Somnolence

Somnolence (somnolentia), an inclination to sleep. Somnolence is characterized by a state of reduced mental activity and general physical lethargy. The occurrence of somnolence is conditioned by various factors, such as fatigue, monotonous stimuli, and others. Somnolence ceases under the influence of various factors, such as emotional excitement, etc. Pathological states of somnolence are observed in various diseases, which include genuine sleep disorders, such as narcolepsy and a special disease described by Kleine under the name of periodic lethargy. The disease is characterized by periodically occurring lethargy lasting from several days to 1-3 weeks; similar attacks usually occur several times within a certain period of time, with complete cessation thereafter. Kleine considers the disease as constitutional and classifies it with paroxysmal states, as well as narcolepsy, picnolepsy, and epilepsy. Kannabich considers periodic lethargy as a symptom of pathological somnolence in cyclothymia. Somnolence is observed in various diseases of internal organs, such as heart diseases, especially in myocarditis, metabolic disorders (diabetes mellitus, azotemia, etc.), in endocrinopathies, which is particularly sharply manifested in myxedema. In nervous diseases, in addition to those mentioned above, it is observed as one of the main symptoms in epidemic encephalitis, in tumors of the brain, and even regardless of localization as a symptom of general increase in intracranial pressure. An epileptic seizure, as well as a migraine attack, ends with somnolence. Nervous exhaustion is often accompanied by somnolence. The therapy of somnolence is determined by etiological factors; in cases of nervous exhaustion, rest and general strengthening treatment are indicated.