A brainstem glioma is a tumor that forms from glial cells, the supportive tissues of the brain. These tumors are located in the brainstem, the structure that connects the brain to the spinal cord. The brainstem manages fundamental operations like heart rate, breathing, and motor skills. While these tumors can be diagnosed in adults, they are more frequently found in children, and their location presents unique challenges for treatment.
Types of Brainstem Gliomas
Brainstem gliomas are categorized by their growth patterns and location. The most common type, especially in children, is the Diffuse Intrinsic Pontine Glioma (DIPG). DIPGs are aggressive, rapidly growing tumors that arise in the pons and infiltrate healthy brain tissue, making them difficult to remove surgically.
Another classification is the focal brainstem glioma. These tumors are more localized, slower-growing, and have defined borders, meaning they do not spread as extensively into surrounding tissue. Focal gliomas are more common in adults and form in areas like the midbrain or medulla. Less common are tectal gliomas, which are slow-growing and located in the tectum of the midbrain.
Associated Symptoms
Problems with balance, coordination, and walking are common signs of a brainstem glioma. Many individuals experience issues with the cranial nerves, which can lead to:
- Weakness on one side of the face
- A drooping eyelid
- Abnormal eye movements
- Difficulties with chewing and swallowing
Limb weakness or numbness can occur if the tumor affects nerve fiber bundles passing through the brainstem. Increased pressure inside the skull, known as intracranial pressure, can cause headaches that are worse in the morning, nausea, and vomiting. In some cases, symptoms can appear and worsen quickly over days or weeks.
The Diagnostic Process
Diagnosis begins with a neurological exam to assess functions like reflexes, balance, and eye movement. The primary tool for confirmation is Magnetic Resonance Imaging (MRI), which provides detailed pictures of the tumor’s location, size, and effect on surrounding structures. This imaging is fundamental to determining the glioma type.
For diffuse tumors like DIPG, a biopsy is often avoided because the surgical risks in this delicate area are very high and can cause more harm. The characteristic appearance of a DIPG on an MRI is sufficient for diagnosis. For focal gliomas that appear more contained, a surgeon may perform a biopsy to obtain a tissue sample for analysis of the tumor’s cell type and grade.
Treatment and Management
Treatment for a brainstem glioma depends on its type, location, and grade. For patients with DIPG, radiation therapy is the primary treatment used to slow the tumor’s growth and relieve symptoms, though it is not a cure. Chemotherapy has shown limited effectiveness, so many patients are encouraged to participate in clinical trials exploring new therapies.
For focal brainstem gliomas, a surgeon may attempt to remove as much of the tumor as possible if it is in an accessible location. Complete removal can sometimes be curative for low-grade focal tumors. After surgery, or if surgery is not an option, radiation and chemotherapy may be used to target remaining tumor cells.
Supportive and palliative care is a part of the management plan for all tumor types. This care focuses on controlling symptoms like pain and nausea, managing neurological issues, and maintaining the best possible quality of life.