Exercise with visual feedback improves postural stability after vestibular schwannoma surgery

We analyzed the effect of 2-week individualized visual feedback-based balance training on the postural control of patients undergoing retrosigmoid microsurgical removal of vestibular schwannoma. We performed prospective evaluation of 17 patients allocated into two groups: feedback group (9 patients, mean age 37 years) and standard physiotherapy group (8 patients, mean age 44 years). Patients in both the groups were treated once per day by intensive rehabilitation from 5th to 14th postoperative day. Rehabilitation of patients in the feedback group was performed using the visual feedback and force platform. Results were evaluated on the beginning and at the end of rehabilitation program (e.g. 5th and 14th postoperative day). Outcome measures included posturography during quiet stance under four different conditions by the modified Clinical Test for Sensory Interaction of Balance. Body sway was evaluated from center of foot pressure. Compensation of Center of pressure (CoP) parameters in stance on firm surface was similar in the control and feedback groups. However, in stance on foam surface with eyes closed the patients from the feedback group were better compensated and CoP parameters differed significantly (p < 0.05). This prospective clinical study suggests that specific exercises with visual feedback improve vestibulospinal compensation in patients after vestibular schwannoma surgery and thus can improve their quality of life.     

Postoperative headache after surgery for vestibular schwannoma

Postoperative headache was studied among 251 patients who underwent operation for vestibular schwannoma. A questionnaire based on the McGill Pain Questionnaire and the Finnish Pain Questionnaire was sent to the patients. Twenty-one expressions describing postoperative headache were extracted with a factor analysis. The pain intensity was expressed on a visual analog scale, and the risk factors for postoperative headache were evaluated. Immediately after the operation, 154 subjects reported headache. Eighty-nine of the patients had had headache before operation, whereas 65 patients experienced headache only after operation. An average of 8.9 years after surgery, 93 patients still reported headache. Headache was a major problem for 27 subjects; 18 of the 27 had suffered from headache before operation. A retrosigmoidal approach, postoperative gait problems, preoperative headache, and small tumor size predicted postoperative problems with headache. When headache is present before operation, it tends to continue after operation, and if headache continues for 1 year, it usually persists without being reduced.     

Delayed facial palsy after vestibular schwannoma surgery

OBJECTIVE: there is a lack of uniformity in the literature of the definition of delayed facial palsy (DFP) after vestibular schwannoma surgery. The aim of this study was to attempt to provide a clear definition of this clinical entity. METHODS: a prospective study was undertaken of all patients, with an intact facial nerve postoperatively, undergoing vestibular schwannoma surgery during a 16-month period. Delayed facial palsy was defined as any worsening of facial function after the initial assessment of postoperative function. RESULTS: a total of 67 patients, operated on between February 1994 and June 1995 satisfied the requirements of the study. Eight of the 67 patients developed a worsening of facial function after the first postoperative day. There were three males and five females with an age range of 29-73 years (mean, 53 years). CONCLUSION: DFP should be defined as any deterioration of facial function after vestibular schwannoma surgery.     

Postural control after vestibular schwannoma resection measured with visual feedback posturography

BACKGROUND: Vestibular symptoms after surgery diminish rapidly, but the simultaneous progress in active postural control has not been fully addressed. OBJECTIVES: The aim was to evaluate the progress in postural control in operated vestibular schwannoma (VS) patients with visual feedback posturography (VFP). METHODS: 36 consecutive patients with unilateral VS were studied with the VFP pre-operatively, 1 month and 3 months after the surgery. The accuracy and velocity of active postural control movements to distant targets in VFP was measured and compared to that of healthy controls. RESULTS: The hold percentage within the targets was significantly reduced in the VS patients compared to the controls (pre-operatively p = 0.005; postoperatively at 1 month p = 0.002 and at 3 months p = 0.017). The sway velocity (SV) within the targets among patients with VS was significantly increased pre-operatively (p = 0.009), at the 1-month (p = 0.004) and at the 3-month follow-up visits (p = 0.016). All the postural control parameters except SV tended to improve slightly postoperatively. The consecutive VFP measurements in individual VS patients correlated statistically significantly (p < 0.001 for all parameters). The abnormality in the pre-operative VFP results correlated statistically significantly with that of postoperative VFP (p = 0.001). CONCLUSIONS: The VFP is an objective and repeatable method, which can be used to assess and follow up the active postural control in individual patients with VS. Persisting abnormality in the VFP seems to be an indication for more aggressive vestibular rehabilitation to normalize the disturbed postural control.     

Contralateral sensorineural hearing loss after vestibular schwannoma surgery

IntroductionContralateral sensorineural hearing loss (CSNHL) after vestibular schwannoma (VS) is a severe complication, especially in those cases in which hearing preservation in the operated side was not possible. There are several theories that attempt to explain this issue, but there is no established guideline of treatment.Material and methodsWe report 4 patients treated in our institution who developed a severe CSNHL after surgery.ResultsOf the 185 cases of VS treated with surgery, 4 patients (2.2%) developed a CSNHL after VS surgery. After medical treatment, partial recovery of hearing occurred in one patient the other 3 patients presented a well-established severe SNHL.ConclusionsEstablished treatment guidelines do not exist, but the use of high doses of corticosteroids has been recommended and cochlear implant in cases with no recovery and complete hearing loss may be useful.     

Eustachian tube function after translabyrinthine vestibular schwannoma surgery

The objective of this study was to evaluate the short-term and long-term effect of the obliteration of the middle ear and the Eustachian tube on its function and on middle ear anatomy. Forty-two patients who underwent a translabyrinthine removal of a vestibular schwannoma were randomly selected from the 329 patients operated on in the last 5 years. According to the length of follow-up they were divided in two groups. The Eustachian tube was found to open in 40% of cases 8 months (group mean) after the operation and at 4 years in 70% of cases (group mean) after the operation. The mechanisms leading to the opening of the tube are discussed. In addition the absence of long-term middle ear disorders in those with a permanently closed Eustachian tube showed that the presence of atrophied connective tissue and scar tissue in the middle ear prevented the retraction of the tympanic membrane. Obliteration of the Eustachian tube and middle ear is an easy and rapid procedure, which is temporary in most cases and does not increase the risk of long-term middle ear disease.     

Auditory pathway function after vestibular schwannoma surgery.

We studied seven patients before and after vestibular schwannoma surgery. Four patients became unilaterally profoundly deaf and three patients preserved their hearing. Cortical responses were recorded with a 122-channel whole-scalp SQUID neuromagnetometer using tone-burst stimuli to the healthy ear. Brainstem auditory evoked potentials (BAEPs) were measured using alternating clicks. Ten healthy volunteers served as a control group. In patients, preoperative cortical response latencies and strengths did not differ significantly from those of controls. However, 6 months after the operation the latency was, on average, 7 ms longer than preoperatively over both hemispheres. BAEPs were in the normal range both before and after the operation. These results suggest that unilateral lesion in peripheral auditory pathways also affects cortical reactivity to stimuli presented to the non-affected ear, possibly reflecting altered binaural interaction in the auditory pathways.     

Quality of life of vestibular schwannoma patients after surgery

The quality of life of vestibular schwannoma (VS) patients after surgery was investigated. The subjects consisted of 236 unilateral VS patients who underwent tumor removal between 1990 and 1997. A questionnaire was sent to all patients regarding their hearing, tinnitus, dizziness and the changes in their daily life after surgery; 176 out of 204 patients (86%) who received the questionnaire completed and returned it. The answers were compared with recent data reported in other clinical studies. Ninety percent of the patients with postoperative class A hearing were satisfied with their hearing. However, only 30% of patients with postoperative class B hearing were satisfied. Tinnitus worsened after surgery more often in patients who underwent a labyrinthectomy than in those who did not. Dizziness improved after surgery in the majority of VS patients. However, 30% of patients had difficulty driving a car and 50% of patients could not enjoy activities such as playing sport after surgery.     

Effects of vestibulo-ocular reflex exercises on vestibular compensation after vestibular schwannoma surgery.

OBJECTIVE: To assess vestibular function in a large group of vestibular schwannoma patients so that we could determine whether simple vestibular exercises speed vestibular dysfunction recovery after tumor removal surgery. STUDY DESIGN: A prospective investigation of the vestibular dysfunction experienced by patients in the first 12 weeks after surgery. SETTING: Vestibular investigation unit at a tertiary referral institution. PATIENTS: Sixty-five patients with identified vestibular schwannoma referred for preoperative vestibular investigations. Thirty-two men and 33 women, with a mean age 51 years (range, 24-77 yr). INTERVENTIONS: There were 27 control patients, 30 exercise patients, and 8 patients that had balance physiotherapy. Exercise patients began simple vestibulo-ocular reflex gaze stabilization exercises 3 days after surgery. MAIN OUTCOME MEASURES: Postoperative vestibular function testing was performed at 2 to 3, 6 to 7, and 10 to 12 weeks after surgery. Objective measurements of vestibular compensation status were as follows: spontaneous nystagmus and sinusoidal harmonic acceleration asymmetry and gain values. Dizziness Handicap Inventory questionnaires were used to assess subjective perceptions. RESULTS: The main findings were reduced dispersion in vestibulo-ocular reflex asymmetry at 2 to 3 weeks, reduced mean in asymmetry at 6 to 7 weeks, less dizziness/imbalance according to the Dizziness Handicap Inventory questionnaire, and that preoperative caloric tests did not predict postoperative severity of vestibular systems. CONCLUSION: This large study provided unique evidence that a program of simple vestibular exercises and education can speed the rate of compensation after vestibular schwannoma surgery.     

Vestibular evoked myogenic and periocular potentials after vestibular schwannoma surgery

OBJECTIVES: We analyzed the behavior of preoperative and postoperative vestibular evoked myogenic potentials (VEMPs) and vestibular evoked periocular potentials (VEPPs) in 3 patients who had vestibular schwannoma and underwent modified translabyrinthine surgery. METHODS: We compared VEMPs and VEPPs, measured with both air-conducted (AC) and bone-conducted (BC) stimulations. Vestibular evoked potentials were measured both in the immediate postoperative period and some months later. RESULTS: At the immediate postoperative examination, VEPPs were preserved in all 3 patients with both AC and BC stimulations. The VEMPs showed stable or improved parameters in 2 of our patients and were absent in the third patient. At the follow-up examination, VEMPs did not show any significant change with respect to the previous evaluation. In contrast, VEPPs were absent in 2 of our patients with AC stimulation and in 1 patient with BC stimulation. CONCLUSIONS: Our results seem to indicate a greater stability and reproducibility of VEMPs compared with VEPPs. In 1 patient, who had a schwannoma of the inferior vestibular nerve, the preservation of VEPPs and the absence of VEMPs in the immediate postoperative period confirm that the saccule represents the origin of VEMPs. Furthermore, these results suggest that not only the saccule, but also the utriculus, could be implicated in the origin of VEPPs.     

Causes of persistent postoperative headache after surgery for vestibular schwannoma

Our aim was to elucidate the aetiology of persistent postoperative headache, a common sequel for several years after vestibular schwannoma surgery through the retrosigmoid approach. Twenty‐seven patients with reported major postoperative headache were tested for vestibular responses and cervico‐collic reflexes. The role of local anaesthesia injected into the neck muscle insertions or around the occipital nerves was evaluated. Sixteen patients operated on for vestibular schwannoma, but without headache, and 12 healthy volunteers served as control groups. Vestibular responses and cervico‐collic reflexes deteriorated equally in the patients regardless of whether or not they had a postoperative headache. Local anaesthesia did not alter the results. The posturography results were increased among both patient groups. Sumatriptan alleviated pain in nine patients and abolished it completely in one out of these nine patients. Vestibular imbalance or abnormal activation of neck muscles do not explain postoperative headache. Occipital nerve entrapment or neuralgia explains the headache in a few patients. The relatively pronounced sumatriptan effect may, however, suggest a trigeminal nerve mediated cause for postoperative headache.     

Hearing preservation surgery in vestibular schwannoma

OBJECTIVES: To study the effect of pre-operative hearing level and tumour size on the hearing outcome of hearing preservation surgery for vestibular schwannoma. STUDY DESIGN AND SETTING: A review of literature conducted at Gruppo Otologico, a tertiary referral centre for neurotology and skull base surgery. RESULTS: A total of 1993 patients in 16 publications addressing the topic of hearing preservation surgery in vestibular schwannoma were analysed. The American Academy of Otolaryngology-Head and Neck Surgery hearing classification system was the classification upon which we based our analysis. CONCLUSION: Defining hearing preservation as class-A hearing, there was a strong inverse relationship between pre-operative hearing and post-operative hearing levels and between tumour size and post-operative hearing levels.     

The incidence of cerebrospinal fluid leak after vestibular schwannoma surgery.

OBJECTIVE: To review the incidence of cerebrospinal fluid leak after vestibular schwannoma removal reported in the literature. DATA SOURCES: MEDLINE and PubMed literature search using the terms "acoustic neuroma" or "vestibular schwannoma," and "cerebrospinal fluid leak" or "cerebrospinal fluid fistula" covering the period from 1985 to the present in the English language literature. A review of bibliographies of these studies was also performed. STUDY SELECTION: Criteria for inclusion in this meta-analysis consisted of the availability of extractable data from studies presenting a defined group of patients who had undergone primary vestibular schwannoma removal and for whom the presence and absence of cerebrospinal fluid leakage was reported. Studies reporting combined approaches were excluded. No duplications of patient populations were included. Twenty-five studies met the inclusion criteria. DATA EXTRACTION: Quality of the studies was determined by the design of each study and the ability to combine the data with the results of other studies. All of the studies were biased by their retrospective, nonrandomized nature. DATA SYNTHESIS: Significance (p < 0.05) was determined using the chi2 test. CONCLUSIONS: Cerebrospinal fluid leak occurred in 10.6% of 2,273 retrosigmoid surgeries, 9.5% of 3,118 translabyrinthine surgeries, and 10.6% of 573 middle fossa surgeries. The type of cerebrospinal fluid leak was not associated with surgical approach. Meningitis was significantly associated with cerebrospinal fluid leak (p < 0.05). Age and tumor size were not associated with cerebrospinal fluid leak.     

Causes of persistent postoperative headache after surgery for vestibular schwannoma.

Our aim was to elucidate the aetiology of persistent postoperative headache, a common sequel for several years after vestibular schwannoma surgery through the retrosigmoid approach. Twenty-seven patients with reported major postoperative headache were tested for vestibular responses and cervico-collic reflexes. The role of local anaesthesia injected into the neck muscle insertions or around the occipital nerves was evaluated. Sixteen patients operated on for vestibular schwannoma, but without headache, and 12 healthy volunteers served as control groups. Vestibular responses and cervico-collic reflexes deteriorated equally in the patients regardless of whether or not they had a postoperative headache. Local anaesthesia did not alter the results. The posturography results were increased among both patient groups. Sumatriptan alleviated pain in nine patients and abolished it completely in one out of these nine patients. Vestibular imbalance or abnormal activation of neck muscles do not explain postoperative headache. Occipital nerve entrapment or neuralgia explains the headache in a few patients. The relatively pronounced sumatriptan effect may, however, suggest a trigeminal nerve mediated cause for postoperative headache.     

Complications in translabyrinthine surgery of vestibular schwannoma

Objective: To evaluate the risk of complications associated with tumor size and patient’s age in translabyrinthine vestibular schwannoma surgery.

Methods: 700 patients with vestibular schwannoma primarily underwent translabyrinthine surgery between 1988 and 2014. Pre- and postoperative data were collected in a database and incidence of the postoperative complications cerebrospinal fluid leakage, meningitis, intracranial hemorrhage (ICH), facial nerve function and mortality were assessed and related to the tumor size and patient’s age and retrospectively evaluated.

Results: The tumor size significantly influenced the incidence of ICH and facial nerve dysfunction whereas age was correlated to facial nerve outcome.

Conclusions: The translabyrinthine approach is a safe surgical procedure with relatively low risks of complications. The tumor size was significantly associated with a higher risk of ICH and facial nerve dysfunction whereas age only influenced the facial nerve outcome.