Key Concepts
Introduction
Brainstem gliomas are a heterogeneous group of central nervous system tumors arising within the brainstem (midbrain, pons, or medulla oblongata). They represent approximately 10-20% of all pediatric brain tumors and 1-2% of adult brain tumors, with a peak incidence between ages 5-10 years. The brainstem is among the most critical anatomical structures in the central nervous system, serving as the conduit for all motor and sensory pathways between the cerebral hemispheres and the spinal cord, housing the cranial nerve nuclei (III through XII), and containing the vital centers that regulate consciousness (reticular activating system), respiration (dorsal and ventral respiratory groups in the medulla), cardiovascular function (vasomotor center, cardiac centers), and autonomic nervous system activity. The critical functional density of the brainstem means that even small tumors can produce devastating neurological deficits, and surgical resection is often impossible without causing unacceptable morbidity. Brainstem gliomas are classified by their growth pattern, location, and histology, which are the primary determinants of prognosis and treatment approach. Diffuse intrinsic pontine glioma (DIPG), now reclassified as diffuse midline glioma H3K27-altered in the WHO 2021 classification, is...