CIDP (Chronic Inflammatory Demyelinating Polyneuropathy) is a rare disorder of the peripheral nerves characterized by gradually increasing weakness of the legs and, to a lesser extent, the arms.
It is the gradual onset as well as the chronic nature of CIDP that differentiates it from GBS. Fortunately, CIDP is even more rare than GBS. The incidence of new cases is estimated to be between 1.5 and 3.6 in a million people (compare to GBS: 1-2 in 100,000).
Like GBS, CIDP is caused by damage to the covering of the nerves, called myelin. It can start at any age and in both genders. Weakness occurs over two or more months.
Unlike GBS, CIDP is not self-limiting (with an end to the acute phase). Left untreated, 30% of CIDP patients will progress to wheelchair dependence. Early recognition and treatment can avoid a significant amount of disability.
||What causes CIDP?
Current theory holds that the body’s immune system which normally protects it, perceives myelin as foreign and attacks it. Just what starts this process is not clear. Some patients are found to have abnormal proteins in their blood, and these may facilitate damage.
||How is CIDP diagnosed?
Diagnosis of CIDP is based on the symptoms of the patient:
- difficulty walking which progressively worsens over a few months
- tingling or other abnormal sensations may also be experienced
- loss of reflexes, such as the knee and ankle jerk
Tests may include:
- an electrical test, a nerve conduction velocity-electromyography study
- a spinal tap, to analyze cerebrospinal fluid
- blood and urine tests, including analysis of proteins
||How is CIDP treated?
Treatment options are similar to GBS treatment, though will not require a lengthy hospital stay:
- Prednisone, similar to protective anti-inflammatory corticosteroids that are normally made by the body, may be used as an initial treatment for several reasons. It often improves strength, can be conveniently taken by mouth, and is inexpensive. Side effects can limit its use.
- High dose Intravenous Immune Globulins (IVIG), protective blood proteins obtained from healthy volunteers, can be readily given through an arm vein.
- Plasma Exchange (PE), or Plasmapheresis, is when some of the patient’s blood is removed and the blood cells returned without the liquid plasma portion of the patient’s blood. It may work by removing harmful antibodies contained in the plasma.
Treatment of CIDP is somewhat of an art. If a patient shows good improvement with an initial treatment but experiences additional weakness, it may be repeated or another therapy may be tried.
If treated early and aggressively, most CIDP patients respond well to therapy that can limit the damage to peripheral nerves and contribute to improved function and quality of life.
There are three general forms of CIDP:
- Progressive form extending over several years
- Recurrent form with multiple episodes that may be separated by months or years
- Monophasic form in which a single episode extends over one to three years without recurrence
||Living with CIDP
Post-treatment life depends on whether the disease was caught early enough to benefit from treatment options. Patients respond in various ways. The gradual onset of CIDP can delay diagnosis by several months or even years, resulting in significant nerve damage that may take several courses of treatment before benefits are seen. The chronic nature of CIDP differentiates long-term care from GBS patients. Adjustments inside the home may need to be made to facilitate a return to normal life.