Is clinical growth index a reliable predictor of tumour growth in vestibular schwannomas?

We have assessed the clinical growth index as an indicator of tumour growth rate in 50 patients with a vestibular schwannoma. Clinical growth index was calculated by measuring the length of history and dividing it by the maximum tumour diameter. Total tumour volumes were also measured from all MRI examinations and an effective tumour volume doubling time was calculated. Radiological growth measurements demonstrated involution in 10/50 patients. The median volume doubling time was 1.65 years (range 20.9-46.3 months, skewness 1.72 years). The median clinical growth index was 0.030 cm per month (range 0-0.270 cm per month, skewness 2.398). There was no significant correlation between volume doubling time and clinical growth index. Identification of rapidly growing tumours with clinical growth index >0.025 cm/month had a positive predictive value of 61%, negative predictive value of 48%, false-positive rate of 30% and false-negative rate of 52%. In conclusion, we have shown that the growth rate of vestibular schwannoma is not related to the clinical growth index and we recommend that this measure should be abandoned in the clinical management of patients where conservative management regimes are being considered.     

Is clinical growth index a reliable predictor of tumour growth in vestibular schwannomas?

Is clinical growth index a reliable predictor of tumour growth in vestibular schwannomas? We have assessed the clinical growth index as an indicator of tumour growth rate in 50 patients with a vestibular schwannoma. Clinical growth index was calculated by measuring the length of history and dividing it by the maximum tumour diameter. Total tumour volumes were also measured from all MRI examinations and an effective tumour volume doubling time was calculated. Radiological growth measurements demonstrated involution in 10/50 patients. The median volume doubling time was 1.65 years (range 20.9‐46.3 months, skewness 1.72 years). The median clinical growth index was 0.030 cm per month (range 0‐0.270 cm per month, skewness 2.398). There was no significant correlation between volume doubling time and clinical growth index. Identification of rapidly growing tumours with clinical growth index >0.025 cm/month had a positive predictive value of 61%, negative predictive value of 48%, false‐positive rate of 30% and false‐negative rate of 52%. In conclusion, we have shown that the growth rate of vestibular schwannoma is not related to the clinical growth index and we recommend that this measure should be abandoned in the clinical management of patients where conservative management regimes are being considered.     

The natural history of untreated vestibular schwannomas. Is there a role for conservative management?

OBJECTIVE: The aim of this study was to investigate the natural history and outcome following the conservative management of a group of patients with unilateral vestibular schwannomas. METHODS: 72 patients with a radiological diagnosis of unilateral vestibular schwannoma were managed conservatively because of poor general health, advanced age, patient preference, small tumour size, minimal symptoms, or tumour in the only/better hearing ear. All patients underwent serial magnetic resonance imaging for assessment of tumour growth, according to American Academy of Otolaryngology-Head & Neck Surgery guidelines (1995). The mean duration of follow-up was 37.8 months (range 12-194 months). Patients were deemed to have failed conservative management if there was evidence of continuous or rapid radiological tumour growth, and/or increasing symptoms or signs. RESULTS: The mean tumour growth rate was 1.16 mm/year (range -0.75 to 9.65 mm/year). Approximately 83% of tumours grew at less than 2 mm/year. Significant tumour growth (total growth > 1 mm) was seen in 36.4%, no or insignificant growth (0-1 mm) in 50%, and negative growth (< 0 mm) in 13.6% of tumours. The growth rate of cerebellopontine angle (CPA) tumours (1.4 mm/year) was significantly greater than that of tumours limited to the internal auditory canal (IAC) (0.2 mm/year) (p = 0.001). Failure of conservative management, in which active treatment was required, occurred in 15.3%. The outcome of these patients appeared to be as favourable as those who underwent primary treatment, without a period of conservative management. The growth rate of tumours in patients who failed conservative management (4.2 mm/year) was significantly greater than that in patients who did not fail (0.5 mm/year) (p < 0.01). No factors predictive of tumour growth were identified. Deterioration of mean pure tone average (0.5, 1, 2, 3 kHz) and speech discrimination scores occurred regardless of whether radiological tumour growth was demonstrated or not. CONCLUSIONS: The majority of vestibular schwannomas are slow growing, although, CPA tumours appear to grow faster than IAC tumours. Deterioration of auditory function occurs even in the absence of tumour growth. Although most Otolaryngologists and Neurosurgeons would agree that the treatment of choice for the majority of vestibular schwannomas is microsurgery, there remains a small group of patients in whom a conservative management approach may be a desirable alternative.     

Is a doctor needed in the adult ENT pre-admission clinic?

OBJECTIVES: Pre-admission clinics are traditionally run jointly by nurses and doctors. Within an adult ENT pre-admission clinic, we wished to assess what doctors added to nurses' pre-clerking, to determine whether doctors were actually needed in the clinic. METHODS: Prospective study, looking at how often doctors, seeing patients after ward-based nurses, changed or added to clerking or tests as organized by nurses. RESULTS: Out of 184 patients, doctors changed or added to nurses' clerking or planned investigations in 47 patients (26 per cent), making 64 different changes. The commonest reasons for changes were ordering blood tests (22 changes), chest X-rays (eight), cancelling due to hypertension (seven), altering drug history (five) and requesting electrocardiograms (five changes). CONCLUSION: Most changes made by doctors could be eliminated by designing a pre-admission clinic protocol that could easily be used by nurses. We recommend that all ENT departments consider implementing nurse-led pre-admission clinics.     

What is the site of origin of cochleovestibular schwannomas?

The belief that cochleovestibular schwannomas arise from the glial-Schwann cell junction has repeatedly been quoted in the literature, although there is no published evidence that supports this statement. A systematic evaluation of the nerve of origin and the precise location of cochleovestibular schwannomas using our respective archival temporal bone collections was conducted. Forty tumors were within the internal auditory canal (IAC), while 10 were intralabyrinthine neoplasms. Of the 40 IAC schwannomas, 4 arose from the cochlear nerve, and 36 from the vestibular nerve. Twenty-one tumors clearly arose lateral to the glial-Schwann cell junction, while 16 tumors filled at least two thirds of the IAC, with the epicenter of the neoplasm located in the mid part or the lateral part of the IAC. Only 3 schwannomas were located in the medial one third of the IAC in the area of the glial-Schwann cell junction. We concluded that cochleovestibular schwannomas may arise anywhere along the course of the axons of the eighth cranial nerve from the glial-Schwann sheath junction up until their terminations within the auditory and vestibular end organs.     

Is the Trachea a Marker of the Type of Environmental Pollution?

OBJECTIVES/HYPOTHESIS: The differentiated character of changes in the mucous relief of the trachea as induced by air containing pollutants from the wastes of nickel-, mercury-, and cement-producing plants and by Candida albicans occurring in the waste disposal site of a large town are identified. The trachea was chosen because it is the entrance gate for the penetration of polluted air into the lungs. Changes on the trachea influence the character and extent of changes in lungs. STUDY DESIGN: Histological study with Viennese grey strain laboratory rabbits and rats caught directly on an investigated site. METHODS: We present new results of the functional morphology of the respiratory system as the results of scanning and transmission electron microscopy studies that can reveal character and range of damage of mucosal relief of trachea relevant to the functional dynamics of mucociliary clearance. Under physiological conditions this mechanism allows that only respirable dust particles enter the deep respiratory tract. RESULTS: In case of a damaged tracheal relief because of exposure to various aerosols, the functional morphology is changed, which aids in understanding the mechanisms damaging to mucociliary clearance induced by living in heavily polluted areas. CONCLUSION: Understanding of these morphological changes on base of detailed electron microscopic findings sheds new light on elaborating novel diagnostic methods for clinical practice.     

MRI screening of the internal auditory canal: Is gadolinium necessary to detect intralabyrinthine schwannomas?

Objective

Non-contrast MRI of the internal auditory canal (IAC) using high-resolution T2WI (T2 weighted image) has been proposed as the primary screening study in patients with sudden or asymmetric sensorineural hearing loss (ASNHL). However, there are concerns that non-contrast MRI may not detect labyrinthine pathology, specifically intralabyrinthine schwannomas (ILSs). The purpose of this study was to determine if non-contrast high-resolution T2WI alone are adequate to exclude these uncommon intralabyrinthine tumors.

What is the real incidence of vestibular schwannoma?

OBJECTIVES: To present the incidence of vestibular schwannoma (VS) in Denmark, compare the incidence with that of previous periods, and discuss the real incidence of VS. DESIGN, SETTING, AND PATIENTS: Prospective registration of all diagnosed VS in Denmark, with a population of 5.1 to 5.2 million, during the 6 years from January 1996 through December 2001. Incidence in this period was compared with that of 3 previous periods (July 1976 through June 1983 [first period], July 1983 through June 1990 [second period], and July 1990 through December 1995 [third period]). RESULTS: In the 1996-2001 period, 542 cases of VS were diagnosed, representing a mean incidence of 17.4 VS/1 million inhabitants per year. Of these, 227 tumors underwent operation, 14 underwent irradiation, and 301 were allocated to observation (wait-and-scan policy). One hundred sixty-six tumors were intrameatal. Size of extrameatal tumors was small in 104; medium in 194; large in 68; and giant (>40 mm) in 10. Compared with incidences of 7.8 VS/1 million inhabitants per year in the first, 9.4 VS/1 million inhabitants in the second, and 12.4 VS/1 million inhabitants in the third periods, the incidence for the 1996-2001 period represents an increase to 17.4 VS/1 million inhabitants per year. The mean incidence for the entire 25.5-year period was 11.5 VS/1 million inhabitants per year. CONCLUSIONS: An estimate of a realistic mean incidence of VS depends on the observation period. Our 25.5-year registration of an entire population showed a mean incidence of 11.5 VS/1 million inhabitants per year. However, the latest period registered represents an incidence of 17.4 VS/1 million inhabitants per year, which, combined with a probable further increase of diagnosed tumors in forthcoming years, suggests a realistic incidence of approximately 13 VS/1 million inhabitants per year.     

Should patients with asymmetrical noise-induced hearing loss be screened for vestibular schwannomas?

The Peterborough ENT department receives many referrals for MoD personnel who have suffered hearing loss from occupational noise exposure. Those patients with asymmetrical sensorineural hearing loss are routinely screened for vestibular schwannomas by MRI scanning. Scan reports from the past 5 years have been reviewed and out of 152 scans, four revealed vestibular schwannomas giving a pick-up rate of 2.5%, which compares favourably with other published pick-up rates. Review of the audiograms in these cases suggests that they can be misleading in this context. The conclusion is that patients with noise-induced asymmetrical hearing loss should be screened for acoustic neuromas.     

What is the optimal number of treatment sessions of vestibular rehabilitation?

Vestibular rehabilitation is effective and safe in patients with instability. However, there is insufficient evidence for distinguishing between efficacies of different dosage of therapies. Therefore, the aim of the present study was to verify whether there were differences between two computerised dynamic posturography (CDP) therapies of different numbers of sessions, in order to establish the optimal strategy. We conducted a prospective, comparative study of two different dosage of CDP therapy (a 5-session group and another of 10-session group) in patients with instability due to chronic unilateral peripheral vestibular disorder. We used balanced block randomisation to include 13 patients in each group. Improvement was assessed using the Dizziness Handicap Inventory and the CDP with the sensorial organisation test (SOT) and limits of stability (LOS). We found a statistically significant improvement in both groups in composite score, visual and vestibular input (SOT); and in reaction time, distance and directional control (LOS). If we compare the groups regarding these improvements, we found that 10-session group showed a greater benefit in distance covered and directional control of LOS. Since significant improvement is obtained with only five sessions, we believe this to be the optimal number of treatment sessions for most patients with chronic unilateral peripheral vestibular disorder. Nevertheless, those patients with more reduced limits of stability, and consequently greater likelihood of falling as a result of their diminished base of support, are candidates for rehabilitation protocols with a greater number of sessions.     

Altered cupular mechanics: a cause of peripheral vestibular disorders?

It has taken many decades to arrive at today's concept of cupula mechanics in the stimulation of endolymphatic flows on the hair cells in the ampullae of the semicircular canal. While Steinhausen assumed free swing-door movement of the cupula in the 1930s, Hillman was the first to demonstrate firm cupula attachment to the ampulla wall as a physiological necessity in the 1970s. In contrast to the present clinical concepts of acute peripheral vestibular functional disorders (circulatory disturbances, viral or bacterial infection, altered electrolytes in the endolymph), this study examines the extent to which an impaired attachment mechanism can trigger peripheral vestibular disorders. For this purpose, we used a pigeon model (n = 8), in which mechanical detachment of the cupula from the ampulla wall was achieved by means of a targeted pressure increase in the ampulla of the lateral semicircular canal. In two additional animals the labyrinth was completely destroyed on one side in order to directly compare partial and complete vestibular disorders. In this way partial damage to the lateral semicircular canal ampulla presents a clinical picture whose symptoms are very similar to those of an idiopathic vestibular disorder in humans. Their intensity and course of compensation differ markedly from the symptoms of complete vestibular destruction. Subsequent histological examination revealed that the hair cells remained intact during the experimental detachment of the cupula. Our results thus show that only altered cupula mechanics seem to trigger the clinical picture of a peripheral vestibular disorder. This may result in completely new approaches to differential diagnosis and the therapy of vestibular neuronitis.     

Does vestibular habituation still have a place in the treatment of benign paroxysmal positional vertigo?

Particle repositioning procedures such as the Epley manoeuvre have become popular in the management of benign paroxysmal positional vertigo (BPPV) at the expense of more traditional therapies such as vestibular habituation. We prospectively analysed the response of consecutive patients presenting with BPPV to treatment with vestibular habituation exercises using a symptom score sheet before and after treatment. This same patient group was then followed up, on average three years, eight months after discharge, to determine their long-term response to treatment. The results of the study demonstrated an excellent short-term response rate to treatment but a high level of recurrence after discharge. Most patients who experienced further symptoms following discharge were however self-reliant and were able to return to their habituation exercises without the need for further medical input. The aim in the management of these patients must be to provide long-term self reliance as well as short-term cure and it may be that this has not yet been well demonstrated with the Epley manoeuvre. It must also be remembered that particle repositioning manoeuvres cannot be used in all patients for example those who suffer with cervical or thoracic spine pathology and that some will fail to respond at all. We believe that vestibular habituation retains a useful role in the treatment of BPPV.     

Is there a consensus in the division of the vocal folds in thirds?

INTRODUCTION: In clinical routine we have noticed a disagreement of ENT-specialists and phoniatricians in the division of the vocal folds in thirds. To show if there is consensus in this field by the german phoniatricians this study was done. MATERIAL AND METHODS: In two parts of a study, a pilot study and a follow up study, we sent twelve different images of the larynx to all german phoniatricians. In six of these images the physicians should set the marks of the ventral and dorsal limitation of the second third of the vocal folds. In six different images a mark should be related to the particular third of the vocal folds. The phoniatricians were asked to assess how certain they were in their valuation. They were asked either, how long they have been working as a physician and how long they have been specialized as a phoniatrician and as an ENT-surgeon. In the follow up study the phoniatricians were requested to first divide up the thirds in a way that the dorsal third corresponds to the cartilaginous part of the vocal folds (scheme 1) and second divide up the thirds in a way that all three thirds correspond to the ligamental part of the vocal folds. DISCUSSION AND FINDINGS: In the pilot study, when no instructions for the division of the thirds were given, the data differed much more than in the follow up study, when the physicians were told to use scheme 1 and scheme 2. That was because some phoniatricians divided up just the ligamental part and others the ligamental plus the cartilaginous part of the vocal folds in thirds. The more the physicians could overlook the membraneous part of the vocal folds the more certain they were in their assessment. CONCLUSION: The assessment of the division of the vocal folds in thirds is more homogeneous when the phoniatricians were requested to divide up the thirds in a way that the dorsal third corresponds to the cartilaginous part of the vocal folds (scheme 1). Therefore we suggest that this way of division should be used further on.