What is Chronic Inflammatory Demyelinating Polyneuropathy?

Types and symptoms
Epidemiology
Case reports
Diagnosis and treatment
References
Further reading

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare, acquired neurological disorder with heterogeneous presentation. It is a peripheral nerve system immune-mediated condition which results in "typical" and "atypical" forms. Although difficulties with cellular and humoral immunity have been demonstrated, the exact cause of CIDP is uncertain.

Areflexia, impaired sensory function in the arms and legs, and fatigue are commonly observed. CIDP's epidemiology differs based on the diagnostic standards applied. For the treatment of CIDP, numerous therapeutic modalities with various mechanisms of action have been developed. Corticosteroids and immunoglobulin are given intravenously or topically, and plasma exchange is recognized as a first-line treatment among them.

​​​​​​​Image Credit: Gorodenkoff/Shutterstock.com

Types and symptoms

An aberrant immune response, that is, when the immune system attacks the myelin sheath that protects the nerves, can lead to the development of CIDP.

CIDP is a chronic illness that can advance in a variety of ways, including relapsing-remitting, stepwise, or gradual progressive. As the condition progresses, axonal damage happens, which makes the symptoms worse. CIDP and its variant forms can manifest with a variety of symptoms.

Typical CIDP, which displays symmetrical sensory and motor symptoms, affects just half of CIDP patients. The remaining cases are of atypical form. Asymmetric motor/sensory dysfunction with proximal and distal weakness is what is referred to as typical CIDP.

Pure sensory or sensory-predominant instances, as well as multifocal cases with persistent conduction block, are examples of atypical cases. Cases with symmetric distal symptoms and signs may also fall within this category.

Epidemiology

The annual incidence of CIDP may be between 0.2 and 1.6 per hundred thousand individuals. Its prevalence might range from 0.8 to 10.3 per 100,000 individuals. Age, gender, and diagnostic criteria can affect the incidence and prevalence rates. Males were more likely than females to have CIDP, and the likelihood could rise with age.

Case reports

Abraham et al. (2017) described a 40-year-old female previously treated with hydroxychloroquine for systemic lupus erythematosus. She had sensory and motor neuropathy that was bilateral, progressive, ascending, and present. A physical examination revealed loss of reflexes, diminished pinprick and vibration sensation in the distal extremities, weakness in all extremities, and an unsteady gait with a wide base.

Antinuclear antibodies, anti-smooth muscle antibodies, anti-dsDNA antibodies, and an erythrocyte sedimentation rate of 75 mm/hr were all positive in laboratory tests. Anemia, low C4, and leukopenia were also noted. The diagnosis of CIDP was confirmed by electromyography. Intravenous immunoglobulin and high-dose steroids helped the patient's neuropathy and muscle weakness.

A positive response to steroids can be predicted by an early clinical CIDP diagnosis supported by serological autoantibody patterns linked to systemic lupus erythematosus. If CIDP is diagnosed early, steroids are successfully administered to most patients. If steroids do not improve, intravenous immunoglobulin, plasmapheresis, or immunosuppressive therapy should be considered.

Diagnosis and treatment

Diagnoses of CIDP can be difficult, which complicates treatment. Clinical characteristics, neurological testing, and electrodiagnostic criteria are utilized to diagnose CIDP. Electromyograms and nerve conduction studies (NCSs) are examples of electrodiagnostic tests. To validate the diagnosis, nerve conduction tests and electrophysiological proof of demyelination are needed. Laboratory testing, increased protein levels in cerebrospinal fluid (CSF), and nerve biopsy can support the diagnosis and aid in excluding other potential causes of neuropathy. A significant rate of misdiagnosis is brought on by variations in CIDP presentation and incorrect interpretation of nerve conduction investigations. Diabetes, chronic hepatitis, HIV/AIDS, inflammatory bowel disease, and systemic lupus erythematosus are a few more illnesses that might co-occur with CIDP.

The Peripheral Nerve Society  (PNS) and European Federation of Neurological Societies (EFNS) make guidelines for CIDP treatments with the aim of easing symptoms and, if feasible, preserving long-term remission. Patients with moderate to severe impairment are advised to have treatment with intravenous immunoglobulin (IVIG) or corticosteroids.

Subcutaneous immunoglobulins (SCIG) offer a different method of administration that could help to alleviate some of the problems with intravenous immunoglobulin administration. Studies on SCIG patient-reported outcomes (PRO) data primarily discussed patient preferences or convenience of use. Increasing response rates or lowering IVIG dosages may be achieved by supplementing IVIG with a concurrent immunosuppressant. If IVIG and corticosteroids are ineffective for a patient, plasma exchange may be a viable alternative therapy.

For the treatment of immune-mediated damage to nerves, novel therapeutic strategies involving chemicals or monoclonal antibodies that interact with Fc receptors on immune cells are now being studied in clinical trials. Due to the varied illness history and absence of surrogate indicators to predict the risk of clinical deterioration, management of CIDP remains difficult despite the existence of numerous recognized medications and the current development of novel therapeutics.

References

• Svačina, M. K. R., & Lehmann, H. C. (2022). Chronic Inflammatory Demyelinating Polyneuropathy (CIDP): Current Therapies and Future Approaches. Current pharmaceutical design, 28(11), 854–862. https://doi.org/10.2174/1381612828666220325102840
• Querol, L., Crabtree, M., Herepath, M., Priedane, E., Viejo Viejo, I., Agush, S., & Sommerer, P. (2021). Systematic literature review of burden of illness in chronic inflammatory demyelinating polyneuropathy (CIDP). Journal of neurology, 268(10), 3706–3716. https://doi.org/10.1007/s00415-020-09998-8
• Kuwabara, S., & Misawa, S. (2019). Chronic Inflammatory Demyelinating Polyneuropathy. Advances in experimental medicine and biology, 1190, 333–343. https://doi.org/10.1007/978-981-32-9636-7_21
• Abraham, H., Kuzhively, J., & Rizvi, S. W. (2017). Chronic Inflammatory Demyelinating Polyneuropathy (CIDP): An Uncommon Manifestation of Systemic Lupus Erythematosus (SLE). The American journal of case reports, 18, 980–983. https://doi.org/10.12659/ajcr.903541
• Bril, V., Blanchette, C. M., Noone, J. M., Runken, M. C., Gelinas, D., & Russell, J. W. (2016). The dilemma of diabetes in chronic inflammatory demyelinating polyneuropathy. Journal of diabetes and its complications, 30(7), 1401–1407. https://doi.org/10.1016/j.jdiacomp.2016.05.007
• Vedeler, C. A., Farbu, E., & Mellgren, S. I. (2013). Chronic inflammatory demyelinating polyneuropathy (CIDP). Acta neurologica Scandinavica. Supplementum, (196), 48–51. https://doi.org/10.1111/ane.12049
• Chronic inflammatory demyelinating polyneuropathy. [Online] Medline Plus. Available at: https://medlineplus.gov/ency/article/000777.htm

Further Reading

• What is Neurology?
• What is Rasmussen's Encephalitis (RE)?
• What is Neuroscience?