Prognostic value of the blink reflex in acoustic neuroma surgery.
OBJECTIVE
The study goal was to demonstrate that blink reflex analysis can predict postoperative facial nerve outcome in cerebellopontine angle tumor surgery.


METHODS
In an open and prospective study conducted at a single tertiary care center over 3 years, 91 subjects with a vestibular schwannoma filling the internal auditory meatus were enrolled and operated on via a translabyrinthine approach. The difference in latency of the early response (DeltaR1) of the blink reflex between the pathologic side and the healthy side was calculated in every patient during a complete electrophysiologic examination of the facial nerve performed on the day before surgery. MIN OUTCOME MEASURES: DeltaR1 was compared with the other preoperative data (tumor volume, facial function), with the perioperative observations (difficulties with the dissection of the facial nerve), and especially with the postoperative status after 1 year. The statistical study was conducted using polynomial regression.


RESULTS
Patients with a negative or zero DeltaR1 have normal facial function at 1 year. For those with a positive DeltaR1 the outcome is not favorable unless the tumor is small. For patients presenting with an immediate complete facial paralysis, the value of DeltaR1 is also indicative of facial function outcome.


CONCLUSIONS
Statistical analysis shows that the blink reflex, through DeltaR1, has an excellent prognostic value in anticipating the difficulties with facial nerve dissection and postoperative facial function after 1 year.
Darrouzet
Vincent
V
Department of Skull Base Surgery, University Hospital of Bordeaux, France. vincent.darrouzet@chu-bordeaux.fr
Hilton
Malcolm
M
Pinder
Darren
D
Wang
Jio-Ling
JL
Guerin
Jean
J
Bebear
Jean-Pierre
JP
D000328:Adult; D000368:Aged; D001767:Blinking; D004210:Dissection / Q000009:adverse effects; D004576:Electromyography; D004594:Electrophysiology / Q000379:methods* / Q000592:standards; D005158:Facial Paralysis / Q000145:classification / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods* / Q000592:standards; D009464:Neuroma, Acoustic / Q000601:surgery*; D011183:Postoperative Complications / Q000175:diagnosis* / Q000209:etiology*; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods* / Q000592:standards; D011379:Prognosis; D011446:Prospective Studies; D011930:Reaction Time; D012044:Regression Analysis; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome