Hypersomnia is a significant increase in sleep duration, usually accompanied by daytime sleepiness. The main signs are: the duration of a night’s sleep of more than 10 hours, constant or paroxysmal daytime sleepiness, lack of significant improvement after daytime sleep, difficulty and prolonged waking up, often with the presence of a symptom of “sleep intoxication”. Disease is diagnosed based on clinical data, test results and polysomnography. Hypersomnia therapy consists in observing a certain sleep regime, treating a causal disease and using stimulant medications.
Hypersomnia is a sleep disorder in the form of an increase in its duration and increased drowsiness. It should be noted that the normal duration of sleep varies significantly and can range from 5 to 12 hours for different people. Therefore, speaking of hypersomnia, the duration of sleep is assessed individually in comparison with the period before the occurrence of sleep problems. It is necessary to distinguish hypersomnia from increased daytime sleepiness with insufficient duration of night sleep due to prevailing life circumstances or insomnia.
In clinical practice, pathology is much less common than insomnia (insomnia). It is not always noticed by the patient himself, but can be detected when he passes a special test. Hypersomnia can be observed with lack of sleep and fatigue; be a side effect of certain medications, enter the clinical picture of narcolepsy and mental disorders; accompany sleep apnea syndrome, trauma and organic brain damage, somatic diseases.
In clinical neurology, hypersomnia is classified mainly according to the etiological principle. According to the cause of hypersomnia, it is divided into psychophysiological, post-traumatic, narcoleptic, psychopathic, idiopathic, associated with respiratory disorders in sleep and caused by somatic diseases.
According to the peculiarities of the manifestation, permanent and paroxysmal hypersomnia are distinguished. Permanent hypersomnia is accompanied by constant drowsiness and a drowsy state throughout the day. Paroxysmal hypersomnia is characterized by sudden attacks of an irresistible desire to sleep, leading to falling asleep even in the most unsuitable conditions for this. Paroxysmal hypersomnia is noted in narcolepsy and cataplexy.
The mode of sleep and wakefulness in the human body is regulated by a complex system of mutual activating and inhibitory effects occurring between the cerebral cortex, subcortical structures, limbic system and reticular formation. Hypersomnia develops as a result of a malfunction of this system, which can be caused by a number of different reasons.
Psychophysiological hypersomnia can occur in healthy people after prolonged lack of sleep, physical and mental fatigue, stress. The development of this type may be associated with taking certain medications, for example, neuroleptics, tranquilizers, antihistamines, hypoglycemic and hypotensive agents.
Posttraumatic hypersomnia is caused by functional disorders of the central nervous system that occur after a traumatic brain injury. Along with trauma, the cause may be organic brain damage: intracerebral tumor, brain abscess, intracerebral hematoma, infectious diseases (neurosyphilis, meningitis, encephalitis), vascular disorders (hemorrhagic stroke, chronic ischemia, ischemic stroke). The development of hypersomnia in patients with sleep-induced respiratory disorders is most likely due to chronic hypoxia of brain tissues.
Hypersomnia is the main clinical symptom of narcolepsy and is often noted with cataplexy. Hypersomnia can also be observed in mental disorders (neurasthenia, hysteria, schizophrenia) and somatic diseases (hypothyroidism, diabetes mellitus, heart failure, cirrhosis of the liver, chronic renal failure). In cases where increased drowsiness occurs for no particular reason and is not related to any disease, it is referred to as idiopathic hypersomnia.
The main sign is periodic or constant daytime sleepiness with a long duration of night sleep. Hypersomnia is often accompanied by an increase in the duration of night sleep up to 12-14 hours. Characterized by difficulty waking up, the inability to get up on the alarm clock, an increase in the transition time from sleep to wakefulness. For some time after waking up, patients with hypersomnia may remain inhibited and not fully awake. At the same time, their condition resembles intoxication, for which this symptom was called “sleep intoxication”.
Daytime drowsiness in various forms can have a permanent or paroxysmal character. It lowers mindfulness and efficiency, interferes with full-fledged work, hinders the normal rhythm of life and forces patients to take breaks for daytime sleep. In some cases, after a nap, patients note relief, but more often the state of drowsiness persists even after prolonged or repeated daytime sleep.
Narcolepsy hypersomnia is characterized by the presence of attacks of forced falling asleep, in which the desire to sleep is so irresistible that patients fall asleep in the most unsuitable places and poses for sleep. Over time, patients with narcolepsy develop a premonition of an upcoming attack and they try to take a more comfortable sleeping position in advance. Narcolepsy hypersomnia can be accompanied by the appearance of hallucinations during falling asleep and waking up, as well as cataplexy of awakening — a significant decrease in muscle tone, which does not allow the patient to make any arbitrary movements in the first minutes after sleep.
Psychopathic hypersomnia is characterized by an unpredictable clinical picture of daytime sleepiness. For example, patients with hysteria may experience a “sleep” lasting several days after a traumatic situation. However, conducting polysomnography during the daytime does not find real signs of sleep in them, but on the contrary, the EEG demonstrates a state of intense wakefulness. It often turns out that patients just lie with their eyes closed.
Post-traumatic hypersomnia develops more often after injuries that are not accompanied by significant damage to brain tissue, and is most likely associated with stress experienced during trauma. In such cases, its clinical picture may be similar to the manifestations of psychopathic hypersomnia.
Idiopathic hypersomnia is more common in young people (15-30 years). Patients complain of constant drowsiness, difficulty waking up from sleep, a feeling of lack of sleep in the morning with a sufficient duration of night sleep. There may be a symptom of “sleep intoxication”. Daytime sleep in such patients brings some relief, but does not completely relieve them from drowsiness. In some cases, idiopathic hypersomnia may be accompanied by episodes of outpatient automatism lasting several seconds. Most often, a similar symptom is observed in patients who refuse daytime sleep.
A state of continuous sleep lasting more than a day is called lethargic sleep. Such hypersomnia is often a manifestation of epidemic lethargic encephalitis or various lesions of the reticular formation.
Since patients themselves cannot always objectively assess their sleep problems, generally accepted tests are used to diagnose hypersomnia: the Stanford sleepiness scale and the sleep latency test.
Polysomnography is of great diagnostic importance. In the case of narcoleptic hypersomnia, polysomnography reveals a shortening of the period of falling asleep, frequent night awakenings and the early onset of the rem sleep phase, while normally rem sleep occurs on average 80 minutes after falling asleep. A similar sleep pattern can be observed with hypersomnia associated with sleep apnea syndrome. In this case, the correct diagnosis can be made by detecting concomitant respiratory disorders during polysomnography. Idiopathic hypersomnia, as well as narcolepsy, is characterized by a shortening of the period of falling asleep, however, the normal ratio of sleep phases and night sleep without frequent awakenings is maintained.
Hypersomnia requires differentiation from asthenia, depression, chronic fatigue syndrome. To exclude the organic nature of pathological drowsiness, a thorough neurological examination, consultation with an ophthalmologist with ophthalmoscopy, Echo-EG, MRI or CT of the brain is carried out. Identifying the connection of hypersomnia with the presence of a somatic disease may require additional consultation with a therapist, endocrinologist, cardiologist, gastroenterologist, nephrologist.
The diagnosis of hypersomnia is usually established by a neurologist if its signs have been observed for at least 1 month and are not associated with a violation of night sleep or taking medications. If, after the disappearance for up to 2 years, its symptoms reappear, then they speak of a recurrent form of the disease.
Successful therapy of hypersomnia is closely related to the effective treatment of the disease, one of the symptoms of which it is. If a complete cure of the underlying disease is not possible (for example, in the case of narcolepsy), then the treatment is aimed at maximizing the quality of life of the patient.
Important in the treatment is the observance of sleep. The patient should exclude work in the evening and night shifts, adhere to the same bedtime, be sure to include 1-2 daytime naps in his routine. It is desirable that the duration of a night’s sleep does not exceed 9 hours. In idiopathic hypersomnia, the recommended duration of daytime sleep is 45 minutes. Along with sleep hygiene, you should avoid drinking alcoholic beverages and eating too heavy food, as well as eating just before bedtime.
To eliminate daytime drowsiness in hypersomnia, stimulants are used: pemoline, dexamphetamine, modafinil, mazindol, propranolol. If the patient has cataplexy, then he is shown to take antidepressants: protriptyline, imipramine, clomipramine, fluoxetine, viloxazine. Dosages of these drugs are selected individually, trying to achieve maximum therapeutic effectiveness with minimal side effects.
Symptoms of posttraumatic hypersomnia are often reversible. The situation is worse with hypersomnia, which develops with narcolepsy or as a result of organic brain damage. And although hypersomnia itself does not pose a threat to the patient’s life, it significantly increases the risk of his death from an accident at work or while driving a car.