PUPILLOMETRIC DISCRIMINATION OF INSOMNIACS

Unlike the multiple sleep latency test, pupillometry does not require sleep to test sleepiness, which may be an advantage in assessing insom niacs. Pupillometry was employed to study possible differences in dayt ime sleepiness between insomniacs and noninsomniacs. Thirty self-defin ed insomniacs and an equal number of noninsomniacs, age 30-50 yr, subm itted to four 10-min pupillometry sessions distributed from early morn ing to bedtime. The sessions consisted of infrared television monitori ng of the pupil in a totally dark, nonstimulating environment. Insomni acs exhibited significantly smaller pupil diameters than noninsomniacs , and this effect persisted in all sessions. However, the size of effe ct averaged about 0.5 mm, and this was judged to be a small magnitude. Heightened subjective sleepiness discriminated the insomniacs in only the midday session. The absence of polysomnography was a methodologic ally limiting factor. Theoretical and clinical implications of these d ata were discussed.