Headache Disability following Observation, Stereotactic Radiosurgery, and Microsurgery for Small-to-Medium Sized Vestibular Schwannoma

Background/Objectives: In a previous study the authors found that ongoing headache was strongly associated with diminished quality of life following treatment of vestibular schwannoma (VS). The objectives of the current study are: 1) to evaluate long-term patient reported headache disability following observation, microsurgery, and stereotactic radiosurgery (SRS) for small-to-medium sized VS; 2) and to examine the influence of preexisting headaches and prior diagnosis of migraine on headache outcome.

Design: Cross-sectional, postal questionnaire survey

Methods: Patients who underwent primary microsurgery, observation, or SRS for sporadic small-to-medium sized VS between 1998 and 2008 were surveyed using the Headache Disability Inventory (HDI) and a VS symptom questionnaire (VSSQ). Associations with total HDI scores and VSSQ responses were examined using Spearman rank correlation coefficients and Kruskal-Wallis or chi-square tests. Associations with HDI scores were further evaluated using multivariable linear regression models after ranking HDI scores.

Results: 280 completed surveys were analyzed. Mean age at treatment was 56.5 and average duration between treatment and time of survey was 7.5 years. There was not a significant difference among groups with respect to gender, history of migraine, preexisting headaches, or time to survey. Patients undergoing microsurgery were significantly younger than those managed with SRS or conservative observation (p < 0.001); tumor size was greatest among surgically managed VS and smallest among observed tumors (p < 0.001).

On univariate analysis, tumor size was not statistically significantly associated with HDI outcome, while younger age (p < 0.001) and female gender predicted a higher (poorer) score (mean 10.76 vs 5.82; p = 0.003). The mean HDI score among patients with a history of migraine was statistically significantly much higher than those without (24.21 vs 4.69; p < 0.001); likewise, patients endorsing a history of severe headaches had significantly worse mean HDI scores compared with those with mild or no headaches (23.37, 12.59 and 2.64 respectively; p < 0.001). Multivariable analysis confirmed that age, a history of migraines, and a history of headaches were independently statistically significantly associated with HDI score (p < 0.001); however, the association between female gender and HDI outcome was no longer significant.

When investigating the association between management strategy and headache disability, univariate analysis demonstrated that the mean post-treatment HDI score among patients who received microsurgery was higher than those managed with observation or SRS (12.65, 6.95 and 6.49 respectively; p = 0.001). Among the subgroup of 58 patients with preexisting migraine, those treated with SRS had the lowest (best) mean HDI scores, followed by observation and microsurgery (15.50, 20.62 and 33.04 respectively; p = 0.023). Similarly, mean HDI scores of the 35 patients reporting preexisting severe headaches were lowest among those receiving SRS, followed by observation and microsurgery (18.88, 19.71 and 31.50 respectively; p = 0.21). However, after controlling for baseline differences between treatment groups, multivariable analysis indicated that management strategy was no longer statistically significantly associated with HDI score.

Conclusions: Patient factors including history of preexisting headaches, prior diagnosis of migraine, and younger age most significantly influence headache disability among subjects with VS. After adjusting for differences in baseline characteristics between groups, management strategy does not appear to significantly impact long-term HDI outcome.