TABLE 2.
Clinical and laboratory data in patients with confirmed diagnosis, overdiagnosis and underdiagnosis of chronic inflammatory demyelinating polyradiculoneuropathy
| Confirmed diagnosis a (n = 65) | Overdiagnosis b (n = 31) | p c | Underdiagnosis d (n = 16) | p e | |
|---|---|---|---|---|---|
| Clinical features f | |||||
| EFNS/PNS clinical criteria, typical | 78 (50/64) h | NA i | NA | 50 (8) j | 0.03 |
| Muscle weakness | 97 (63) | 81 (25) | 0.01 | 100 (16) | 1.00 |
| Asymmetric muscle weakness | 5 (3/63) | 20 (5/25) | 0.04 | 19 (3) | 0.09 |
| Proximal muscle weakness | 86 (56) | 52 (16) | <0.01 | 100 (16) | 0.19 |
| Distal muscle weakness | 95 (62) | 77 (24) | 0.01 | 100 (16) | 1.00 |
| Only distal muscle weakness | 11 (7) | 29 (9) | 0.03 | 0 (0) | 0.34 |
| Sensory dysfunction | 88 (57) | 94 (29) | 0.49 | 81 (13) | 0.45 |
| Reduced or absent reflexes | 95 (62) | 84 (26) | 0.11 | 100 (16) | 1.00 |
| Cranial nerve dysfunction | 15 (10) | 7 (2) | 0.33 | 6 (1) | 0.68 |
| Disease progression ≥2 months | 99 (64) g | 84 (26) | 0.01 | 100 (16) | 1.00 |
| Diagnostic features | |||||
| EFNS/PNS electrodiagnostic criteria | 100 (65) k | 35 (11) l | <0.01 | 100 (16) l | — |
| EFNS/PNS electrodiagnostic criteria, definite | 94 (60/64) k | 23 (7) l | <0.01 | 88 (14) l | 0.59 |
|
IgM paraprotein demonstrated With anti‐MAG |
10 (5/48) m 0 (0) |
10 (3/27) n 67 (2) |
— |
19 (3/15) o 0 (0) |
— |
| CSF protein level g/L | 0.83 (0.24–4.35) | 0.80 (0.21–4.48) | 1.00 | 0.56 (0.37–80) | 0.08 |
| Elevated CSF protein level with normal cell count | 67 (36/53) | 74 (14/19) | 0.51 | 50 (4/8) | 0.45 |
| > 0.58–1.00 g/L | 49 (17/35) | 40 (4/10) | — | 100 (4/4) | — |
| > 1.00 g/L | 51 (18/35) | 60 (6/10) | — | 0 (0/0) | — |
| MRI nerve root/plexuses enhancement and/or enlargement | 0 (0/5) | 0 (0/2) | — | 0 (0/1) | — |
| Nerve biopsy demyelination and/or remyelination | 25 (1/4) | 0 (0/3) | — | 0 (0/0) | — |
| EFNS/PNS diagnostic category | 100 (65) | NA | NA | 100 (16) | 1 |
Data presented as percentages (number) or median (range).
Abbreviations: CIDP, chronic inflammatory demyelinating polyradiculoneuropathy; CSF, cerebrospinal fluid; EFNS/PNS, European Federation of Neurological Societies/Peripheral Nerve Society; Erasmus MC, Erasmus University Medical Centre; IgM anti‐MAG antibodies, immunoglobulin isotype M antibodies to myelin‐associated glycoprotein; MRI, magnetic resonance imaging; NA, not applicable.
Confirmed diagnosis: patients referred with a diagnosis of CIDP that was confirmed at the Erasmus MC.
Overdiagnosis: patients referred with a diagnosis of CIDP that was revised to another diagnosis at the Erasmus MC.
Confirmed diagnosis vs. overdiagnosis.
Underdiagnosis: patients referred with another diagnosis that was revised to CIDP at the Erasmus MC.
Confirmed diagnosis vs. underdiagnosis.
Evaluation at Erasmus MC.
Progressing >4 weeks and IVIg‐dependent.
Clinical atypical CIDP phenotypes: predominantly distal (n = 3), asymmetric (n = 2), predominantly motor (n = 3), predominantly sensory (n = 5), chronic immune sensory polyradiculopathy (CISP) (n = 1).
Overdiagnosed patients were not classified according to the EFNS/PNS clinical criteria.
Clinical atypical CIDP phenotypes: predominantly distal (n = 2), asymmetric (n = 3), predominantly motor (n = 3).
All but 12 nerve conduction studies were performed at the Erasmus MC.
All nerve conduction studies were performed at the Erasmus MC.
Not tested (n = 6), test performed unknown/test results unknown (n = 11).
Not tested (n = 1), test performed unknown/test results unknown (n = 3).
Not tested (n = 1).