Influence of critical illness on axonal loss in Guillain-Barré syndrome

In this study we sought to determine whether axonal damage in severe Guillain-Barré syndrome (GBS) was secondary to critical illness polyneuropathy (CIP) in the intensive care unit (ICU) by reviewing comorbidities in patients who had initial and follow-up electromyographic (EMG) studies. Patients were classified as demyelinating (EMG-D) or axonal (EMG-A) according to findings on the second EMG. A critical illness (CI) score, derived from components of the APACHE II score, assessed the severity of critical illness in the ICU. Forty-one patients were admitted to the ICU and had a follow-up EMG. Of these, 28 (68%) developed an EMG-A pattern. There was no difference in the timing of the second EMG (mean, 23 days) between the two groups. The mean CI score (10.7 for EMG-A vs. 9.2 for EMG-D, P = 0.47) and frequency of sepsis (89% vs. 77%, P = 0.36) were similar between the groups. Mean strength (0-100, Medical Research Council scale) and Hughes disability scores for the EMG-A group were significantly worse at admission, nadir, and discharge. EMG-A patients had significantly more days on the ventilator (25 vs. 11), in the ICU (26 vs. 15), and in the hospital (29 vs. 18). Sixty-eight percent of patients with GBS in the ICU developed axon loss, but this was not related to the usual precipitants of CIP.