Peripheral nerve involvement in wild-type transthyretin amyloidosis

• Published in: Neurological sciences Vol. 44; no. 1; pp. 351 - 354
• Main Authors: Campagnolo, Marta, Cacciavillani, Mario, Cipriani, Alberto, Salvalaggio, Alessandro, Castellani, Francesca, Pilichou, Kalliopi, Briani, Chiara
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.01.2023; Springer Nature B.V
• Subjects: Age; Aged; Aged, 80 and over; Amyloid Neuropathies, Familial - complications; Amyloid Neuropathies, Familial - diagnostic imaging; Amyloidosis; Autonomic nervous system; Brief Communication; Carpal Tunnel Syndrome; Humans; Hypotension; Male; Medicine; Medicine & Public Health; Nervous system; Neurological complications; Neurology; Neuroradiology; Neurosciences; Neurosurgery; Peripheral nerves; Peripheral Nerves - diagnostic imaging; Peripheral neuropathy; Prealbumin; Psychiatry; Quality of Life; Scintigraphy; Transthyretin; Autonomic function; Amyloidosis; Peripheral neuropathy; Transthyretin; Quality of life
• ISSN: 1590-1874; 1590-3478; 1590-3478
• DOI: 10.1007/s10072-022-06459-0

Introduction and aimrpose Neurological involvement other than carpal tunnel syndrome (CTS) has rarely been observed in wild-type transthyretin amyloidosis (ATTRwt). The aim of our study was to investigate peripheral nerve involvement in ATTRwt. Methods Patients diagnosed with ATTRwt (negative molecular testing, confirmed cardiac uptake at bone scintigraphy, Perugini score 2 or 3) were considered. Sixteen men (mean age 75 ± 6.2, range 65–86 years) were enrolled. Neurological examination (Neuropathy Impairment Score, NIS), questionnaires on autonomic function and quality of life (QoL), electrodiagnostic studies (EDX), nerve ultrasound, and Sudoscan (electrochemical skin conductance, ESC) were performed. The presence of peripheral neuropathy was defined according to the detection of any abnormal finding at lower limbs other than CTS at EDX studies, regardless of NIS scores. Results Ten (62.5%) ATTRwt had abnormal NIS scores. At EDX, CTS was observed in 13/16 (81.2%), with 3/16 (18.8%) presenting also axonal peripheral neuropathy. Extensive workup ruled out common causes of neuropathy. Eight (50%) ATTRwt patients had orthostatic hypotension (OH). Abnormal ESC was observed in 9/14 (64%) ATTRwt patients. Discussion Despite being uncommon, we observed peripheral nervous system involvement in ATTRwt (large and small fiber dysfunction). Being elderly, ATTRwt patients may have age-related conditions acting as confounding factors for the diagnosis of neuropathy that however can be detected with a careful examination and use of specific tests, including those for autonomic dysfunction.