What's In a Name? Important Differences Between GBS, CIDP and Related Disorders

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What's In a Name? Important Differences
Between GBS, CIDP and Related Disorders
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David S. Saperstein, M.D., Phoenix Neurological Associates, Phoenix, AZ

This article will discuss the differences between Guillain Barre Syndrome (GBS) and related conditions. Recently I have seen cases where misunderstanding of these concepts led to less than ideal management. I have also frequently observed confusion about terminology among patients and physicians.

GBS may also be referred to as acute inflammatory demyelinating polyneuropathy (AIDP). This emphasizes the acute nature of this disorder: symptoms come on abruptly and progress rather quickly. Symptoms stop progressing, often within 2 weeks, and usually not more than 4 weeks. After a period of weeks to months, patients then begin to experience improvement. Although the majority of patients with GBS will do rather well, not all patients will recover fully and may experience chronic weakness, numbness, fatigue or pain. Once symptoms stabilize, there is rarely any further deterioration.

Chronic inflammatory demyelinating polyneuropathy (CIDP) produces manifestations similar to GBS, but there are important differences. Symptoms tend to come on more slowly and progress for a longer period of time. Patients may stabilize and recover, but then experience a return of symptoms in the future (this is referred to as the relapsing form of CIDP). Alternatively, patients may experience progressive CIDP wherein there is slow, continuous progression without a period of stabilization. By definition, if there is progression of symptoms beyond 8 weeks, the patient has CIDP. Patients with CIDP often need sustained treatment, but many experience complete remission or at least improve and stabilize on medication.

A less well-appreciated disorder is subacute demyelinating polyneuropathy (SIDP). SIDP is defined by a progression of symptoms for more than 4 weeks but less than 8 weeks. In other words, the time frame falls in between that of GBS and CIDP. This is an uncommon but interesting group of patients. It is necessary to identify these patients because there can be important considerations regarding their treatment (see below).

The most important reasons for distinguishing between GBS, SIDP and CIDP are to help anticipate outcome and to determine the optimal therapy. Patients with GBS are usually treated with a course of either of two therapies: intravenous immunoglobulin (IVIg) or plasma exchange (PE). IVIg and PE are equally effective (and there is not an advantage to using both treatments). Typically, a single course of treatment is given, usually as soon as possible after diagnosis. The goal of treatment is to hasten improvement. Patients with GBS will improve without treatment; IVIg or PE just accelerate recovery. As discussed above, the full extent of recovery will not occur for many months (or even years). This is an important point that is often not appreciated. Some GBS patients certainly do improve quickly and dramatically after being treated with IVIg or PE. However, most do not. Therefore, repeat courses of IVIg or PE or treatment with a different therapy are typically not indicated.

A number of GBS patients will have permanent symptoms. These symptoms are from nerve damage. IVIg and PE treat inflammation of the nerve, but do not help with nerve recovery. Nerve recovery can occur, but takes time. Persistent symptoms do not mean a person has CIDP. CIDP is diagnosed when there is continued progression of symptoms (not continued persistence of symptoms).

In contrast to GBS, CIDP patients are treated with repeated courses of IVIg or PE (or daily doses of other medications such as prednisone, azathioprine, cyclosporine or mycophenolate mofetil). Without sustained treatment, patients with CIDP will usually relapse and continue to worsen. Over time, the amount of medication can be decreased in many patients and, in some patients, treatment can be discontinued entirely.

Finally, we come to SIDP. Treatment is usually as for GBS: a single course of IVIg or PE. This will be sufficient for many of these patients. However, some SIDP patients are actually CIDP patients who got treated before they could declare themselves by progressing for 8 or more weeks. If they are not watched closely, patients with SIDP can quickly deteriorate. These patients will need more sustained treatment, as in the case for CIDP.

Now that I have defined the syndromes, I would like to give some examples of how incomplete appreciation of these disorders can lead to misunderstandings regarding therapy. I have seen several patients with SIDP diagnosed with GBS and treated with a single course of IVIg or PE. That is appropriate, but then when these patients subsequently worsened after a few weeks or months, they were either not re-treated or they were repeatedly treated with just a single course of therapy. They would improve and then worsen again and again. In such cases, continued treatment is needed to stabilize these patients (such as IVIg administered every month). A different error is to give a GBS patient IVIg or PE to treat chronic, stable, persistent symptoms. These treatments will not help. Recall that the persistent symptoms are due to damaged nerves. At the current time, we do not have therapies to restore the damaged nerves (but there are medications that can be used to help nerve pain).

Hopefully this review has helped clarify the distinctions between GBS, SIDP and CIDP and illustrate the differing outcomes and treatment approaches for these disorders.

Article from the Summer 2006 GBS Newsletter

Residual Effects Following Guillain-Barre' Disability After “Recovery” From GBS
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