Pre-Operative Subarachnoid Haemorrhage in a Patient With Spinal Tumour

Abstract

Primary headaches are closely related to sleep. Modifications in the patterns of arousal during sleep have been reported in migraine, especially in the nights preceding a headache attack. We aimed at evaluating the pattern of arousal from sleep in a group of patients affected by sleep-related migraine. We enrolled 10 consecutive patients, three males and seven females, aged between 20 and 62 years, who presented frequent attacks of migraine without aura (more than five per month), closely related to sleep (more than one-half of the attacks occurred during sleep, causing an awakening). A control group was studied, matched for age and sex. Patients and controls underwent a full-night polysomnographic study, following adaptation; arousal pattern was studied by the scoring of the high-frequency EEG arousal and by the cyclic alternating pattern (CAP). Migraineurs showed a lower CAP rate in non-rapid eye movement (NREM) sleep and, in particular, a lower number of A1 phases (low-frequency, high-amplitude EEG bursts) compared with the controls. Migraineurs also showed a lower index of high-frequency EEG arousals during rapid eye movement (REM) sleep. The reduction in the CAP rate indicates a lower level of arousal fluctuation in NREM sleep. The reduced arousal index in REM suggests a dysfunction in neural structures involved in both the control of REM sleep and the pathophysiology of migraine, such as the hypothalamus and the brainstem.

Study of sleep microstructure in patients of migraine without aura

“…This is comparable with previous studies, which also found a reduction of CAP duration in patients with prevalently nocturnal MOA, in the presence of a normal sleep macrostructure [10], or a reduction of K/Dburst index with features of disturbed sleep [25]. Additionally, the phase A2 and A3 indices were decreased in this study, which were not in agreement with the findings of other studies where the reduction in CAP phase was predominantly seen during phase A1 subtype [10]. We also found a significant reduction in the number of CAP cycles and CAP sequences in patients with migraine as compared to controls.…”

“…Therefore, it may be hypothesized that the reduced arousability during REM sleep may result in the failure of brain mechanisms in halting migraine attacks, which may in turn be responsible for the predilection of migraine attacks to occur during this sleep stage. These findings support the conclusions of previous studies, which also found reduction in frequency of arousals during these deeper stages (N3 and REM) of sleep [4,10,19]. Likewise, a reduction in the total CAP rate, as well as a reduction in the amount of cycling from CAP phase "A" to phase "B" and vice versa, alongside decreased A2/A3 indices in our patients with MOA, may show an impaired ability of the brain to terminate an attack of migraine even during NREM sleep.…”

“…However, the overall arousal indices as well as the arousal index during NREM were comparable with those of healthy controls. These findings are similar to the previous studies, which found comparable overall arousal indices as well as NREM arousal indices among [10,25]. It has also been reported that the arousal density and α power of REM sleep as well as the β power of slow wave sleep (SWS) are reduced in the nights preceding a migraine attack [26].…”

“…We also found a significant reduction in the number of CAP cycles and CAP sequences in patients with migraine as compared to controls. This is in contrast to previous studies, which found comparable number of CAP cycles and CAP sequences in patients with MOA and healthy controls [10]. The sleep microstructural alterations in patients with MOA in the present study group and comparison of these findings with a previous study by Della has been summarized in Table 3.…”

“…Studies have also shown that patients with narcolepsy have a significantly higher prevalence of migraine [9] as compared to the general population. However, another study on patients of migraine without aura found a significant reduction of cortical arousals during REM sleep and a reduced cyclic alternating pattern (CAP) rate, suggesting a reduced reactivity to incoming stimuli which may be responsible for the occurrence of migraine attacks during sleep [10]. These findings may be attributed to some similarities in the neural pathways involved in arousal systems, as well as in the pathophysiology of migraine.…”