Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
(Chronic Acquired Demyelinating Polyneuropathy; Chronic Relapsing Polyneuropathy)
Chronic inflammatory demyelinating polyneuropathy is an immune-mediated polyneuropathy characterized by symmetric weakness of proximal and distal muscles and by progression continuing > 2 mo.
(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 mo differentiates CIDP from Guillain-Barré syndrome, which is monophasic and self-limited. CIDP develops in 3 to 10% of patients with Guillain-Barré syndrome.
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 WBC count) and demyelination, detected by electrodiagnostic testing.
Nerve biopsy, which can also detect demyelination, is seldom needed.
Often, deciding which therapy to offer first is difficult.
IVIG is better tolerated than corticosteroids and has fewer adverse effects, but IVIG may be associated with earlier deterioration after treatment is stopped. Subcutaneous IG may be as effective as IVIG.
Plasma exchange is the most invasive of the 3 options and thus offered last.
Immunosuppressants (eg, azathioprine) may be helpful and can reduce corticosteroid dependence.
Treatment may be needed for a long time.
Although symptoms of CIDP resemble those of Guillain-Barré syndrome, the two can be differentiated based on how long symptoms have continued to progress (ie, > 2 mo 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.