Early diagnosis in patients with transthyretin familial amyloid polyneuropathy: A comparative study

Introduction and objective: Transthyretin-associated familial amyloid polyneuropathy (TTR-FAP) is a disease caused by the deposit of abnormal transthyretin on tissues, mainly nerves. Small nerve fibers are altered earlier during the course of the disease; hence, detection of their involvement may have serious consequences on the natural history of disease.

Methods: A cross-sectional, observational study, was carried out on symptomatic patients, involving the conduct of several tests for small nerve fibers: Vibration, Touch Pressure (TP) and Heat Pain (HP). Results were compared with those obtained during a conventional neurological examination carried out on a group of healthy individuals.

Results: Fifteen symptomatic patients were recruited at an early stage of the disease (60% stage 1), along with 13 healthy individuals, with both patient groups having similar epidemiological characteristics in terms of gender, age, weight, height or BMI. A comparison carried out between the neuropsychological tests performed revealed statistically significant differences: Vibration (P<.05), TP (P<.05) and HP (P<.05, except volar forearm).

Conclusions: The neurophysiological tests performed revealed significant differences between both groups, allowing for an earlier detection of neurological injuries compared to conventional neurological examinations.