Cerebral exhaustion is a not uncommon cause of wakefulness in cases uncomplicated with fever. It is usually the result of chronic conditions of ill-health and depression, such as are often encountered as the result of various cachexias or of dyspepsia, with or without the abuse of alcohol, tea, coffee, or tobacco. Overwork, debilitating discharges, pregnancy, parturition, mental anxiety, depressing emotions, chronic heart disease, and incipient insanity are fruitful causes of the exhaustion which produces this most distressing form of insomnia. In such cases the cessation of healthy nutrition leads to a condition of excessive instability in the cerebral tissues. The oxygen which they receive from the blood is not stored with any degree of permanence, but tends to pass directly into stable combinations with the oxidizable elements of the brain. Consciousness is thus continually aroused. The state of such a patient presents a very close analogy to the condition of the victim of diabetes whose liver refuses to retain its glycogen. The inordinate discharge of sugar into the blood not only exhausts the tissues of the liver, but also excites other organs—notably the kidneys—to excessive and unwholesome activity. In somewhat similar fashion, the failure of the brain to assimilate and to retain oxygen leads to an abnormal intramolecular oxidation, which excites an excessive and unwholesome activity on the part of the Ego in another region—namely, in the field of consciousness. Such wakefulness might justly be termed a psychical diabetes.
This variety of insomnia has frequently been ascribed to cerebral anæmia occurring as a part of a general spanæmia. But this universal impoverishment of the blood, though a sufficient cause of the morbid instability, the irritable weakness, of the cortical tissues, does not necessarily imply a comparatively bloodless condition of the brain. Unequal circulation and local hyperæmia in different organs of the body are no unusual consequences of the anæmic state. Slight disturbances suffice to arouse the brain of such a patient. The vaso-motor apparatus shares in the general irritability, permitting blood to inundate the cortical substance almost without provocation. The unstable protoplasm is only imperfectly renovated, usually at the expense of the other tissues of the body. The weary patient, busying himself with an unwilling review of the events of the day, tosses long upon his couch before he can secure the approach of “tired Nature's sweet restorer, balmy sleep.” When at length he yields, his slumbers are brief, and the latter part of the night is but a repetition of the earlier vigil.
Such patients need a very radical course of general treatment. A complete change of habits should be effected. A long vacation in the country, or, best of all, a protracted voyage in a sailing vessel, is desirable. Hot foot-baths, with cold affusion upon the head, and warm sponge-baths, or even the full bath in tepid water, at bedtime, are of great service as means of tranquillizing the nervous system. The indications for medicinal treatment, besides attention to the predisposing cachexia, are twofold—to calm and to nourish the enfeebled nervous substance. Opiates calm, but do not nourish—they hinder the process of nutrition; hence the sufferer wakes unrefreshed by the sleep which they procure, and is soon in a condition worse than ever. The same objection lies against the continuous use of the bromides. But alcohol and its hypnotic derivatives (chloral, paraldehyde, etc.) not only calm the excitable brain, but they also furnish to the tissues a certain amount of diffusible nutriment which suffices to steady the brain until a change of occupation, with rest and wholesome food, can produce a complete restoration of its normal stability. To this effect of alcohol must be ascribed its value as an hypnotic in the wakefulness of old people who cannot sleep without a preliminary nightcap. A moderate draught of hot toddy in such cases serves to arouse the feeble heart and to equalize the circulation by the production of a moderate degree of general vascular dilatation. The sugar and water afford an easily assimilated food, while the alcohol benumbs the cortical protoplasm to a degree which favors the cessation of conscious perception. If administered in excessive doses, it is not sleep but anæsthetic intoxication which follows. If this condition be unduly repeated, the phenomena of chronic alcoholism supervene, with all the horrible forms of insomnia that accompany cerebral starvation and delirium tremens. Non-alcoholic nerve-stimulants and tonics, with careful administration of easily-digested food, are then more than ever needed to overcome the neurasthenic wakefulness.
Insomnia from Active Cerebral Congestion.
Still another form of sleeplessness is often experienced as a result of actual inflammation in some portion of the body, either involving the intracranial contents directly or reacting upon the brain through the medium of its circulation. In such cases many of the symptoms of acute inflammation are present. The head aches, the temples throb, the face and eyes are suffused with blood, the temperature is considerably increased. The senses become exalted, ideas pursue a tumultuous course, there may be actual delirium. These disturbances are due to an active hyperæmia of the brain. The substance of the cortex becomes hyperexcitable, and the ordinary incitements of sense produce an exaggerated effect in consciousness. The patient does not sleep, and he feels no need of sleep, because the nutrition of the brain is sustained at the expense of the remainder of the wasting body. The most speedy and effectual relief in such cases is obtained through a diminution of the current of blood in the brain. Moderate compression of the carotid arteries has been proposed as theoretically useful. Sedatives, like aconite, conium, digitalis, veratrum viride, ipecacuanha, and tartar emetic are useful, either alone if pain be absent or combined with opiates if the patient is suffering. Dover's powder or tartar emetic and morphia in small doses was formerly in general use. If there be a disposition to nausea the substitution of aconite for antimony is of great value. A combination of morphia, bromide of potassium, and chloral hydrate often gives excellent results. Paraldehyde may be preferable to chloral by reason of its more thoroughly sedative effect. Derivative measures—mercurial cathartics, cupping, leeching, or even general bleeding—may become necessary in certain cases. After the acute stage is passed blisters behind the ears should be employed. In the sleeplessness of acute mania Newington28 has used mustard baths with great satisfaction.
28 Brain, vol. i. p. 126.
Coma.
Turning now to the other extreme, we find a class of cases in which the disorder consists not in wakefulness, but in an excess of sleep. Excluding those exceptional cases in which healthy individuals, as a consequence of inordinate physical exertion, have slept for many hours beyond their ordinary limit, every extraordinary manifestation of sleep-like unconsciousness must partake of the nature of coma. Between natural sleep and this condition may be placed the distinction that the one is always the effect of natural physiological processes, while the other is always the result of injury, of disease, or of some form of intoxication. Comatose unconsciousness may be the result of cerebral compression caused by traumatic impact or by the presence of inflammatory exudations. Intracranial tumors, embolisms, thrombi, degeneration of tissue, diseases of the arteries of the brain—in short, every morbid change of which the liquids and the solids within the cranium are capable—may become the causes of coma. So also the blood and lymph, contaminated with the products of internal disintegration, may benumb the brain with comatose sleep. Again, the tissues of the brain may be overwhelmed with poisons introduced from without the body, and thus a condition of coma may result. Few diseases, therefore, exist without the possibility of coma as one of their consequences—a coma which, however, must not be confounded with the genuine sleep which sometimes occupies the larger part of certain stages of convalescence from acute illness. During such convalescence there is a reversion to the infantile type of nutrition, with all its need of prolonged and frequent periods of repose. Like normal sleep, the comatose condition admits of considerable variation of intensity. The patient may sometimes be partially roused, as from the coma of alcoholic intoxication, and he may finally recover complete consciousness, but very often the reverse is the fact. The coma deepens into paralysis, and death terminates the scene without the slightest manifestation of sensibility or intelligence.
Sleeping Dropsy (Maladie du Sommeil).
A singular disorder, characterized by daily paroxysms of somnolence, tending to become more and more continuous and profound until merged in fatal coma, is encountered among the negro inhabitants of the Atlantic coast of tropical Africa. Similar cases have been occasionally reported in other regions of the world, but it is among the Africans that they have been principally observed. For our knowledge of this disease we are chiefly indebted to the writings of Clark,29 an English surgeon residing at Sierra Leone, and of Guérin,30 a surgeon in the French navy, who enjoyed unusual opportunities for its study among the laborers recently brought from Africa to the island of Martinique. According to these observers, the onset of the malady is gradual, commencing with a slight frontal headache. Very soon a disposition to sleep after meals is remarked. This becomes increasingly urgent, and the paroxysms of sleep are prolonged, until at length the patient becomes continually soperose. The wakeful intervals are marked by a sluggish state of the intellectual faculties. The pulse is not accelerated, but remains full and soft. The veins of the sclerotic become turgid and the eyeball seems unusually prominent. The temperature does not increase, but rather tends to diminish its figure. The skin becomes dry and moderately cool. The tongue continues moist, and is covered with a white fur. The contents of the bowels and of the bladder are regularly voided, and the appetite persists with considerable vigor. Finally, the patient becomes completely comatose and dies quietly. Sometimes, however, the evolution of the disease is less tranquil. Epileptiform convulsions, followed by progressively deepening paroxysms of coma, interrupt its course, until a continuous muscular tremor marks the closing period. At the same time the pulse grows weaker and more frequent, until its movements cease in death. Recovery is almost unknown, though the duration of the disease often varies from three months to a year or longer. Examination of the body after death has thus far yielded very negative results: the sinuses and larger vessels of the brain are engorged with blood, but no evidence of inflammation is anywhere apparent. The other organs present no pathological alterations whatever. These observations seem to indicate that the disease originates in some form of general blood-poisoning rather than in any local inflammation or degeneration, and Clark has called attention to an enlargement of the cervical glands as a feature of the malady. According to G. H. Bachelder,31 the native physicians cure the disease by extirpation of the affected glands. He has also observed an initial lesion in the nasal mucous membrane. If this be confirmed, the malady will take its place among the forms of coma produced by septic poisoning.