Recurrent laryngeal nerve pathology in spasmodic dysphonia

Area of Science:

• Neurology
• Otolaryngology
• Pathology

Background:

• Spasmodic (spastic) dysphonia has historically been viewed as psychogenic.
• Previous surgical interventions targeting the recurrent laryngeal nerve showed some efficacy.
• The underlying etiology of spasmodic dysphonia remains largely unexplained.

Purpose of the Study:

• To investigate the organic etiology of spasmodic dysphonia.
• To evaluate the efficacy of recurrent laryngeal nerve sectioning.
• To correlate microscopic findings with clinical presentation.

Main Methods:

• A controlled study involving recurrent laryngeal nerve sectioning in patients with spasmodic dysphonia.
• Examination of nerve sections using light and electron microscopy.
• Special stains for myelin were employed for light microscopy.

Main Results:

• Demyelination was identified in the majority of recurrent laryngeal nerve samples via electron microscopy.
• Surgical intervention resulted in improved voice production in patients.
• Potential correlations were noted with other cranial nerve disorders of unknown origin.

Conclusions:

• Findings suggest an organic basis for spasmodic dysphonia, specifically demyelination of the recurrent laryngeal nerve.
• The results support a potential link between spasmodic dysphonia and other cranial nerve syndromes like trigeminal neuralgia and hemifacial spasm.
• Further research is warranted to elucidate the precise pathophysiology and potential shared etiologies.