Alternate Names: Sarcoidosis - nervous system
Causes and Risks: Sarcoidosis is a chronic disorder that affects many body systems. Over 90% of cases involve the lungs and may also involve any other area of the body. About 5% of cases will involve some portion of the nervous system (neurosarcoidosis). The disorder involves an abnormal immune system response resulting in deposits of white blood cells and abnormal tissue cells in the affected organ.
Neurosarcoidosis may affect any part of the nervous system. Sudden, transient facial palsy is common with involvement of cranial nerve VII. Any nerve can be involved, including the nerves of the eye and the nerves that control taste, smell, or hearing. It may also involve a part of the brain called the hypothalamus which is involved in regulating many body functions. Muscle weakness or sensory losses can occur with peripheral nerve involvement. The brain or spinal cord may also be involved.
Neurosarcoidosis is a clinically significant complication of sarcoidosis because it increases the risk of permanent disability and, in some cases, death.
Sarcoidosis occurs in highly variable groups. In the U.S. it is more common in African-Americans, while in Europe it is more common in Caucasians. The disorder is slightly more common in people 25 to 50 years old, particularly women, but can occur at any age and to either sex. It is very rare in pediatrics. If it occurs in children, sarcoidosis usually involves the lungs.
Prevention: Treatment of known sarcoidosis may reduce development of neurologic symptoms in some cases.
Symptoms: Involvement of the pituitary gland can cause:
Involvement of the brain or cranial nerves:Involvement of one or more peripheral nerves:Note: The symptoms are highly variable. Any part of the nervous system may become involved in neurosarcoidosis. Involvement may be a single nerve, multiple nerves, or generalized.
Signs and Tests:
An examination may indicate single nerve dysfunction (mononeuropathy) or dysfunction of multiple peripheral nerves (sensorimotor polyneuropathy). Signs may mimic diabetes insipidus, hypopituitarism, optic neuritis, meningitis, space-occupying lesions such as tumors, or other neurologic disorders.
A history of sarcoidosis followed by neurologic symptoms is highly suggestive of neurosarcoidosis. Blood tests are nonspecific. A lumbar puncture may show signs of inflammation. Elevated levels of angiotensin converting enzyme may be found in the blood or CSF.
If sarcoidosis is suspected but not already known, a chest X-ray often reveals lesions typical of the disorder. Nerve biopsy of affected nerve tissue confirms the disorder.
Treatment: There is no known cure for the disorder. Treatment is indicated if symptoms are severe or progressive. The goal of treatment is to reduce symptoms.
Corticosteroids such as Prednisone are prescribed to reduce inflammation. They are often prescribed long-term, for months to years, or until symptoms subside. Other medications, particularly medications that suppress the immune system, may also be recommended.
Symptoms should be treated. For example, a numb body part should be protected from harm. Weak areas may require physical therapy or appliances to aid mobility and ability to function. Psychiatric disorders or dementia may require safety interventions, assistance with care, and other treatments. Pituitary disorders may respond to conventional treatments such as hormone replacement.
Prognosis: The probable outcome varies. Some cases resolve spontaneously in 4 to 6 months. Other cases continue intermittently for the rest of the person’s life. About 5% of people with sarcoidosis of any type will die as a direct result of the disorder, most commonly when brainstem or heart involvement causes cardiac arrest.
Complications:
- Permanent neurologic losses
- Progressive neurologic losses
- Brainstem involvement (rare, but life threatening)
Note: Complications are variable depending on which portion of the nervous system is involved and the response to treatment.
Call your health care provider if you have sarcoidosis and any neurologic symptoms occur.
Call your health care provider any time there is a sudden loss of sensation, movement, or function.
