Study of sleep microstructure in patients of migraine without aura

Although the relationship between sleep and migraine has been widely reported, studies on sleep microstructure are few. The aim was to study and compare microstructural polysomnographic characteristics in patients of "migraine without aura" (MOA) with controls.

Twenty-five patients of MOA and 25 age- and gender-matched healthy controls were subjected to overnight polysomnography. Microstructural sleep analysis, including arousal and cyclic alternating pattern (CAP) analysis was performed. Arousals and CAP parameters were compared between the two groups using the Mann-Whitney U test (p ≤ 0.05).

The overall arousal index (p = 0.528) and that during non-rapid eye movement (NREM) sleep (p = 0.503) were comparable between the two groups. However, the arousal index was lower in migraineurs during rapid eye movement (REM) sleep (p = 0.001). The overall CAP rate (p = 0.020) as well as the number of CAP cycles and sequences (p = 0.032) was lower among migraineurs. The total phase A duration (p < 0.0001) was increased, and conversely, phase B duration (p = 0.001) was decreased in migraineurs. The phase A1 duration (p = 0.036) was higher in migraineurs. Finally, phase A1 (p = 0.357) index was comparable, and conversely, A2 (p < 0.0001) and A3 (p = 0.020) indices were decreased in migraineurs.

This study showed a decreased REM arousability as well as a decreased overall CAP rate and CAP cycling in patients with migraine as compared to controls. This indicates that there is probably an alteration of the arousal mechanisms in patients with migraine that may facilitate the occurrence of headache paroxysms during sleep.