Quantified sensory abnormalities in early genetically verified transthyretin amyloid polyneuropathy.
Transthyretin amyloid neuropathy of type 1 (Swedish-Portuguese type) is an autosomally inherited progressive disease with a Val30Met mutation, causing generalized sensory-motor polyneuropathy. Quantitative sensory testing (QST) quantifies thermal threshold changes in patients with manifest general polyneuropathy, but its applicability at an early clinical stage of a strict biochemically defined disease has not yet been shown. Thermal QST was performed in 23 patients having a positive Val30Met marker and clinical symptoms of peripheral small-fiber neuropathy but normal electrophysiological findings and compared to a reference group of 43 healthy volunteers, both subdivided into age groups < or =45 and >45 years. Significant differences between patients and controls were found at all test sites in both age groups, except for warm thresholds at the medial lower leg in those >45 years. QST thus demonstrated elevated thermal thresholds before the development of electrophysiological abnormalities, which indicate large-fiber involvement. These findings confirm that QST is a useful method for documentation of developing polyneuropathy.
Heldestad
Victoria
V
Department of Pharmacology and Clinical Neurosciences, Division of Clinical Neurophysiology, Umeå University, SE-90187 Umeå, Sweden.
Nordh
Erik
E
D000328:Adult; D000367:Age Factors; D017772:Amyloid Neuropathies / Q000150:complications* / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008715:Methionine / Q000235:genetics; D010525:Peripheral Nerves / Q000503:physiopathology*; D011228:Prealbumin / Q000235:genetics; D012684:Sensory Thresholds / Q000502:physiology*; D020886:Somatosensory Disorders / Q000209:etiology* / Q000235:genetics; D013696:Temperature; D014633:Valine / Q000235:genetics
D011228:Prealbumin; D008715:Methionine; D014633:Valine