Neurological and electroneurography findings in patients with systemic sclerosis and symptoms of neuropathic pain in extremities

Objective: To analyze neurological and electroneurography (ENG) findings in patients with systemic sclerosis (SSc) and symptoms of neuropathic pain in upper and lower extremities. Patients and methods: Using the PainDetect questionnaire, 42 consecutive patients with SSc (38 women and 4 men) were screened for the presence of neuropathic pain in upper and/or lower extremities. Patients with previously diagnosed diabetes or other metabolic diseases, malignancy, other autoimmune disorders, or any neurological or psychiatric disease, were not included. Neurological examination, ENG, and laboratory analyses (glycated hemoglobin—HbAC, and vitamin B12) were performed in SSc patients with neuropathic pain in extremities. Methods of descriptive statistics were used to summarize the data. Results: Eleven patients (26.2%) had significant symptoms of neuropathic pain in extremities. Neurological examination indicated polyneuropathy in 10/11 (90.9%) of patients. Symmetrical hyperesthesia in the lower and/or upper extremities was found in ten patients. Symmetrical hyporeflexia was found in 7/11 (63.6%) of patients in the arms, and 6/11 (54.4%) of patients in the legs. Proprioception was diminished in 3/11 (27.3%), whilst pallhypesthesia was present in all patients. However, polyneuropathy could be confirmed by ENG only in four out of ten SSc patients, who had typical neurological findings for polyneuropathy. Hypoesthesia in a specific lumbar root dermatome, suggesting radiculopathy, was found in 6/11 (54.5%) of patients. Asymmetrical hyporeflexia was noticed in 2/11 (18.1%) of patients in the lower limbs. Seven patients (63.6%) had signs of radiculopathy in at least one root dermatome on ENG. Conclusion: A significant number of SSc patients with neuropathic pain in the upper and/or lower extremities have symptoms and signs of polyneuropathy undetectable by ENG, which indirectly suggests the presence of small-fiber polyneuropathy in these patients. In some patients, radiculopathy cannot be excluded as possible co-morbid non-scleroderma condition associated with neuropathic pain.