Skull Base Meningiomas
What is a Skull Base Meningioma?
A skull base meningioma is usually a slow-growing tumour that develops from the meninges - the protective layers covering the brain and spinal cord - at the base of the skull. The skull base is the lower part of the skull that supports the brain and houses critical structures, including the cranial nerves, brainstem, and major arteries. Most meningiomas are benign (non-cancerous), but because they grow near important nerves and blood vessels, they can still cause serious symptoms by pressing on nearby structures. Skull base meningiomas may occur near areas such as the optic nerves, brainstem, cranial nerves, or major arteries.
What Causes Skull Base Meningioma?
The exact cause of a skull base meningioma is not fully understood. It develops when cells in the meninges begin to grow abnormally and form a tumour. Most cases occur without a clear reason, but several factors may increase the risk, including:
- Genetic changes in meningeal cells
- Previous exposure to radiation, especially to the head
- Hormonal influences, as meningiomas are more common in women
- Increasing age, particularly in older adults
- Inherited conditions such as Neurofibromatosis Type 2, which can raise the risk of developing meningiomas
- A possible link with obesity and certain lifestyle factors
What are the Signs and Symptoms of Skull Base Meningioma?
The signs and symptoms of a skull base meningioma vary depending on the tumour’s size and the nerves or brain structures it affects. Because these tumours usually grow slowly, symptoms may develop gradually over time.
Common signs and symptoms include:
- Persistent headaches
- Vision changes or double vision
- Hearing loss or ringing in the ears
- Facial numbness, pain, or weakness
- Difficulty swallowing or speaking
- Balance problems or dizziness
- Weakness in the arms or legs
- Memory or personality changes
- Seizures in some cases
How is Skull Base Meningioma Diagnosed?
A skull base meningioma is diagnosed through a combination of medical history, neurological examination, and imaging tests. Doctors commonly use MRI scans to identify the tumour’s size, location, and effect on nearby brain structures and nerves. CT scans may also help assess the involvement of the skull bones. In some cases, additional tests such as vision, hearing, or balance evaluations are performed. A biopsy may be recommended to confirm the diagnosis and determine the tumour type if surgery is performed.
How is Skull Base Meningioma Treated?
Treatment for a skull base meningioma depends on the tumour’s size, location, growth rate, symptoms, and the patient’s overall health. Common treatment options include:
- Observation (watchful waiting): Small, slow-growing tumours without symptoms may be monitored with regular MRI scans.
- Surgery: Neurosurgeons may remove as much of the tumour as safely possible while protecting nearby nerves and blood vessels.
- Radiation therapy: Techniques such as stereotactic radiosurgery or focused radiation may be used to treat remaining tumour tissue or tumours that cannot be fully removed surgically.
- Combination treatment: Some patients may require both surgery and radiation therapy for better tumour control.
- Supportive care: Medicines and rehabilitation therapies may help manage symptoms such as seizures, headaches, balance problems, or nerve-related difficulties.
