What Happens in the Other Eye? Blink Reflex Alterations in Contralateral Side After Facial Palsy

Abstract

Alterations in blink reflex excitability may occur in the contralateral side (CLS) and in the symptomatic side after peripheral facial palsy (PFP). In this study, the alterations of blink reflex in CLS were evaluated in cases with PFP who showed "three different types" of recovery. For this purpose, the R2 response area and recovery curve of the blink reflex were evaluated. The study included 51 patients suffering from PFP and 20 age- and sex-matched healthy controls. Cases with PFP were divided into three groups: patients with PFP with partially cured and accompanied by synkinesis (postfacial syndrome), patients with PFP with residual weakness, and patients who suffered from recurrent PFP. All three groups' R2 values of CLS were compared with the values of controls and patients who had synkinesis. The CLS of all three groups' R2 area values were found to be significantly higher when compared with controls. These values were found to be highest in patients who suffered from recurrent PFP. Hyperexcitability occurs in CLS after PFP and this is highest in patients who suffer from recurrent PFP. It suggested that the contralateral reorganization caused by peripheral nerve damage correlates with the severity of the lesion and the recurrence of axon damage enhances the excitability of the reflex cycle, which affects the contralateral facial nucleus.