Table 4.

Reported diagnostic criteria, clinical characteristics, and response to treatment for pure motor chronic inflammatory demyelinating polyradiculoneuropathy

References	Number of patients or frequency	Clinical definition	Electrodiagnostic criteria for diagnosis	Exclusion criteria with respect to the specific variant	Disability (compared with typical CIDP)	Response to treatment
1996	3%	Motor symptoms and signs only [30]	NM	NM	NM	NM
1997	10%	Pure or predominantly motor syndrome [37]	NM	NM	NM	NM
2001	4	Pure motor involvement without sensory signs and symptoms [31]	Normal findings on electrophysiological testing of sensory fibres	NM	NM	4/4 (100%) patients improved after IVIg, 0/4 after steroids
2003	6%	Symmetrical pure motor deficit, with no sensory signs or symptoms [16]	Absence of sensory abnormalities on neurophysiological examination	NM	NM	20% of the patients improved after steroids, 5/5 (100%) after IVIg, 1/3 (33%) after PLEx
2009	2.2%	As per 2010 EFNS/PNS guidelines [2]	NM	NM	NM	NM
2010	5	Motor symptoms without sensory symptoms, except for mild distal paresthesia [32]	Almost normal results in sensory conduction studies	NM	NM	5/5 (100%) patients improved after IVIg, 2/2 (100%) after PLEx, 0/5 after steroids
2014	4%	As per 2010 EFNS/PNS guidelines [4]	NM	NM	NM	NM
2019	4%	1. Weakness, without sensory symptoms or signs, in a polyneuropathic distribution, symmetric or asymmetric. 2. Symptoms may start anywhere in the body. Other possible symptoms: cramps, fatigue, tremor, motor cranial nerve palsy [7▪▪]	With or without abnormal sensory nerve conduction studies	1. Sensory symptoms/signs including sensory ataxia. 2. Autonomic dysfunction. 3. Neuropathic pain. 4. Multifocal distribution	Similar	3/7 (43%) patients improved after steroids, 14/17 (82%) after IVIg
2019	4%	Motor neuropathy without sensory disturbance [8▪▪]	NM	Clinical picture of typical CIDP or other atypical variants	Similar	NM
2020	2.2%	As per 2010 EFNS/PNS guidelines [9]	NM	Clinical picture of typical CIDP or other atypical variants	NM	NM
2020	2%	Symmetric or asymmetric pure motor polyneuropathy without sensory symptoms or signs at diagnosis [33]	NM	Clinical picture of typical CIDP or other atypical variants	NM	12/16 (75%) patients improved after IVIg, 4/5 (80%) after steroids, 2/5 (40%) after PLEx

CIDP, chronic inflammatory demyelinating polyradiculoneuropathy; EFNS/PNS, European Federation of Neurological Societies/Peripheral Nerve Society; IVIg, intravenous immunoglobulin; NM, not mentioned; PLEx, plasma exchange.