Talampanel in Treating Patients With Recurrent High-Grade Glioma

DISEASE CHARACTERISTICS: Histologically confirmed high-grade glioma, including any of the following: Glioblastoma multiforme Anaplastic astrocytoma Anaplastic oligodendroglioma Anaplastic mixed oligoastrocytoma Malignant astrocytoma not otherwise specified Patients with clinical and radiographic diagnosis of brain stem glioma are also eligible Evidence of tumor progression by MRI or CT scan Scan must be performed while patient is on a stable steroid dose for at least 5 days Must have failed prior radiotherapy Residual disease after prior resection of recurrent or progressive tumor is allowed PATIENT CHARACTERISTICS: Age 18 and over Performance status Karnofsky 60-100% Life expectancy More than 8 weeks Hematopoietic Absolute neutrophil count greater than 1,500/mm^3 Platelet count at least 100,000/mm^3 (transfusion independent) Hemoglobin at least 10 g/dL (transfusion allowed) Hepatic Bilirubin less than 2 times upper limit of normal (ULN) SGOT less than 2 times ULN No significant active hepatic disease Renal Creatinine less than 1.5 mg/dL OR Creatinine clearance at least 60 mL/min No significant active renal disease Cardiac No significant active cardiac disease Other Not pregnant or nursing Negative pregnancy test Fertile patients must use 2 effective methods of contraception during and for 2 months after study participation Able to swallow whole capsules No active infection requiring IV antibiotics No significant active psychiatric disease that would preclude use of the study drug No other significant uncontrolled medical illness that would preclude study participation No other active life-threatening malignancy PRIOR CONCURRENT THERAPY: Biologic therapy At least 1 week since prior interferon or thalidomide No concurrent anticancer immunotherapy Chemotherapy At least 2 weeks since prior vincristine At least 3 weeks since prior procarbazine At least 6 weeks since prior nitrosoureas No other concurrent anticancer chemotherapy Endocrine therapy See Disease Characteristics At least 1 week since prior tamoxifen Concurrent steroids for the control of increased intracranial pressure allowed Radiotherapy See Disease Characteristics At least 4 weeks since prior radiotherapy No concurrent anticancer radiotherapy Surgery See Disease Characteristics Prior recent resection of recurrent or progressive disease allowed Other Recovered from all prior therapy At least 1 week since prior noncytotoxic agents (e.g., isotretinoin), except for radiosensitizers At least 4 weeks since prior investigational agents At least 4 weeks since prior cytotoxic therapy No other concurrent investigational agents