The departures from the course of natural sleep which have been thus considered are not so much the direct consequence of acute disease as the result of structural deviation from the normal type of the nervous system. We must now briefly review the strictly pathological modifications to which sleep is liable.
Lithæmic Insomnia.
Among those who indulge freely in the pleasures of the table a form of insomnia is not uncommon. Originating at first in mere overloading of the stomach, and consisting in a direct irritation of the brain through the medium of the intervening nervous apparatus, sleeplessness finally becomes a symptom of more serious mischief. The tissues become charged with nitrogenous waste, and a lithæmic25 or gouty condition is established. Such patients are wakeful, or if they sleep their slumbers are imperfect and unrefreshing.26 Grinding of the teeth,27 noticed by Graves during the sleep of the gouty, is a symptom indicative of a highly irritable condition of important ganglia at the base of the brain. These symptoms are sometimes associated with turgidity of the superficial vessels of the head, indicating imperfect function of the circulatory organs, with a tendency to accumulation of the blood in the venous channels of the body. The sleep of such partially-asphyxiated patients is fitful, irregular, and akin to stupor. Occurring in the subjects of periodical gout, these disturbances of sleep become increasingly serious as the paroxysm is approached, until loss of sleep and the unrefreshing character of such slumber as may be obtained become important factors among the causes of failing health.
25 DaCosta, “Nervous Symptoms of Lithæmia,” Am. Journ. Med. Sci., Oct., 1881.
26 Dyce Duckworth, “Insomnia in Persons of Gouty Disposition,” Brain, July, 1881.
27 Trousseau, Clinical Medicine, Am. ed., vol. iv. p. 362.
For all such patients a proper recognition of the cause of their disorder is essential. This must be corrected by measures appropriate to the treatment of the gouty diathesis. Since the condition of the cerebral tissues is a state of irritation caused by the presence of excrementitious substances, such hypnotic remedies must be selected as will not interfere with the defecation of those tissues. Bromide of potassium, valerian, scutellaria, hyoscyamus, hops, and cannabis indica are useful, together with all that class of drugs which quiet the brain without hindering the process of excretion. Chloral hydrate often produces an excellent result, but care should be taken to prevent its habitual use.
Febrile Insomnia.
Closely related with the sleeplessness of lithæmia are the disturbances of repose which attend the evolution of the various specific fevers. In many cases the condition varies all the way from stupor to delirium. Excessive somnolence, such as often ushers in the fever, is an indication for evacuant treatment. Cerebral excitement calls for remedies like the bromides and chloral hydrate, which do not interfere with elimination. If pain, like headache or backache, be a symptom demanding attention, the addition of morphia in small doses forms a valuable reinforcement for the hypnotic mixture; but, as a general rule, opiates should be used with a sparing hand. The various resources of hydrotherapy are often invaluable when wakefulness results from the cutaneous irritability of the eruptive fevers. During the later stages of a protracted illness the occurrence of insomnia should direct attention to the nutrition of the patient. Wakefulness is then the symptom of an irritable weakness of the brain, demanding remedies which delay the process of disassimilation. The failing power of the heart requires attention, and diffusible nutriment must be given to convey the elements needful for restoration of the exhausted brain. These indications are most perfectly answered by the associated administration of opiates with alcohol, milk, and beef-juice in small and frequent doses.