Tokuda Hospital Sofia


Sleep Medicine Article by Associate Professor Dr. Ivan Staykov PhD - Neurology Clinic Department Chief

Despite that fact that sleeping accounts for a quarter to a third of our lives, the development of sleep medicine has been neglected for centuries. This medical discipline is a new branch of medical science and has been rapidly and dynamically developing over the last two-three decades. Sleeping disorders and restlessness are one of the most common problems people face in their everyday lifes. Approximately, 20-30% of the population is affected by these types of disorders.

From a physiological perspective there are two types of sleep: sleep with rapid eye movements (REM) and sleep without rapid eye-movements. Non REM sleep has four different stages, which are separate and have certain sequences and durations which make up one complete sleep cycle lasting about 90 minutes.

During a normal nights sleep 4-5 sleep cycles occur. Sleep begins with a light sleep phase divided into primary and secondary stages and sleep continues into the deep sleep phase divided into the third and fourth stage. After the fourth stage dreaming occurs.

According to international sleep disorder classifications, sleep disturbances can be divided into four main groups and total 84 types of disorder.  Dyssomnia is one of the four main groups and is characterized by disruption to the duration, integrity, depth, and quality of sleep. These are the most common type of sleep disorders which includes health conditions such as Obstructive Sleep Apnea (OSA), restless leg syndrome, psychophysiological insomnia, narcolepsy, and others. Disorders associated with falling asleep and staying asleep at termed insomnia which leads to increased sleepiness and hypersomnia.  

Obstructive Sleep Apnea (OSA) syndrome is the most common sleep breathing disorder and the most common form of hypersomnia (excessive sleepiness). Among middle age people OSA is registered among 4% of males and 2% of females.

The condition is characterized as repeated and continuing for more than 10 second breathing interruptions (apnea) or breathing flow reductions (hypoapnea). Among the clinically significant forms of OSA over 20 to 30 apnea or hypoapnea episodes per hour are observed. Apnea and hypoapnea episodes almost always lead to waking up as the body restores normal breathing patterns.  These repeating waking up episodes disrupt normal sleep patterns and especially disrupt deep sleep phases.

The main symptoms of OSA are apnea breathing pauses (breathing stops during sleep and often partners in the sleeping in the same bed notice the pauses), pronounced daytime sleepiness, waking up with an accelerated heart rate or headaches, restless sleep, and a waking feeling of a lack of breath and/or a panic sensation. Patients wake up feeling exhausted, with diminished concentration, and often find themselves dozing off while driving. The consequences of daytime sleepiness because of non-treated OSA are sexual dysfunction, marital problems, low work productivity, cognitive deficits, work place accidents, and driving accidents. Approxiametly half of those affected by OSA

About half of patients with OCA have high blood pressure, and among approximately half of patients whom have had strokes also have sleep breathing disorders.

It has been established that OSA is an independent risk factor for ischemic cerebral stroke which has been shown to raises stroke risk by 2 times. The suspected mechanisms for this are continuously high blood pressure, chronic night time reductions in cerebral blood flow, damage to blood vessels, and increased atherosclerotic processes. Often those with OSA have other risk factors for strokes such as hypertension and obesity. Breathing interruptions during sleep lead to oxygen de-saturation (lack of oxygen supply), which can lead to developing cardiovascular health issues later in life. Upon indications of OSA, the recommended diagnostic method is nighttime respiratory polygraphs; conducted by and managed by physicians with specialized equipment in a controlled sleep laboratory setting.  

OSA treatment consists of taking general measures, treating con-concurrent diseases, as well as utilizing specialized treatment equipment and even conducting surgical interventions. General measures include going on a sleep schedule, losing weight, sleeping on one’s side, stopping both alcohol and sleep medication use, and others. The use of alcohol and sleeping medications, especially benzodiazepines, reduce muscle tone and increases the frequency and duration of breathing pauses.  

The main treatmentfor OSA is administering continuous positive pressure to the respiratory system (CPAP)with a device fitted with a nasal mask. The presence of excessive day time sleepiness is a medical indication to implement CPAP therapy. During CPAP treatment, the patient breathes spontaneously while receiving a slightly elevated positive pressure air supply via a nasal mask. This therapy resolves apnea and breathing flow reductions (hypoapnea). The exact pressure administered for each patient is automatically regulated by our CPAP titration equipment located in our specialized sleep medicine laboratory.

OSA surgical therapy involves expanding the upper respiratory tract airways including plastic surgery on the uvula, palate, or the throat structures which is recommended for younger patients with mild forms of OSA.

OSA has a progressive character and it significantly increases risks for cerebral and cardiovascular diseases. With CPAP therapy, OSA and hypersomnia reduces and disappears and this therapy is the best treatment available for moderate to severe cases of OSA.

We offer respiratory polygraphs and CPAP titration services upon advance scheduling in our sleep medicine laboratory of our neurology clinic. Our OSA services are performed over the course of two nights, the first night to perform diagnostic testing and the second night for provide CPAP treatment for those diagnosed with OSA.  

To schedule an appointment or for questions please refer to our sleep medicine lab contact details:

Telephone: +359 02 403 44 52

GSM: +359 895 280 038




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Hospital location

51B "Nikola I. Vaptsarov" blvd. (if you drive, the entrance is from "At. Dukov" str.), "Hladilnika" distr., 1407 "Lozenets".

The hospital has a parking lot. The first 30 min. are free of charge, then a fee of 3 bgn/hours applies.

Public transport:
Buses: №88, 120
Shuttle bus: 32

Subway: Getting off at "James Bourchier" station, after that walking through "Lozenets" distr., or tram №10, taking off at "Nikola I. Vaptsarov" stop. or a bus №88, taking ff at "Tokuda Hospital" stop.


From the Central Railway Station

Bus line №305 getting off at "Romanian embassy" stop
From "Romanian embassy" stop – Bus line №120 getting off at "Tokuda Hospital" stop.
(after the traffic lights at "Atanas Dukov" str.

With a subway, from "Central Railway Station" station, getting off at "James Bourchier" station, after that walking through "Lozenets" distr., or tram №10, taking off at "Nikola I. Vaptsarov" stop. or a bus №88, taking ff at "Tokuda Hospital" stop.