Extensive neurophysiological investigation in Guillain-Barré patients, focussing on motor unit abnormalities and weakness

Guillain-Barré syndrome is a severe post-infectious polyneuropathy. Its
cardinal symptom is weakness. Weakness is responsible for life-threatening
complications in the acute phase and for residual disability. Unfortunately, in
many patients current treatment options only have a modest effect. The
development of more effective, targeted therapies requires improved
understanding of GBS pathophysiology and refined classification of patients
into pathophysiologically homogeneous subgroups. Despite its importance in
GBS, the pathophysiology of weakness is only partly understood. We have
evidence that indicates that the terminal axolemma and neuromuscular junction
are involved in the acute phase of GBS in patients. GBS is currently classified
in three subgroups. However, this simple classification of GBS patients is
inadequate to understand the observed clinical heterogeneity that occurs within
each of the subtypes. Some patients are only mildly affected and remain
ambulant, while others have to be ventilated in an intensive care environment
and may suffer lasting handicaps. Recovery and outcome are equally variable.
More advanced electrophysiological techniques are now available (muscle scan,
excitability testing, and multichannel recordings to improve insight in the
pathophysiology of weakness in GBS, and to further classify GBS patients in
electrodiagnostic and prognostic subgroups. We expect that at the end of the
project, we further understand the pathofysiology of weakness and the working
mechanism of IVIg treatment and that we can better identify poor prognostic
subgroups that may benefit from additional treatment in the future.

1)To determine the contribution of reversible dysfunction of nerve terminals to
weakness
2) To identify electrophysiological patterns that improve classification of GBS
patients, and that discriminate between patients with good and poor prognosis
3) To clarify the pathophysiological substrates of residual weakness

observational, longitudinal study

The patients will have to undergo neurophysiological investigations. Except for
the single fiber electromyography (SFEMG) (twice only), the investigations are
non-invasive. There are no risks. During the first two weeks of admittance, the
"scan"will be daily, more extensive neurophysiological testeing will be done
once a week. After discharge at wk tests will be done at week 6, 13, 26, 52 and
104.