[Clinical and electrophysiologic studies of facial nerve function after hypoglossal-facial nerve anastomosis]

Hemihypoglossal-facial nerve anastomosis: results and electromyographic characterization

INTRODUCTION

The facial nerve surgery belongs to the basic procedures during lateral skull base approaches. Its damage has serious medical and psychological consequences, and therefore mastery of reconstruction and correction techniques should belong to the repertoire of skull base surgeons. The goal of this study was to demonstrate usefulness of electromyographic follow-up in facial nerve reconstruction.

MATERIAL AND METHODS

A total of 16 patients underwent hemihypoglossal-facial anastomosis between 2005 and 2017. Most of the primary lesions came from vestibular schwannoma surgery. All patients were examined with electromyography and scored according to the House-Brackmann and IOWA grading scales. Function of the tongue has been evaluated.

RESULTS

Ten patients achieved definitive House-Brackmann grade 3 score (62.5%). We did not observe any association with the patient's age, previous irradiation and the etiology of the damage. Electromyography showed pathological spontaneous activity after the first surgery. Incipient regeneration potentials were detected in 4-17 months (average 7.6) and reached maximum in 6.5-18 months (average 16). Electromyographic assessment of the effect of tongue movement showed better mimic voluntary activity by swallowing or by moving the tongue up. There was no relationship between the start of activity and the interval to achieving maximal activity.

CONCLUSION

Hemihypoglossal-facial nerve anastomosis is a safe procedure and it is an optimal solution for cases lacking a proximal stump or in the case of reconstruction in the second stage. Electromyography can predict initial reinnervation activity after reconstructive procedures. During subsequent follow-up it can help to discover insufficiently recovering patients, however clinical characteristics are crucial.

[Hypoglossal facial anastomosis as a solution to a total peripheral facial palsy. Our experience]

Hypoglossal-facial anastomosis was performed in four patients with total peripheral facial palsy after removal of cerebellopontine tumors (three patients with neurinoma) and pontine aneurysm (one patient). The anastomosis was performed after a period of 3 months to one year from surgery. The results obtained, concerning the facial activity, were clinically valued according to the tests used (questionnary, and the House-Brackmann paralysis index); the EnOG was used for its electrophysiological assessment. The follow-up period was 4 years with a good facial recovery in three patients and poor in one (class V, 27% in ENoG). We observe that the improvement in function greatly depends on the early surgical process performance.

Postoperative functional evaluation of different reanimation techniques for facial nerve repair

BACKGROUND

The facial nerve function after facial-facial nerve anastomosis, grafting, hypoglossal-facial nerve anastomosis, hypoglossal-facial interpositional jump nerve anastomosis, or a combined approach was analyzed.

METHODS

Facial function was assessed after operation using a 7-point visual analog scale (VAS) and by electromyography (EMG) in 53 patients. The final result was judged by May's facial nerve grading system.

RESULTS

Voluntary EMG activity occurred on average 4.52 +/- 1.31 months after operation. Initial facial movements were visible after 5.41 +/- 1.80 months. Facial function related to the VAS finally reached 44% of normal value. The result was judged May's grade I in 13%, grade II in 34%, grade III in 28%, and grade IV in 25% of patients. A significant difference in outcome between different reconstruction types was not seen. Age over 60 years was related to worse outcome.

CONCLUSIONS

A correct selection of the best method in the individual situation presumed, all analyzed facial reanimation techniques seem to lead nearly similar and satisfactory results.