More recent findings reveal possible parasomnias involving sleep-related behaviors triggered by SDB—in particular, sleepwalking, night terrors, RBD, and sleep-related eating disorder. Further complicating the matter is that sedative/hypnotics can provoke both SDB events and these behavioral parasomnias. Ongoing studies are attempting to untangle these interwoven factors.
Perhaps most intriguing is that SDB events may provoke nightmares, RBD, and sleepwalking episodes. It stands to reason that any choking episode can initially produced intense fear, anxiety, and/or panic. Pagel and Kwiatkowski19 studied nightmares in 400 patients who were also evaluated polysomnographically for SDB. Patients with severe SDB had fewer recalled nightmares than those with milder disease (30% vs 70%, respectively). This may be because patients with severe SDB have reduced REM sleep, are less likely to fully awaken, or have habituated to the awaken-ings with choking and gasping. It would be interesting to see whether this relationship reverses in patients with PTSD, given that severe SDB is associated with increased norepinepherine turnover due to sympathetic nervous system up-regulation in response sleep disturbance.
Sleep problems (and especially nightmares) are cardinal symptoms of PTSD. Our data strongly support an association between SDB and PTSD.5 This association has also been reported by others.20 Krakow and colleagues21 posit an arousal-based mechanism initiated by posttraumatic stress–promoting SDB development in trauma survivors. Of note: continuous PAP treatment of obstructive sleep apnea improved insomnia, nightmares, and PTSD symptoms, which may indicate that causality is bi-directional.21-23
Sleep loss or disturbance, whether associated with SDB or other conditions, can impair an individual’s coping mechanisms. When sleepy, we are easily frustrated and must make more effort to perform otherwise mindless and rote tasks. In patients who already have difficulty in functioning, especially those prone to impatience, anger, panic, and/or denial, the additional stressor of impaired sleep can exceed the capacity of their defense mechanisms. Thus, SDB can create a special vulnerability to psychological problems—especially anxiety.
Attention deficit. Recent studies suggest a relationship between SDB and ADHD in pediatric patients. Findings suggest that many children and adolescents (25% to 50%) with ADHD have sleep problems.24 In attention and hyperactivity among general pediatric patients have been shown to be associated with increased daytime sleepiness, snoring, and other symptoms of SDB.25
Youssef and colleagues26 found a high incidence (20% to 30%) of obstructive sleep apnea in patients with full ADHD syndrome; once obstructive sleep apnea was treated, improvements in behavior, inattention, and overall ADHD were seen. Naseem and colleagues27 reported on 3 patients with adult hyperactivity; all 3 patients suffered from symptoms of obstructive sleep apnea. With continuous PAP, 2 of the 3 patients showed improvement in their sleep and hyperactivity symptoms.
The vast majority of patients with SDB report sleepiness. If the sleepiness level exceeds the individual’s compensatory alertness mechanisms, he may resort to additional strategies to maintain focus (eg, caffeine(Drug information on caffeine) ingestion). Arousal and attention are fundamental to most cognitive tasks, particularly those that require quick or well-timed responses.28 However, beyond simple attentiveness, diminished executive task abilities (sometimes considered frontal lobe functions) were correlated with sleepiness and, thus by association, with SDB.29