Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
(Chronic Acquired Demyelinating Polyneuropathy; Chronic Relapsing Polyneuropathy)
(See also Overview of Peripheral Nervous System Disorders.)
Symptoms of chronic inflammatory demyelinating polyneuropathy (CIDP) resemble those of Guillain-Barré syndrome. However, progression for > 2 months differentiates CIDP from Guillain-Barré syndrome, which is monophasic and self-limited. CIDP develops in 2 to 5% of patients initially diagnosed with Guillain-Barré syndrome.
The cause is thought to be autoimmune, resulting in demyelination.
CIDP typically starts insidiously and may slowly worsen or follow a pattern of relapses and recovery; between relapses, recovery may be partial or complete. Flaccid weakness, usually in the limbs, predominates in most patients; it is typically more prominent than sensory abnormalities (eg, paresthesias of hands and feet). Deep tendon reflexes are lost.
In most patients, autonomic function is affected less than it is in Guillain-Barré syndrome, Also, weakness may be asymmetric and progress more slowly than in Guillain-Barré syndrome.
Testing includes CSF analysis and electrodiagnostic tests. Results are similar to those in Guillain-Barré syndrome, including albuminocytologic dissociation (increased protein but normal white blood cell count) and demyelination, detected by electrodiagnostic testing.
Nerve biopsy, which can also detect demyelination, is seldom needed.
IVIG, although more expensive, is often offered first to patients with chronic inflammatory demyelinating polyneuropathy because of the following:
However, recent evidence suggests that pulsed corticosteroids may result in longer remissions and have a lower rate of serious adverse effects than IVIG. Pulsed corticosteroids may be given as follows:
Some patients may benefit from a combination of IVIG and corticosteroids.
Plasma exchange also does not have the long-term adverse effects of corticosteroids, but it often requires an indwelling port and, because of the large fluid shifts, may cause hypotension. Patients who do not respond to IVIG or who have severe disease may be offered plasma exchange, but because plasma exchange is invasive and has risks, it is best used as a way to de-escalate severe deterioration rather than as long-term maintenance treatment.
Subcutaneous immunoglobulin (SCIG) may be as effective as IVIG.
Immunosuppressants (eg, azathioprine) may be helpful and can reduce corticosteroid dependence.
Treatment may be needed for a long time.
Although symptoms of chronic inflammatory demyelinating polyneuropathy resemble those of Guillain-Barré syndrome, the two can be differentiated based on how long symptoms have continued to progress (ie, > 2 months for CIDP).
Symptoms start insidiously and may slowly worsen or follow a pattern of relapses and recovery.
CNS analysis and electrodiagnostic test results are similar to those of Guillain-Barré syndrome.
Treat with IVIG and corticosteroids, but in severe cases, consider plasma exchange; immunosuppressants may help and can reduce dependence on corticosteroids.