Chronic Inflammatory Demyelinating Polyradiculoneuropathy Clinical Presentation

Chronic inflammatory demyelinating polyradiculoneuropathy most frequently starts insidiously and evolves slowly, either in a slowly progressive (more than 60% of patients) or relapsing manner (approximately one third of patients), with partial or complete recovery between recurrences.

• Periods of worsening and improvement usually last weeks or months. Patients with a younger age of onset are said to have a higher frequency of relapsing course.
• Because of the insidious onset of CIDP, documenting precipitating illnesses or events is very difficult. However, preceding infection has been reported infrequently. Both respiratory and gastrointestinal infections have been cited, but no causative organism has been identified.
• Initial symptoms include weakness of the limbs, both proximal and distal, with proximal muscles affected at least as severely as distal.
• Sensory symptoms are common, such as tingling and numbness of hands and feet, but usually motor symptoms predominate.
• Only a small proportion of patients (approximately 16%) have a relatively acute or subacute onset of symptoms, with subsequent steadily progressive or fluctuating course.
• Children usually have a more precipitous onset of symptoms.
• Most experts consider the necessary duration of symptoms to be greater than 8 weeks for the diagnosis of CIDP to be made.
• Autonomic system dysfunction can occur; in such a case, the patient would complain of orthostatic dizziness, problems with bowel and bladder functions, and cardiac problems.

Pertinent findings are limited to the nervous system, except for cases of CADP associated with other diseases, as already mentioned. Depending on the associated systemic disorder, abnormalities on physical examination may be found in multiple organ systems. Patients should be examined in detail for signs of autoimmune, inflammatory, and neoplastic conditions.

• Cranial nerves

  • Cranial nerves may be involved, particularly CN VII, with paralysis of both upper and lower facial muscles. Diplopia can occur with the involvement of CN III, IV, or VI. Rarely, bulbar muscles (eg, palate, tongue) can be affected.
  • Papilledema with pseudotumor cerebri syndrome (eg, headaches, transient visual obscurations, pulsatile tinnitus, visual field defects) are observed rarely in patients with CIDP and are due to a very high CSF protein level (usually >1000 mg/mL).
• Gait frequently is abnormal.
• Type of gait depends on location of weakness and degree of proprioceptive loss. With significant weakness in the lower extremities, patients may walk with steppage (ie, high elevation of both feet to compensate for weakness of foot dorsiflexors) or a slapping gait (ie, due to deficit of proprioception in the feet).
• Children are said to have more profound gait abnormalities than adults.
• Motor system

  • Usually relatively symmetric weakness of both proximal and distal muscles is present in upper and lower extremities.
  • Muscle tone can be normal or decreased. Hypotonia, atrophy, and fasciculations may be present.
• Deep tendon reflexes: Reflexes characteristically are diminished or absent even in regions with only mild weakness.
• Sensory system

  • Large-diameter, heavily myelinated fibers are affected most severely, leading to proprioceptive and vibratory deficits.
  • Loss or decrease of pain (ie, pinprick) and temperature sensations is less common.
  • Stocking-glove distribution of sensory deficits is typical.
  • Neuropathic pain in affected extremities may occur.
• Coordination: Patients may have sensory ataxia with positive Romberg sign due to damage to the large nerve fibers that convey proprioception.
• Pathological reflexes: Pathological reflexes (eg, Babinski, Chaddock, Oppenheim) usually are not observed in patients with CIDP.

Chronic inflammatory demyelinating polyradiculoneuropathy is most frequently an idiopathic illness, but it has been known to occur with several conditions. In those cases, the associated condition is included in the main diagnosis (eg, CIDP with systemic lupus erythematosus, CIDP with HIV infection, CIDP associated with hepatitis B or C) to separate those cases from the idiopathic variety. Most reported conditions associated with CIDP are listed below.

• CIDP associated with other disorders cannot be distinguished clinically from isolated CIDP except where mentioned in this section. The disease mechanisms for all these disorders are not known. They appear to be immunologic; in some instances, antibody-mediated mechanisms have been shown to play a role.
• Vasculitis does not seem to be involved; physiologic and pathologic differences can distinguish the multifocal variants of CADP from vasculitic mononeuritis multiplex. Vasculitic neuropathies cause wallerian degeneration with minimal signs, if any, of segmental demyelination on biopsy and electromyographic studies (EMG). The multifocal variants of CADP have prominent conduction block and slowing—hallmarks of segmental demyelination.
• HIV infection: In these patients, mild lymphocytic pleocytosis and increased gamma globulin level in the CSF are seen frequently. CIDP has been observed with early disease and later on in the course of AIDS.
• Hodgkin lymphoma: Neuropathy associated with Hodgkin lymphoma is not caused by direct infiltration of the peripheral nerves but is a consequence of the autoimmune cascade that occurs with this disease; the mechanism is not completely clear.
• Paraproteinemias and/or plasma cell dyscrasias

  • CADP is seen with monoclonal gammopathies (eg, monoclonal gammopathy of unknown significance [MGUS]), most frequently gammopathy of IgM. Evidence exists to suggest that CADP with IgM MGUS has specific clinical and electrophysiologic characteristics. Patients usually have predominance of distal sensory symptoms that are greater than motor symptoms. Conduction slowing on nerve conduction testing is accentuated in distal nerve segments. Fifty percent of patients with IgM-associated neuropathies have antibodies directed against MAG, a protein found in noncompact myelin of peripheral nerves. Whether any clinical difference exists between patients with IgM gammopathy without anti-MAG antibodies and those with anti-MAG antibodies is not clear. In both cases, the response to immunosuppressive and/or immunomodulatory treatment is poor. However, a number of reports, including a double-blind controlled trial, describe a response to rituximab, a monoclonal antibody directed against B cells.
  • Some paraproteinemias occur as isolated phenomena and some are by-products of malignant cells, as in the cases of Waldenström macroglobulinemia and myeloma. In myeloma-associated neuropathy, the abnormal paraprotein usually consists mostly of lambda light chain component. Combination of osteosclerotic myeloma, organomegaly, endocrinopathy, M protein, sensorimotor neuropathy, and pigmentary skin changes is referred to as POEMS syndrome. In POEMS syndrome, the M protein is typically immunoglobulin G (IgG).
  • The association of CIDP with IgG or immunoglobulin A (IgA) gammopathy is less clear. IgG paraproteins can occur in 5% of the population and it is unclear that the incidence of IgG paraproteins is excessive in patients with demyelinating neuropathy. Patients with CIDP and IgG or IgA paraproteins have identical clinical and electrophysiologic features to patients with CIDP and no paraprotein. Response to treatment is also the same.
• Multiple sclerosis: Reports describe CNS white matter changes in patients with CIDP. Whether a true association exists between CIDP and multiple sclerosis remains unclear.
• Systemic lupus erythematosus
• Chronic active hepatitis (B or C): CIDP associated with hepatitis should be differentiated from cryoglobulinemic vasculitis. The latter causes either symmetric distal sensorimotor polyneuropathy or mononeuropathy multiplex but on pathologic examination shows wallerian degeneration and not the segmental demyelination seen in CIDP. Patients can respond to standard CIDP treatments, but in some patients, treatment of the hepatitis infection is associated with remission of the CIDP.
• Inflammatory bowel disease (IBD): CIDP has been described in association with Crohn disease and other inflammatory bowel conditions, although no direct correlation between the 2 afflictions is known. The mechanism of development of CIDP is presumed to be an autoimmune abnormality that is also causing the primary problem in inflammatory bowel disease, although the details are not known. The situation has become complicated with the recognition that TNF-alpha therapies used for IBD can cause CIDP.
• TNF-alpha blockers: CIDP, Lewis-Sumner syndrome, and multifocal motor neuropathy have been described in patients with rheumatoid arthritis and IBD who are treated with TNF-alpha blockers, particularly etanercept and infliximab. In some cases, discontinuation of the medication was associated with remission of the inflammatory neuropathy.
• Diabetes mellitus: Whether an increased incidence of CIDP occurs in patients with diabetes mellitus remains unclear. The most recent literature has not corroborated earlier reports of an association.
• Pregnancy: Pregnancy is known to exacerbate CIDP. Worsening usually occurs in the third trimester or in the postpartum period.