Subacute Inflammatory Demyelinating Polyneuropathy (SIDP) Secondary to Tumor Necrosis Factor (TNF)-Alpha Inhibitor (Adalimumab) for the Treatment of Rheumatoid Arthritis: A Case Report
Natalie Bartnik1, Mark Grady2, Sean Beattie1, Laith Maali1
1University of Kansas Medical Center, 2Children’s Mercy Hospital
Objective:
To report a rare case of Tumor Necrosis Factor-Alpha Inhibitor (Adalimumab) induced SIDP.
Background:
Among the many patients being treated with TNF-alpha inhibitors for autoimmune and rheumatologic conditions, there have been several case reports of demyelinating lesions. However, these complications tend to occur several months or years after initiation of the therapy, the mechanism by which this occurs remains unclear. We present a rare case of SIDP with symptom onset six weeks after the initiation of Adalimumab.
Results:
A 51-year-old female with newly diagnosed rheumatoid arthritis was treated with a total of five biweekly doses of Adalimumab. Halfway through her treatment, she developed flu-like symptoms followed by bilateral hand and foot numbness. During this time, she remained afebrile and tested negative for SARS-CoV-2. This progressed over six weeks to decreased grip strength and difficulty walking requiring a walker. Her examination demonstrated stocking-glove pattern of decreased pinprick, vibration, and soft touch sensation distal to elbows and mid-calves; positive Romberg, diffusely diminished DTRs, negative Hoffman and Babinski; and wide based gait. Labs and imaging were significant for ANA titer 1:80 (reference </= 1:80), mild FLAIR signal of central pons and bifrontal subcortical white matter, and contrast enhancement of the cauda equina. She underwent five days of IV immunoglobulin (IVIG) treatment during which time she experienced improvement in her strength, sensation and gait, however did not return fully back to baseline.
Conclusions:
This case represents a clinical diagnosis of SIDP in an otherwise neurologically intact woman shortly after initiation of treatment with Adalimumab for rheumatoid arthritis. This patient experienced a demyelinating process that was particularly early in her treatment course compared to other cases identified in our literature review. Onset of demyelination cases vary by anti-TNF agent used and rheumatologic condition, but tend to be months to years after initiation or discontinuation.