Table Of ContentBY THE SAME AUTHOR
HANDBOOK OF PHYSIOLOGY
HALLIBURTON AND MCDOWALL
An up-to-date text-book for students and
practitioners of medicine. 19th edition.
Completely revised.
THE SCIENCE OF SIGNS
AND SYMPTOMS
IN RELATION TO MODERN DIAGNOSIS
AND TREATMENT
A TEXTBOOK FOR GENERAL PRACTITIONERS
OF MEDICINE
BY
ROBERT JOHN STEWART McDOWALL
D.Sc, M.B., F.R.C.P. (Edin.)
Professor of Physiology, King's College, University of London
WITH THE ASSISTANCE OF
HUGH ALEXANDER DUNLOP
M.D., M.R.C.P.
Physician to the Metropolitan and Royal Waterloo Hospitals
Late Medical Registrar, Westminster Hospital
THIRD EDITLON
LONDON
WILLIAM HEINEMANN
(MEDICAL BOOKS) LIMITED
1934
Printed in Great Britain
PREFACE TO THIRD EDITION
WHEN I first wrote this book I did so because it seemed there
was a need for such a volume, but I had scarcely anticipated that
within two years I should be asked to prepare two more editions.
Once again I express my gratitude to reviewers who must have
done much to contribute to its success. Fortunately most of
them were aware of the limit of human capacity and of the
difficulty of collecting material. With the assistance of my
clinical colleague, Dr. Hugh Dunlop, I have been able to extend
the scale to many points hitherto omitted. Many chapters have
also been remodelled. This has necessitated a slight increase in
size, but makes the book much more complete.
The book was originally intended for practitioners and this end
is still kept in view, but it appears that the book has had an appeal
to teachers and to students preparing for higher examinations.
I trust, however, that in the years to come it will help to impress
those responsible for medical curricula that there exists a science
of Symptomatology as clearly defined and as valuable as its sister
sciences Pharmacology and Pathology in its present accepted
sense. It may be remarked that the word " symptom," although
commonly used in a subjective sense, may from its derivation be
held to include objective signs.
In its preparation the book owes much to the publishers, who
have done all possible to assist me. In addition to those men
tioned in previous editions, the following have been good enough
to give me much advice and help : Dr. C. R. Boland, Professor
Clarke Kennedy, Dr. J. W. Linnell, Dr. W. Robson, and Professor
0. de Wesselow. To those I owe my best thanks.
The Table on p. 110 is reprinted from Dr. Traquair's paper on
" Fields of Vision in Intracranial Lesions " (British Medical
Journal, August 5th, 1933, p. 230) with permission.
EXTRACT FROM PREFACE TO
SECOND EDITION
IN addition to those previously thanked, I am specially grateful
in this respect to Sir Farquhar Buzzard, Professor Stanley
Davidson, Dr. Geoffrey Evans, Professor Gulland, Professor Hay,
Dr. A. F. Hurst and Dr. K. D. Wilkinson. Many others, espe
cially Dr. A. E. Barclay, Professor Morison, and Dr. H. T. Flint,
have answered specific questions on special points. It has,
unfortunately, not been possible for me to incorporate the views
of all because of consideration of space and of the debatable
nature of some of the points. I should, however, like to take this
opportunity of asking readers not to hesitate ta draw my attention
to matters which they think ought to be inserted, for it is obviously
impossible for any single person to have a full knowledge of
modern Medicine, Surgery, Pathology, and Physiology. It should
perhaps be said that the book is not intended to give every disease
in which any symptom occurs, but rather to give examples of
diseases in relation to symptom production.
vi
PREFACE TO FIRST EDITION
SOME years ago it was my fortune to take an active part in the
teaching of clinical medicine, and during that period it was
firmly impressed upon me that if medicine and surgery are to
progress as they ought some definite attempt should be made to
bring clinical work and the sciences closer together. This iö done
spasmodically by some clinical teachers, but for the most part
they have not time to teach how signs and symptoms are pro
duced as well as the essentials of diagnosis and treatment. This
book is intended to fill the gap, but in such a way that it will
be understood by those who have long since forgotten their
sciences, but who wish a more intimate knowledge of the more
scientific side of medicine.
The book is based on an earlier work, " Clinical Physiology/ '
of which two editions, one British and one American, have
become exhausted. The appreciation which it has received
suggested that the scope of the book might be extended, but with
the extension a new title was necessary to indicate more clearly
the aim of the book.
It is difficult to survey such a wide and ever-enlarging field
and it is almost inevitable that the book contains many state
ments which workers in special fields may criticise, but their
criticism will I trust be outweighed by the many kind letters
I have received from general practitioners quite unknown to me
who found that " Clinical Physiology " had added greatly to the
interest of their daily toil.
The volume generally adheres to the title, but as there are
many other matters of great interest and importance which are
relevant, these have been included at suitable places.
In the preparation of the book I owe much to many friends.
In addition to those previously thanked I have received much
vii
PREFACE TO FIRST EDITION
personal assistance from Professor Hartridge and Dr. E. P.
Poulton. The reading of the proofs was kindly undertaken in
part by Dr. Marjory Gillespie and Dr. Hewitt, and systematically
by Dr. G. A. Clark, Miss A. Shore, and Margaret Watson, whose
suggestions and corrections have been invaluable. The last
named also prepared the work for the press.
LIST OF ILLUSTRATIONS
PIQ. PAGE
1. THE EFFERENTP ATHSO F THE CENTRAL NERVOUSS YSTEM
Facing 17
2. DIAGRAMO F THE INTERNAL CAPSULE , * 18
3. DIAGRAMIN DICATTIHNEG C HIEF FUNCTIOONF ST HE CEREBRAL
CORTEX . . 19
4. DIAGRAMOF CUTANEOUS AREASO F POSTERIOR NERVER OOTS. 33
3. THE AFFERENT PATHS OF THE CENTRAL NERVOUSS YSTEM
Pacing 39
6. THE NERVE PATHSRE LATED TO SIGHT . . Facing 108
7. DIAGRAMOF THE EAR . . 120
8. COMBINED POLYGRAPHIACN D ELECTROCARDIOGRAPHIC
RECORDS. . Facing 152
.
9. KORMALA ND ABNORMABLL OODC ELLS . Facing 189
. .
10. ABNORMABLL OODC ELLS Facing 193
.
11. DIALRAMOF THE AUTONOMICN ERVOUSS YSTEM , 454
xv
THE SCIENCE OF SIGNS
AND SYMPTOMS
CHAPTER I
LIFE AS A CLINICAL ENTITY
You never know what life is till you die.
BROWNING.
LIFE is the most treasured possession of man. Its prolongation
and amelioration must ever be the great purpose of the clinician.
Its origin and nature are the greatest problems of medical science.
Life may be identified with the power of doing something.
Before the full power of doing external work is attained, the
human organism passes through a series of stages during which
this power of doing something is very limited. Although these
stages merge into each other, some of them are of more interest
than others to the clinician. At first the organism is capable
only of growth, but as it becomes differentiated its capacity for
work develops. Of special interest is the commencement of
movement in muscle, particularly that of the heart, whose beat
may be appreciated at the fourth month of intra-uterine life.
At this stage, however, the maternal blood supplies all that is
required for growth and movement, and takes away metabolic
products of the developing organism, whose organs, for the most
part, are incapable of such function. At the sixth month the
foetus is legally viable, for it is then capable under suitable
conditions of maintaining a separate existence, though in practice
this capability is not attained until the seventh month. This
stage is so important medico-legally that it may be well to
summarize the evidence that it has been reached. The eyelids
are separated ; the pupillary membrane is disappearing ; the
face only is free from lanugo ; the nails have not quite grown to
the ends of the fingers ; and there is no cartilage in the ears and
nose. From the sixth month onwards the foetus is increasingly
S.S. 1 B
2 THE SCIENCE OF SIGNS AND SYMPTOMS
capable of separate existence, and, by the ninth month, it has
attained full foetal maturity.
At birth, the fœtus, now called a child, becomes responsible
for its own digestion, metabolism, and excretion of waste products.
In particular, it is responsible for its own respiration, and evidence
of air having entered the lungs is of great medico-legal significance
as indicating that the child has been born alive. There are,
however, certain fallacies in this sign, but for these reference
must be made to a medico-legal textbook. In England, if the
child is seen to breathe, move its limbs, heard to cry, or if an artery
or the heart is seen to pulsate, the child is considered to be alive.
In Scotland, evidence of respiration or crying is required. In
France, viability is also required. It is a curious anomaly in
England, that a child born alive, say, at the fifth month, though
it may not be viable, is still capable of inheriting property,
and legally transmitting it.
Life, as a clinical entity, must be considered to centre in the
circulation and respiration ; and in lower animals, such as the
frog, the heart is capable of performing external work quite
independently of any other organ. It will continue to beat for a
considerable period provided it is not allowed to become dry,
and its temperature remains that at which metabolism can go on.
We believe that this property of contraction is inherent in heart
muscle itself, which is also peculiar in that it contains large stores
of energy, and, in the frog, is able to obtain oxygen from the air.
The mammalian heart, however, is more specialized. Though
it has the same inherent property to beat, it will not do so except
under certain conditions. It is essential that it should be supplied,
via its coronary arteries, with an isotonic fluid at body tempera
ture and at a pressure comparable with that in its aorta. The
fluid must also be well oxygenated and neutral, or very slightly
alkaline in reaction. It is a fact of scientific interest, that the
mere raising of pressure in the coronary arteries is sufficient to
start the heart-beat, although the other factors mentioned are
essential for longer action. For still more prolonged action,
nourishment and hormones to assist metabolism are necessary.
A consideration of the above gives an indication of the essentials
of mammalian life in its simplest form, and what conditions must
be maintained if it is to continue even for a short period. If we
apply these facts to the intact animal, we have, for the essentials
of life (as a clinical entity) : heart action, supported by body
heat ; blood pressure ; adequate respiration ; and the maintenance
