The behaviour of residual tumour after the intentional incomplete excision of a vestibular schwannoma: is it such a bad thing to leave some behind?

OBJECTIVES: To evaluate the biological behaviour of tumour remnants intentionally left in the surgical bed following the incomplete excision of vestibular schwannomas (VS) and to review the relation between extent of resection and preservation of facial nerve function. METHODS: A retrospective chart review of 450 patients who underwent surgery for resection of VS over 23 years (1992-2014). Of these, 50 (11%) patients had residual tumour intentionally left on/around the facial nerve (near-total or subtotal excision) to preserve facial nerve function intra-operatively. The growth of residual tumour was evaluated using serial magnetic resonance imaging scanning; pre- and postoperative facial nerve function was assessed using the House-Brackmann grading scale. SETTING: Tertiary referral neurotology unit. RESULTS: Of the 42 non-NF2 cases where the tumour was intentionally incompletely excised, 28 (67%) patients underwent subtotal resection (mean follow-up 68.5 ± 39.0 months) and 14 (33%) underwent near-total resection (mean follow-up 72.9 ± 48.3 months). Three patients (all in subtotal resection group) showed regrowth. This was not statistically different from the near-total resection group (χ2 = 0.92, P = 0.31). The mean overall growth for these cases was 0.68 mm ± 0.32 mm/year. 5 (one near total, four subtotal) of the eight NF2 patients (62.5%) were excluded from our analysis. In the non-NF2 group, poor facial nerve outcomes (House-Brackmann scores of III-IV) were seen in 2/14 and V-VI in 3/14 of the near total compared with 7/25 and 4/25 respectively in the subtotal group. CONCLUSIONS: Given that the primary surgery for the VS was only for tumours that were relatively large or grew during conservative treatment, the low rate of tumour remnant growth (7%) is reassuring. It may be appropriate to have a lower threshold for leaving tumour on the facial nerve in non-NF2 patients where complete resection may jeopardise facial nerve function.

Olfactory and cochleovestibular dysfunction after head injury in the workplace: an updated series.

OBJECTIVES: The objective of this study was to determine the incidence of olfactory dysfunction in workers following head injury in the work place, to define its relationship to the site, severity of injury and direction of force. The demographics of head injured workers were also assessed to determine whether those with olfactory loss were more likely to have sustained a cochleovestibular injury. DESIGN: Retrospective case analysis. SETTING: Tertiary referral university hospital in Toronto, Ontario. PARTICIPANTS: A total of 3438 consecutive patients referred from the Workplace Safety and Insurance Board (WSIB) in the province of Ontario who sustained a work-related head injury were assessed between 1987 and 2014. MAIN OUTCOME MEASURES: Olfactory and cochleovestibular dysfunction assessed by history, clinical examination and subjective and objective tests. RESULTS: Olfactory dysfunction (OD) was identified in 413 of 3438 patients (12.0%) of which 321 were diagnosed with anosmia and 92 with hyposmia. In our series, injuries from a fall were the commonest cause for OD and a frontal or mid-face impact was more likely to result in OD than other regions (P = 0.0002). A loss of consciousness (LOC) of any duration correlated with OD. In those with olfactory dysfunction, an associated skull fracture occurred in 37.1% of patients and a CSF leak in 4.1%, which was significantly higher compared with those without OD(<0.0001). Patients with OD had a higher incidence of cochlear and vestibular loss (19.9% and 20.6%, respectively) compared with those without OD (14.3% and 17.1%, respectively). CONCLUSIONS: Post-traumatic olfactory dysfunction is more likely to occur in patients who experienced a moderate to severe head injury, LOC and more likely to result from a frontal or mid-face blow to the skull. Cochleovestibular dysfunction is likely to occur concurrently with olfactory dysfunction.

Intratympanic therapy in Meniere's syndrome or disease: up to date evidence for clinical practice.

BACKGROUND: Meniere's syndrome or disease (MS/D) is typically characterised by episodic vertigo, aural fullness, tinnitus and fluctuating hearing loss. There are multiple options available for treatment with variation in consensus on the best intervention. OBJECTIVE: To evaluate the evidence on the efficacy of intratympanic therapies [steroids, gentamicin, antivirals and other therapies] on the frequency and severity of vertigo and other symptoms of MS/D. SEARCH STRATEGY: A literature search was performed on AMED, EMBASE, HMIC, MEDLINE, PsycINFO, BNI, CINAHL, HEALTH BUSINESS ELITE, CENTRAL and Cochrane Ear, Nose and Throat disorders group trials register using various MeSH. The search was restricted to English and human subjects, and the last date of search was December 2014. SELECTION CRITERIA: Randomised controlled trials of intratympanic therapies [steroids, gentamicin antivirals and latanoprost] versus a placebo or another treatment. RESULTS: We analysed 8 RCT's comparing intratympanic steroids, gentamicin, ganciclovir (antiviral) and latanoprost versus another form of intratympanic treatment or placebo. CONCLUSIONS: On the basis of 6 RCT's (n = 242), there is evidence to support the effectiveness of intratympanic steroids and gentamicin to control symptoms of vertigo in MS/D albeit with a risk of hearing loss with gentamicin. However, there was no consensus found on doses or treatment protocols. There was no evidence to support the use of other forms of intratympanic therapy (antivirals and latanoprost) in MS/D.

Positive pressure therapy for Meniere's syndrome/disease with a Meniett device: a systematic review of randomised controlled trials.

BACKGROUND: Incidence rates of Meniere's syndrome/disease vary considerably from 157 per 100 000 in the United Kingdom to 15 per 100 000 in the United States. A wide range of treatments are used for the treatment of the condition with no consensus on the most effective intervention. OBJECTIVES: To assess the effectiveness of the Meniett device in reducing the frequency and severity of vertigo in Meniere's syndrome/disease. SEARCH METHODS: The Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific abstracts; ICTRP and additional sources for published and unpublished trials were searched. The date of the last search was 13th May 2014. SELECTION CRITERIA: Four randomised controlled trials (RCTs) were identified that compared the efficacy of the Meniett device versus a placebo device in patients with Meniere's 'disease' as defined by the AAOO criterion. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed study eligibility and risk of bias and extracted data. The outcome data were dichotomous for all the included trials. MAIN RESULTS: The four RCTs compared 123 patients with the Meniett device against 114 patients with the placebo device from four RCT's over a follow-up period of 2 weeks to 4 months. There was a significant overall 61% reduction in the frequency of vertigo in both groups (mean no vertigo days per month of 8-3). However, this reduction was not significantly different between the two groups in any study or on meta-analysis [mean difference in vertigo-free days between Meniett and placebo device of 0.77 days over a 1-month period (95% CI - 0.82, 1.83) P = 0.45]. There were also no substantive data to support a greater reduction in the severity of the vertigo or any other outcome with the Meniett device compared with the placebo device. AUTHORS CONCLUSIONS: No evidence was found to justify the use of the Meniett device in Meniere's syndrome/disease.

Use of monopolar cautery in patient with a vagal nerve stimulator during neuromuscular scoliosis surgery.

It is a historic and common practice while performing spine surgery on patients with a VNS has been to have the patient's neurologist turn off the VNS generator in the pre-operative anesthetic care unit and to use bipolar rather than monopolar electrocautery. Here we report a case of a 16-year-old male patient with cerebral palsy and refractory epilepsy managed with an implanted VNS who had scoliosis surgery (and subsequent hip surgery) conducted with the use of monopolar cautery. Although VNS manufacturer guidelines suggest that monopolar cautery should be avoided, perioperative care providers should consider its selective use in high-risk instances (with greater risks of morbidity and mortality due to blood loss which outweigh the risk of surgical re-insertion of a VNS) such as cardiac or major orthopedic surgery. Considering the number of patients with VNS devices presenting for major orthopedic surgery is increasing, it is important to have an approach and strategy for perioperative management of VNS devices.

Longitudinal Assessment of Enhancing Foci of Abnormal Signal Intensity in Neurofibromatosis Type 1.

BACKGROUND AND PURPOSE: Patients with neurofibromatosis 1 are at increased risk of developing brain tumors, and differentiation from contrast-enhancing foci of abnormal signal intensity can be challenging. We aimed to longitudinally characterize rare, enhancing foci of abnormal signal intensity based on location and demographics. MATERIALS AND METHODS: A total of 109 MR imaging datasets from 19 consecutive patients (7 male; mean age, 8.6 years; range, 2.3-16.8 years) with neurofibromatosis 1 and a total of 23 contrast-enhancing parenchymal lesions initially classified as foci of abnormal signal intensity were included. The mean follow-up period was 6.5 years (range, 1-13.8 years). Enhancing foci of abnormal signal intensity were followed up with respect to presence, location, and volume. Linear regression analysis was performed. RESULTS: Location, mean peak volume, and decrease in enhancing volume over time of the 23 lesions were as follows: 10 splenium of the corpus callosum (295 mm3, 5 decreasing, 3 completely resolving, 2 surgical intervention for change in imaging appearance later confirmed to be gangliocytoma and astrocytoma WHO II), 1 body of the corpus callosum (44 mm3, decreasing), 2 frontal lobe white matter (32 mm3, 1 completely resolving), 3 globus pallidus (50 mm3, all completely resolving), 6 cerebellum (206 mm3, 3 decreasing, 1 completely resolving), and 1 midbrain (34 mm3). On average, splenium lesions began to decrease in size at 12.2 years, posterior fossa lesions at 17.1 years, and other locations at 9.4 years of age. CONCLUSIONS: Albeit very rare, contrast-enhancing lesions in patients with neurofibromatosis 1 may regress over time. Follow-up MR imaging aids in ascertaining regression. The development of atypical features should prompt further evaluation for underlying tumors.

Evaluation of cost effectiveness for conservative and active management strategies for acoustic neuroma.

OBJECTIVE: To determine whether economic costs associated with a conservative management strategy for unilateral acoustic neuroma offer an economic advantage over active management options. DESIGN: Cost and sensitivity analysis on a prospective cohort. SETTING: Single centre study within a tertiary referral centre in Toronto, Canada. PARTICIPANTS: 72 patients (32 males, 40 females) aged 36 to 78 years with unilateral acoustic neuroma were assigned initially to a conservative management strategy. Entry criteria were small tumour size (less than 15 mm in the cerebellopontine angle), patient preference and/or significant co-morbidity. INTERVENTIONS: MRI scanning was performed every 6 months for the first year, annually subsequently and then every 2-3 years as required. Clinical review occurred every 6 months. Failure of conservative management led to active treatment. MAIN OUTCOME MEASURES: Cost analysis was performed to determine the mean total cost per patient for continued conservative management over the follow up period compared to the mean upfront total cost per patient undergoing active intervention. RESULTS: Cost analysis within the Canadian health care system determined the mean total cost per patient for microsurgical removal at CAD$22,402 (12,545 pounds; 14,561 euros), for gamma knife radiotherapy at CAD$27659 (15,489 pounds; 17,978 euros), for LINAC radiotherapy at CAD$9,003(5,041 pounds; 5,852 euros) and for conservative management at CAD$9,651 (5,405 pounds;6,273 euros) over the follow-up timeframe. CONCLUSION: An economic advantage can be demonstrated for the conservative management of acoustic neuromas compared to microsurgical removal and gamma knife radiotherapy on the proviso that no increase in active treatment complications arose from continued tumour growth during the period of observation.

The role of surgery in the management of intracranial gliomas: current concepts.

The role of surgery in the management of human gliomas has been controversial. The results from numerous neurosurgical series are inconsistent. The current adjuvant therapies have facilitated treatment of patients, and have rendered neurosurgical removal without morbidity or mortality more commonplace than ever before. Here, we investigated the role of surgery in the management of adults with low- and high-grade gliomas. Even though there is substantial evidence which claims that surgery per se has a role to play in extending patient survival, there is a paucity of randomized clinical trials on this subject, and little in the way of Class II data to support these claims. However, this should not divert patients away from surgery, because there may be additional benefits from a concerted effort to remove a tumor completely. At the present time, it seems best that clinicians continue to individualize patient treatment based on a myriad of factors that relate to the patient, the patient's tumor, and the known biology of the disease.

Gauging the effectiveness of canal occlusion surgery: how I do it.

BACKGROUND: Transmastoid occlusion of the posterior or superior semicircular canal is an effective and safe management option in patients with refractory benign paroxysmal positional vertigo or symptomatic superior semicircular canal dehiscence. A method of quantifying successful canal occlusion surgery is described. METHODS: This paper presents representative patients with intractable benign paroxysmal positional vertigo or symptomatic superior semicircular canal dehiscence, who underwent transmastoid occlusion of the posterior or superior semicircular canal respectively. Vestibular function was assessed pre- and post-operatively. The video head impulse test was included as a measure of semicircular canal and vestibulo-ocular reflex functions. RESULTS: Post-operative video head impulse testing showed reduced vestibulo-ocular reflex gain in occluded canals. Gain remained normal in the non-operated canals. Post-operative audiometry demonstrated no change in hearing in the benign paroxysmal positional vertigo patient and slight hearing improvement in the superior semicircular canal dehiscence syndrome patient. CONCLUSION: Transmastoid occlusion of the posterior or superior semicircular canal is effective and safe for treating troublesome benign paroxysmal positional vertigo or symptomatic superior semicircular canal dehiscence. Post-operative video head impulse testing demonstrating a reduction in vestibulo-ocular reflex gain can reliably confirm successful occlusion of the canal and is a useful adjunct in post-operative evaluation.

Telomere maintenance and dysfunction predict recurrence in paediatric ependymoma.

We have recently described the enzymatic subunit of telomerase (hTERT) as an important prognostic marker for paediatric ependymoma. Because of the lack of good, representative pre-clinical models for ependymoma, we took advantage of our large cohort of ependymoma patients, some with multiple recurrences, to investigate telomere biology in these tumours. Our cohort consisted of 133 ependymomas from 83 paediatric patients and included 31 patients with recurrences. Clinical outcome was measured as overall survival, progression-free survival and response to therapy. In all 133 tumours, hTERT expression correlated with proliferative markers, including MIB-1 index (P<0.0001) and mitotic index (P=0.005), as well as overall tumour grade (P=0.001), but not with other markers of anaplasia. There was no correlation between telomere length and hTERT expression or survival. Surprisingly, prior radiation or chemotherapy neither induced sustained DNA damage nor affected telomere maintenance in recurrent tumours. There was an inverse correlation between hTERT expression and telomere dysfunction as measured by gamma H2AX expression (P=0.016). Combining gamma H2AX and hTERT expressions could segregate tumours into three different survival groups (log rank, P<0.0001) such that those patients whose tumours expressed hTERT and showed no evidence of DNA damage had the worst outcome. This study emphasises the importance of telomere biology as a prognostic tool and telomerase inhibition as a therapeutic target for paediatric ependymoma. Furthermore, we have demonstrated that analysing tumours as they progress in vivo is a viable approach to studying tumour biology in humans.

Conservative management of vestibular schwannomas: third review of a 10-year prospective study.

Seventy-two patients with a unilateral vestibular schwannoma have been treated conservatively for a median of 121 months. They have been followed prospectively by serial clinical examination, MRI scans and audiometry. Twenty-five patients (35%, 95% CI: 24-47) failed conservative management and required active intervention during the study. No factors predictive of tumour growth or failure of conservative management could be identified. Seventy-five per cent of failures occurred in the first half of the 10-year study. The median growth rate for all tumours at 10 years was 1 mm/year (range -0.53-7.84). Cerebellopontine angle tumours grew faster (1.4 mm/year) than intracanalicular tumours (0 mm/year, P < 0.01); 92% had growth rates under 2 mm/year. Hearing deteriorated substantially even in tumours that did not grow, but did so faster in tumours that grew significantly (mean deterioration in pure tone average at 0.5, 1, 2 and 3 kHz was 36 dB; speech discrimination scores deteriorated by 40%). Patients who failed conservative management had clinical outcomes that were not different from those who underwent primary treatment without a period of conservative management.

Clipping of sigmoid sinus diverticulum: how I do it.

OBJECTIVE: To report two cases of transmastoid clipping of a sigmoid sinus diverticulum. METHODS: Two patients with pulsatile tinnitus resulting from a sigmoid sinus diverticulum underwent clipping at the diverticulum neck using intra-operative Doppler ultrasonography. RESULTS: At six months' follow up, both patients reported complete resolution of pulsatile tinnitus with no complications. CONCLUSION: Transmastoid clipping of a sigmoid sinus diverticulum can be a safe and effective method of managing pulsatile tinnitus resulting from a sigmoid sinus diverticulum.