Neurological Examinations of Patients Initially Diagnosed With Wild-Type Transthyretin Amyloidosis (wtATTR)

Abstract

Background Relevance of wild-type ATTR amyloidosis (wtATTR) is increasing, due to improved therapeutic and diagnostic options. Despite the significant prevalence of neurological manifestations, there remains low awareness towards the disease, resulting in delayed diagnoses and treatment commencements. Systematic clinical and neurophysiological characterisations of large neurological collectives are lacking, as well as examination of correlations between neurological and cardiological involvement.

Methods 75 patients with confirmed initial diagnosis of wtATTR amyloidosis underwent standardised clinical and extended neurophysiological examination (quantitative sensory testing, nerve conduction studies, sympathetic skin response, autonomic testing). Furthermore, cardiac involvement was quantified using laboratory and clinical scores, as well as cardiac tracer uptake in scintigraphy.

Results 84% of the patients suffered from carpal tunnel syndrome (CTS), 62% with bilateral involvement. Neuropathy was present in 71%; one third showed spinal stenosis. CTS operation was performed a median of 10 years before diagnosis. Clinically, the absence of Achilles reflexes and impaired pallesthesia were particularly impressive. No correlation was found between the severity of neurological symptoms and cardiological or scintigraphic parameters.

Conclusions We were able to perform a precise clinical and neurophysiological characterisation in a large cohort of patients. We detected a predominant peripheral neuropathy pattern in a large majority of patients. However, the extent of neurological damage did not correlate with cardiac involvement. The findings may contribute to enhanced awareness among neurologists, potentially leading to earlier diagnosis and initiation of treatment.