Conditions related to base-of-skull tumors: symptoms
and treatments
Trigeminal neuralgia
Also called tic doloreux, this painful condition involves the trigeminal nerve,
which provides sensation to the side of the face and the head. It is characterized
by episodes of intense, shooting, electric shock-like facial pain that may
occur spontaneously or be triggered by such activities as talking, brushing
teeth or chewing. The disorder is more common in women than in men and rarely
affects anyone younger than 50.
Trigeminal neuralgia is sometimes caused by benign tumors or multiple sclerosis, but most often is an idiopathic condition in that there is no specific cause. Our experience is that trigeminal neuralgia most often can be traced to a blood vessel compressing the trigeminal nerve, causing it to fire in an erratic fashion and producing the severe pain syndrome. The diagnosis is made on the basis of an MRI scan, which rules out a structural pathology.
At the Center for Cranial Base Surgery, several treatment options, all of which offer variable rates of success in controlling pain, are available and are decided on jointly by patients, their families and the medical team. They are:
- microvascular decompression of the nerve - Through a small opening in the skull behind the ear, the surgeon separates the compressing blood vessel from the nerve at the brainstem and repositions it with small padding.
- percutaneous balloon compression of the nerve - A needle is inserted through the patient's cheek into the trigeminal nerve and ganglion. A small balloon catheter is then inserted and inflated to produce compression and partial damage to the nerve and ganglion.
- stereotactic radiation for the trigeminal root - A focused beam of radiation is directed into the nerve root in front of the brainstem.
Hemifacial spasm
This rare neuromuscular disorder is characterized by frequent involuntary contractions of the muscles on one side of the face. It usually begins with tics or spasms of the eyelid, sometimes gradually over several months or years. In its severest form, spasms may be strong enough to force the eye to close or the mouth to pull up at an angle. Hemifacial spasm, which is aggravated by anxiety and stress, can produce significant functional disability and social difficulties for patients.
Hemifacial spasms may be caused by facial nerve injury or a tumor, although imaging studies do not often show these abnormalities. Our experience is that very commonly, hemifacial spasm is caused by a blood vessel pressing on the facial nerve where it connects with the brainstem.
Treatments available are:
- botulinum toxin (Botox) injection into the affected muscles, which results in temporary weakness or paralysis of the affected muscles. This procedure must be repeated at intervals as the medication wears off.
- Microsurgery is the more permanent treatment. Using microsurgical techniques, the compressing blood vessel is identified and, through a small incision behind the ear, the surgeon separates the nerve and blood vessel, leaving small padding in place.
Glossopharyngeal neuralgia
This condition is similar to trigeminal neuralgia in that patients experience
sharp, shooting, electric shock-type pain, but in the back of the throat and
the base of the tongue on one side, instead of in the face. Pain episodes
are usually brought on by chewing or swallowing.
Although such pain may be associated with a tumor or lesion, the condition most often results from a blood vessel compressing the nerves as they exit the brainstem. Initial treatment is usually with medication, followed by surgery if relief is not provided. The most effective surgical technique, and one that is successfully performed here, involves making a small incision behind the ear and separating the compressing blood vessel or partially removing a few of the glossopharyngeal nerve rootlets.