Case Presentation
A 45-year-old male with no prior medical history was diagnosed with AS about ten years ago following bilateral Achilles tendonitis, rupture of the left Achilles tendon, inflammatory low back pain, positive HLA B27, and increased inflammatory markers. Sacroiliac X-ray showed bilateral Sacroiliitis (Figure 1), then he was managed with Sulfasalazine and NSAID at anti-inflammatory. About one year ago, the case felt tingling and numbness, firstly in the upper limbs and then in the lower limbs. Upon consultation with a rheumatologist, he underwent tests such as EMG-NCV, vitamin B12, and folate levels. EMG-NCV result showed axonal-type sensory-motor polyneuropathy and laboratory tests demonstrated a normal range of vitamin B12 and folate levels. Laboratory tests showed in Table 1.
Considering the inconsistency between the patient’s neuropathy and AS, additional examinations were performed, including CT scans of the lungs, abdomen, and pelvis and tumor marker tests to investigate the possibility of malignancy. The tumor markers range is shown in Table 1. All requested tests demonstrated normal results, and the criteria for demyelinating neuropathy were absent in the EMG-NCV; this neuropathy subtype was not considered a potential etiology. Eventually, based on the findings, no justification for the patient’s neuropathy was identified, and the absence of any secondary cause was proposed as the etiology; hence, AS considers an etiology of Axonal Sensory-Motor Polyneuropathy, a rare presentation for this disease.