Distinguishing acute-onset CIDP from fluctuating Guillain-Barre syndrome: a prospective study.

OBJECTIVE The aim of the study was to provide criteria that can help to distinguish between GBS-TRF and A-CIDP in the early phase of disease. BACKGROUND The distinction between Guillain-Barré syndrome (GBS) with fluctuations shortly after start of treatment (treatment-related fluctuations, or GBS-TRF) and chronic inflammatory demyelinating polyneuropathy with acute onset (A-CIDP) is difficult but important because prognosis and treatment strategy largely differ. METHODS Patients with GBS (n = 170) were included in a prospective longitudinal study. Patients with GBS-TRF (n = 16) and patients with A-CIDP (n = 8) were analyzed and compared. Extended clinical data, biologic material, and electrophysiologic data were collected during 1 year follow-up. RESULTS The first TRF in the GBS-TRF group always occurred within 8 weeks (median 18 days; range 10-54 days) from onset of weakness. In the GBS-TRF group, 5 (31%) patients had a second TRF and none had more TRFs. At all timepoints, patients in the A-CIDP group were less severely affected than patients with GBS-TRF, did not need artificial ventilation, rarely had cranial nerve dysfunction, and tended to have more CIDP-like electrophysiologic abnormalities. More GBS-TRF patients were severely affected and more patients had sensory disturbances when compared to the GBS group without fluctuations. CONCLUSIONS The diagnosis of acute-onset chronic inflammatory demyelinating polyneuropathy (CIDP) should be considered when a patient thought to have Guillain-Barré syndrome deteriorates again after 8 weeks from onset or when deterioration occurs 3 times or more. Especially when the patient remains able to walk independently and has no cranial nerve dysfunction or electrophysiologic features likely to be compatible with CIDP, maintenance treatment for CIDP should be considered.