Neurological Disorders: CIDP

CIDP is an unofficial but commonly used abbreviation by medical staff for chronic inflammatory demyelinating polyadiculoneuropathy. This condition, as the name implies is a type of neuropathy (nerve disease) and it evolves slowly (chronic disease). A neurologist commonly involves in the management of these patients.

It is considered to be the chronic variant of AIDP (Acute Inflammatory Demyelinating Polyradiculoneuropathy or GBS/Guillain Barre Syndrome).

Both are inflammatory diseases (also autoimmune type disorders) because certain inflammatory process triggers these diseases. They are autoimmune disorders because the immune system in the body, instead of helping, paradoxically attacks tissues or organs of one's own body.

It is one of the several different physiological processes occurring in the body to help with defending the body from any external threats like infection or other insults and also facilitate the healing process.

There are two types; acute & chronic. The acute inflammation is characterized by pain, swelling, increased local temperature, reddened discoloration and loss of function of the affected part of the body. The chronic inflammation also produces similar changes but may not be as intense as acute type.

Inflammatory process is expected to help our body all the time, but sometimes this process crosses the boundaries and then it can produce more damage than help. Also at times this process occurs in body without any need for it, and this almost always will result in some harm to the body, and CIDP is one such example.

With CIDP, the inflammatory process damages the myelin sheath, an insulation material wrapping around certain types of nerves, usually the large-diameter type nerve fibers. The myelin enhances the conduction of electrical signals (nerve impulses) along these nerves significantly. If there is damage to the myelin structure then the conduction along the nerves slows down and this will affect various motor and sensory functions of the limbs and body and that is exactly what happens with CIDP.

Actually myelin tissue is also present in the Central nervous system (the brain & spinal cord) but this is not affected as it has certain structural differences with the one found along the peripheral nerves.

This nerve-disease is also called as polyradiculoneuropathy since the myelin tissue damage frequently involves the spinal nerve rots as well.

• Symptoms generally begin in the lower extremities then slowly move upwards
• Tingling sensation (pins & needles)
• Numbness feeling
• Weakness of the limb muscles
• Gradual thinning (wasting or atrophy) of muscles
• Sensory deficits (decreased sensation over the limbs)
• Absent or decreased deep tendon reflexes
• Bowel/bladder disturbances like incontinence, retention, diarrhea, constipation etc
• Heart rate, blood pressure and temperature abnormalities
• Sexual dysfunction

Chronic inflammatory demyelinating polyradiculoneuropathy is a chronic disease and has a variable course. Generally it progresses slowly and results in more and more disability. Intermittent acute exacerbations can occur too.

An EMG/NCS (electromyography and nerve conduction study) is necessary to confirm the diagnosis of this condition. It will show a predominantly segmental demyelinating picture. If uniform demyelination is seen it might favor the diagnosis of CMT (Charcoat Marie Tooth disease).

A bunch of blood tests may be ordered to rule out any known medical conditions causing polyneuropathy and such tests might include B12, ESR, ANA, blood sugar, thyroid tests, serum protein electrophoresis, HIV test etc.

Sometimes a nerve biopsy is necessary to arrive at the proper diagnosis.

Steroids are considered as the drug of choice and oral prednisolone is usually started. If condition is severe intravenous steroids may be given for first few days followed by oral steroids. Other immunosuppressive agents like azathioprne, cyclosporine can be tried too if steroids are not tolerated or not effective.

For acute exacerbations intravenous immunoglobulins, plasmapheresis, intravenous steroids are some of the options.

Patients may require symptomatic treatment for their numbness, tingling and nerve pain symptoms and gabapentin, duloxetine are some of the choices.

Physical and occupation therapy is employed as necessary. For severe cases assistive devices may be necessary.