Validation of the Semmes-Weinstein monofilaments to evaluate the pain threshold in patients with migraine

• Grant number: 12/02867-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2012
• End date: March 31, 2014
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Débora Bevilaqua Grossi
• Grantee: Jaqueline Nisa de Cassia Grunewald
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Migraine is one of the most frequent headaches in the population. In migraine, pathophysiology occurs the awareness of the caudal trigeminal nucleus which predisposes patients to develop allodynia, a symptom defined as pain in response to a no painful stimulus. The Semmes-Weinstein monofilament is commonly used to assess skin sensitivity, each of the monofilaments produced a load when applied to the skin. The objective of this study is to evaluate the load applied by the monofilament and the validity of this instrument to assess pain threshold (PPT) in migraine patients. The study will be included in this study, 60 women, 30 with at least one acute migraine per month, diagnosed according to the criteria of the International Classification of Headache, and 30 controls without migraine, aged 18 to 60 years. Will be excluded volunteers with diseases that affect the sensitive skin or cognition. Will be assessed at five points on the frontal and masseter muscle bilaterally and in the region of the right forearm. We will couple a load cell on the Von Frey Digital to check the load applied in grams by monofilament, which enables verification of the pressure applied on a display. To check the validity of monofilament, after 15 minutes will be a new assessment of the patient, and the order of the points the same as the first evaluation. After the examinations, the load found on the display will be compared to the pre-load established by the monofilament, and comparisons are made between the results of the two assessments. It is expected that monofilament can be used to evaluate the pain threshold.(AU)