The skull base is extremely delicate because every nerve connects to the brain through this area. It also houses the large blood vessels that supply oxygen to the brain. The most common form of abnormality that would require surgery in this area is a tumor, often benign. This is also a common location for an abnormality of a blood vessel or aneurysm.

Skull base neurosurgery typically involves removing the bone at the base of the skull to expose the tumor or aneurysm with minimal contact with the brain. Otolaryngologists (physicians who treat the ear, nose and throat) and neurosurgeons can remove tumors through the nose to avoid the facial or skull incisions associated with major surgery.

Risk Factors

Doctors are unsure of what specifically causes skull-based tumors. In rare cases, they have been linked to radiation exposure and genetics. The cause of aneurysms at the base of the skull also is largely unknown; however, a small percentage is genetically transmitted. Cigarette smoking and high blood pressure can cause aneurysms to grow and bleed.


Skull-based tumors usually do not show symptoms until they grow to a size where they exert pressure on the nerves and brain. These tumors can cause a variety of neurological symptoms such as headaches, vomiting, drowsiness, first-time seizures, double vision, facial pain or twitching, hearing loss, loss of balance or dizziness, hoarseness, speech difficulties, change in personality and tongue weakness. Aneurysms usually do not cause symptoms until they bleed. Tumors and aneurysms can be detected through tests such as MRI, CT, MRA and a standard angiography.

Treatment Options

Alternatives to surgery can include chemotherapy, embolization and radiation. 

If surgery is selected, surgeons access the skull base through the ear bone, at the temple beneath the brain, above the eye, through the nose or from the neck. Brain surgery is sometimes performed during the procedure as well. Surgeons take care to minimize the size of the bone opening to help ease recovery.

After surgery, it is necessary to reconstruct the layers covering the brain to prevent the leakage of brain and spinal fluid. Tissue from other areas of the body may be used to help with this reconstruction.

Surgical Refinements

Surgeons at Spring Valley Hospital take care to minimize the size of a bone opening during skull base surgery so that recovery may be faster. Refinements in skull base surgery techniques now allow our neurosurgeons to treat brain tumors that were previously thought to be inoperable.

Individual results may vary. There are risks associated with any surgical procedure. Talk with your doctor about these risks to find out if minimally invasive surgery is right for you.