Characteristics of Carpal Tunnel Syndrome in Wild-Type Transthyretin Amyloidosis
Angela Russell1, Shahin Khayambashi2, Nowell Fine3, Sameer Chhibber4, Christopher Hahn5
1Department of Clinical Neurosciences, Alberta Health Services & University of Calgary, 2Department of Clinical Neurosciences, 3University of Calgary, 4Alberta Neurologic Centre, 5Alberta Health Services
Objective:

The purpose of our study was to evaluate the prevalence, clinical features, severity, and disease course of carpal tunnel syndrome (CTS) in wild-type transthyretin amyloidosis (wtATTR) patients, as well as the risk of recurrence following carpal tunnel release (CTR).

Background:

Wild-type transthyretin amyloidosis is an important cause of infiltrative cardiomyopathy, particularly in older males. Carpal tunnel syndrome is one of the most common extra-cardiac manifestations of wtATTR and can predate cardiac symptoms by 5-10 years. The association between CTS and wtATTR has been described in several case series; however, the characteristics of CTS in this population remain poorly understood.

Design/Methods:

This retrospective cohort study reports findings from a single-center experience of routine neurological screening of newly diagnosed wtATTR patients including nerve conduction studies. Consecutive wtATTR patients between 2014 and 2021 were included.

Results:

Seventy-nine wtATTR patients were included; 73 (92%) males, mean age of 79 years. Seventy-one (90%) met electrodiagnostic criteria for median neuropathy at the wrist (MNW), 50% had a prior diagnosis and 50% were newly diagnosed at screening. The majority with MNW were symptomatic (53, 67%) with moderate or severe disease (66, 84%) bilaterally (42, 53%) on electrophysiologic testing. Fifty-six percent of our asymptomatic patients had moderate disease at the time of screening. Nineteen (24%) had recurrent CTS despite previous CTR. At the time of screening, 19 (24%) were prescribed wrist splinting and 36 (46%) were referred for CTR.

Conclusions:

Median neuropathy at the wrist affects the vast majority of wtATTR patients. CTS was confirmed in 67% of our patients, most had bilateral disease with moderate to severe MNW on electrophysiology at the time of wtATTR diagnosis. Recurrence after CTR was seen in 27% of our patients at the time of screening, which is higher than the rate of recurrence in the general population, estimated at 3-20%.

10.1212/WNL.0000000000203687