Pathology features
Unlike secondary hypersomnias, where the basic principle and foundation of treatment is finding and eliminating the root cause of excessive sleepiness, narcolepsy is a classic example of primary hypersomnia. Moreover, it is the most significant disorder in this group of pathologies.
Epidemiological data show that the prevalence of the disease is highly variable: the incidence ranges from one case per thousand people to one case per hundreds of thousands of the population. Considering the etiology and pathogenesis, it should be emphasized that genetic factors play a significant role in the development of this condition. Disease manifestation usually occurs in adolescence and young adulthood. Much less frequently, the first symptoms debut in childhood or middle age.
Clinical presentation
The key complaint of patients that remains with them throughout life is pronounced, excessive daytime sleepiness. Interestingly, other concomitant symptoms of the disease often gradually regress as the patient grows older and ages.
The clinical presentation distinguishes several main manifestations:
- Imperative daytime sleep attacks: these are completely irresistible sleep episodes. They can easily occur in a calm and monotonous environment (while riding transport, during a movie theater session). However, the main danger lies in the fact that attacks can also develop against the background of active activities, including driving a car. The duration of such episodes varies from a few minutes to several tens of minutes, and their frequency can reach several prolonged attacks within a single day.
- Cataplectic attacks: sudden development of diffuse or partial muscle atonia.
- Sleep paralysis: this is a state of cataplexy that occurs exclusively during transitional periods—upon falling asleep or during awakening.
- Hallucinations: perceptual disturbances are divided into hypnagogic (those that appear during the process of falling asleep) and hypnopompic (occurring upon awakening).
- Sleep disturbances at night: night rest becomes restless, accompanied by frequent awakenings, and dreams are very vivid, often frightening in nature.
Treatment approaches and restrictions
Narcolepsy therapy aims to alleviate symptoms. Symptomatic pharmacotherapy includes several groups of drugs:
- Stimulating α-adrenomimetics: used to eliminate daytime sleepiness (e.g., modafinil — it is important to note that the drug is not yet registered in the Russian Federation).
- Drugs improving night sleep: sodium oxybate is used (also not yet registered in the Russian Federation).
- Non-sedating tricyclic antidepressants: imipramine, clomipramine. They show the highest efficacy in eliminating cataplectic attacks.
In addition to medications, non-pharmacological therapy aimed at optimizing the patient's daily routine plays a crucial role. It is recommended to schedule short rest intervals with the opportunity for voluntary sleep during the day. It is necessary to ensure sufficient night sleep duration. Regular physical activity, which should be completed a few hours before bedtime, has a positive effect. Alcohol and any medications with a sedative effect must be strictly excluded from therapy and the diet.
Contraindications for activities: Due to the risk of uncontrolled sleep attacks and sudden muscle weakness (cataplexy), patients are strictly contraindicated from activities that could cause harm to themselves or others. This includes driving a car, working at heights, as well as professional activities near bodies of water and similar hazardous professions.
Differential diagnosis of sleep disorders
When complaining of daytime sleepiness and night sleep disturbances, narcolepsy is differentiated from sleep-related breathing disorders, where the most frequent pathology is sleep apnea syndrome. This condition manifests as repeated breathing cessations during sleep.
Two key concepts are distinguished:
- Apnea (Apnea) — cessation of breathing during sleep lasting more than 10 seconds.
- Hypopnea (Hypopnea) — episodes of significant decrease in blood oxygenation (by more than 4%) without complete cessation of breathing.
To record apnea episodes and precisely diagnose the type of disorders, comprehensive instrumental recording—polysomnography—is used. During the study, the following parameters are recorded: electroencephalogram (EEG / EEG), electrooculogram (EOG / EOG), electromyogram (EMG / EMG), heart rate (HR / HR), blood oxygen saturation (SpO2), oro-nasal airflow, chest and abdominal wall movements, as well as the acoustic phenomenon (snoring).
Class and exam questions
At what age does narcolepsy most commonly begin?
Manifestation of the disease most commonly occurs in adolescence and young adulthood. Onset in childhood or middle age is significantly less common.
What hallucinations are characteristic of this disease?
Patients experience hypnagogic hallucinations (perceptual disturbances appearing when falling asleep) and hypnopompic ones (appearing upon awakening).
Can a patient with narcolepsy drive a car?
No, this is strictly contraindicated. Uncontrolled imperative sleep attacks and cataplexy episodes can cause irreversible harm to the patient and others on the road.
What drugs are used to treat cataplexy attacks?
Non-sedating tricyclic antidepressants, such as imipramine and clomipramine, are used with high efficacy to eliminate cataplectic attacks.
What else to study on this topic
- Pathogenesis and classification of sleep apneas (central and obstructive)
- Polysomnographic picture in various types of apnea
- Principles of polysomnography data interpretation (EEG, EOG, EMG)
- Differential diagnosis of primary and secondary hypersomnias
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