Polysomnography

Polysomnography is recommended in a wide spectrum of clinical situations related to sleep. Below are the most common indications for performing this study:

1. Sleep Apnea Diagnosis Sleep apnea (both obstructive, caused by mechanical closure of the upper airways, and central, resulting from disorders in the brain’s respiratory center) is the most common indication for polysomnography. The study allows for the precise determination of the type (OSA or CSA), severity, and characteristics of apnea episodes. We record parameters including the lowest blood saturation level, the duration of individual apneas, and their relationship to body position and sleep stages, which is essential for selecting the optimal therapeutic strategy.

Common symptoms suggesting the need for polysomnography when sleep apnea is suspected:

• Loud, irregular snoring with breathing pauses (observed, for example, by a partner).

• Excessive nighttime sweating.

• Frequent waking with a feeling of breathlessness (nocturnal “choking” episodes).

• Excessive daytime sleepiness and chronic fatigue despite seemingly sufficient sleep time.

• Difficulty concentrating and memory problems.

• Morning headaches and a dry mouth upon waking

2. Diagnosis of Central Hypersomnias Central hypersomnias are a group of less common neurological disorders characterized by excessive daytime sleepiness not related to sleep-disordered breathing. This group includes narcolepsy, Kleine-Levin syndrome, and idiopathic central hypersomnia. Noctur-nal polysomnography, combined with a subsequent daytime MSLT (Multiple Sleep Latency Test), al-lows for an objective assessment of how quickly a patient falls asleep during the day and whether sudden REM sleep episodes occur immediately after falling asleep (characteristic of narcolepsy). The study also helps distinguish primary hypersomnias (neurological) from secondary ones caused by me-dications, depression, or other medical conditions. Furthermore, it assesses sleep architecture for fragmentation (frequent awakenings), which can also cause excessive daytime sleepiness.

3. Differentiating Parasomnias and Seizures Parasomnias are a group of disorders involving abnor-mal or undesirable behaviors during sleep or upon waking. They are not caused by epileptic seizures, although symptoms can sometimes appear similar. The most well-known parasomnias include som-nambulism (sleepwalking), night terrors, and confusional arousals. Polysomnography with simulta-neous video recording allows for a detailed analysis of these episodes. Unlike epileptic seizures, para-somnias do not show characteristic EEG changes or a preceding “aura,” and these incidents often oc-cur at consistent times of the night according to the natural sleep cycle. The study can also help de-tect triggers for parasomnias, such as sleep fragmentation caused by sleep apnea.

4. Diagnosis of Sleep-Related Movement Disorders These include Restless Legs Syndrome (RLS), Periodic Limb Movement Disorder (PLMS), and other abnormal motor activities. Polysomnography re-cords the characteristic patterns of these movements. For example, in PLMS, the legs perform repe-titive movements lasting several seconds, occurring in series every few dozen seconds. Unlike seizu-res, these movements are predictable, are preceded by EEG changes, and are often accompanied by brief sleep-fragmenting micro-arousals. The study assesses how much these movements affect sleep quality and distinguishes primary movement disorders from secondary ones (caused by iron de-ficiency, kidney disease, or certain medications).

5. Treatment-Resistant Insomnia This is a state where conventional pharmacological and behavioral therapies do not bring expected improvement. Polysomnography may be recommended to detect hi-dden causes of sleep disturbances, such as unconscious micro-arousals caused by periodic limb movements, subclinical (mild) sleep apnea, or other previously unnoticed fragmentation disorders. The study provides an objective measurement of how much a patient actually sleeps and the quality of that sleep compared to the patient’s subjective perception. It often turns out that the patient sle-eps more than they think, but their sleep is significantly fragmented. It can also reveal “paradoxical insomnia,” where objective sleep parameters are relatively normal, but the patient feels chronic sleep deprivation—which requires a different, specialized therapeutic approach.

6. Sleep Bruxism Sleep bruxism is involuntary nighttime teeth grinding or clenching, which can lead to serious dental damage, headaches, and temporomandibular joint disorders. Polysomnography with simultaneous EMG recording of the jaw muscles allows for an accurate assessment of the frequency, severity, and duration of bruxism episodes. It also identifies which sleep stages these episodes occur in and if they are accompanied by micro-arousals. The study helps distinguish primary bruxism from secondary bruxism related to sleep apnea, RLS, certain medications (especially SSRI antide-pressants), or neurological disorders.

7. Night Groaning (Catathrenia) Catathrenia is a disorder involving long, drawn-out groans during exhalation while sleeping. These sounds can be very loud and significantly disturb a partner’s sleep. Unlike snoring (which occurs during inhalation), catathrenia groans occur during exhalation—mainly in the REM phase. Polysomnography with audio recording enables a detailed analysis of these sounds, determining their timing and differentiating catathrenia from other nocturnal vocalization disorders or seizures. The study is also important to check for co-occurring sleep apnea.