Fatigue is a common symptom in patients with Guillain-Barré Syndrome and CIDP. The mechanisms of fatigue are still incompletely understood but fatigue can be one of the most disabling symptoms for GBS/CIDP patients. There are at least three different ways that fatigue can manifest itself. The first is a generalized lack of energy and the feeling of being ''all in'' pretty much all of the time. For people who have this symptom it is often most pronounced in the morning and gets somewhat better as the day goes on. The second symptom of fatigue is mental exhaustion, similar to the experience of taking a rigorous written examination or speaking in a foreign language without recent practice for an extended period. The third symptom of fatigue is reduced muscular endurance and the inability to perform tasks that previously presented no or little challenge. Someone who can now do only one pushup where previously they could easily perform 40 has clearly developed muscular fatigability. This symptom is the most relevant one for people with Guillain-Barré Syndrome. In Guillain-Barré Syndrome, muscular fatigability is very dramatic in the acute phase of the illness due to the demyelination occurring within the nerves. Nerve segments that contain demyelinative segments cannot conduct trains of impulses faithfully and marked fatigability in the affected muscles is the result. The same is true in patients with CIDP where muscular fatigability and weakness go hand in hand.

Thus, fatigue may be a major issue for patients with GBS and CIDP. When persistent muscular weakness is present in patients with GBS long after the acute onset, there is no medical therapy that will reverse the treatment. Plasma exchange or intravenous immunoglobulin or other medical therapies are not effective for people who have failed to completely recover from GBS. Rehabilitation strategies including muscular strengthening and aerobic exercise may be appropriate under the supervision of a trained physician. For patients with CIDP who have persistent weakness, there may be a benefited to immunesuppressive therapies to help improve strength. For patients who have completely recovered strength after GBS or those with CIDP who have no persistent weakness, muscle strengthening exercise and cardiovascular aerobic exercise is usually very helpful. Deconditioning after GBS and CIDP are extremely common and lead to a substantial feeling of fatigue that is both generalized and also muscular. A reconditioning program underage supervision of a rehabilitation expert is often extremely helpful.

In one study, 40% of patients with GBS still reported significant fatigue two years after onset. Of those patients reporting fatigue, 59% of patients displayed at most only minor motor impairment. Thus fatigue in GBS long after the acute event might be due to a change in lifestyle rather than persistent demyelination (Bernsen et al 2001). In another study (Merkies et al 1998), 80% of patients with some persistent weakness 3-6 years after GBS onset experienced persistent fatigue and a majority of patients who have regained normal strength also reported severe fatigue.

Treatable causes of persistent fatigue in GBS/CIDP include a non-nourishing sleep pattern that can often be improved with intervention by a trained physician. Depression can also be a major cause of persistent fatigue and is often responsive to appropriate medical therapy with antidepressant medication. Persistent pain which can occasionally occur in patients with CIDP and GBS may also rob one of energy and appropriate treatment for the pain can be very helpful in reducing fatigue. Finally, gaining weight and getting out of shape are both common contributories fatigue in GBS/CIDP. Reconditioning exercises and weight loss may be of great help.

In summary, fatigue is very common in patients with GBS/CIDP and a number of aspects of fatigue are in fact treatable as summarized above. More studies are needed to more completely understand the mechanisms of fatigue but there is no need to wait for these studies to seek treatment.