Fig. 2

Loss of pigmented neurons in the locus coeruleus in PSP. a Combined scatter and boxplots showing the total number of pigmented neurons in the left locus coeruleus in controls and patients. b There was a negative correlation between the number of pigmented neurons and the PSP rating scale (PSPRS) (n = 20, weighted least-square regression F(1, 19) = 5.9, p = 0.026)). The dot size for each individual scales with interval from assessment to death as a function of disease duration. c The percentage of pigmented neurons with tau-inclusions in controls and PSP. d The positive correlation between the number of pigmented neurons and number of pigmented neurons with tau-inclusions. Each dot represents an individual case, and for PSP cases (a-d), different colours of the dot represent specific PSP clinical phenotypes, i.e., black – probable PSP Richardson’s Syndrome, grey – possible PSP-SL, white – possible PSP-CBS. The lower and upper hinges of the grey boxes show the 25th and 75th percentiles, while the horizontal bar represent the median values. Whisker-plots display the range of data within 1.5 of the inter-quartile range, indicating that no extreme outlying values were observed. The linear regression lines are plotted in panel b and d