Sentence:  Another physical impact of urbanization in Asia has been the intensification of the primacy of capital cities. Most countries in the region—except China, Vietnam, and India—are well known for suffering from “<WSD>macrocephaly</WSD> disease.” Capital cities such as Tokyo, Taipei, Seoul, Jakarta, Manila, and Bangkok have a population that is more than double that of the next largest metropolitan area. 
Meaning of the word marked with <WSD> tags:  The excessive concentration of population and development in a single centre, to the detriment of other areas.