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).

New insights into the clinical evaluation of hereditary transthyretin amyloidosis patients: a single center's experience.

Over the last decade, new medical treatment modalities have emerged based on increased insights into amyloid formation. With the increased possibilities for treatment of amyloidosis caused by transthyretin (TTR) amyloid deposits comes the need for diagnostic procedures for early diagnosis and better tools to follow disease progression. This is of particular importance in clinical trials evaluating the efficacy of new treatments.

Comparison of quantitative sensory testing and heart rate variability in Swedish Val30Met ATTR.

Patients with transthyretin amyloidosis (ATTR) polyneuropathy, a hereditary fatal disease, often report defects in both thermal perception and autonomic nervous system function as their first clinical symptoms. While elevated thermal perception thresholds (TPT) for cold and warmth only recently have been shown as an early marker of small nerve fiber dysfunction in these patients, heart rate variability (HRV) has frequently been used to quantify autonomic neuropathy. The main purpose with this report was to elucidate a possible relationship between estimates of HRV and TPT in a selected group of early and late-onset Swedish Val30Met ATTR patients.

Reproducibility and influence of test modality order on thermal perception and thermal pain thresholds in quantitative sensory testing.

Objective: To evaluate the reproducibility of quantitative sensory testing (QST), performed with the method-of-limits (MLI) at different test intervals, by assessing the inter- and intra-individual variation of thermal cold (CT) and warm (WT) perception thresholds, and of thermal cold- (CPT) and heat pain (HPT) thresholds.

Methods: QST with the MLI was performed in 38 healthy subjects in three repeated and pseudo-randomized test sessions, done at three occasions (days 1, 2 and 7).

Results: At repeated testing, none of the thermal threshold estimates showed systematic significant differences, neither between days nor between sessions within the same day, when determined as first tests (FT), and for CT and WT also after thermal pain assessment (aTPA).

An animal model to study health effects during continuous low-dose exposure to the nerve agent VX.

In the present study, we have developed an animal model to study long-term health effects of continuous exposure of toxic chemical agents, in awake, freely moving rats. The aim was to evaluate the effect of low-dose exposure of the nerve agent VX, and to find specific biomarkers for intoxication. To exclude the influence of stress, we used an implanted radio-telemetric device for online registration of physiological parameters, and an osmotic pump, implanted subcutaneously, for continuous exposure of the toxic agent.

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.