Epilepsy in patients with brain tumours: epidemiology, mechanisms, and management

Safety profile of carmustine wafers in malignant glioma: a review of controlled trials and a decade of clinical experience

BACKGROUND

Carmustine (1,3-bis [2-chloroethyl]-1-nitrosourea, or BCNU) wafers are approved for recurrent glioblastoma and newly diagnosed malignant glioma (MG). Based on considerable clinical experience and use in multimodal regimens, the safety of BCNU wafers needs a re-evaluation.

SCOPE

A review of literature from 1996 to February 2008 was conducted on the safety of BCNU wafer in MG patients using search criteria in Medline, EMBASE, and BIOSIS. Abstracts from relevant US and European meetings were also evaluated. Three Phase III (two were pivotal) and 26 non-Phase III studies met inclusion criteria. Overall incidence was estimated for each adverse event (AE), and data from individual studies were summarised as median (range) rates. Comparisons were based on consistent similarities or differences across overall incidence, median rate and range.

FINDINGS

BCNU wafer group AE rates from the two pivotal Phase III trials ranged from 4-23% for cerebral oedema, 4-9% for intracranial hypertension, 14-16% for healing abnormalities, 5% for CSF leaks, 4-5% for intracranial infection, 19-33% for seizures, 10% for deep vein thrombosis, and 8% for pulmonary embolus. There were no notable differences in AE rates between the two pivotal Phase III and 26 non-Phase III studies. For the non-pivotal studies, the overall incidence of AEs was low, ranging from 0.2% for intracranial hypertension to 9.6% for healing abnormalities. Healing abnormalities, intracranial infection, and seizures were the most consistently reported AEs, having been observed in 16, 12, and 11 studies, respectively. Rates of healing abnormalities appeared higher in recurrent than in newly diagnosed disease. There were no notable differences between BCNU wafer plus adjuvant treatment (e.g., temozolomide) and BCNU wafer alone, with the exception of haematologic toxicity.

CONCLUSION

This review of safety data for BCNU wafers provides reassurance that the AE rates reported in current treatment strategies including multimodal treatment approaches are comparable to those observed in the initial registration studies. The broad range of AE rates may reflect differences in the perioperative and postoperative management. Clinical experience suggests that strategies may exist to reduce the risk of complications.

Brain lesions manifesting as psychiatric disorders: eight cases

Sometimes patients with organic brain lesions in neurologically silent brain areas might present only with psychiatric symptoms, such as depression, anxiety disorders, schizophrenia, anorexia nervosa, or cognitive dysfunction. This study presents eight cases of patients with brain lesions (four cases of meningiomas, one case of intracerebral cysts, one case of anaplastic oligodendroglioma, one case of multiform glioblastoma, and one case of occlusive hydrocephalus) who, for a significant period of time, were diagnosed and treated for psychiatric disorders (three cases of Alzheimer's disease, two cases of schizoaffective disorder, one case of schizophrenia, one case of depression, and one case of organic emotional lability disorder). When neurologic symptoms developed, they underwent neuroimaging studies and organic brain lesions were diagnosed. Further treatment required neurosurgical interventions. These cases show that brain tumors can be neurologically silent for a sufficient period of time and manifest as psychiatric disorders. Therefore, neuroimaging studies are needed when atypical changes in mental status or neurologic symptoms and signs develop.

Efficacy, tolerability, and side effects of oxcarbazepine monotherapy: a prospective study in adult and elderly patients with newly diagnosed partial epilepsy

OBJECTIVE

The aim of the study described here was to investigate the efficacy, tolerability, and side effects of oxcarbazepine (OXC) monotherapy in newly diagnosed, previously untreated adult and elderly patients with partial epilepsy.

METHODS

We prospectively analyzed and recorded the efficacy, tolerability, and side effects of OXC monotherapy. The results were analyzed on the basis of etiologic classifications and age distributions. Remission was defined as seizure freedom for at least 1 year.

RESULTS

A total of 147 patients were evaluated in a single center for a median of 18 months (range: 14-36 months). Overall, 92 patients (62.6%) were seizure free for at least 12 months and 55 of them (37.4%) were unresponsive despite treatment with the maximum tolerable dose of OXC. There was a significant difference in the outcomes of patients with cryptogenic (75% remission) and symptomatic (51.9% remission) epilepsy (P=0.004). Patients with cerebral tumors did worse than the remainder of the patients in the symptomatic group (36.7% remission) (P=0.03). Results were favorable for the elderly; 14 patients (73.6%) in the elderly subgroup became seizure free for at least 1 year, and the remission was achieved with low to moderate doses (approximately 900 mg/day). Overall, 13 patients (8.8%) discontinued OXC due to intolerable side effects. Side effects leading to discontinuation were: Stevens-Johnson syndrome (n=2, 1.4%); fatigue and drowsiness (n=2, 1.4%); dizziness, nausea, and vomiting with normal laboratory tests (n=2, 1.4%); dizziness, nausea, and vomiting with serum Na levels <130 mEq/L (n=5, 3.4%); and elevated serum gamma-glutamyl transferase levels (GGT>200mg/dL) (n=1, 0.7%). OXC proved to be a tolerable drug for the elderly; only one patient experienced symptomatic hyponatremia with mild symptoms and responded well to fluid restriction, which did not lead to discontinuation of OXC.

CONCLUSION

Although the limitations of our study include its open-label design, the results suggest that OXC monotherapy may be regarded as an effective first-line monotherapy option for adult and elderly patients with partial epilepsy, but has low efficacy in patients with cerebral tumors.

Seizures and epilepsy in cancer: etiologies, evaluation, and management

Seizure and epilepsy are common neurologic issues in cancer patients. Etiologies include structural abnormalities of the brain (eg, brain metastasis), cerebrovascular disease, reversible posterior leukoencephalopathy syndrome (RPLS), and radiation toxicity. Seizures associated with these etiologies often have focal features. Metabolic causes include hypoglycemia, electrolyte abnormalities, tumor lysis syndrome, thrombotic thrombocytopenic purpura (TTP), and medications used in cancer. A careful clinical evaluation can suggest the seizure etiology and guide subsequent work-up. Nonconvulsive status epilepticus should be suspected with persistent decreased level of consciousness following a seizure. Certain etiologies, such as RPLS and TTP, must be treated aggressively to minimize permanent neurologic injury. Routine prophylaxis with antiepileptic drugs (AEDs) is not recommended in patients with primary brain tumors or brain metastasis who have never had a seizure. Where indicated, the selection of AEDs should take into consideration side effects and interactions with chemotherapy. For this reason, non-enzyme-inducing AEDs are preferable in the cancer setting.

Supportive management of patients with brain tumors

Management issues for patients with brain tumors include peritumoral edema, symptomatic seizures, venous thromboembolism, headache, pain, fatigue and neuropsychological complaints. Vasogenic edema is typically ameliorated with the lowest dose possible of corticosteroid. Seizures are managed with attention to additional or complicated side effects of antiepileptic drugs and their interactions with chemotherapy, and primary prevention with antiepileptic medications is not recommended. Appropriate treatments for headache, pain, fatigue and neuropsychological complaints are important, but are not yet well standardized. Above all, patients' personal goals regarding their priorities at the end of life have the most importance.

Neuropsychological features of lesion-related epilepsy in adults: an overview

Lesional epilepsy is thought to be a direct consequence of focal brain lesions of dysgenetic, neoplastic, vascular, or traumatic origin. It has been estimated that at least half of all epilepsies are the result of such lesions. The current discussion includes an overview of the cognitive and behavioral presentations in adults with epilepsy secondary to focal pathology. The neuropsychological presentation in this population is influenced by many factors, including the location and nature of the underlying lesion, seizure characteristics, the effects of treatment, and patient variables. Few studies attempt to disentangle the specific contributions of these variables to cognitive performance. However, where available studies examining the separable effects of seizure-related variables on cognitive functioning in individuals with lesional epilepsy are also reviewed. This overview includes a discussion of focal malformations of cortical and vascular development and select foreign tissue and acquired lesions.