506 



SLEEP 



extent into the causation of almost every form of 

 mental alienation. They arise from ximilar causes. 

 Many of the tragedies of life are due solely to the 

 prolonged ain of sleep. Insomnia or continued 

 sleeplessness mav cause death from exhaustion. 

 Sleep, on the otner hand, is a powerful curative 

 agent one that alone suffices to determine re- 

 covery. It has been well called ' the chiefest thing 

 in physic.' 



Sleeplessness is a symptom designed to subserve 

 a highly conservative purpose. It attracts atten- 

 tion in some to ailments that might otherwise 

 elude detection ; in others it maintains conscious- 

 ness requisite for the preservation of life. Sleep- 

 lessness is symptomatic of cerebral activity. This 

 may be originated and per]>eluated in divers ways. 

 It may arise from mental causes, for the mind is 

 dependent on the brain for its external manifesta- 

 tion. In mental overwork, worn-, grief, suspense, 

 &c. the int. lli-ciiial or emotional centres respec- 

 tively grow hypera-mic. At night the vaso-motor 

 nerves that dominate the arterial vessels, worn out 

 by continued inhibition, fail to moderate the supply 

 of blood to these centres, and so the man is im- 

 pelled to work and to worry, and he is prevented 

 from sleeping. In the early stages he is long in 

 falling asleep, and when he does it is to dream of 

 his work and worry. Eventually insomnia becomes 

 pronounced. Sleeplessness may depend on faulty 

 conditions in the brain itself. Cerebral cells 

 primarily or congenitally feeble, or secondarily 

 debilitated by unhealthy conditions, display their 

 enfeeblement in an incompetency to accumulate 

 nervous force. Their molecules are rearranged in 

 a preternaturally unstable manner, and they dis- 

 charge their latent energy in response to trifling 

 excitations. Such cells are designated 'explosive. 

 The peripheral cells generally participate in the 

 enfeeblement, and they and their conducting nerves 

 transmit impressions in a rapid and exaggerated 

 manner. The reaction-time is lessened. This is 

 a fruitful source of wnkefulness in neurasthenia 

 and its allied conditions. Sleeplessness from this 

 cause usually appears at the eimchs of life, and 

 iimler privations or strains. The patient gets to 

 sleep easily, but awakes in two or three hours, to 

 remain awake till five or six in the morning. The 

 awaking is often attended by distress and misery. 

 It is in this elans of ca-ses that insomnia often occurs 

 and recurs mysteriously. All neurotic diseases 

 tend to recur paroxysmally ; a bad sleep-habit 

 once acquired is liable to return from time to time 

 from very trivial causes. 



Sleeplessness may result from a blood -supply 

 altered either as regards quantity or quality. The 

 cerebral cells are very sensitive to their environ- 

 ment ; they liear excess and deprivation badly. 

 II vper.emiii and amemia of the brain are conse- 

 quently productive of cerebral unrest and of wake- 

 fiilness ; and these brain-conditions may arise from 

 diseases of the heart, lungs, anil other organs, which 

 secondarily implicate the cerebral circulation. The 

 brain textures are unfavourably affected by altera- 

 tions of vascular tension ; high tension is unfavour- 

 able to sleep. They are equally disturbed by over- 

 heated blood such as pertains to feverish states. 

 They are similarly perturbed by blood contaminated 

 by peccant matters, such as those of gout, rheuma- 

 tism, syphilis, malaria, &c. ; hence the sleep dis- 

 turbance in these diseases, and also that which 

 follows the excessive use of tobacco, alcohol, &r. 

 In the latter class the patients get to sleep 

 quickly, to awake at two or three in the morning, 

 to lie awake for some hours ; and they are often 

 awakened by slight external excitations. 



Sleeplessness may be originated by sensory 

 stimuli, which cause contraction of the peripheral 

 and dilatation of the cerebral blood-vessels, 



acceleration of the heart's action, and an increase 

 of arterial tension. They also cause dilatation of 

 tin' pupils, and change the ehanu-ter of the respira- 

 tions ; these IMTOIIU- deeper, quicker, and more 

 uUloniinal. Consciousness of external things can 

 alone be aroused by impressions transmitted to 

 the brain textures (themselves insensitive) be- 

 i-oinin^ enlivened into sensations and iileas through 

 the agency of the mind. When excitations are of 

 siillnient intensity to cause sensations wakeful- 

 ness is inevitable. Excitations may be instigated 

 in the most varied ways : they include pain of all 

 kinds, and many impressions arising out of diges- 

 tive and other derangements. They affect the 

 neurasthenic, gouty, and rheumatic unduly. 



It is evident that successful treatment depends 

 on accuracy of diagnosis. In each and every case 

 the sleeping conditions of the sufferer should be 

 attended to. Exercise and food should I* projior- 

 tii mate to the body and to the strength of diges- 

 tion. The primn* via- and the state of the skin 

 must not lie neglected. A good habit of sleep 

 should l>e assiduously cultivated. In sleeplessness 

 due to mental causes change of work should be 

 advised, that new centres may be called into opera- 

 tion, and the overwrought ones correspondingly 

 relieved. It is in these cases alone that devices 

 for getting to sleep, such as the monotonous 

 counting of figures, sheep, &c., are efficacious. 

 In bad cases the judicious use of pure hypnotics 

 is helpful ; they force the mind into oblivion. 

 Dru^s, like potassium bromide and chloral hydrate, 

 which act chiefly on the brain centres that function 

 thought, and induce sleep that closely resembles 

 natural sleep, are called pure hypnotics, in con- 

 tradistinction to many substances, as narcotic-, 

 analgesics, anodynes, soporifics, &c. , .that arrest 

 pain, diminish sensibility, and disturb in a pro- 

 nounced manner the functions of the brain and 

 nervous system. 



When wakefulness is due to neurasthenic condi- 

 tions, tonics, increased nutrition, the abandonment 

 of excesses, change of air and scene are indicated ; 

 electricity and suitable baths are useful adjuncts ; 

 hypnotics should l>e sparingly employed. Sleepless 

 ness due to hypera-mic conditions of the brain is to 

 be met by antiphlogistic treatment ; that which 

 depends on aniprnia, by tonics, &c. In both, posture 

 during sleep will repay attention. That which 

 originates from gouty, rheumatic, syphilitic, and 

 like poisons only yields to the alleviation of the 

 constitutional state. 



In sleeplessness due to sensory stimuli and pain, 

 care must be taken to ensure the removal or mitiga- 

 tion of these, that the sleep they prevent may 

 supervene. Medicines analgesics or anodynes 

 such as belladonna, should lie first selected, for 

 they act as indirect hypnotics by operating chiefly 

 on the nerve-terminals. When such remedies fail, 

 narcotics, as morphine and opium, are culled for ; 

 they not only lessen perceptivity in the brain ami 

 sensitivity in the nerve-endings, but they diminish 

 the conduct ivity of the nerves. Such wide-reaching 

 drugs have many disadvantages in such cases, but. 

 pure hypnotics are useless. Hypnotics, narcotics, 

 and sleep-inducing medicines should never be taken 

 except under medical advice. To dnig the brain 

 into quiescence without remedying the cause of the 

 cerebral activity will in many cases only aggravate 

 the evil, for they will lie complicated by a dni".- 

 taking habit 'in most instances drugs are best, 

 avoided. 



Good bibliographies of thin subject are to be found in 

 OopeUnd'i Dirt, of Mtd. (vol. iii. pt. 2, Lond. 1858) ; in 

 Did. Knrt/fl. dft Seitncei Mi'ilimlm. art. ' Snmincil' 

 (er. iii. torn. 10, 1881 ): lo in Nelo' Medical Iii,imt 

 ( Lond. 1891 ). The following may be consulted in con- 

 nection with the physiology of sleep : Cappie, Tin Intra- 



