Different types of benign and malignant tumors may develop in the skull base. Among the frequent ones are meningiomas and vestibular schwannomas (aka acoustic neurinoma). The skull base comprises the lower part of the skull including transitions to the cervical spine, the nasopharynx and the eye cavity. Tumors in this area often affect the basal parts of the brain (e.g. brain stem) and the 12 cranial nerves. Frequently tumors become symptomatic by affecting these structures.

If cranial nerves are affected, typical symptoms include: Olfactory and taste disorders (olfactory nerve); blurred vision (optic nerve); double vision (3 eye muscle nerves); facial pain or numbness in parts of the face (trigeminal nerve); weakness of parts of the facial muscles (facial nerve); hearing loss, ringing in the ears = tinnitus (auditory nerve); dizziness and vertigo (vestibulocochlear nerve); dysphagia, hoarseness (lower cranial nerves); weakness of the face, head and shoulder muscles.

Other symptoms, such as gait disturbance, paralysis and numbness throughout the body can be caused by affection of the brain stem. By occluding the outflow of cerebrospinal fluid (CSF) patients may develop gait disorders, memory problems, headaches and disorders of bladder control. Hormonal disorders may also occur with tumors in the region of the pituitary gland.

Most skull base tumors can be detected by MRI and CT. Additional exams include investigation of the functions of the cranial nerves such as auditory, visual and vestibular testing. Electrophysiological studies of the functions (eg, brainstem, AEP) complete these tests. For highly vascularized tumors sometimes a vascular imaging (angiography) and possible occlusion of vessels (embolization) is useful.

For the treatment of skull base tumors a good collaboration of several experts in interdisciplinary centers is often the best way. We therefore discuss our patients in an interdisciplinary tumor board. The mostly slow-growing skull base tumors do usually not require urgent treatment. Radiation therapy and radiosurgery can be very successful in some tumors and may be used in addition to surgery. The goal of surgery is to eliminate the cause of existing and preventing or delaying the onset of new symptoms.