Neurofibromatosis

Neurofibromatosis is a designation for a whole group of congenital genetic diseases. The best known are neurofibromatosis type 1 and 2. Generally speaking, these diseases are linked with more frequent occurrence of various both benign and malignant tumors in various organs and tissues.

Neurofibromatosis type 1

Neurofibromatosis type 1 is also called von Recklinghausen disease and it is the most common type of neurofibromatosis.

Causes

The cause is a congenital disorder due to a genetic mutation that affects chromosome number 17. The mutation results in increased proliferation of some cells.

Symptoms

The disease manifests with frequent occurrence of neurofibromas under the skin and in some internal organs. Neurofibromas are benign tumors that arise from covers of peripheral nerve fibers and they usually look like a firm bulge under the skin. The neurofibromas are benign, but they can compress adjacent nerves and blood vessels. The patient also has spots on the skin, whose color resembles white coffee (Café au lait spots). Patients with type 1 neurofibromatosis have an increased risk of hypertension, pheochromocytoma and certain brain tumors (gliomas including malignant glioblastoma multiforme). Bone system is also affected manifesting with bone pain, curved spine and disorders of walk.

Neurofibromatosis type 2

This disorder is much rarer than neurofibromatosis type 1. In the population it is about ten times less common and its symptoms are slightly different.

Causes

Neurofibromatosis type 2 is also a result of inherited genetic mutation. In this case, however, the disorder is localized in chromosome 22.

Symptoms

Neurofibromatosis type 2 typically manifests with bilateral vestibular schwannoma (a benign tumor affecting the eighth cranial nerve leading auditory and statokinetic information from the inner ear). This may result in dizziness, tinnitus and hearing loss. The occurrence of brain tumors and spinal cord tumors (e.g. meningiomas) is increased. The tumors can cause a variety of neurological disorders including epileptic seizures, muscle paralysis, disrupted sensitivity of various body parts, urinary and fecal incontinence, personality changes and dementia. 

Diagnosis

The particular type of neurofibromatosis may be determined by a genetic analysis that may be performed even by an embryo. Such prenatal diagnostics is performed in families where more cases of the neurofibromatosis have been reported. The presence and size of individual tumors is determined mostly by imaging techniques (ultrasound, computed tomography and magnetic resonance imaging).

Treatment

The disease can not be prevented as it is inherited. The benign tumors may be removed surgically (for cosmetic reasons) and some brain tumors may be destroyed by using the Leksell gamma knife. If a malignant tumor occurs, then it is treated surgically or by other means.