Curriculum · Neurology
Brainstem glioma and diffuse intrinsic pontine glioma
What it is
A brainstem glioma is a glioma, usually an astrocytoma, arising in the brainstem, that is the pons, midbrain or medulla. The most common type is the diffuse intrinsic pontine glioma (DIPG). It is mostly seen in children, with a peak at 5-10 years.
How it presents
The picture is built from what the brainstem carries:
- Cranial nerve palsies, for example CN VI and CN VII.
- Long tract signs such as hemiparesis.
- Ataxia.
- Dysphagia and dysarthria.
How it is diagnosed
MRI carries the diagnosis: an enlarged pons with T2 hyperintensity, poorly defined margins, and usually no contrast enhancement. Biopsy is often not performed because the location is risky, and imaging is usually diagnostic. The histology, where it is had, is usually a high-grade glioma, for example a diffuse midline glioma with the H3K27M mutation.