Objective

To critically analyze each reported case of malignant transformation of vestibular schwannoma (VS) after either stereotactic radiosurgery (SRS) or microsurgery (MS).

Data sources

We searched the Pubmed/Medline database using the relevant key words vestibular schwannoma, acoustic neuroma, malignant, transformation, radiation, induced, stereotactic, radiosurgery, malignancy, GammaKnife, and CyberKnife and combinations thereof.

Study selection

Inclusion criteria for malignant transformation of VS after SRS included histopathology of initially benign VS, subsequent histopathology confirming malignant VS, reasonable latency period between malignancy and benign diagnoses.

Data extraction

A neurotologist and a skull base neurosurgeon independently assessed each case report for quality, entry, exclusion criteria, and comparability of extracted data.

Data synthesis

We calculated median age, latency times, and survival times for each case report.

Results

Malignant transformation has been documented to occur after either SRS or MS. Eight cases were included that showed histopathologic evidence of malignant transformation after SRS and MS. Four cases of malignant transformation were included that demonstrated malignant transformation after MS only. Malignant transformation of VS can also occur de novo, and de novo malignant VSs are also encountered, which can confound a causal inference from either SRS or MS. Eighteen cases of primary malignant VS were included. Studies that were identified but not included in the review are summarized and tabulated. We found 12 studies of malignant transformation associated with NF2.

Conclusion

The potential mechanism leading to malignant transformation of VS seems more obvious for SRS and is less understood for MS. Given a low incidence of de novo malignant schwannoma, the possibility that these are spontaneous events in either setting cannot be ruled out. Risk of malignant transformation of VS after either SRS or MS is not zero; however, the magnitude of this risk is probably minimal based on the evidence from eight histopathologically confirmed cases.

Objectives

To evaluate the outcomes and complications of transcanal excision of exostoses using micro-osteotomes, without a postauricular incision or the use of the drill.

Study design

A retrospective chart review of patients undergoing exostoses excision.

Setting

Tertiary Care Medical Center.

Subjects and methods

All of the patients underwent surgical removal of the exostoses using only a 1 or 2 mm micro-osteotomes. Patients were followed postoperatively and associated complications were evaluated.

Results

One-hundred thirty-eight ears in 106 patients were treated for obstructive exostosis. The average age of patients was 43 ± 16 years. Of these, 99 were man (93%) and 7 were woman (7%). A majority of the patients (84%, n = 89) had 90 to 100% obstruction of the ear canal. Complete ear canal healing was observed in 80% of patients by 3 weeks. All but one patient had healed by 6 weeks postoperatively. There were 9 (6.5%) slit tympanic membrane perforations that healed with intraoperative gelfoam or fascia myringoplasty. One patient had an anterior canal mobilization which required Xeroform packing for 3 weeks for stabilization. There were no postoperative vertigo, facial paresis, conductive/sensorineural hearing loss, soft tissue stenoses, and no skin grafting required.

Conclusions

This is the first study to report a series of patients performing solely a transcanal approach using micro-osteotomes for removing exostoses. Results indicate that it is a safe procedure with low complication rate and expeditious healing. Patients with 100% obstruction can have this procedure performed with no significant increase in morbidity.

Background

With the increasing prevalence of electronic readers (e-readers) for vocational and professional uses, it is important to discover if there are visual consequences in the use of these products. There are no studies in the literature quantifying the incidence or severity of eyestrain, nor are there clinical characteristics that may predispose to these symptoms with e-reader use.

Purpose

The primary objective of this pilot study was to assess the degree of eyestrain associated with e-reader use compared to traditional paper format. The secondary outcomes of this study were to assess the rate of eyestrain associated with e-reader use and identify any clinical characteristics that may be associated with the development of eyestrain.

Methods

Forty-four students were randomly assigned to study (e-reader iPAD) and control (print) groups. Participant posture, luminosity of the room, and reading distance from reading device were measured during a 1-h session for both groups. At the end of the session, questionnaires were administered to determine symptoms.

Results

Significantly higher rates of eyestrain (p = 0.008) and irritation (p = 0.011) were found among the iPAD study group as compared to the print 'control' group. The study group was also 4.9 times more likely to report severe eyestrain (95 % CI [1.4, 16.9]). No clinical characteristics predisposing to eyestrain could be identified.

Conclusions

These findings conclude that reading on e-readers may induce increased levels of irritation and eyestrain. Predisposing factors, etiology, and potential remedial interventions remain to be determined.

Objective

To understand the differences in characteristics of neurofibromatosis type 2 (NF2) and sporadic patients with surgically excised vestibular schwannomas in the state of California.

Study design

Cross-sectional.

Setting, subjects, and methods

The records of all patients who underwent vestibular schwannoma excision between 1997 and 2011 were extracted from the California Hospital Inpatient Discharge Databases (CHIDD). NF2 cases were identified using ICD-9-CM diagnosis code 237.72, neurofibromatosis, type 2. All other cases were recoded as sporadic. Trends in total number and population-adjusted rates (per 1 million California residents) of surgery, demographics, hospital case volume, state of residency, complications, length of stay, total charges, expected source of payment, and disposition were examined.

Results

Vestibular schwannoma (VS) excision was performed on 7017 patients, of which 464 patients (6.6%) had NF2. The population-adjusted surgery rate declined from 11.8 to 6.2 (P < .001) for sporadic cases and from 0.3 to 0.2 (P = .01) for NF2 cases over the study period. NF2 was associated with younger age (mean, 32.9 vs 51.3), higher rate of other complications (8.8% vs 4.4%) and facial nerve complications (32.3% vs 16.8%), higher total charges (median $70,106 vs $46,395), longer stay (median 5 vs 4), and high volume hospitals (80.4% vs 48.8%) (all P < .001).

Conclusion

The surgery rates for vestibular schwannoma excision for both sporadic and NF2 patients have declined, but the decline is more prominent for sporadic cases. NF2 patients tend to be younger and have a longer hospitalization and possibly higher corresponding hospital charges compared to patients with sporadic VS.