Heart rate variability analysis in sheep affected by transmissible spongiform encephalopathies

Area of Science:

• Veterinary Neurology
• Animal Pathology
• Prion Disease Research

Background:

• Autonomic nervous system function is assessed via heart rate variability (HRV).
• Brainstem diseases, including transmissible spongiform encephalopathies (TSEs) in sheep, can impair HRV.
• TSEs involve prion protein accumulation in the sheep brainstem, affecting the parasympathetic nervous system.

Purpose of the Study:

• To evaluate heart rate variability (HRV) analysis as a potential diagnostic aid for transmissible spongiform encephalopathies (TSEs) in sheep.
• To determine if HRV can differentiate between TSE-affected sheep and healthy controls.

Main Methods:

• Comparison of HRV indices between 41 clinical TSE cases (scrapie and bovine spongiform encephalopathy) and 11 control sheep.
• Inclusion of six suspect cases and sheep experimentally exposed to BSE, confirmed negative postmortem.
• Analysis of median heart rate differences based on gender and disease status.

Main Results:

• No significant differences in HRV indices were observed between clinical TSE cases and control sheep.
• Median heart rate differed significantly only by gender, being higher in female TSE cases than controls.
• Ovine classical BSE cases showed higher median heart rates in females compared to castrated males.

Conclusions:

• Heart rate variability (HRV) analysis is not a useful diagnostic aid for diagnosing TSEs in sheep.
• The study did not find HRV to be a reliable biomarker for TSEs in the ovine population.