Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder in which there is inflammation of nerve roots and peripheral nerves and destruction of the fatty protective covering (myelin sheath) over the nerves.

• This affects how fast the nerve signals are transmitted and leads to loss of nerve fibers, which causes weakness, paralysis and/or impairment in motor function, especially of the arms and legs (limbs).
• Sensory disturbance may also be present.
• The motor and sensory impairments usually affect both sides of the body (symmetrical), and the degree of severity and the course of disease may vary from case to case.
• Some affected individuals may follow a slow steady pattern of symptoms while others may have symptoms that stabilize and then relapse.

Break down of the words Chronic inflammatory demyelinating polyneuropathy:

• Chronic means that the disease occurs over a long period of time.
• Inflammatory indicates that the nerve damage occurs due to the presence of inflammation, a complex process involving the immune system.
• Demyelinating means the damage affects the protein coating (myelin) around the nerve fibers.
• Polyneuropathy means that the disease affects more than one nerve.

CIDP is sometimes thought of as the chronic form of acute inflammatory demyelinating polyneuropathy (AIDP), the most common form of Guillain Barré syndrome (GBS), in the United States and Europe. In contrast to GBS, most patients with CIDP cannot identify a preceding viral or infectious illness.

• GBS is a subacute disorder that progresses over 3-4 weeks after an illness, then plateaus and usually improves over months and does not recur.
• CIDP, by definition has ongoing symptoms for over 8 weeks and usually does not improve unless ongoing treatment is given. What set it apart from other diseases similar to it is that there seems to be no viral infection present approximately 3 months before the disease is apparent.

Signs & Symptoms:

• The chief symptoms of CIDP are slowly progressive (over at least 2 months) symmetric weakness of both muscles around the hip and shoulder as well as of the hands and feet (both proximal and distal muscles).
• Nerve signals become altered causing impairment in motor function and/or abnormal, or loss of, sensation.
• There are usually some alterations of sensation causing incoordination, numbness, tingling, or prickling sensations.
• Some patients only have sensory symptoms and signs but have the typical abnormalities of nerve conduction and respond to treatment as in CIDP in which weakness predominates. This is considered the sensory variant of CIDP.
• Other symptoms of CIDP include fatigue, burning, pain, clumsiness, difficulty swallowing and double vision.
• The neurologic examination will show weak muscles that may have lost their bulk and definition (atrophy).  Deep tendon reflexes are reduced or absent. Walking will be abnormal and responses to various sensory stimuli will be impaired.

Causes

• The exact cause of CIDP is unknown but there are strong indications that CIDP is an autoimmune disorder.
  • Autoimmune disorders occur when the body’s natural defenses (antibodies and lymphocytes) against invading organisms suddenly begin to attack perfectly healthy tissue. The cause of autoimmune disorders is unknown.

Affected Populations

• CIDP is a rare disorder that can affect any age group and the onset of the disorder may begin during any decade of life. However, the peak period patients develop it is in the 5th to 7th decade of life.
• CIDP affects males twice as often as females (M2:F1) and the average age of onset is 50.
• The prevalence of CIDP is estimated to be around 5-7 cases per 100,000 individuals.
• As many as 40,000 people in the U.S. may have the condition, but it’s hard to know how many people have it as it isn’t easy to diagnose.
• The Lewis-Sumner form of this condition is considered a rare disease with only 50 cases reported up to 2004. A total of 90 cases had been reported by 2009.

Prognosis

• The disease is a treatable cause of acquired neuropathy and initiation of early treatment to prevent loss of nerve axons is recommended.
• Post-treatment life depends on whether the disease was caught early enough to benefit from treatment options and some individuals may be left with some residual numbness or weakness.
  • The gradual onset of CIDP can delay diagnosis by several months or even years, resulting in significant nerve damage that may limit and delay the response to therapy.
  • The chronic nature of CIDP requires long-term care of patients and accommodations in the home may be needed to facilitate daily living activities.
• The course of CIDP varies widely among individuals. Some may have a bout of CIDP followed by spontaneous recovery, while others may have many bouts with partial recovery in between relapses.
• There is no cure for CIDP. The treatment does suppress activity of the disease by dampening down inflammation of the nerves. We are only able to treat the effects of the disease, not the disease itself. Until more is known about the causes of the abnormal immune response against the nerves, this will remain the mainstay of treatment.

The GBS CIDP Foundation International has publications for patients and their caregivers.

Resources & Additional Reading

• NORD - Chronic Inflammatory Demyelinating Polyneuropathy (Includes list of support organizations with locations, phone #’s and websites)
• NIH Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) Information Page
• GBS/CIDP - Recently Diagnosed with CIDP (Included “Managing your CIDP” video presented by Dr Kenneth Gorson in June 2015)
• Wikipedia - Chronic inflammatory demyelinating polyneuropathy
• American Association of Neuromuscular & Electrodiagnostic Medicine - Chronic Inflammatory Demyelinating Polyneuropathy
• Salford Royal NHS Foundation Trust; National Database Clinical, Lead Author Amanda Woodall - C.I.D.P. Patients information sheets