The tests and exams used to confirm a neurofibromatosis diagnosis vary depending on the type of the disorder suspected. For example, neurofibromatosis 1 (NF1) causes physical symptoms apparent to the naked eye such as cafe au lait spots while neurofibromatosis 2 (NF2) affects balance and hearing. The rarer schwannomatosis type usually manifests as chronic pain. The examining physician may order eye and ear exams as well as a full physical exam and imaging tests like x-rays. Genetic testing can also be requested and can be performed in the prenatal stage.
When diagnosing NF1, the examining physician will usually focus on the disease’s most common physical signs. At least six cafe au lait spots should be found on the patient’s skin as well as freckling in the groin area. There may also be at least two Lisch nodules and neurofibromas. Some patients may have bony lesions or an optic pathway tumor. Many NF1 patients will also have a first-degree relative with the disorder and are shorter with a larger than average head.
A neurofibromatosis diagnosis of the type NF1 can usually be made within the first two years of a patient’s life. Prenatal genetic testing for NF1 also exists, confirming the presence or absence of the NF1 mutation before birth. Additional testing usually includes eye exams and imaging like x-rays and computerized tomography scans to help locate bony lesions and tumors.
NF2 is a rarer type of this disorder and is inherited in approximately half the cases. It is characterized by tumors on the acoustic and vestibular nerve branches. As a result, the patient will likely have balance issues, ringing in the ears, and even hearing loss. Cataracts may also be present. A neurofibromatosis diagnosis of this type usually involves an ear exam or hearing test and a family history of the disorder.
The rarest form of this disorder is schwannomatosis. Patients with this type usually develop schwannomas all over or in a specific part of the body but not on the vestibular nerve. Chronic pain is the characteristic symptom, although some patients also experience tingling and numbness. When confirming a neurofibromatosis diagnosis of this type, the treating physician will look for schwannomas. Prenatal testing for NF2 is available but with an accuracy rate of around 65 percent while no genetic testing for schwannomatosis exists.
Any neurofibromatosis diagnosis can be difficult for the patient because it is a progressive disorder that will usually get worse with time. In most cases of NF1, the symptoms are mild and the patient will have a normal life expectancy. Those with NF2 will likely experience worsening balance and hearing. Surgical options can remove large and malignant tumors as they develop, providing some relief. Most patients with neurofibromatosis do lead normal lives, requiring only monitoring.
