Characterization of non-length-dependent small-fiber sensory neuropathy

Introduction: Non-length-dependent small-fiber sensory neuropathy (NLD-SFSN) is not as well characterized as length-dependent small-fiber sensory neuropathy (LDSFSN). Methods: Sixty-three patients with NLD-SFSN were compared with 175 patients with LD-SFSN for their demographics and disease associations. Results: Age was younger in those with NLD-SFSN (45.5 ± 13.1 years) than in those with LD-SFSN (55.1 ± 11.4 years, P < 0.001). Forty-six of 63 (73.0%) patients were women in the NLD-SFSN group, whereas 84 of 175 (48.0%) were women in the LD-SFSN group (P < 0.001). Disease associations were identified in 26 of 63 (41.3%) patients with NLD-SFSN, including diabetes or prediabetes in 10 (15.9%), connective tissue diseases in 6 (9.5%), thyroid dysfunction in 4 (6.3%), sarcoidosis in 3 (4.8%), vitamin B12 deficiency in 2 (3.2%), and paraproteinemia in 1 (1.6%). Immune-mediated conditions were present in 9 of 63 (14.3%) patients with NLD-SFSN and 6 of 175 (3.4%) patients with LDSFSN (P =0.012). Conclusions: NLD-SFSN is more common in women, presents at a younger age, and is more likely to be associated with immune-mediated conditions than LD-SFSN.