The recurrent laryngeal nerve in spastic dysphonia. A light and electron microscopic study.

Sections of right or left recurrent laryngeal nerve (RLN), removed from patients with spastic dysphonia (SD) at the time of surgery, were studied using light and electron microscopy and were compared with control RLNs. In both groups, small, medium and large-sized myelinated nerve fibres were found in the RLN. Furthermore, numerous unmyelinated axons intermingled with the myelinated fibres were detected in the control group as well as in SD specimens. Slight morphometric differences were also found between the two groups, but these cannot explain the causation of spastic dysphonia.