CDIP, or chronic inflammatory demyelinating polyradiculoneuropathy, is an immune-mediated polyneuropathy which presents similarly to Guillain-Barré Syndrome (GBS). However, it is not as dangerous as GBS. Patients present with symmetric proximal and distal weakness with reduced or absent deep tendon reflexes, just like GBS. The difference is that in typical CDIP, patients have prominent sensory signs, no autonomic dysfunction, no facial weakness, no preceding infectious illness, and most importantly no respiratory failure. It also continues to progress past 4 weeks.
CSF is not diagnostic, and may show albuminocytologic dissociation. The diagnostic test is nerve conduction studies.
Allen JA. Chronic Demyelinating Polyneuropathies. Continuum 2017;23(5):1310–1331