Developing in the nerve sheath at the base and skull and originating from its namesake cells—glial cells that create a myelin sheath around nerves to protect information transmissions through the peripheral nervous system—trigeminal schwannomas are a type of intracranial tumor. Slow growing and most often benign, these types of tumors typically aren’t dangerous unless they grow to such as size as to exert pressure on the brain.
While the specific causes of schwannomas are unknown, simply put tumors are abnormal growths due to unnecessary cell multiplication that serves no proper function in the human body. Typically, cell multiplication is controlled by suppressor genes, which continually act to protect cells from cancer-causing genes known as oncogenes. However, when suppressor genes fail because of changes in their protein coding, tumor can develop as cell division becomes unregulated.
Whereas our body’s built-in defenses find and destroy these abnormal cells, naturally occurring chemicals sometimes hamper the ability of our immune system to see these cells, as which point they become strong enough and exist in large enough numbers to overpower any of body’s defenses.
Many patients who have a trigeminal schwannoma have no symptoms at all, while some do experience pain or numbness in the face, headaches and auditory problems. In rare and more serious cases seizures may occur, as may changes in mood or behavior and cognitive difficulties.
A diagnosis of trigeminal schwannoma is attained from neurological exam combined with image testing such as CT scans and MRIs. A biopsy of the tumor may also be necessary to determine its malignant or benign nature.
Treatments for tumors of the skull base such as trigeminal schwannomas include different surgeries to remove the tumor. The type of surgery depends on the location and size of the anomaly but include endonasal endoscopic surgery, a craniotomy using an endoscopic or endoscopic assisted microsurgery, all of which are minimally invasive procedures. If the tumor is malignant or cannot be removed completely, radiation therapy may be recommended after surgery.