Neurofibromatosis.

Neurofibromatosis (NF) is a spectrum of disorders that manifest in a variety of ways. As part of the NF spectrum, many different anatomic abnormalities can develop that cause neurologic problems. The central nervous system may be directly involved or may be affected by tumor impingement. Optic pathway gliomas may also occur. The multiple neurofibromas characteristic of the most common form of NF, Von Recklinghausen disease, have a propensity to grow anywhere along nerve pathways. Therefore, the peripheral nervous system can be extensively involved. The neurofibromas may range in size from small, circumscribed tumors to gigantic plexiform tumors that insinuate into adjacent normal tissues and may compromise their function. Other neurologic problems of a functional nature can occur as well: learning disabilities, seizures, incoordination, and sensory abnormalities, among others. Computerized tomography (CT) and magnetic resonance imaging (MRI) scans are valuable diagnostic studies for identification and follow-up of tumors and other neurologic problems that may be investigated with these techniques. Plain radiographs are useful for investigating skeletal abnormalities in the skull, the ribs, the spine, and the limbs. Neurologic studies, including electroencephalography (EEG), brain-stem evoked response (BSER) or auditory brain stem response (ABR), visual evoked response (VER), nerve conduction velocity (NCV), and electromyography (EMG) provide additional information regarding specific symptom-indicated problems.