protein inhibiting calcium release. Brain tumor patients are frequently on chemotherapy or other drugs that induce cytochrome P450, causing significant drug interactions. However, levetiracetam does not induce the P450 system and does not exhibit any relevant drug interactions. Intravenous delivery is as bioavailable as the oral medication allowing it to be used in emergency situations. Levetiracetam is an attractive option for brain tumor patients suffering from seizures, but also can be used prophylactically in patients with brain tumors, or patients undergoing neurological surgery. Emerging studies have also demonstrated that levetiracetam can increase the sensitivity of Glioblastoma tumors to the chemotherapy drug temozolomide. Levetiracetam is a safe alternative to conventional antiepileptic drugs and an emerging tool for brain tumor patients combating seizures.

Levetiracetam use in the critical care setting

Intravenous (IV) levetiracetam (LEV) is currently approved as an alternative or replacement therapy for patients unable to take the oral form of this antiepileptic drug (AED). The oral form has Food and Drug Administration (FDA) indications for adjunctive therapy in the treatment of partial onset epilepsy ages 1 month or more, myoclonic seizures associated with juvenile myoclonic epilepsy starting with the age of 12 and primary generalized tonic-clonic seizures in people 6 years and older. Since the initial introduction, oral and IV LEV has been evaluated in various studies conducted in the critical care setting for the treatment of status epilepticus, stroke-related seizures, seizures following subarachnoid or intracerebral hemorrhage, post-traumatic seizures, tumor-related seizures, and seizures in critically ill patients. Additionally, studies evaluating rapid infusion of IV LEV and therapeutic monitoring of serum LEV levels in different patient populations have been performed. In this review we present the current state of knowledge on LEV use in the critical care setting focusing on the IV uses and discuss future research needs.

Intractable epilepsy in paralimbic Word Health Organization Grade II gliomas: should the hippocampus be resected when not invaded by the tumor?

OBJECT

Beyond its oncological benefit, surgery could improve seizure control in paralimbic frontotemporoinsular or temporoinsular WHO Grade II gliomas generating intractable seizures. However, no studies have examined the impact of hippocampal resection on chronic epilepsy when the hippocampus is not invaded by Grade II gliomas. Here, the authors compared the epileptological outcomes and return to work in 2 groups of patients who underwent surgery with or without hippocampectomy for paralimbic Grade II gliomas eliciting intractable epilepsy despite no tumoral involvement of the hippocampus.

METHODS

Surgery was performed in 15 consecutive patients who were unable to work (median Karnofsky Performance Scale [KPS] Score 70) because of refractory epilepsy due to paralimbic Grade II gliomas that were not invading the hippocampus. In Group A (8 patients), the hippocampus was preserved. In Group B (7 patients), glioma removal was associated with hippocampectomy.

RESULTS

No patient died or suffered a permanent deficit after surgery. Postoperatively, in Group A, no patients were seizure free (4 patients were in Engel Class II and 4 were in Class III). In Group B, all 7 patients were seizure free (Class I) (p = 0.02). Only 62.5% of patients returned to work in Group A, whereas all patients are working full time in Group B. The postsurgical median KPS score was 85 in Group A, that is, not significantly improved in comparison with the preoperative score, while the postsurgical median KPS was 95 in Group B, that is, significantly improved in comparison with the preoperative score (p = 0.03).

CONCLUSIONS

The authors' data support, for the first time, the significant impact of hippocampectomy in patients with intractable epilepsy generated by a paralimbic Grade II glioma, even if it does not invade the hippocampus. Hippocampal resection allowed seizure control in all patients, with an improvement in KPS scores, since all patients resumed their social and professional activities. Thus, the authors suggest performing a resection of the nontumoral hippocampus in addition to resection of the tumor in patients with refractory epilepsy due to paralimbic Grade II gliomas.

Pediatric brain tumors and epilepsy

Seizures are a common complication of pediatric brain tumors and their treatment. This article reviews the epidemiology, evaluation, and treatment of seizures in children with brain tumors. Seizures in known brain tumor patients may signify tumor progression or recurrence, or treatment-related brain damage, as well as other causes, including low drug levels and metabolic disturbances. Careful selection of antiepileptic medications is needed in this population. There are advantages to nonenzyme-inducing antiepileptic drugs including valproic acid, which has potential antitumoral properties as a histone deacetylase inhibitor. Tumor surgery cures many cases of pediatric tumor-associated seizures, and some children are controlled with anti-epileptic medication, however additional epilepsy surgery may be needed for refractory cases.

Intravenous and oral levetiracetam in patients with a suspected primary brain tumor and symptomatic seizures undergoing neurosurgery: the HELLO trial

BACKGROUND

Levetiracetam (LEV) is a newer anticonvulsant with a favorable safety profile. There seem to be no relevant drug interactions, and an intravenous formulation is available. Therefore, LEV might be a suitable drug for the perioperative anticonvulsive therapy of patients with suspected brain tumors undergoing neurosurgery.

METHODS

In this prospective study (NCT00571155) patients with suspected primary brain tumors and tumor-related seizures were perioperatively treated with oral and intravenous LEV up to 4 weeks before and until 4 weeks after a planned neurosurgical procedure.

FINDINGS

Thirty patients with brain tumor-related seizures and intended neurosurgery were included. Three patients did not undergo the scheduled surgery after enrollment, and two patients were lost to follow-up. Therefore, 25 patients were fully evaluable. After initiation of therapy with LEV, 100% of the patients were seizure-free in the pre-surgery phase (3 days up to 4 weeks before surgery), 88% in the 48 h post-surgery phase and 84% in the early follow-up phase (48 h to 4 weeks post surgery). Treatment failure even after dose escalation to 3,000 mg/day occurred in three patients. No serious adverse events related to the treatment with LEV occurred.

CONCLUSION

Our data show the feasibility and safety of oral and intravenous LEV in the perioperative treatment of tumor-related seizures. Although this was a single arm study, the efficacy of LEV appears promising. Considering the side effects and interactions of other anticonvulsants, LEV seems to be a favorable option in the perioperative treatment of brain tumor-related seizures.

Tumor-associated epilepsy

Tumor-associated epilepsy is an important contributor to morbidity in patients with brain tumors. Proposed pathophysiological mechanisms to explain these effects range from neuronal and glial dysfunction to deranged vascular homeostasis, to ionic and pH changes. Perilesional tissue alterations play a vital role in the generation of tumor-associated seizures. Clinical studies have determined that tumor-associated seizures are usually focal with secondary generalization and often resistant to antiepileptic drugs. Tumor histopathological characteristics and location are independent factors that impact seizure burden. Further understanding of the mechanisms of tumor-associated epilepsy may lead to new types of treatments targeted at perilesional tissue alterations.

Management of epilepsy in oncological patients

INTRODUCTION

Comorbidity between epilepsy and cancer is elevated. As a life-time condition, it is not impossible for a patient with epilepsy to have a cancer at some point. Besides, at least 30% of patients with primary brain tumors have epileptic seizures, but also in patients with metastatic infiltrating lesions of the central nervous system and with extracerebral tumors, epilepsy can be related. Seizures may also appear associated with paraneoplastic syndromes, such as limbic encephalitis and metabolic and infectious complications of chemotherapy and radiotherapy.

RESULTS

The precise mechanisms by which brain tumors and the other conditions mentioned above produce seizures are not fully understood, but are reviewed in this article, as well as the many different therapeutic options that may be used in the treatment of epileptic seizures. Pharmacological treatment poses various controversies, such as the utility of prophylactic treatment, interactions between antiepileptic drugs (AEDs) and chemotherapeutic drugs and the complications derived from the adverse effects of AEDs in this population. Finally, other treatments are proposed such as chemotherapy, radiotherapy and surgery, the rational application of which allows for an improvement in the patients' quality of life.

CONCLUSION

In order to arrive at a diagnosis, the different causes that could condition the appearance of epileptic seizures in cancer patients must be known. After this, the most adequate treatment should be chosen, thus ensuring the comprehensive treatment of cancer and epilepsy.

Brain tumors and epilepsy: pathophysiology of peritumoral changes

Epilepsy commonly develops among patients with brain tumors, frequently even as the presenting symptom, and such patients consequently experience substantial morbidity from both the seizures and the underlying disease. At clinical presentation, these seizures are most commonly focal with secondary generalization and conventional medical management is often met with less efficacy. The molecular pathophysiology of these seizures is being elucidated with findings that both the tumoral and peritumoral microenvironments may exhibit epileptogenic phenotypes owing to disordered neuronal connectivity and regulation, impaired glial cell function, and the presence of altered vascular supply and permeability. Neoplastic tissue can itself be the initiation site of seizure activity, particularly for tumors arising from neuronal cell lines, such as gangliogliomas or dysembryoblastic neuroepithelial tumors. Conversely, a growing intracranial lesion can both structurally and functionally alter the surrounding brain tissue with edema, vascular insufficiency, inflammation, and release of metabolically active molecules, hence also promoting seizure activity. The involved mechanisms are certain to be multifactorial and depend on specific tumor histology, integrity of the blood brain barrier, and characteristics of the peritumoral environment. Understanding these changes that underlie tumor-related epilepsy may have roles in both optimal medical management for the seizure symptom and optimal surgical objective and management of the underlying disease.

Frequency of seizures in patients with newly diagnosed brain tumors: A retrospective review

Brain tumors may lead to symptomatic epilepsy. A retrospective analysis was undertaken to evaluate the frequency of seizure as the presenting symptom leading to brain tumor diagnosis in adults. One hundred and forty-seven consecutive patients with newly diagnosed brain tumors were analyzed regarding the frequency of seizures as the initial presenting symptoms and those subsequently developing seizures. One hundred twelve patients had primary central nervous system tumors (CNS) and 35 had metastatic lesions. Statistical evaluation was carried out using the Chi-square test with p values of <0.05 considered to be statistically significant. Astrocytomas and meningiomas were the most common primary CNS tumors in this study. Of these, oligodendrogliomas and grade 2 astrocytomas were significantly more likely to present with seizures (p<0.001). Seizures were a frequent presenting symptom, occurring in over 38% of those with primary brain neoplasms and 20% of those with cerebral metastases. Primary location of tumor also correlated amongst primary CNS tumors and was associated with a trend in seizure risk: parietal (80%); temporal (74%); frontal (62%); and occipital (0%) (p<0.5). The findings highlight the importance of obtaining appropriate evaluation for underlying malignancy in adults with new-onset seizures as well as provide more information to the patient for prognosis and counseling.

Levetiracetam use in critically ill patients

INTRODUCTION

Levetiracetam (LEV) is used in the setting of acute brain injury for seizure treatment or prophylaxis but its safety and efficacy in this setting is unknown.

METHOD

We retrospectively analyzed the patterns of use and safety/efficacy of LEV in 379 patients treated in the neuroscience intensive care unit (NSICU). We extracted from the charts clinical data including diagnosis, AED therapy before and during stay in the NSICU, complications of treatment, length of stay, and clinical outcomes (improvement, Glasgow Coma Scale, and death). We analyzed the data using binary and ordered (multi-category) logistic regression.

RESULTS

Overall, our findings are that phenytoin used prior to the NSICU admission was frequently replaced with LEV monotherapy (P < 0.001). Patients treated with LEV monotherapy when compared to other AEDs had lower complication rates and shorter NSICU stays. Older patients and patients with brain tumors or strokes were preferentially treated with LEV for prevention and/or management of seizures (all P < or = 0.014).

DISCUSSION

The results of this study suggest that LEV is a frequently used AED in the setting of acute brain injury and that it may be a desirable alternative to phenytoin. Prospective studies evaluating the long-term safety, efficacy and outcomes of LEV in this setting are indicated.

Medical management of patients with brain tumors

The most common medical problems in brain tumor patients include the management of seizures, peritumoral edema, medication side effects, venous thromboembolism (VTE), fatigue and cognitive dysfunction. Despite their importance, there are relatively few studies specifically addressing these issues. There is increasing evidence that brain tumor patients who have not had a seizure do not benefit from prophylactic antiepileptic medications. Patients on corticosteroids are at greater risk of Pneumocystis jerovecii pneumonia and may benefit from prophylactic therapy. There is also growing evidence suggesting that anticoagulation may be more effective than inferior vena cava IVC) filtration devices for treating VTE in brain tumor patients and the risk of hemorrhage with anticoagulation is relatively small. Low-molecular weight heparin may be more effective than coumadin. Medications such as modafinil and methylphenidate have assumed an increasing role in the treatment of fatigue, while donepezil and memantine may be helpful with memory loss.