Patterns of facial nerve synkinesis.

Facial nerve synkinesis is an extremely distressing sequela of facial paralysis, and its prevention and treatment are less than adequate. Improved therapeutic interventions await better understanding of its pathogenesis. In this study, 11 patients with synkinesis and 11 normal control subjects were quantitatively assessed using a new computer-assisted, motion-sensitive system. Two additional, informative cases presenting at the completion of the study are also briefly reported. The observed synkinetic patterns appear predictable and nonrandom. In addition, these observations tend to raise doubts that the aberrant fiber regeneration hypothesis is the sole explanation of synkinesis. They further implicate facial nuclear hyperexcitability as an explanation in at least some cases of synkinesis. Understanding these patterns enhances clinical detection and evaluation and may lead to a better knowledge of the fundamental pathophysiology of synkinesis and its prevention.