_The appetite of sleep.--The Physiology of sleep.--Etiology of
insomnia.--Symptomatic insomnia.--Intrinsic insomnia.--Varieties
of intrinsic insomnia.--Psychic insomnia.--Emotional shock
and prolonged mental strain as causes of insomnia.--The
nervous temperament.--Symptoms of intrinsic insomnia.--Toxic
insomnia.--Insomnia from tobacco.--Alcoholic insomnia.--Insomnia from
tea or from coffee.--Gouty insomnia.--Senile insomnia._
The important subject of insomnia has engaged my attention for a long
time. In 1878 I delivered a clinical lecture on the causes and cure
of insomnia to the students of the Birmingham Medical School, in the
Queen’s Hospital, and the matter of this discourse was afterwards
further published in _The Lancet_, on June 15th and 22nd of that year.
This lecture I revised and rewrote entirely afterwards, embodying in it
some additions from my later experience in practice, and, so enlarged,
it was included in each of the two editions, of 1886 and 1891, of my
“Contributions to Practical Medicine.” In the autumn of the year 1900,
I reviewed the subject again in two clinical lectures which I gave at
my hospital, and these were issued in print in _The British Medical
Journal_, on December 1st and 8th, 1900. These last lectures, in which
I have tried to bring their subject up to a point at least abreast of
our latest knowledge in the principles and practice of medicine, I
have revised and rewritten; and I have amplified them, especially in
their therapeutic parts. So rewrought, they form the contents of the
following essay. This work, done as to the causes and cure of insomnia,
that is, done as to particular diagnostic and therapeutic efforts in
which the skill of the physician and the resources of our art are
often taxed severely, in the intricacies of a difficult, delicate,
and abstruse subject, I have tried to accomplish in the spirit of the
Baconian philosophy, in the spirit of that aphorism of Bacon which
Sydenham prefixed to his renowned “Tractatus de Podagra et Hydrope,”
namely, “Non fingendum aut excogitandum, sed inveniendum, quid Natura
faciat, aut ferat.” The result of my pleasant labours I venture now
to offer to the judgment of my profession. My lectures on insomnia
were delivered for the instruction of medical students in my clinical
class; they are further published in these pages in the hope that they
may help my medical readers in practice. In view of the conditions of
the original delivery of these utterances, I have decided, in revising
them, to preserve their colloquial style. Furthermore, in preparation
for this present publication of these lectures, (1904,) I have revised
them again, and made some additions to the therapeutics of my subject.
Sleep is a function of life, and life, in some sense, may be said to
be a function of sleep, in man, in the animals which are a little
lower than he is, in some sort in plants, in everything which lives.
The living organism which cannot sleep cannot live. For all beings
endowed with the crowning mercy of consciousness sleep is a pleasure as
well as an appetite, and it is a necessity as well as both. For these
conscious beings, strung as they are in their sentience to the most
exquisite responses in the world’s vast chorus of living harmonies,
sleep is indeed and in truth “tired nature’s sweet restorer.” For
man, at the head of such beings, and perhaps the only of them which
knows the cark of a mind’s unrepose, or the wear of “that unrest which
men miscall delight,” sleep it is indeed which smoothes out life’s
fretting creases and “knits up the ravelled sleeve of care.” That you
may become practitioners of medicine you are students in this place
of the manifold sciences of medicine in some of their chief practical
bearings, mingled with the inexorable simplicities and with the endless
intricacies of the art of healing. You are clinical students here of
that cherished art of ours, an art which is of men philanthropic and
of time perennial, as its lovely figure stands revealed in all its
subtle and splendid details, firm and broad based upon the blended
foundations of its great constituent sciences. You are students in this
hospital I love of that great art of ours in clinical medicine, in its
concrete application to individual cases of human suffering, no two of
them indeed ever quite identical, no more than are identical a tree’s
waving leaves or the billows of the rolling sea. Let us press forward
together, in all the absorbing zest of the pursuit which is ours, to
the brightest understanding which yet there may be of the intimate
nature of sleep. Let us collect, discriminate and sort the causes which
make for insomnia. Let us sift and sum up all which our sciences and
our art, our experience, and even our empiricism, of which last I am
not ashamed, have of tried adoption for its cure. In this work your
physiological training, your clinical insight, your utilitarian aim,
and even your poetic fancy and your literary culture, may all find
coördinated play, in the comprehension and in the verbal depiction of
functions and maladies which are intricate with our lives, associate
with our highest attributes, and woven in woof and warp into the very
texture of all our pains and of all our pleasures.
Favoured by your kind attention, I purpose to offer you some
considerations upon the vital function of sleep, and upon the
conditions, causes, and cure of insomnia, based upon a somewhat
long and successful experience of those subjects in practice, as a
physician. These subjects are certainly of first-rate importance in
relation to our knowledge of the science and our practice of the art
of medicine. Possibly you may scarcely be able to appreciate their
relative importance while you are, as yet, only hospital students.
Later in your careers, when you become engaged in actual practice
among the sick, and especially when you take part in what is called
private practice, often will you be confronted by the perplexities
of insomnia, and often will your pleasant duty lie in successfully
unravelling the causes of sleeplessness, on that soundest principle of
causation and of therapeutics, _cessante causâ cessat et effectus_,
and in curing insomnia by counteracting those causes, and by making
their tiresome and diresome effects to cease. I hope to be able to
show you that in such happy results the science and the art of the
physician may play a successful part. Like thirst and like hunger,
sleep is an appetite. We may define an appetite, in the words of the
philosopher Bain, to be a craving produced by the recurring wants and
necessities of our bodily or organic life.[2] An appetite, strictly
so-called, has two characteristic marks, and these marks are strikingly
characteristic of sleep; these marks are two conditions which are true
to sleep--namely, its periodic recurrence and its organic necessity. We
know that the natural course of a human life brings on sleep without
the volition of the individual willing the event. The true character
of sleep as a veritable appetite appears when it is resisted. Under
such resistance the individual person experiences what is called, in
metaphysical parlance, a “massive” form of uneasiness, discomfort, and
pain. The will of the individual, in the presence of this uneasiness,
is energetically urged to remove such discomfort and unrest, and is
urged from pain towards pleasure, is urged to obtain the gratification
of relief in what Bain called “the corresponding voluminous pleasure
of falling asleep.”[3] In this imperatively urgent volitional impulse
is the appetite of sleep. Sleep is a desire; with the further
characteristics of its organic necessity, and its periodic recurrence,
it ranks as one of our appetites.
The intimate physiology of sleep is a difficult subject, and the
difficulties of its explanations have been the topics of much
controversy, and such controversy appears to have issued from various
combinations of the teachings of observation, of experiment, and of
analogical and other reasoning, upon the phenomena of sleep. I do not
propose to follow at length the details of this part of our subject. As
a clinical teacher I must not overload your memories, but rather must
I try to make easy your mental digestion. For our practical purposes I
think we may understand that two distinct, but associated and related,
vital changes occur in sleep. The one is some intrinsic change in
those ultimate tissue elements of the brain which are concerned in
consciousness; the other and “coarser” change is a diminished supply
of blood to the brain, and especially to the blood vessels of the
cortex of that organ. The former change is at present undemonstrable,
excepting by inferential reasoning. Perhaps there is some essential
and intrinsic change in the brain, and perhaps there also is some
such change in the spinal cord and ganglionic nervous system, both
of rhythmic occurrence, and both conditions of healthy sleep.
Perhaps there is a functional depression of these parts in sleep,
and especially of the cerebral cells, arising from “an accumulation
in and around them,” as Sir Thomas Lauder Brunton puts the matter as
to the cerebral cells in sleep, of some of the products of normal
tissue waste. Perhaps for normal sleep an intrinsic change of this
kind must gain the wide distribution I have mentioned. It is likely
that there is in sleep a rhythmic change such as I have indicated, and
that this change is sustained by the physiological effects of some
of the issuants of those tissue changes, muscular and nervous, which
especially occur in the active waking state of the body.
Perhaps for our sleep we must drown our cerebral cells in a kind of
auto-intoxication with the ashes of our waking fires. We may usefully
recall this view of the subject when we use exercise and fatigue
as remedies for insomnia. The proof of the other broad change in
sleep--namely, diminished blood supply to the brain, and especially to
its cortex, rests on inference from physiological analogies, on various
observations, and on the solid basis of direct experimental evidence.
We must note, however, that the human brain, in its perceptive,
cogitative, and volitional functions, in these great divisions of
consciousness, is not the only part which sleeps. The whole living body
sleeps. The changes which the event of sleep declares certainly extend
beyond mere loss of consciousness; they extend to secretion, to the
action of the heart and blood vessels in the general circulation of the
blood, to respiration, to “reflexes,” and so extend to all the tissue
modifications, and to all the other vital activities, upon which such
manifold transitions depend. In order to complete your precognitions
of the physiology of sleep, before we pass on to consider the several
conditions of insomnia and their appropriate therapeutics, I may refer
your attention to the admirable accounts of these subjects to be
found in the text-books of Dr. Augustus Waller[4] and of Sir Michael
Foster.[5] From each of these volumes I offer a brief quotation, which
sufficiently illustrates our subject for my present purpose. On that
part of his subject which is so important to us from a therapeutical
standpoint--namely, the state of the cerebral circulation during sleep,
Dr. Waller says:
“Although there is no doubt that in coma--a pathological state similar
in some respects to physiological sleep--the cerebral vessels are
congested, the observations of Durham on the exposed cerebrum of
sleeping dogs, and of Jackson on the retinal vessels of sleeping
infants, are to the effect that vessels shrink in sleep, and we may
therefore feel reasonably assured that the sleeping brain, in common
with other resting organs, receives less blood than in its state of
activity. Moreover, Mosso’s investigations on exposed human brains
afford evidence that the organ becomes more vascular during mental
activity....”
That sleep concerns the whole body, and not the brain alone, is well
put by Sir Michael Foster. He says:
“Though the phenomena of sleep are largely confined to the central
nervous system, and especially to the cerebral hemispheres, the whole
body shares in the condition. The pulse and breathing are slower; the
intestine, the bladder, and other internal muscular mechanisms are
more or less at rest, and the secreting organs are less active, some
apparently being wholly quiescent; the secretion of mucus attending a
nasal catarrh is largely diminished during slumber, and the sleeper
on waking rubs his eyes to bring back to his conjunctiva the needed
moisture. The output of carbonic acid, and the intake of oxygen,
especially the former, is lessened; the urine is less abundant, and the
urea falls. Indeed, the whole metabolism and the dependent temperature
of the body are lowered; but we cannot say at present how far these are
the indirect results of the condition of the nervous system, or how far
they indicate a partial slumbering of the several tissues.”
You may find an interesting and instructive employment if you follow
Sir Michael Foster through his discussion of the exact state of the
body, and especially of the brain, in sleep. He points out, what is now
generally accepted, that an alteration of the cerebral circulation is
not the whole of sleep. He judges that “the essence of the condition is
rather to be sought in purely molecular changes,” and then he goes on
to suggest a resemblance between the systole and diastole of the heart
and the sleeping and waking of the brain; and then he dwells on the
various periodicities which may be observed in the activities of the
human body, and even suggests that the fundamental rhythm of the heart
may be a reflection of the mysterious cycles of the universe, while it
may yet be only the result of the inherent vibrations of the molecules
of its own proper structure.
If we exclude from our consideration the insomnia which is a
concomitant of some forms of unsoundness of mind, and which kind of
insomnia I do not propose to deal with in these lectures, you will
find that absent or imperfect sleep, inability to sleep at all, or
at a convenient time, or long enough, without the aid of drugs,
is a frequent consequence or complication of numerous and varied
conditions of disease. Etiology, as you know, is that division of the
science of medicine which has to do with the causes of disease. The
etiology of insomnia embraces the enumeration of all the causes of
the malady. These causes are numerous, and a classification of the
varieties of insomnia, upon the basis of their causal distinctions, is
somewhat difficult. Let me recommend to you, for use in practice, the
following classification of the varieties of sleeplessness under our
consideration. It is the best etiological arrangement I can form, of
the causal intricacies of our subject. It is a classification which
you will find of service clinically, when you pursue the discovery of
the particular causation of any given case of sleeplessness. Cases of
insomnia seem to divide themselves naturally into two groups, namely,
of cases of what may be called _symptomatic insomnia_, and of cases of
what may be called _intrinsic insomnia_. Symptomatic insomnia attends
a vast variety of morbid states, and is secondary to them, or is part
of them. Intrinsic insomnia, as we shall see later on, is capable of
distinct definition, and it breaks up naturally and simply into three
smaller divisions, upon a causal principle of division.
As to symptomatic insomnia, pain, if severe enough, and from
whatever cause arising; pyrexial elevation of temperature; frequent
coughing, such as often occurs in pulmonary consumption; dyspnœa,
such, for instance, as results from obstructive dilatation of the
cardiac cavities, and appears to require an extraordinary vigilance
of the nervous centres for the maintenance of the vital processes
of respiration and circulation--are clinical conditions of disease
which may prevent, shorten, or break up sleep. Such conditions are
frequently met with in medical practice, as single causes of insomnia,
or as conjoint causes of it in various combinations. In such and in
similar instances the cause of the sleeplessness is obvious, and the
consequential character of the insomnia--that is, its dependence upon
a distinct and sufficient cause--is clear. For the therapeutic control
of this kind of insomnia we may employ with success one of two curative
methods, or we may employ a judicious combination of these methods,
such combination being founded upon a skilled appreciation of the
especial needs of each individual case. We may control sleeplessness
of the kind in question either by the exhibition of remedies which
directly cause sleep, that is to say, by the administration of some
of the drugs which we know as hypnotics or soporifics, or we may
control it by the employment of measures which combat the cause of the
insomnia, by removing pain, by reducing the heat of fever, by quelling
cough, by relieving cardiac disturbance and dyspnœal discomfort, and so
on; or by using in conjunction hypnotics and remedies addressed to the
removal of the cause of the sleeplessness. In such cases of symptomatic
insomnia, as in medical practice generally, you will find that it
is convenient to your duties, and that it tends to the thoroughness
of your ministrations, if you regard the therapeutic indications
of each case from the well-known standpoints, respectively, of the
_indicatio causalis_, of the _indicatio morbi_, and of the _indicatio
symptomatica_. By a judicious combination of the remedies so suggested
you will be able to deal successfully with cases of symptomatic
insomnia. By regarding the cause of the illness with which you have
to deal as a medical attendant, by regarding the various pathological
processes which underlie the progress of that illness, and by regarding
the symptoms of that illness, by regarding these points in turn, or
together, or in various combinations, with a judicious therapeutic
intention, you may arrange your remedial efforts upon a systematic and
comprehensive basis.
Now let us consider the details of intrinsic insomnia. There is a
simple inability to sleep, which you will often be required to cure--a
kind of insomnia which may be called for the sake of simplicity,
but perhaps scarcely with strict truth, _insomnia per se_. This is
a kind of wakefulness for which we cannot discover an objective or
obvious physical cause; it is a kind of wakefulness which seems to
depend upon an inability of the brain and nervous system generally to
adapt themselves to the conditions which are necessary for sleep. We
meet with this disorder more in private than in hospital practice.
It occurs mostly in persons who are members of what are known as the
upper and upper middle classes. It occurs mostly in persons of high
mental endowment and of neurotic temperament. The malady is of extreme
importance, and, happily, if its causes be understood and judiciously
corrected and controlled, there are few affections which are more
within the sphere of curative therapeutics. I think I can succeed
in showing you how to unravel the complex causes and discover the
successful treatment of this kind of insomnia.
The causes and the course of particular instances of intrinsic insomnia
present some striking differences. You must know these differences,
and be ready to recognise them, for the knowledge of them clears up
alike the therapeutics, the successful treatment, and the prognosis of
individual cases of the malady. I have found it to be convenient in
practice to arrange the different clinical varieties of such insomnia
into groups, in which the cause of the affection is the principle of
division. These groups I call respectively the _psychic_, the _toxic_,
and the _senile_. Let us see how these divisions work out in detail.
The brain in natural sleep is, as we have seen, relatively anæmic. The
cerebral arteries, as we have seen, are more filled with blood than
during sleep, when the brain is in full waking and working activity.
When thought is active, the parts of the brain concerned are living
relatively rapidly; they are actively receiving nourishment from
the blood, and they are, too, actively ridding themselves of the
waste products of their vitality. In sound natural sleep the brain
is inactive, excepting those parts of it which are concerned in the
processes of organic life. In sleep the blood flows to and through
the brain in streams which are smaller and gentler than in the
waking state. The cells concerned in thought, volition, and feeling
are not expending energy, they are renewing it and storing it--they
are resting. Any cause, however little we may be able to trace the
details of its operation, which directly prevents a repose duly deep
of a sufficient number of those brain cells which are the organs of
conscious thought, will render sleep impossible; relative cerebral
hyperæmia is an inseparable consequence of such activity, and such
relative cerebral hyperæmia becomes a concurrent, but subordinate,
cause of insomnia. Here there is progression through a vicious circle
of two terms, in which the impulse of the morbid movement springs
from the cerebral cells. So we see that there are causes of insomnia
which we may fairly regard as acting primarily in sustaining cerebral
activity, and with it, and in consequence of it, relative cerebral
hyperæmia, which hyperæmia becomes a contributory cause of the cells
keeping awake.
In some other cases of intrinsic insomnia I think we may regard the
malady as arising primarily in a perversion of the cerebral blood
supply. Any cause which prevents the brain from becoming relatively
anæmic in a sufficient degree for sleep will produce sleeplessness. Any
ingested agent which sustains cerebral hyperæmia, or any pathological
change which impairs sufficiently the contractility of the smaller
cerebral arteries, may prevent wholly, or in part, the occurrence of
such a degree and extent of cerebral anæmia as is required for the
production of sleep, and without which sleep cannot be.
So there are causes of insomnia which act primarily in exciting and
in sustaining a relative cerebral hyperæmia, and with it, and in
consequence of it a cerebral activity which is wakeful. Here there is
again a progression through a vicious circle of two terms, but one in
which the impulse of the morbid movement springs from the cerebral
blood vessels. In conscious cerebral activity, which, as we have seen,
is a complex condition of at least dual causation, in which thought
certainly implies increased blood flow, and increased blood flow
sustains thought, perhaps it may be considered that we cannot, with
strict accuracy, allow initiative precedence to either of the causes
which are essential to the common result. In medical reasoning there
is little which is so difficult as tracing effects up to their causes,
and there is little so easy as the invention of causes for effects.
Let this caution make you wary. Take due pains in practice to analyse
the causation of each particular case of intrinsic insomnia. When you
make such analysis you will find that in some cases of sleeplessness,
as in the psychic group, undue and protracted cerebral activity is the
primary vice, and that in others, as in the toxic and senile varieties,
relative cerebral hyperæmia is the initial error, and wakeful cerebral
action its direct consequence.
Our present consideration of our subject has advanced to a point
at which we may usefully illustrate our generalizations with some
sketches of particular instances of intrinsic insomnia, as they are
met with in medical practice. In a case of psychic insomnia some
sudden emotional shock of a depressing kind, as grief at the death
of a beloved relative, will sometimes be found to have produced at
once persistent sleeplessness, which sleeplessness will only yield to
carefully directed therapeutic procedures. Again, prolonged mental
strain, in all its varied phases, is a common cause of the psychic
variety of insomnia. Our patient may be a student preparing for an
examination. For weeks, in spite of fatigue, he may have shortened his
hours for sleep that he might lengthen his time for reading; and he may
have been in the habit of keeping himself awake, when he could have
readily fallen asleep, by drinking strong tea or coffee, or by smoking
tobacco. But he could always go to sleep at once when he went to bed,
and sleep soundly, until, after some weeks of his abnormal work, with
the nearer approach of the examination bringing increased anxiety as to
the result of the ordeal, he found he began to sleep badly or almost
not to sleep at all. He grew miserable; he could not remember what
he read; he felt unfit for any exertion; and he could not face his
examination. Or, our patient may be a young professional man. He has
commenced practice, or rather to wait for practice, as a barrister, a
solicitor, a physician, or a surgeon. He begins to find that causes
or cases have not been waiting for his advent; clients or patients
are “few and far between.” For a time he manfully struggles on, his
hope and his health sustaining him; but these at last yield under the
continued pressure of new disappointments and accumulating anxieties.
He may want money; his friends will give it to him readily if he will
ask for it, but his pride prevents him. It is not a gift or a loan he
needs; he does not want to beg or to borrow money; he yearns to earn
it. And while he has been hoping and waiting, and growing sick with
the failure of his expectations, he has been working early and late
in his exacting studies--perhaps straining his powers in preparation
for some higher examination, and, it may be withal, adding the denial
of due sleep and exercise, and so he has been wasting and wearing his
psychical and physical energies, in the trust that he might thus so
skill himself the more as to secure the longed-for practice. At last
he has fairly broken down. He has grown thinner; he looks haggard; he
is filled with groundless fears; he is weighed down with the ineffable
misery of insomnia; he has headache constantly, and noises in his ears;
he thinks his memory is failing; he is dull and listless; he has been
lying awake for hours after going to bed, or, waking in the “small
hours,” he has been unable to sleep again, and when he has slept he has
had horrid dreams; and he comes to us for help because he can scarcely
sleep at all, and he is possessed by the fear that he is going mad.
His misery is urgent; it excludes all other joys and most other pains;
it is the unspeakable misery of intrinsic insomnia, the insomnia which
hangs on no solacing peg of causal pain. Here we observe particular
instances in which acute or continued mental strain is the primary
cause of the sleeplessness. Where the shock has been sudden and severe
it has been sufficient to rouse a given group of cells into persistent
activity, and to produce psychic insomnia suddenly. So produced, the
sleeplessness may become a persistent trouble, which yields only to
judicious therapeutic procedures. In other cases, and more commonly,
the insomnia has only arisen after prolonged mental strain, as that
which a student may undergo in over-reading for an examination, as
that of continued financial anxiety, or that of arduous and sustained
literary composition. Where the shock has been sudden and severe
enough, there has resulted a persistent wakeful activity. Where the
strain has been less intense, but kept up long, a monotonous group of
ideas has been maintained in exhausting recurrence. In either case it
would appear that sleeplessness did not occur until there arose from
exhaustion partial or complete vasomotor paralysis of the intra-cranial
blood vessels; it arose when the arterioles of the brain had no longer
that contractility without which sleep is impossible. In these forms
of insomnia unnatural excitation of the cerebral cells is probably the
initial fault. This point of view, we shall find just now, gives the
best working hypothesis for our treatment.
Here I must further direct your attention to the question of the causal
association of what is known as the nervous temperament with intrinsic
insomnia, and especially with this psychic variety of the malady. In
my experience, the subjects of the psychic variety of insomnia are
mostly men, and almost invariably men of the temperament which is
known in medicine as the nervous temperament. I advise you to study
temperaments. Their recognition is of much value in diagnosis, in
prognosis, and in therapeutics. A temperament may be defined as “that
individual peculiarity of physical organisation by which the manner of
acting, feeling, and thinking of every person is permanently affected,”
and the nervous temperament is marked by great sensitiveness and
activity of the nervous system.[6] We have lately been too ready to
ignore temperaments; our fathers studied them better and regarded them
more than we do. But I shall not go to any authority for a portrait
of the nervous temperament; I shall describe it to you as I judge I
have found it in a physician’s practice. I use the phrase nervous
temperament to indicate a distinct type of outward form, of manner, of
habits, of tendencies, and of personal aptitudes, physiological and
pathological. Temperaments present their various types most frequently
in men. Comparatively few women exhibit a well-marked temperament; but
when a woman is of the nervous temperament, in her the temperament is
mostly very distinct indeed. In frequent instances, two or more of the
different kinds of temperament may appear to be blended in one patient;
we have a compound of reciprocally modified temperaments.[7] A man of
distinctly nervous temperament has a quick manner; he is nearly always
in a hurry; he is apt to talk volubly and to eat quickly; if he does
not know us well, he fidgets in his hands, or legs, or face when he is
speaking; he talks abruptly, earnestly, and fluently, often splitting
up his phrases, or recalling and correcting them, and especially
modifying qualifying words, such as adverbs and adjectives, in his
anxious desire to express what he conceives to be the finest shades
of truth. A man of this temperament is apt to “overdo” everything
into which his feelings enter, and his feelings enter prominently
into most of his doings. He is apt for hobbies; and he is often a
diligent collector of curiosities. When he becomes a patient, he is
harassed about some trivial symptom; he has felt his heart beating,
and he thereupon fancies he has some deadly cardiac disease; he
thinks his memory is failing, and he forthwith imagines he is going
mad. Your elucidation of temperamental details in medical practice
will develop your clinical observation and acumen. _Ars medici est in
observationibus_ is a maxim of our schools which was a favourite one of
that excellent clinician and successful physician, the late Sir Andrew
Clark, and this proverb of ours is very true in the detection of the
signs of the nervous temperament.
A man who has suffered much from intrinsic insomnia becomes the subject
of a well-marked group of symptoms, subjective and objective. Most
of them are given by certain writers amongst the signs of cerebral
hyperæmia. It is probable that they mark a particular variety of
exhaustion of the brain, attended by more or less of an abnormal
increase of blood in the brain, and accompanied by some general
prostration of the bodily powers. These concomitants of insomnia, as
I have found them, I now describe to you. The patient has a dull and
listless look; his eyes are wanting in vivacity; the upper lids may
droop a little, and they may be slightly swollen. The complexion is
sallow. There is headache; of this there are two kinds, which either
co-exist or occur separately. The commoner variety of headache is a
dull pain felt over the whole of the vertex, together with a vague and
widespread feeling of oppression in the head; the other is a sharp,
shooting pain, which comes on suddenly, and usually in single flashes,
and which gives the idea of a knife being driven through the head from
one temple to the other. Occasionally the patient feels giddiness
momentarily; this may cause a false step, but it never lasts long
enough to give rise to staggering. The skin of the scalp, especially
near the sagittal suture, may be tender. There are noises in the ears,
in one or in both, usually of a low-pitched whistling character. This
tinnitus aurium may come on suddenly, and without apparent cause, as
when the patient is talking quietly, or it may only arise when the
patient’s attention is more closely occupied, as in writing a letter
or in casting up figures. A striking sign in the group of symptoms we
are considering is a slight impairment of hearing. The patient may be
unaware of it, but those with whom he lives have noticed that he often
asks them to repeat what they say to him because he could not quite
catch their words. He may also complain of seeing spots before his
eyes--little cobwebby black lines, _muscæ volitantes_, which come and
go and float about, or, perhaps, bright, bluish, phosphorescent-like
specks, phosphenes, which seem fixed for a moment, one before each
eye, and which only appear when he first directs his eyes towards an
object. There are usually some abnormal sensations in the skin; not
formication, such as is apt to arise in organic nervous disease, but
a sharp, transitory, and isolated prickling, as of the movement of
a single pin, which lasts only for an instant, and affects either
the limbs or the trunk, mostly the former. There may be a peculiar
twitching of muscles. This is a state of involuntary muscular movement
of which I have made original and independent observation, and of which
I know of no previous description, either oral or written. It is not
a vibratory tremor, like that of progressive muscular atrophy, nor is
it a contraction of a whole muscle, or of a group of muscles, such as
arises in true convulsion. But, while the patient is sitting still,
a considerable part of a muscle becomes the subject of rapid clonic
movements, and these are wholly independent of his volition. These
movements mostly occur in one of the lower extremities, and they are
rarely sufficient to move the position of the limb; they usually affect
the lower part of one vastus internus, and last for about a minute. The
patient can feel the movements by attending to the affected part, and
he can also feel that the muscle moves by applying his hand to it. In
such a case there is often also an unnatural and painful sensitiveness
to external impressions. The patient craves for quiet. A bright light
troubles him. Noises, the sight of moving objects, touches, as of
the hand of a friend upon his shoulder, annoy him. There is not an
increased sensitiveness to external impressions, but impressions which
are enjoyed or unnoticed in health become irritants.
In the toxic variety of intrinsic insomnia the cause of the
sleeplessness acts primarily upon the blood vessels of the brain,
giving rise to some degree of arterial hyperæmia. Cerebral vascularity,
especially the arterial supply of the cortex of the brain, is
maintained at such a height and so long by some poisonous agent that
conscious cerebral activity--that is, wakefulness--is an inevitable
consequence. Such a poison may be introduced into the body from
without, or it may be a product of diseased processes arising within
the body itself. Of course, I use the word “poison” in a restricted
sense; I do not mean something which kills, but only something which
produces abnormal manifestations in the living body. The poisons with
which we have here to do are not lethal poisons, but milder noxious
agents which produce certain distinct and abnormal manifestations.
Tobacco, alcohol, tea and coffee are the external poisons which most
frequently cause sleeplessness; internal or autogenetic poisons causing
intrinsic insomnia may be found in certain waste products of tissue
metamorphosis which accumulate in the bodies of gouty persons, or in
the bodies of persons whose kidneys are inadequate.
Possibly, as our knowledge of auto-intoxication shall increase, some
other forms of auto-intoxication may be found to cause intrinsic
insomnia, and the exact details of the causal chain may be made
out. Clinical experience has suggested to me that insomnia may
sometimes be a neurosis having its origin in toxic absorptions by
the gastro-intestinal mucous tract. Certainly intrinsic insomnia is
found in practice to come and go with constipation and the relief of
constipation. The explanation of such association of symptoms may
be a toxic one. The word “copræmia” is coming into medical use, to
signify a kind of poisoning of the blood by noxious principles derived
from retained fæces. Sallowness of the skin, what may be called fæcal
anæmia, anorexia, “biliousness,” and asthenia mark this condition, and,
in some cases, intrinsic insomnia may be added to its characteristics.
With regard to the smoking of tobacco, many a man cannot sleep either
sufficiently or soundly simply because he smokes excessively. Smokers
often find by their own experience that they sleep badly if they smoke
more than their usual quantity of tobacco, or if they smoke tobacco of
a stronger kind than that to which they are accustomed. So a smoker
who suffers from insomnia may find the cure of his sleeplessness in
the restriction of his smoking. He need not give up, nor shorten,
nor change his work, nor need he change his “surroundings”; if he
restrict his smoking, he soon sleeps well. So also as to snuff-taking
in relation to insomnia. Men of nervous temperament, or men into
whose temperament there enters a distinct and considerable blending
of the nervous element, often smoke tobacco or take snuff largely.
The consumption of tobacco by smoking or snuff-taking stimulates the
cerebral circulation. This stimulation, if pushed to undue limits,
induces cerebral vasomotor debility, with a consequent tendency to
persistent conscious thought, and so to wakefulness.
Similarly, too, the drinking of alcoholic beverages causes insomnia.
The man who drinks to commencing drunkenness mostly sleeps soundly,
if not well. But many a so-called moderate drinker knows that he
sleeps badly if he take a little more than his usual quantity of
wine, for instance, after dinner, or even his usual quantity of some
unusual wine. Alcohol, when it passes from the stomach to the blood,
flushes and dilates the smaller blood vessels, especially those of
the brain; if such a condition be maintained, sleep is disturbed or
wanting. We have all seen clinical examples of the insomnia of delirium
tremens: the patient cannot sleep because the lesser arteries of his
brain are weakened, perhaps paralysed, by alcohol, and sleepless
cerebral activity is the inevitable consequence. Far short of what
is usually called alcoholism, we often meet with cases of insomnia
in which alcohol alone is the cause of shortened, interrupted, and
disturbed sleep. The patient may pride himself upon his moderate use of
fermented stimulants, and he may be wholly ignorant of the cause of the
sleeplessness for which he consults us. We fail to find any sufficient
psychic cause for his insomnia; but if we take away or diminish his
wine or his grog, or induce him to consume it before the evening, we
find he soon begins to sleep well.
Again, the effects of the consumption of tea and coffee in causing
sleeplessness are well known. This effect is so obvious that patients
usually remedy it for themselves. As you well know, tea in the form of
an infusion and coffee in the form of an infusion or of a decoction are
used generally in civilised countries as the daily beverages of the
people. Tea leaves contain an alkaloid which has been called theine,
and coffee seeds contain an alkaloid which has been called caffeine,
and theine and caffeine have been shown to be identical; both these
leaves and these seeds contain besides certain oily principles. With
regard to tea, what may be called its physiological action appears to
depend on the joint action of its theine and of the volatile oil which
tea leaves contain. What is called green tea is produced by drying the
fresh leaves on a heated iron plate until they become shrivelled; while
black tea is manufactured by placing the leaves in heaps and allowing
them so to lie while they undergo a kind of fermentation, after
which they are dried. Green tea and black tea are powerful cerebral
stimulants, exciting the mental faculties and the cerebral circulation,
and tending to prevent sleep. Coffee, too, is a cerebral stimulant and
antisoporific. It is sometimes used in medicine for these properties,
to counteract the effects of opium and of its derivative narcotics, and
of other narcotic poisons. Some people are extremely susceptible to the
sleep-preventing effects of tea or of coffee; others, by use, do not
feel such effects, even when considerable quantities of those beverages
are consumed. In all cases of bad sleeping you should make sure that
tea or coffee is not taken to excess, neither near bedtime.
In gouty persons, quite apart from secondary wakefulness caused by
their gouty pains, there may be some intrinsic insomnia, of a kind
which is probably toxic in its causation. So, also, intrinsic insomnia
may afflict a patient whose kidneys are failing, who has renal
inadequacy. In such cases it would seem to appear that the accumulation
in the blood, in consequence of deficient excretion, of the products of
tissue-metamorphosis causes a general restlessness which disposes to
insomnia. Insomnia so caused is not severe, and it is rarely complete.
There is slumber rather than sleep. There is restlessness, perhaps
some excessive irritability to certain external impressions, short
and broken sleep, and what may be called superficial sleep, rather
than prolonged wakefulness. In this connection I may remind you that
you should observe the tension of your patient’s pulse. A patient may
complain that he sleeps very badly, that he lies in bed awake for
some hours and has great difficulty in “getting off” to sleep, that
he sleeps lightly, awakens often, and dreams much. You may find he
has a pulse of increased and high tension, with accentuation of the
aortic second sound, and with the cardiac first sound lengthened and
muffled, perhaps reduplicated, at the apex of the heart. In a case
of chronic kidney disease there may be also the physical signs which
mark the characteristic cardiac hypertrophy which accompanies chronic
contracting nephritis, and is an effect of it or a concurrent effect
of a remoter pathological cause. Insomnia in such cases is likely to
be due to the maintenance of a state of high tension in the cerebral
arteries, the tension in them not falling sufficiently for prolonged,
deep, and dreamless sleep. In practice you will find the causation of
many of these cases of insomnia, and you will find sound therapeutic
indications, too, in the signs of the gouty diathesis or in the
discovery of albuminuria. Here I must give you a caution, which you
may usefully remember in practice, namely, never accept a patient’s
statement that he is gouty without the establishment by your own
observation of facts sufficient for such a diagnosis. Insomnia which
is purely nervous may be wrongly attributed to gout, and depletory
measures of treatment may be adopted when corroborants are really
indicated. The diagnosis of gout is a diagnosis for which patients
often have a tender affection, and I am afraid it is a diagnosis which
is often erroneously made, and wrongly handed on through a succession
of credulous advisers. Do not fall into the frequent error of making
a diagnosis of gout because a specimen of your patient’s urine which
is brought to you shows a deposit which to the naked eye is like unto
grains of cayenne pepper, and which deposit is made up of aggregated
crystals of uric acid. Such a sediment may be only an innocent result
of an acid fermentation, such as frequently arises in urine after its
voidance, without any pathological significance whatsoever.
As I have already told you, there is a senile form of intrinsic
insomnia. Remember that senility is a term of which the primary
absoluteness is largely modified in particular cases by relative
qualifications. Some persons are senile early, others only later. With
much truth it may be said that a person is not as old as his years,
at least in a pathological sense, but as old as his arteries. You
may perhaps have observed amongst your friends that an exaggerated
appreciation of the merits and value of early rising often increases
as age advances. The broken and short sleep of many old persons is
mainly, if not entirely, the result of senile degeneration of the
smaller cerebral arteries. In such degeneration those blood vessels are
less elastic and less contractile than in health, and a degenerative
weakening of their walls often leads to their permanent dilatation;
the smaller cerebral arteries, so changed by a pathological process,
are physically unable, by reason of a diminution of their resilience
and of their contractility, to adapt themselves normally to such a
condition of relative arterial anæmia as is of the essence of healthy
sleep. The tendency of this condition of the blood vessels of the
brain to prevent, to lessen, or to interrupt sleep is probably to a
great extent counteracted, in many cases, by the cardiac feebleness
which so frequently, and which, within certain limits, it may be said
fortunately, co-exists with senile vascular changes. When arteries are
brittle, cardiac failure, within certain limits, may be regarded as a
conservative lesion, in the sense that such failure tends to save from
arterial rupture and the consequences of cerebral hemorrhage.