[Doctor Profile] “Sleep disorders come from illness, not laziness… left untreated they can threaten life”

 "We spend about a third of our lives asleep, yet the importance of sleep is overlooked. Sleep disorders can cause and worsen a number of physical conditions, so accurate testing and diagnosis are needed."

Hong Seung-bong, Director of the Epilepsy & Sleep Center, said this when we met on the 26th at St. Peter’s Hospital in Gangnam, Seoul, emphasizing the importance of managing sleep health. Interest in sleep health has grown compared with the past, he said, but many people still do not properly understand the importance of specialized testing. He stressed that while health insurance coverage for polysomnography has improved patients’ access to it, the process of having the test results accurately interpreted by an experienced neurology specialist is no less important than the diagnosis itself.

There are dozens of sleep disorders, the main ones being insomnia, sleep apnea, narcolepsy, idiopathic hypersomnia, restless legs syndrome, circadian rhythm sleep disorders and REM sleep behavior disorder. Apart from insomnia and sleep apnea, however, a good many of these conditions are mistaken for lifestyle problems or their cause is misidentified, so patients quite often fail to receive appropriate care.

Idiopathic hypersomnia and narcolepsy, in which sleepiness becomes overwhelming even during the day, are conditions that arise from a deficiency of orexin, the hormone that keeps people awake. Even so, they are often dismissed as personal traits — 'sleeps a lot' or 'lazy' — and in many cases the right time for treatment is missed. There are also cases in which patients with restless legs syndrome, who cannot get to sleep because of numbness and discomfort in the legs, fail to recognize this as a sleep disorder and visit an orthopedics department instead.

Center Director Hong said, "There was even a case in which a patient with restless legs syndrome was misdiagnosed with a disc problem and almost underwent surgery," adding, "When a misdiagnosis occurs, a patient who could improve with drug therapy alone may end up receiving unnecessary treatment."

If left unaddressed, sleep disorders can cause or worsen a variety of conditions. Insomnia raises the risk of hypertension, diabetes, heart disease and dementia, and also affects mental health, contributing to depression and anxiety disorders. Sleep apnea causes severe hypoxia and can be a cause of cardiovascular disease or sudden death. Narcolepsy not only creates difficulties at school and at work but also increases the risk of various safety accidents and traffic accidents. Long-term sleep deprivation can affect overall health and even life expectancy.

Accordingly, if it keeps taking more than 30 minutes to fall asleep, or if waking frequently and being unable to sleep deeply continues for three months or more, a specialist examination is needed. A sleep study should also be considered by those who snore heavily or are suspected of having sleep apnea, those who remain severely sleepy during the day even after sleeping seven hours or more, and those with a history of hypertension, diabetes or stroke.

Polysomnography diagnoses sleep disorders by using the EEG to check the depth and quality of sleep and the frequency of arousals, and by comprehensively recording and analyzing a range of biosignals during sleep, including the electrocardiogram, oxygen saturation, airflow and leg movements. However, because the accuracy of the results can vary with the laboratory environment and the testing method, careful checking is also needed when choosing where to be tested. It is important to look at whether an environment is provided in which the patient can sleep as naturally as usual, whether experienced sleep study technologists carry out the test, and whether a sleep specialist personally interprets the results. In particular, since a variety of biosignals including the EEG have to be interpreted together, care and interpretation by a neurologist with a strong understanding of brain and nervous system disorders are important, he explained.

Center Director Hong explained, "In sleep laboratories that are short of staff, patients are sometimes woken at 4 to 6 a.m. and the study is brought to a hurried end; in that case the sleep architecture is recorded abnormally and the results can be wrong," adding, "Carrying out the study in a laboratory that operates 24 hours a day, letting the patient fall asleep and wake according to their usual pattern, helps produce a more accurate diagnosis." He went on, "It is also very important that an experienced neurologist interprets the test results," and said, "In the United States and Europe, only physicians who have completed a sleep medicine fellowship of a year or more are qualified to run a sleep laboratory, but Korea has no such system yet, so patients need to check the expertise of the medical staff for themselves."

The Sleep Center at St. Peter's Hospital operates a 24-hour testing system staffed in shifts by dedicated EEG and sleep study technologists, and has a diagnostic framework that links video EEG with polysomnography. The system was built on Center Director Hong's experience as head of the Epilepsy and Sleep Center at Samsung Medical Center, and the center also runs an open testing system under which patients referred from other medical institutions can undergo detailed examination.

Center Director Hong said, "Sleep disorders can be treated perfectly well once they are accurately diagnosed, so I recommend having accurate tests carried out by an experienced sleep medicine specialist and receiving treatment matched to the cause," adding, "Recovering good-quality sleep is the first step toward a lively daily life and restored physical and mental health."