J Neurol Surg B Skull Base 2016; 77 - FP-18-01
DOI: 10.1055/s-0036-1592527

Geographic Distribution of Vestibular Schwannomas in West of Scotland since 2000

L. Caulley 1, 2, M. Sawada 3, Kelsey Hinther 4, Shueh Lim 5, John Crowther 5, Georgios Kontorinis 5
  • 1Department of Otolaryngology – Head and Neck Surgery, University of Ottawa, Ottawa, Ontario, Canada
  • 2The Ottawa Hospital, Ottawa, Ontario, Canada
  • 3Department of Geography, University of Ottawa, Ottawa, Ontario, Canada
  • 4Undergraduate Medicine Program, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
  • 5Department of Otolaryngology – Head and Neck Surgery, Queen Elizabeth University Hospital, Glasgow, United Kingdom

Objective: Despite the large number of studies on vestibular schwannomas (VS), extensive demographic works are rare. We aimed at presenting a geographical distribution of VS covering West of Scotland and a population of approximately three million over a period of 15 years.

Methods: VS prevalence was estimated and mapped; 520 adults diagnosed with sporadic VS between 2000 and 2015 were identified through the West of Scotland Skull Base database. Postcodes were mapped and analyzed using ArcGIS. We looked for any spatial dependency of VS nationally (Moran's I); a cartographic representation of raw counts and related demographic factors was also created.

Results: Between 2000 and 2015, raw standardized incidence ratios of vestibular schwannomas were found to be elevated in Paisley, Western Isles, Ayrshire and Glasgow regions. This geographical distribution was not incidental as there was a spatial correlation with certain areas of Scotland demonstrating significantly higher incidence of VS (Moran's I=0.078, p = 0.019). The mean age of individuals at the time of diagnosis was 57.5 years with a minimum age of 26 years and maximum age of 88 years. Of the individuals diagnosed with VS, 53.1% were male and 46.7% were female.

Conclusion: Our data show, for the first time, that there is a geographic distribution of VS, which is not incidental. This can be attributed to the links between primary and tertiary care and the socioeconomic background in these areas. Potential correlation with causal factors cannot be excluded.