Table 2

Incidence of moyamoya disease according to region

Author, yearRegionStudy periodTotal populationNo of cases*Incidence definite MMDIncidence definite MMD and probable MMDIncidence definite MMD and probable MMD and MMSCase finding methodDiagnostic guideline used for diagnosis§
Wakai 19974Japan19941260.35A100%§§
Kuriyama 20085Japan20031120.54A100%§§
Baba 200714Japan: Hokkaido2002–20065 630 000267 (233/34/0)0.84 (0.60–1.07)0.94 (0.69–1.19)B100%
Hung 200715Taiwan1978–1995920.02 (0.003–0.04)**C100%††
Miao 201016China: Nanjing2000–20076 200 000202 (202/0/0)0.41 (0.28–0.54)C, D100%
Wetjen 199818USA: Iowa1973–19972 500 00030 (26/3/1)0.04 (−0.04–0.12)0.05 (−0.04–0.12)0.05 (−0.04–0.12)D, E100%
Uchino 200517USA: California, Washington1987–19982980.09D46%‡‡
Graham 199719USA: Hawaii1987–19961 200 00021 (21/0/0)0.17 (−0.06–0.40)D, F100%
  • * Number of cases on which the incidence calculation was based. Between brackets are the numbers of patients with definite MMD, probable MMD and MMS, respectively.

  • Incidences are displayed per 100 000 population with their 95% CI.

  • Case finding methods used to identify patients with moyamoya: A=regionwide survey by means of a questionnaire sent to a randomly selected sample of departments of neurosurgery, neurology and paediatrics; B=certification system of registered intractable diseases of the Ministry of Health, Labour and Welfare in Japan; C=patients selected from major medical centres; D=searching hospital discharge database for diagnosis of moyamoya (eg, by reviewing International Classification of Disease-9 codes);E=stroke database; F=regionwide survey by means of a questionnaire sent to all practising neurologists, neurosurgeons and neuroradiologists.

  • § Percentage of patients in which the clinical diagnosis was made based on cerebral angiography or MRI/MR angiography.13

  • Incidences as reported. Incidences could not be recalculated.

  • §§ The number of probable cases was not specified.

  • ** Incidence calculated based on the total number of patients with MMD divided by the mean population between 1987 and 1995 (based on the population of Taiwan according to http://www.census.gov/ipc/www/idb/country.php).

  • †† According to the criteria of Yonekawa.20 Not reported whether patients with probable MMD were included; MMS excluded.

  • ‡‡ Classification criteria not reported; MMS included.

  • MMD, moyamoya disease; MMS, moyamoya syndrome.