Antineoplaston Therapy in Treating Patients With Recurrent or Refractory Oligodendroglioma

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed incurable oligodendroglioma that progressed during or is recurrent or residual after initial therapy, including radiotherapy and/or chemotherapy * Measurable tumor by MRI scan performed within two weeks prior to study entry * Tumor must be at least 5 mm * No brain stem tumors PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * Karnofsky 60-100% Life expectancy: * At least 2 months Hematopoietic: * WBC at least 2,000/mm\^3 * Platelet count at least 50,000/mm\^3 Hepatic: * Bilirubin no greater than 2.5 mg/dL * SGOT/SGPT no greater than 5 times upper limit of normal * No hepatic failure Renal: * Creatinine no greater than 2.5 mg/dL * No history of renal conditions that contraindicate high dosages of sodium Cardiovascular: * No severe heart disease * No uncontrolled hypertension * No history of congestive heart failure * No history of other cardiovascular conditions that contraindicate high dosages of sodium Pulmonary: * No severe lung disease (e.g., chronic obstructive pulmonary disease) Other: * Not pregnant or nursing * Fertile patients must use effective contraception during and for 4 weeks after study participation * No serious active infections * No other serious concurrent disease PRIOR CONCURRENT THERAPY: Biologic therapy: * See Disease Characteristics * At least 4 weeks since prior immunotherapy Chemotherapy: * See Disease Characteristics * At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas) Endocrine therapy: * Concurrent corticosteroids allowed Radiotherapy: * See Disease Characteristics * At least 8 weeks since prior radiotherapy Surgery: * Recovered from any prior surgery Other: * No prior antineoplaston therapy