Sleep is a complex process that involves many areas in the brain including the pedunculopontine nucleus (PPD), lateral dorsal tegmentum (LDT), locus coeruleus (LC), preoptic area, posterior hypothalamus, and a flip flop switch in a harmonious manner. Moreover, many neurotransmitters are involved in this process [11]. So, any condition that leads to disruption of the aforementioned components would affect sleep, this includes many neurological disorders, and far and away stroke comes in the center.
Though sleep disorders are widely prevalent and markedly transform the quality of life status of patients, they are usually a forsaken category by physicians while managing a stroke patient, whether acutely or during secondary prevention plan. There are no clear guidelines on how to deal with these disorders after a stroke or throughout the secondary prevention journey. In addition, that topic is not under spotlights in the regional and national stroke conferences and meetings.
This study used an easy applicable questionnaire, which is quick to perform, and thus constitute a tool that could be practically applied in everyday practice.
As mooted earlier, sleep and stroke have definite relationship, stroke affects sleep microstructures in different ways, different studies indicated an association between different stroke sites and or side of stroke and the affection of REM and non-REM sleep [12, 13]. Moreover, different markers as il-1, IL-6, and TNF-α that are incremented in a stroke had been found to result from sleep deprivation and insomnia [14,15,16,17,18]; hence, early detection of sleep disorders is mandatory to prevent further damage.
A respectable sector of stroke patients (20%–63%) manifests by different sleep disorders as hypersomnia, insomnia, parasomnias, circadian rhythm disorders, periodic limb movement disorder, and sleep-disordered breathing [19]. In our study, it was found that 70.6 % had sleep disorders, auscultating raised points in this discussion, it is definitely an enormous issue.
Hence, sympathetic overactivity and reduced cerebral blood flow are the suggested mechanisms for the occurrence of some sleep disorders like insomnia, SDB [20], and periodic leg movements, as well as instigation of the development of stoke. Proper management of these disorders is mandatory for stroke secondary prevention and might unfold and clear up reasons behind recurrent strokes in optimally treated patients. In a recent study, earlier this year (the basic project) that used a survey on 842 patients with stroke in south Texas, SDB represented a modifiable factor associated with a higher rate of recurrent stroke and poor functional outcome [21].
SDB is more prevalent in stroke than non-stroke patients [22], in our study, 29.3 % had possible SDB by the Apnea index questionnaire to be confirmed by polysomnography, different studies reported a prevalence rate range between 43 and 72%, higher prevalence might be attributed to preexisting SDB and not counting de novo cases only [23,24,25]. In a study done in Switzerland, better stroke outcome, and less morbidity and mortality was associated with a lower Apnea, and Apnea/Hypopnea Index [22]. Under recognition of SDB lead to high functional impairment in the long term.
Furthermore, in a systematic review about insomnia after stroke, it was found that insomnia prevalence ranges from 14 % to 59 % in studies used clinical diagnostic tools and 19.8% to 69% using non-clinical diagnostic tools and a variety of diagnostic questionnaires, and in that systematic review, one study reported association between cortical lesions and poor sleep quality [26], in our cross-sectional study insomnia prevalence was 14.7 % with 10.7 % had initial insomnia. Insomnia stands as independent risk factor for cerebrovascular reactivity (CVR) and aggravation of sympathetic hyperactivity [27], thus early detection and management is mandatory. Different factors enact in this as the external environment in the stroke unit (frequent medication, stress related to the recently developed illness, frequent medication), comorbid psychiatric disorders such as anxiety and depression, in addition to the effect of the inflammatory mediators released by the damaged tissue as mentioned earlier in this text.
This study has a limitation that polysomnography was not done to confirm the presence of different as sleep-disordered breathing and parasomnia. But it represents a simple bedside screening way for the detection of post-stroke sleep disorders that would help physicians and healthcare personals who are engaged with stroke patients to better manage these disorders.
In conclusion, sleep and stroke have a definite relationship, sleep disorders are broadly prevailing after stroke, and resulting damage hinders the process of rehabilitation, and holds up neuronal plasticity and consequently impecunious functional outcome. Simple questionnaires are easy applicable methods for screening of such disorders post-stroke. Guidelines needed regarding screening and management of Sleep disorders after the stroke through further larger cohort studies.