Figure. Sporadic and familial dementias in developing countries.

Red-shaded countries have prevalence or incidence estimates of all dementias that have been determined to be similar (>5%) to those in developed countries (grey-shaded countries). Blue-shaded countries have significantly lower prevalence (<3%) of dementia. Sample sizes for the estimates in the various studies were between 700 and 3200 individuals. Green-shaded areas show countries where there are published cases of dementia or subtypes (AD or VaD), where risk factors have been examined but prevalence or incidence are unknown. Reliable information was not available for countries without shading. Red spots show locations of families with neurodegenerative and vascular disorders causing dementia including AD, Parkinson's disease, Lewy body disease, frontotemporal lobar degeneration, Huntington's disease, amyotrophic lateral sclerosis, and CADASIL. Information on dementia prevalence and types was derived from many sources.²²,²⁹,³¹,³⁵,³⁷–³⁹,⁴¹,⁴⁵,⁴⁶,⁴⁹–⁵²,⁵⁸,⁶²–⁷³