Cerebral asymmetry in a selected Chinese population

Previous studies have demonstrated anatomical differences between the two cerebral hemispheres and ethnic differences in cerebral asymmetry. This study examined asymmetry of Chinese living in Shanghai. Measurements were taken across the frontal, mid-cerebral and occipital regions from normal head computed tomography (CT) scans of 200 Chinese Shanghai residents (100 male and 100 female, aged 6-73 years, average 48.7 years). The results were compared with reported data in the literature. The following results were found: (i) In the frontal region the right side was larger than the left in 57.5% of cases, equal in 10.5% and smaller in 32% of cases; in the mid-cerebral region the right side was larger than the left in 65.5% of cases, equal in 12.5% and smaller in 22% of cases; in the occipital regions the right side was larger than the left in 34.5% of cases, equal in 8.5% and smaller in 57% of cases. The average right-left differences between the frontal, mid-cerebral and occipital regions were 0.43 mm, 0.9 mm and 0.4 mm respectively. No difference in cerebral asymmetry existed between males and females. The occipital lobes showed the greatest individual asymmetry. The distribution of cerebral asymmetry of Chinese in Shanghai showed similarity to North American Whites rather than North American Blacks, but the average right-left differences were smaller than those of Whites.