Comparison of clinical features and treatment response in atypical and typical CIDP
| DADS (n=34) | Pure sensory (n=16) | Pure motor (n=17) | LSS (n=17) | Typical CIDP (n=376) | P values | |
| Gender (M:F) | 24:10 | 10:6 | 8:9 | 16:1 | 235:141 | 0.0079* |
| Age at onset, years; mean (range) | 58 (20–79) | 57 (31–75) | 53 (11–82) | 48 (27–75) | 49 (5–86) | 0.0032† |
| Disease duration, years; mean (range) | 8 (0.5–26) | 5 (0.5–17) | 10 (0.5–28) | 7 (0.5–24) | 8.5 (0.5–60) | NS |
| Fulfilment of EFNS/PNS criteria | 24 (70.5%) | 12 (75%) | 15 (88%) | 13 (76%) | 310 (82%) | NS |
| Increased CSF proteins; positive/tested | 26/29 (90%) | 10/15 (67%) | 7/9 (78%) | 5/13 (38%) | 243/284 (85.5%) | 0.0002* |
| Mean CSF proteins, mg/dL (range) | 93 (52–379) | 86 (46–193) | 171 (47–679) | 82 (61–146) | 123 (46–1000) | NS |
| Nerve imaging; positive/tested | 7/7 | 5/5 | 0/0 | 6/7 (86%) | 26/36 (72%) | NS |
| Nerve biopsy; positive/tested | 2/4 (50%) | 1/4 (25%) | 0/0 | 0/1 | 21/36 (58%) | NS |
| MRC sum score; mean (range) | 58 (48–60) | 60 (60–60) | 51 (36–60) | 57 (49–60) | 53.5 (26–60) | 0.0003† |
| I-RODS score; mean (range) | 39 (16–48) | 38 (23–47) | 31 (11–48) | 40 (26–47) | 33 (1–48) | 0.0027†; 0.0301* |
| INCAT disability score; mean (range) | 1.5 (0–6) | 1.7 (0–3) | 3.5 (0–10) | 2 (0–6) | 2.7 (0–10) | 0.0005† |
| Quality of life score; mean (range) | 7 (1–9) | 7 (5–9) | 8 (5–13) | 7 (5–9) | 8 (5–14) | 0.0030† |
| Overall treatment response | 16/25 (64%) | 9/10 (90%) | 15/17 (88%) | 10/15 (67%) | 299/344 (87%) | 0.0050†; 0.0433* |
| EFNS/PNS only‡ | 9/15 (60%) | 8/8 (100%) | 14/15 (93%) | 7/11 (64%) | 191/216 (88%) | 0.0107† 0.0075* |
| Corticosteroids | 9/16 (56%) | 4/6 (67%) | 3/7 (43%) | 6/9 (67%) | 110/215 (51%) | NS |
| Intravenous immunoglobulin | 9/18 (50%) | 6/7 (86%) | 14/17 (82%) | 5/12 (42%) | 233/299 (78%) | 0.0178†; 0.0086* |
| EFNS/PNS only‡ | 6/12 (50%) | 4/5 (80%) | 13/16 (82%) | 3/9 (33%) | 139/185 (75%) | 0.0852† 0.0123* |
*Typical CIDP vs LSS.
†Typical CIDP vs DADS.
‡Fulfilling the EFNS/PNS diagnostic criteria for definite or probable CIDP with the only exceptions of two patients with typical CIDP and one with purely motor CIDP who fulfilled the criteria for possible CIDP.
§Typical CIDP vs pure sensory.
¶Typical CIDP vs pure motor.
CIDP, chronic inflammatory demyelinating polyradiculoneuropathy; CSF, cerebrospinal fluid; DADS, distal acquired demyelinating symmetric neuropathy; EFNS/PNS, European Federation of Neurological Societies/Peripheral Nerve Society; F, female; INCAT, inflammatory neuropathy cause and treatment; I-RODS, Inflammatory Rasch Overall Disability Scale; LSS, Lewis-Sumner syndrome; M, male; MRC, Medical Research Council; NS, not significant.