Spatial acuity for pain and its relationship with somatic sensory and autonomic measures in small fiber neuropathy

• Grant number: 15/25893-3
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: April 01, 2016
• End date: March 31, 2017
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Amilton Antunes Barreira
• Grantee: Rodrigo Melo Conde
• Supervisor: Frank Birklein
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Institution abroad: Johannes Gutenberg University Mainz (JGU), Germany
• Associated to the scholarship: 13/03150-3 - Evaluation of the sweat losses in sensory polyganglionopathy (SPG), BP.DR

Abstract

Small Fiber neuropathy (SFN) is a subtype of peripheral neuropathy that specifically affects the thin fibers (somatic sensory and/or autonomic) and their functions. There is no "gold standard" for diagnosing SFN although a diagnostic criteria has been proposed based on the occurrence of at least two abnormal tests at clinical examination, quantitative sensory testing (QST) and skin biopsy. The two-point discrimination (2PD) threshold test is mostly used to evaluate tactile spatial resolution in clinical practice. Recently, it was reported for the first time a whole-body map of 2PD for pain in healthy young individuals. The authors used 2 identical Nd:YAP laser pulses to stimulate A-delta and un-myelinated C fibers without co-activating mechanoreceptors in eleven body regions. To our knowledge, the 2PD for pain and touch was never tested in multiple body regions in patients with small-fiber neuropathy. The objectives of this study are to provide a body map of the two-point discrimination threshold for pain and touch in patients with Small Fiber Neuropathy, to verify relationship among two-point discrimination threshold for pain and touch, warm and cold sensation and the sudomotor axon reflex test, and to identify whether the two-point discrimination threshold for pain is able to help diagnose patients with small fiber neuropathy. The present research project has clinical importance because the assessment of pain with lasers can quantitatively evaluate the function of small fibers and may help diagnose small fiber neuropathy. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

STEENKEN, LIVIA; CONDE, RODRIGO M.; MUELLER, JULIA K.; ESCOLANO-LOZANO, FABIOLA; BIRKLEIN, FRANK; DIMOVA, VIOLETA. Nociceptive two-point discrimination acuity and body representation failure in polyneuropathy. SCANDINAVIAN JOURNAL OF PAIN, v. 23, n. 1, p. 10-pg., 2022-08-04. (15/25893-3)