Wild-Type Reovirus in Combination With Sargramostim in Treating Younger Patients With High-Grade Relapsed or Refractory Brain Tumors

Inclusion Criteria: * Histological confirmation of a high grade (grade 3 or 4) primary brain tumor either classified as a glioma (including astrocytoma, anaplastic oligodendroglioma and glioblastoma multiforme), medulloblastoma, atypical teratoid/rhabdoid tumor (AT/RT) or primitive neuroectodermal tumor (PNET) * Note: Patients with diffuse intrinsic pontine glioma (DIPG) are exempt from this confirmation of tumor if characteristic radiologic findings are noted on magnetic resonance imaging (MRI) * Patients must have no known curative therapy available * Evidence of tumor progression by MRI scan following radiation therapy or following the most recent anti-tumor therapy; note: patients who have had surgical treatment at recurrence are eligible if they had a resection with measurable residual disease on postoperative imaging or if there is imaging evidence of disease progression as compared to the first postoperative scan * Measurable disease: measurable by gadolinium MRI scan * Absolute neutrophil count (ANC) \>= 750 /uL obtained =\< 7 days prior to registration * Absolute lymphocyte count (ALC) \>= 250/uL obtained =\< 7 days prior to registration * Platelet count (PLT) \>= 75,000 /uL without transfusions obtained =\< 7 days prior to registration * Hemoglobin \>= 7.0 gm/dL obtained =\< 7 days prior to registration * Total bilirubin =\< 1.5 times upper limit of institutional normal (ULN) for age obtained =\< 7 days prior to registration * Aspartate transaminase (AST) =\< 3 …