(See also Overview of Peripheral Nervous System Disorders Overview of Peripheral Nervous System Disorders The peripheral nervous system refers to parts of the nervous system outside the brain and spinal cord. It includes the cranial nerves and spinal nerves from their origin to their end. The anterior... read more .)
Symptoms of chronic inflammatory demyelinating polyneuropathy (CIDP) resemble those of Guillain-Barré syndrome Guillain-Barré Syndrome (GBS) Guillain-Barré syndrome is an acute, usually rapidly progressive but self-limited inflammatory polyneuropathy characterized by muscular weakness and mild distal sensory loss. Cause is thought... read more . 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 Overview of Demyelinating Disorders Myelin sheaths cover many nerve fibers in the central and peripheral nervous system; they accelerate axonal transmission of neural impulses. Disorders that affect myelin interrupt nerve transmission... read more .
Symptoms and Signs of CIDP
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.
Diagnosis of CIDP
Cerebrospinal fluid (CSF) analysis and electrodiagnostic tests
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.
Treatment of CIDP
IV immune globulin (IVIG)
IVIG, although more expensive, is often offered first to patients with chronic inflammatory demyelinating polyneuropathy because of the following:
It does not have the many adverse effects of long-term corticosteroid use.
It is easier to administer than plasma exchange.
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:
Dexamethasone 40 mg orally a day for 4 consecutive days each month for 6 cycles
Dexamethasone orally once a week for 3 months with monthly dose adjustments based on the patient's clinical status
IV methylprednisolone 500 mg once a day for 4 consecutive days each month for 6 months
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.
CSF 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.