Summary of patients developing multifocal motor neuropathy with conduction block following treatment with anti-TNF-α agents. Three cases2,3 were not included as they were considered to represent acute multifocal motor neuropathy.
| Reference | Patient | Drug | Presentation | Treatment/Outcome |
|---|---|---|---|---|
| 8 | 60-year-old man with RA 11 yrs | Infliximab 3 mg/kg with methotrexate and prednisolone | Developed progressive upper and lower motor limb weakness 5 mo after treatment with infliximab. EMG+ for conduction block. Antibodies to GM-1 not tested | Infliximab discontinued and IVIG 1 g/kg for 2 days given with rapid improvement. Total 4 monthly pulses |
| 6 | 40-year-old woman with RA | Infliximab 3 mg/kg q 8 weeks Jan 2003 | Oct 2003 progressive symptoms right hand. EMG definite conduction block. IgM anti-GM1+ (1:640) | Infliximab discontinued March 2004. Treated with IVIG for 2 days monthly with clinical and EMG improvement after 11 mo followup |
| 5 | 54-year-old man with AS 10 yrs | Infliximab 2005 (5 mg/kg/wk) IV q 8 weeks | June 2006 progressive weakness L hand, later R foot (drop), and R arm/hand. EMG+ for conduction block | Infliximab stopped Dec 2006. Spontaneously improved with only mild residual weakness by October 2007 |
| 9 | 34-year-old woman with chronic hepatitis C, polyarthritis, and cryoglobulinemia | Started on infliximab in June 2003 (3 mg/kg) | After 4 infusions, developed progressive weakness of both hands and R foot. Anti-GM1 antibodies+. EMG+ for pure polyneuropathy with conduction block | Infliximab discontinued. Treatment with IVIG (dose not reported) led to complete response within weeks |
| 10 | 39-year-old man with hidradenitis suppurativa | Infliximab, unknown dose | Symptoms after 4 infusions. Further details not described | Treatment and followup not described |
| 3 | 45-year-old man with psoriasis 15 yrs and psoriatic arthritis 8 yrs | Infliximab 5 mg/kg 3 doses; changed to etanercept for lack of effect 50 mg/wk for 6 mo; eventually changed back to infliximab 5 mg/kg | Had infusion reaction with last infusion and noted progressive hand weakness 8 weeks later. EMG+ for multifocal conduction block | Infliximab stopped and treated twice with IVIG 2 g/kg with no effect. Underwent plasma exchange × 4, then treated with simultaneous IVIG and plasma exchange. Full recovery |
RA: rheumatoid arthritis; AS: ankylosing spondylitis; TNF: tumor necrosis factor; EMG: electromyogram; IVIG: intravenous immunoglobulin.