Neurosarcoidosis is a complication of sarcoidosis in which inflammation and abnormal deposits occur in the brain, spinal cord, and other areas of the nervous system.
Sarcoidosis - nervous system
Causes, incidence, and risk factors:
Sarcoidosis is a long-term (chronic) disorder that affects many parts of the body, mostly the lungs. In a small number of patients, the disease involves some part of the nervous system. This is called neurosarcoidosis.
Neurosarcoidosis may affect any part of the nervous system. Sudden, facial weakness (facial palsy )is common and involves the nerves to the muscles of the face (cranial nerve VII). Any nerve in the skull can be affected, including those in the eye and those that control taste, smell, or hearing.
The condition can also affect a part of the brain called the hypothalamus, which is involved in regulating many body functions such as temperature, sleep, and stress responses.
Muscle weakness or sensory losses can occur with peripheral nerve involvement. Other areas of the brain, including the pituitary gland at the base of the brain, or the spinal cord may also be involved.
Involvement of the pituitary gland can cause:
Involvement of the brain or cranial nerves can cause:
Involvement of one or more peripheral nerves:
Note: The symptoms vary. Any part of the nervous system can be affected.
Signs and tests:
An exam may show problems with one or more nerves.
A history of sarcoidosis followed nerve-related symptoms highly suggests neurosarcoidosis. However, symptoms of the condition can mimic other medical disorders, including diabetes insipidus , hypopituitarism , optic neuritis , meningitis , and certain tumors.
Blood tests are not very helpful in diagnosing the condition. A lumbar puncture may show signs of inflammation. Increased levels of angiotensin-converting enzyme may be found in the blood or cerebrospinal fluid (CSF).
MRI of the brain may be helpful. A chest x-ray often reveals signs of the sarcoidosis. Nerve biopsy of affected nerve tissue confirms the disorder.
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 until symptom get better or go away. You may need to take the medicines for months, even years.
Other medications, particularly those that suppress the immune system, may also be recommended.
If you have numbness, weakness, vision or hearing problems, or other problems due to damage of the nerves in the brain, you may need physical therapy, braces, a cane, or walker.
Psychiatric disorders or dementia may require medication for depression, safety interventions, and assistance with care.
Pituitary disorders may respond to hormone replacement.
Some cases go away on their own in 4-6 months. Other cases continue off and on for the rest of the person's life. Neurosarcoidosis can cause permanent disability and, in some cases, death.
Complications vary depending on which part of the nervous system is involved and how you respond to treatment. Slowly worsening or permanent loss of neurological function is possible. In rare cases, the brainstem may be involved. This is life threatening.
Calling your health care provider:
Call your health care provider if you have sarcoidosis and any neurological symptoms occur.
Go to the emergency room or call the local emergency number (such as 911) if you have a sudden loss of sensation, movement, or body function.
Treatment of sarcoidosis turns off the body's faulty immune response before your nerves become damaged. This may reduce the chance that neurological symptoms will occur.
References: Lower EE, Weiss KL. Neurosarcoidosis. Clin Chest Med. 2008 Sep;29(3):475-92, ix. Review.