Enlarged cross-sectional area in peripheral nerves in Swedish patients with hereditary V30M transthyretin amyloidosis

INTRODUCTION: In hereditary transthyretin amyloidosis (ATTRv), two different fibrillar forms causing the amyloid deposition, have been identified, displaying substantially cardiac or neuropathic symptoms. Neuropathic symptoms are more frequent in early-onset patients, whereas late-onset patients, besides cardiac symptoms, seem to develop carpal tunnel syndrome, more often. With ultrasonography (US) of peripheral nerves, it is possible to distinguish structural changes, and enlarged cross-sectional area (CSA). The main purpose of this study was, for the first time, to elucidate US of peripheral nerves in Swedish ATTRv patients at an early stage of the disease, and to evaluate possible early enlarged CSA. MATERIAL AND METHODS: This prospective study included first visit data of 13 patients, aged 30–88 years, of which 11 with late-onset age. All had a positive V30M mutation. Eight men and six women (aged 28–74 years) served as controls. RESULTS: Significantly enlarged CSA was seen in ATTRv patients for the tibial nerve at the ankle (p = .001), the sural nerve (p < .001), the peroneal nerve at the popliteal fossa (p = .003), and the ulnar nerve at the middle upper arm (p = .007). CONCLUSION: US of peripheral nerves could be a valuable tool in disease evaluation and could facilitate monitoring of disease progression.