Neurosarcoidosis is a complication of sarcoidosis involving inflammation and abnormal deposits in the tissues of the nervous system (which includes the brain, the spinal cord, and other nerves).
Causes, incidence, and risk factors
Sarcoidosis is a chronic disorder that affects many body systems. The majority of cases involve the lungs, but the condition can affect any area of the body.
Sarcoidosis is characterized by an abnormal immune system response that produces deposits of white blood cells and abnormal tissue cells in the affected organ. A small percentage of cases will involve some portion of the nervous system (neurosarcoidosis).
Neurosarcoidosis may affect any part of the nervous system. Sudden, transient facial palsy (facial weakness) is common with involvement of cranial nerve VII. Any nerve can be affected, including the nerves of the eye and the nerves 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 or the spinal cord may also be involved. Neurosarcoidosis can cause permanent disability and, in some cases, death.
Sarcoidosis occurs in highly variable groups. In the U.S. it is more common in blacks, while in Europe it is more common in whites. The disorder is slightly more common in people aged 25-50, particularly women, but can occur at any age and to either gender. It is very rare in children. When it does affect children, sarcoidosis usually involves the lungs.
Involvement of the pituitary gland can cause:
- High urine output
- Excessive thirst
- Changes in Menstrual Periods
- Excessive tiredness (fatigue)
Involvement of the brain or cranial nerves:
- Facial palsy (weakness, drooping)
- Dementia or delirium o Confusion, disorientation o Loss of memory, judgment, or calculation skills
- Psychiatric disturbances (any)
- Loss of sense of smell
- Loss of sense of taste, abnormal tastes
- Decreased hearing
- Vision abnormalities
- Dizziness or vertigo (abnormal sensation of movement)
- Speech impairment
Involvement of one or more peripheral nerves:
- Loss of sensation in any body part
- Abnormal sensations in any body part
- Loss of movement of any body part (joint stiffness)
- Weakness of any body part
Note: The symptoms are highly variable. Any part of the nervous system can be affected, from a single nerve to multiple nerves to many different sites in the nervous system.
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 cerebrospinal fluid (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.
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 for months to years, or until symptoms subside. Other medications, particularly those 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 such as medication for depression. Pituitary disorders may respond to conventional treatments such as hormone replacement.
The probable outcome varies. Some cases resolve on their own in 4-6 months. Other cases continue intermittently for the rest of the person’s life.
- 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.
Calling your health care provider
Call your health care provider if you have sarcoidosis and any neurologic symptoms occur.
Go to the emergency room or call the local emergency number (such as 911) if there is a sudden loss of sensation, movement, or function.
Treatment of known sarcoidosis may reduce the chance that neurologic symptoms will occur by shutting off the immune system before the abnormal response can harm nerves.
by Sharon M. Smith, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.