Validation of the mgh symptom screen for small-fiber polyneuropathy for the portuguese population

  • Beatriz Maria Sousa Pinto Reis Gonçalves (Student)

Student thesis: Master's Thesis


Small-Fibre Polyneuropathy (SFNP) are nerve dysfunctions of thinly my elinated and unmyelinated neurons, normally symmetrical and often of unknown cause, frequently under diagnosed and undertreated. The Massachusetts General Hospital Symptom Screenfor Small-Fiber Polyneuropathy (MGH-SSS) is a measure to screen of SFPN, but this instrument was not yet validated for the Portuguese population. The main aim of this dissertation was to validate the Portuguese version of MGH-SSS questionnaire. The MGH-SSS was translated according to the international guidelines and then presented to a group of 362 individuals(315 healthy and 47 FM) with other questionnaires measuring symptoms related to SFPN. Exploratory factorial analysis, internal consistency and convergent validity were investigated. Results from a subsample of 43 Fibromyalgia patients and 41 matched healthy individuals (HC) were compared to assess the sensitivity of the questionnaire. Finally, the MGH-SSS and an experimental pain (heat, cold and pressure thresholds, cold pressor test) and neuropsychological assessment (MoCA and digit span) was performed in 13 healthy individuals with the aim of providing clues for future experimental studies. Factorial analysis indicated, as in the original version, a five-component solution(miscellaneous; somatosensory; microvascular/circulation; gastrointestinal; and pelvic/urological). The internal consistency and convergent validity were excellent. FM demonstrated significantly higher scores in all symptoms, components and total of the MGH-SSS than HC, and the expected correlations between MGH-SSS and the questionnaires measuring everyday symptoms. In the experimental study it was found correlations between cognitive functioning and heat pain threshold. Besides, the method provided a good start for further studies.In summary, the Portuguese version of the MGH-SSS demonstrated a clinically relevant factorial structure, excellent internal consistency, convergent validity and different symptom severity between HC and patients with probable SFPN. Based on these findings it may be a valuable resource for improving diagnose and assessment of idiopathic SFPN in clinical and research settings.
Date of Award4 Nov 2020
Original languageEnglish
Awarding Institution
  • Universidade Católica Portuguesa
SupervisorRita Canaipa (Supervisor) & Roi Treister (Co-Supervisor)


  • SFPN
  • Fibromyalgia
  • Pain
  • Cognition


  • Mestrado em Neuropsicologia

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