Skull base surgery refers to a group of operations to remove the brain or nerve tumors that occur at the bottom of the brain.
Your brain rests in a bony chamber called the ‘cranium’ or the ‘skull’. It protects the brain from injuries. On the top of the skull are large and smooth bones that provide a round appearance to the head.
At the base of the skull are bones that separate the skull from organs in the face. There are three large depressions in the skull at its base. These depressions or fossae act as seats for the brain. Three fossae in the skull are the anterior, middle, and posterior cranial fossae.
There are several openings in these fossae for the spinal cord and cranial nerves from the brain to pass down. Similarly, there are large canals for the arteries and veins that supply and drain blood from the brain to pass through.
Skull base tumors occur at the base of the brain as it meets the skull base. During a minimally invasive skull base surgery, the neurosurgeon makes use of the natural openings in the cavities of the skull base like the nasal, orbital, oral cavities. Some skull base surgeries use an artificial opening in the skull bone through a craniotomy.
Skull base surgery help to remove cancerous and non-cancerous tumors at the base of the brain. It also helps in treating bony tumors at the skull base as well as at the top vertebrae.
- Skull Base Surgery – When ToDo?
Skull base surgery can help in treating the following conditions.
- Cysts in the base of the brains like arachnoid, dermoid cysts, etc.
- Infections like osteomyelitis of the skull base.
- Acoustic neuroma, a tumor of the vestibulocochlear nerve that supplies the ear.
- Tumors of and close to the pituitary gland like pituitary adenomas and craniopharyngiomas.
- Benign tumors of the meninges like meningiomas.
- Skull base chordomas which are malignant cancers.
Apart from this, skull base surgery can also correct problems with the nerves and blood vessels. These include:
- Trigeminal neuralgia- It is a painful condition that affects the trigeminal nerve that carries sensations from the face to the brain.
- Hemifacial spasm- A condition where there is sporadic twitching of the muscles on one side of the face. It occurs due to pressure on the facial nerve due to a tumor or aneurysm.
- Cerebral aneurysms in the base of the brain- These are enlargement in the cerebral arteries in some areas.
Injuries to the head and face can also damage the bones in the base of the skull. Fractures of the base of the skull will also need surgery for correction.
Craniosynostosis, a birth defect that causes an abnormal skull shape, also needs a skull base surgery. In this condition, the sutures or fibrous joints that connect the skull bones close prematurely. It causes a lot of pressure in the brain as it develops.
- What are the symptoms due to problems in the skull base?
If you have problems in the base of the brain or the skull, some of the common symptoms you will have include;
- Pain in the face- You may have pain in some areas of the face. The areas of pain will depend on the location and type of problem you have.
- Headaches- Tumours, as well as other problems, will give you recurrent headaches.
- Dizziness- Compression on some nerves or blood vessels close the skull base can make you feel dizzy. Loss of balance will occur if the problem is severe.
- Numbness or weakness of the face- This happens due to problems with cranial nerves as they exit the skull base. Compression on the sensory nerves causes numbness while on the motor nerves, it causes weakness.
- Problems with the vision- It occurs due to effects on the optic nerve
- Hearing problems- Tumors like acoustic neuromas can cause hearing loss and a ringing of the ears or tinnitus
All these symptoms can occur due to other problems as well. For an accurate diagnosis, you will need a few tests to confirm the problem.