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