Cerebrospinal fluid total protein in Guillain-Barré syndrome variants: correlations with clinical category, severity, and electrophysiology.

The discriminative value of CSF total protein (CSF-TP) in subtypes of Guillain-Barré syndrome has not been well documented in North-American patients. We reviewed 173 cases from a single institution, comprising the following clinical categories of neuropathy: 134 Sensorimotor (SM) GBS, 13 Motor (M) GBS, 8 Localized (L) GBS, and 18 Miller Fisher syndrome (MFS). We grouped the electrophysiological interpretation in primarily demyelinating, primarily axonal and normal / equivocal categories. Mean CSF-TP were substantially higher for SM and L-GBS, as well as cases classified as Acute-onset chronic inflammatory demyelinating polyneuropathy. They were lower for M-GBS and L-GBS. The most statistically significant correlation was found for elevated CSF-TP in GBS cases showing an electrophysiologic pattern classified as demyelinating (1.56 g/L) compared with axonal (0.68 g/L) or normal/ equivocal patterns (0.65 g/L). There was a correlation between CSF-TP and time interval between symptom onset and lumbar puncture. There was a weak correlation between CSF-TP and maximal overall-clinical severity grade, which was likely mostly determined by the electorphysiological pattern. Though CSF-TP is a sensitive test for GBS in the second week after onset, it may not be a reliable predictor of clinical severity. There is a robust association of CSF-TP elevation and a demyelinative electrophysiologic pattern and a suggestion that lower mean CSF-TP values can be expected in GBS-spectrum disorders thought to represent nodo-paranodopathies.