Table 2.

Volume of subcortical structures (mm3). Data are presented as mean ± SD.

Structure	Healthy controls	Paradoxical insomnia	Psychophysiological insomnia
Left accumbens	832 ± 134	791 ± 119	794 ± 166
Left amygdala	1845 ± 288	1616 ± 335	1805 ± 268
Left caudate*$	4804 ± 535	4654 ± 655	4627 ± 390
Left hippocampus	5074 ± 438	4760 ± 518	5129 ± 553
Left pallidum	1840 ± 198	1758 ± 180	1845 ± 220
Left putamen	5259 ± 547	4967 ± 516	5157 ± 494
Left thalamus	8086 ± 706	7462 ± 757	8006 ± 706
Right accumbens	679 ± 127	633 ± 131	650 ± 103
Right amygdala	1805 ± 312	1725 ± 295	1705 ± 300
Right caudate#	4937 ± 565	4758 ± 559	4685 ± 406
Right hippocampus	5160 ± 434	4959 ± 455	5307 ± 422
Right pallidum	1827 ± 193	1736 ± 189	1831 ± 152
Right putamen	5226 ± 553	4958 ± 526	5085 ± 510
Right thalamus	7809 ± 681	7265 ± 739	7823 ± 643

^*Comparing control with paradoxical insomnia (F = 6.273, P = 0.014).

^$Comparing paradoxical with psychophysiological insomnia (F = 4.666, P = 0.035).

^#Comparing paradoxical with psychophysiological insomnia (F = 7.592, P = 0.008).