Long term phonatory function following acoustic neuroma surgery: a cohort study

Abstract

Background: Acoustic neuroma (AN) is a well-recognized cause of neurological morbidity, peripheral facial paralysis being one of the most prevalent. Phonatory dysfunction in the late post-operative term has not been properly addressed so far.Objective: The objective of this study is to describe the outcomes of phonatory function on the long-term follow-up of AN surgery and identify its prognostic factors.Material and methods: This cohort study included patients submitted to AN surgery from 1999 to 2014, with a mean follow up of 6.4 ± 4.5 years. To evaluate the phonatory function, we performed a combination of noninvasive acoustic and aerodynamic measurements including vocal intensity and stability, maximum declination rate of the glottal airflow (MDR) and transglottal pressure scale (TP).Results: 101 patients were studied. 25 (24.7%) presented a deficit in phonatory function. Women comprised 56% and the mean age was 42.4 ± 13.8 years (range19–80). 100% presented reduced expiratory airflow capacity with excessive manifestation of the laryngeal musculature (TP > 1,23s ;MDR/z/<MDR/s/). Dysphonic patients presented more neurofibromatosis II (NF II) (40% vs 12.7% p = .002), large tumors (3.8 ± 1.1 p = .002) and needed less surgeries (≥256.7% vs 74.6%, p = .0073) in univariate analysis. NFII and tumor size were predictive of dysphonia according to multivariate analysis (NFII-OR 5.57, p = .006; tumor size-each 1 cm, OR1.68, p = .062).Conclusion: The late postoperative prevalence of dysphonia corresponded to 24.7%. Dysphonia could be secondary to the hyperfunction of laryngeal musculature explained by the reduced expiratory airflow found in our patients. Tumor size and NF II were predictors for the occurrence of dysphonia in the present study.HighlightsThe comprise of phonation function can be a morbidity of AN surgeryNF II and tumor size were predictive of dysphonia on late postoperative periodData of hypofunction secondary to the phonatory hyperfunction were unanimous in the dysphonic patients.The early diagnosis and treatment of phonation function could avoid alterations of pneumophono-articulatory coordination and projection deficiency.