Histological and ultrastructural evidence that recurrent laryngeal neuropathy is a bilateral mononeuropathy limited to recurrent laryngeal nerves.

The research article investigates whether Recurrent laryngeal neuropathy (RLN), a common nerve disease in horses, is a mono- or polyneuropathy. The study concludes that RLN should be categorized as a bilateral mononeuropathy, affecting both sides of the recurrent laryngeal nerves.

Research Objective and Methodology

• The main aim of this research was to understand the nature of Recurrent laryngeal neuropathy (RLN), a prevalent and impairing peripheral nerve disease in horses.
• The focus was to ascertain whether the nerve injury was localized to a single nerve, known as mononeuropathy, or it was spread across multiple nerves, which is referred to as polyneuropathy.
• A comprehension of the distribution of neuropathological lesions in RLN-affected horses is fundamental to the deeper understanding of the cause of this disease.
• The researchers utilized a methodical approach to examine multiple long peripheral nerves and their corresponding muscles in three clinically affected RLN horses.

Research Findings

• The study found severe lesions in the left as well as right recurrent laryngeal nerves in all horses, both at the distal and, in one case, also the proximal ends.
• No primary axonal lesions were evident in other nerves, and there were no changes found in their corresponding muscles. This highlighted that the damage was primarily localized to the recurrent laryngeal nerves only.

Research Conclusions

• Based on the findings, the study concluded that RLN is not a polyneuropathy but should be classified as a bilateral mononeuropathy. This means the disease is concentrated and affects both the left and right recurrent laryngeal nerves in horses.
• The study prompts future research to further investigate the genetic and local factors that specifically affect the recurrent laryngeal nerves in RLN-affected horses.