No morphometric abnormality recurrent laryngeal nerve in spastic dysphonia

Area of Science:

• Neurology
• Otolaryngology
• Pathology

Background:

• Spastic dysphonia is a phonation disorder.
• Surgical resection of the recurrent laryngeal nerve (RLN) often improves spastic dysphonia.
• The underlying neuropathology of spastic dysphonia remains unclear.

Purpose of the Study:

• To investigate potential neuropathic abnormalities in the recurrent laryngeal nerve (RLN) of patients with spastic dysphonia.
• To compare the histological and morphological features of RLN in spastic dysphonia patients versus a control group.

Main Methods:

• Biopsies of the RLN were obtained during surgery from nine spastic dysphonia patients and eight laryngeal cancer patients (controls).
• Morphology, median fiber diameter, density, and size distribution of nerve fibers were evaluated for different nerve regions and the whole nerve.
• Teased fiber morphologies were also assessed.

Main Results:

• The recurrent laryngeal nerve (RLN) exhibited distinct regions with characteristic fiber compositions in both groups.
• No significant differences in morphology, fiber diameter, density, or size distribution were observed between the RLN of spastic dysphonia patients and controls.
• Teased fiber analysis also revealed no significant distinctions.

Conclusions:

• This study did not find evidence of neuropathic abnormality in the recurrent laryngeal nerve (RLN) of spastic dysphonia patients.
• The findings do not support previous reports suggesting a neuropathic basis for spastic dysphonia.
• Further research may be needed to elucidate the etiology of spastic dysphonia.