Heightened public awareness of sleep disorders has significantly increased the demand for sleep studies. There is ever increasing number of sleep studies being done and report of the results are shared by the sleep specialists and the primary care physicians. Understanding the information discussed in the overnight sleep study report is crucial as it provides significant insight into the sleep pathophysiology in relation to patient symptoms. The purpose of this article is to provide a simple and easy method to interpret the reported results of polysomnography for the physicians and other health care providers. This will facilitate better understanding of the underlying pathophysiology of the sleep disorder and appropriate management of patients.
Parasomnias are characterized by undesirable motor, verbal or experiential phenomenon / behaviors occurring in relation to sleep and sleep wake transition phases. They are believed to occur due to incomplete arousal from different sleep states, abnormal intrusions of wakefulness into different stages of sleep as well as de-afferentation of generators of locomotion from generators of sleep. They are classified as sleep wake transition parasomnias, NREM (non-rapid eye movement), REM (rapid eye movement) parasomnias and miscellaneous group. Accurate diagnosis of various parasomnias is important as they are associated with distinct group of predisposing factors. Associated conditions that require different treatment considerations which may be as innocuous as identification and removal of predisposing factors and reassurance. Correct diagnosis also invokes right differential diagnostic considerations and further investigations. Understanding of the underlying pathophysiology, semiological features and natural history of the particular parasomnia aids in counseling the patient and the parents, safety precautions to be undertaken and addressing psychosocial complications which are one of the most distressing factors for the patients. Correct diagnosis can be established fairly accurately based on careful and detailed clinical interview (including account from parents and bed partner), age of onset, time of occurrence, polysomnographic (PSG) studies and rarely an extended montage to study electrographic characteristics for differentiation with an ictal event.
Abbreviations: REM – rapid eye movement, NREM – non-rapid eye movement, PSG – Polysomnography, EEG – electroencephalography, CNS – central nervous system, ICSD – international classification of sleep disorders, EMG – electromyography, BXD – benzodiazepines, TCA – tricyclic antidepressant, PTSD – post-traumatic stress disorder, ISP – isolated sleep paralysis, RISP – recurrent isolated sleep paralysis, RBD – REM sleep behavior disorder, OSA – obstructive sleep apnea, NPD – nocturnal paroxysmal dystonia, UTI – urinary tract infection, NES – nocturnal eating syndrome, RLS – restless leg syndrome, PLMS – periodic limb movement of sleep, RDI – respiratory disturbance index, SPECT – single photon emission computerized tomography, MAO – monoamine oxidase, SRED – sleep related eating disorder, CPAP – continuous positive airway pressure.
Adequate sleep is necessary for physical and mental well being. Sleep is influenced by multiple factors such as physiological, psychological, environmental and sociocultural factors. Sleep hygiene refers to the habits, environmental factors, and practices that may influence the length and quality of one\'s sleep. It is rarely effective when used alone, particularly in those with severe or chronic insomnia, but it makes the basis for more specific behavioral intervention. It is usually a component of Cognitive Behaviour Therapy treatment programs for insomnia. So, the most important step in non pharmacological treatment is the institution of proper sleep hygiene, or good sleep habits.
Objectives: To examine various factors, primarily socioeconomic, psychological, and physiological, which influence the decision of patients diagnosed with obstructive sleep apnea (OSA) to purchase a continuous positive airway pressure (CPAP) device.
Methods: The first phase involved 343 patients, undergoing polysomnography (PSG), with informed consent from amongst 1,098 subjects, who presented to a comprehensive Sleep Center in Chennai, India.
Among those diagnosed with OSA, a certain number were recommended CPAP therapy, based on the test results and clinical appropriateness. The second phase involved follow-up of these patients prescribed with CPAP. Patients were interviewed on whether they purchased CPAP devices or not, and the most relevant reasons for their decision.
Results: All 343 subjects who underwent the PSG were diagnosed with varying degrees of OSA. Among them, 291 were recommended to use a CPAP device. 41.9% of patients who were prescribed CPAP purchased the device. Out of these, 84.42% responded that it improved their quality of life and relieved OSA symptoms. Those who did not purchase CPAP, stated reasons such as high device cost (36.69%), deferment due to lack of awareness and education (17.75%), lack of awareness on the cost benefits of the device (11.24%), and discomfort during usage (8.88%).
Conclusion: Patients who used CPAP device report improved quality of life. However, amongst those who did not opt for CPAP therapy, socioeconomic factors appear to be the foremost deterrent followed by other factors such as lack of understanding of the importance of therapy and perceived discomfort with the equipment & interface.
Vanita C Ramrakhiyani,
Abhijit G Deshpande,
Prajakta A Deshpande,
Prasad C Karnik
How to cite this article:
Ramrakhiyani VC, Deshpande AG, Deshpande PA, Karnik PC. Psychomotor vigilance task- objective sleep disorder screening tool for Indian population. Indian Sleep Med 2012; 7 (4):157-162.
Introduction / Objective: The primary objective of the current pilot observational study was to establish feasibility and acceptability of sleep disorder screening tools, viz, Epworth Sleepiness Scale (ESS) and Psychomotor Vigilance Task (PVT) in Indian Population. The study also aimed to compare the sensitivity and specificity of both the screening tests. The outcome of the study will provide the threshold values for PVT to determine positive and negative diagnosis.
Method: It was a community based study in clinical settings. Patients visiting sleep clinic during period of year August 2011 to year September 2012 formed the study population. The sample population included 66 patients; 49 males and 17 females with mean age of 45 (age range 14-75). All subjects administered ESS as well as 10 minute PVT followed by confirmatory tools such as Nocturnal Polysomnogram, MSLT and Actigraphy. ESS score >10 was considered positive. The presence of any of intrinsic or extrinsic sleep disorder is considered a positive diagnosis. Bayesian theorem was applied to determine sensitivity and specificity of tests administered.
Results: Sensitivity of PVT was found to be high as 90.16 % as compared to that of ESS as 39.3%. However the specificity for both the tests was found to be equal at 100%. Among PVT measurements, number of lapses and average reaction time were found to be co-relating with a sleep disorder diagnosis.
Conclusion: Individuals having low ESS score were diagnosed with sleep problems which were well predicted in their PVT results. For Indian population, PVT assessment is more sensitive screening tool for sleep disorders as compared to ESS. Although, when administered together, chances of missing any sleep problem are minimised. It was a pilot study and needs to be further validated with larger population.