Part 6

_The liver_ diminishes in size and weight by about one half; atrophy of considerable areas may expose the vessels and ducts on the surface of the organ. Boyd’s tables show a difference of 18 oz. between the weights in persons in the decade 20–30 and in those over 80. Microscopically atrophy of the lobules and of the cells in the centres of the lobules have been described (Luciani[152]), but the latter change is not constant, for in a woman of 93 Salimbeni and Gery[153] definitely noted that the cells were not atrophied. That such atrophy of the liver cells is pathological is perhaps supported by D. Symmers’s[154] observation that in the pancreas of such cases the islands of Langerhans may show moderate enlargement, as if to compensate for failure of the glycogenic function of the liver. Pigmentation of the cells by a lipochrome is excessive, and the name brown atrophy has been applied to the condition which is seen in the other viscera of the old.

_The lungs_ become smaller, lighter, and the elastic tissue degenerates; this is atrophous emphysema, and the chest capacity diminishes. Roussy and Leroux[155] found that these lungs commonly show endarteritis obliterans and fibrosis, conditions which favour infarction, infection, and the terminal bronchopneumonia to which the aged are so prone.

_The voluntary muscles_, according to Durante,[156] contain many fibres with large globules of fat; but Jewesbury and Topley,[157] who describe coarse fat globules mingled with brown pigment in the immediate neighbourhood of the muscle nuclei in 50 per cent of cases of various kinds, and almost constantly in old subjects, regard this condition as independent of true fatty degeneration, and are doubtful if it has any pathological significance. Excessive fatty and fibrotic change is found in cases of senile paraplegia without any lesion in the spinal cord or brain.

_Heart._--Some difference of opinion exists as to the condition of the heart; Parkes Weber[158] says that the only true senile change is diminution in size and weight; this as it is worded is no doubt correct; but pure atrophy is less rare in the heart than in most parts of the senile body. Charcot[159] indeed stated that it does not atrophy in old age, but preserves the dimensions of middle life. The heart may even hypertrophy in old people; this is pathological; Councilman[160] found it in 248, or 43 per cent, of 580 persons over 60 years of age, and could not refer it to aortic or renal arteriosclerosis or to the diminished capillary area in the skin; but the average blood pressure 158 systolic/88 diastolic of the cases with cardiac hypertrophy was higher than that 130/78 of the others.

Fatty degeneration of the myocardium is very frequent; Charcot stated that at the Salpêtrière it was almost constant in old women, but according to Councilman there is no clear evidence that it produces permanent injury or functional insufficiency; he noted some fibrosis in 15 per cent of his cases. Atrophy of the epicardial fat--serous atrophy--is common, and increase of the so-called lipochrome pigment in the muscular fibres which become smaller and fewer--brown atrophy--is frequent as it is in the other organs in old age.

Chronic valvulitis and subendocardial fibrosis are, like arteriosclerosis, common morbid changes.

_Arteriosclerosis_, contrary to what has been stated by Huchard and others, is not constant in a considerable degree in old people, and therefore cannot, as Demange and others considered, be regarded as the cause of the atrophic changes seen in old age. Arteriosclerosis is due to several factors, namely, infection and intoxication of various kinds and to damage caused by long-continued high arterial blood pressure. The primary changes are degeneration and weakness, however brought about, in the middle coat. Ophülz[161] has recently discussed the question whether the degeneration is entirely or largely a senile change; if it were so, the curve of the incidence of arterial sclerosis would begin gradually about the age of 40 years, so as to include premature cases, and rise slowly until the age of 55 years, when there would be a sudden increase to 80 or 90 per cent, and at the age of 70 it would be improbable that any one would be free from well-marked arteriosclerosis. He found that the curve of incidence was very different from this; beginning much earlier its rise is gradual all the way without any sudden increase, and indeed seems, if anything, to be retarded by old age. Old persons may have practically healthy arteries, so, although arteriosclerosis may undoubtedly produce atrophy and senile changes in the tissues and organs by diminishing the blood supply, for example in the case of the red granular kidney, it cannot be regarded as the causal factor in healthy old age.

The primary calcification of the middle coat, sometimes called Mönckeberg’s sclerosis, which leads to the formation of regular rings in the degenerated muscular media and the “pipe-stem” arteries associated with senile gangrene, may be independent of, or combined with, endarterial sclerosis. It follows fatty degeneration of the media, which is the commonest form of medial degeneration in the aged, and specially picks out the elastic fibres.[162] The femoral, tibial, radial arteries and the aorta are most often affected. It is difficult to estimate its incidence, but that it is not very common, at any rate in a high degree, seems probable from the comparative infrequency of its detection in _x_-ray examinations of the lower limbs in old people. It would be natural to associate its occurrence with the rarefaction of bone that goes on in advanced life, and so to consider it as in some respects different from the secondary calcification in endarteritic sclerosis; in answer to an enquiry Professor W. T. Councilman of Harvard kindly wrote to me that he did not regard calcification as characteristic of any particular type of arterial disease, lime salts being in certain cases more easily deposited in any pre-existing lesions. Klotz describes fatty and calcareous change in the middle third of the media of the aorta as quite characteristic of senescence.

Cazalis’s famous aphorism “man is as old as his arteries” is true in so far that the state of the arteries is a good index of the general condition, for they are extremely prone to suffer as the result of infection, toxaemia, and strain; strictly speaking, therefore, the state of the arteries is not so much an index of the individual’s age as of his adventures.

Phlebosclerosis, analogous to arteriosclerosis, is common, and dilatation, often due to stagnation and lack of the normal _vis a tergo_, of the veins is a familiar change in the aged.

The capillary area is diminished in the skin and elsewhere, but not uncommonly there are dilated venules or angiomas on the skin; the latter, commoner on the trunk and upper limbs and in men, were formerly known as “de Morgan’s spots” and were thought to accompany cancer, but the association is only due to a rough correspondence of their age incidence.

_The blood_ of healthy octogenarians may not show any departure from that of the earlier periods of life as regards the number of the reds and the amount of haemoglobin (Hansen[163]), though some have described a secondary anaemia. Thus in a female centenarian Macnaughton[164] found slight secondary anaemia with a normal number of leucocytes, the differential count showing a relative lymphocytosis. The red bone marrow diminishes, its place being taken by fat cells.

_The lymphoid tissues_ undergo atrophy all over the body including the leucoblastic bone marrow, but though it does not appear that the blood shows any definite change in the leucocyte count it is tempting to correlate the diminution of resistance to acute infections, such as pneumonia and erysipelas, with the atrophy of the lymphoid tissue. The alimentary canal often shows lymphoid atrophy in a high degree, but two normal Peyer’s patches were present in a man reputed to be 106 years old (G. Rolleston[165]).

_The spleen_, in common with the lymphoid tissues elsewhere, shows atrophy, sometimes to an extreme degree, so that instead of the normal weight of 7 oz. it weighs a few drams only. The capsule is thrown into folds, and is somewhat opaque; from atrophy of the pulp and Malpighian corpuscles the vessels and fibrous trabeculae become prominent. _The thymus_, contrary to the general opinion that it undergoes involution long before puberty, has been found by Hammar[166] to increase in size up to puberty when involution begins, but proceeds so gradually that even in old age it is functional.

The _thyroid_, unless there is cystic change, is smaller than natural; thus out of 40 thyroid glands from individuals between the ages of six months and 77 years the smallest was in a woman aged 77 (Hale-White[167]). In colour it is darkish brown and on section rather dry. Dr. Donaldson, Lecturer on Pathology at St. George’s Hospital, has specially examined 19 thyroid glands from patients between the ages of 57 and 93; of these five showed cystic change; they all showed increase in the amount of fibrous tissue which was progressive with age, and in the absence of cystic change the size of the vesicles and amount of colloid material were diminished.

_The Parathyroids._--From examination of a number of specimens Dr. Donaldson finds that in old people the parathyroids appear to be free from retrogressive changes, but he cautiously requires further experience before concluding that this is the rule.

The _adrenals_ show involutionary atrophy in common with the body as a whole, but sometimes the cortex is enlarged from excess of lipoids, usually associated with considerable atheroma, and may also show adenomas. As the increase in size of the adrenals is cortical its relation to high blood pressure, if any, is that of a remote result, namely from arteriosclerosis, and not causal as has been suggested. According to G. M. Findlay[168] the amount of lipochrome in the cells of the adrenals increases with advancing years and is accompanied by the appearance of melanin in their nuclei.

The _kidneys_ show definite atrophy, and Councilman,[169] who has recently made a study of them in 580 persons over 60 years of age, calls the condition chronic atrophic nephropathy. The fat in the renal pelvis is more obvious than usual, the capsules are slightly thickened and occasionally but by no means always adherent, the surface finely rough and sometimes showing small cysts, but the large and irregular depressions characteristic of a granular kidney are not common. There are, however, areas of fibrosis, and the cortex and medulla are equally atrophied. Microscopically some glomeruli are fibroid, others smaller than natural. In three-fourths of his cases the renal vessels showed arteriosclerosis due to primary atrophy of the media with compensatory hypertrophy of the intima; but Councilman gives reasons for hesitation in accepting the obvious conclusion that the senile kidney is the result of the vascular change.

_The prostate_ shows some degrees of enlargement after the age of fifty in the vast majority of men, but in only a percentage of these are there symptoms referable to it. Kenneth Walker[170] finds that the maximum size is reached at the age of 60 and that from then onwards there is a slow diminution in size; among 340 men between 80 and 90 there were 11, or 3·2 per cent, and among 92 men between 90 and 100 one only with hypertrophy of the prostate (Humphry). The causation of prostatic hypertrophy has been much discussed; that its association with arteriosclerosis (Launois[171]) is anything more than a coincidence, the two conditions being common in the later years of life, seems improbable; Walker found the two associated in 10 per cent, and he regards the change as part of a general enlargement and thickening of the peri-urethral, sub-cervical, and sub-trigonal glands, and, as the interstitial cells in the testes become fewer and degenerated, he considers that the prostatic enlargement is possibly a degeneration connected with a disturbance of the endocrine balance. Nemenow[172] argued that prostatic enlargement was due to proliferation of the interstitial cells following senile atrophy of the seminal tubules of the testes, but K. Walker found that in prostatic enlargement the interstitial cells are diminished rather than increased in number. An interesting parallel has been drawn between the involutionary changes in the mamma and the prostate, and it is probable that the same underlying factor is at work in both (Walker, Paul). Hertoghe[173] regarded some cases of prostatic hypertrophy as due to senile dysthyroidism, and recently benefit has been reported from thyroid medication and also from prostatic extract. Dr. Leonard Williams has told me of cases, as yet unpublished, showing well-marked relief of symptoms and diminution in the size of prostatic enlargement after doses of thyroid extract (½ grain once) and colloidal iodine (one dram three times) daily. The prostatic plexus of veins is often enlarged and may contain phleboliths.

The _testes_ become smaller, softer, and commonly show some atrophy of the tubules with disappearance of the epithelial lining and thickening of the basement membrane; but the testes of old men may be free from any such change and the spermatozoa in the vesiculae seminales may be active. According to K. Walker the interstitial cells gradually diminish in number from the age of 30, but they may be present in men over 80, and Mott[174] remarks that their persistence may account for an increased and perverted sexual appetite, due to stimulation of the desire without the power to perform the sexual act.

The _penis_ becomes smaller, often retracted, the _glans_ harder, and the _scrotum_ smaller.

The _ovaries_ become shrivelled and fibrotic; the ova disappear or small cysts may form. It is difficult to find statements about the presence or absence of interstitial cells in the senile ovary. Professor Turnbull has kindly informed me that in old women an occasional cell which might be, but is not certainly, an interstitial cell is visible, and that if they are interstitial cells their number must be small and their development poor.

The _uterus_ becomes small, its cavity round, and the cervical canal may be obliterated. The _external genitals_ atrophy.

The _mamma_ in women shows involution changes and when excessive (cystic disease) these may, as Paul[175] has pointed out, be compared with prostatic enlargement in the male.

VII

PHYSIOLOGY OF OLD AGE

The basis of the physiology of old age is progressive diminution in functional activity, which corresponds to the characteristic structural atrophy of the organs and tissues. Thus the lowered functional activity of its glands is manifest in the dry skin; according to Haneborg[176] there is usually a fall in the percentage of hydrochloric acid in the gastric juice, though Bell[177] disputes this. The lessened amount of mucus from the intestine probably plays some part in the tendency to constipation. Other evidences of lowered metabolic rate are seen in the diminished efficiency of the acid-base equilibrium (MacNider[178]) and the increased degree of urea-nitrogen in the blood, as shown in 50 per cent of 41 persons between 70 and 88 years of age examined by Rappleye.[179]

_Temperature._--Before the era of the clinical thermometer it was supposed that the body temperature of the aged was below normal. This belief was part of the ancient view that the cause of old age was exhaustion by the natural heat of the radical moisture which, like lamp oil, supported the innate heat and with the passage of years could not be supplied as perfectly as before; as a result of this loss of radical moisture the body was thought gradually to dry and cool.[180] But it is now known that the internal temperature is almost constant at all ages, and Charcot proved that the only real difference is that the axillary is lower than the rectal reading; this is due to the diminished vascularity of the skin and to the corresponding fall in the loss of heat, which again may be correlated with the lower metabolic rate of old age. Aub and Dubois’[181] observations on six men between 77 and 83 years of age, mainly with arteriosclerosis, granular kidney, and emphysema, showed that the basal metabolism was 12 per cent below the average for men between 20 and 50.

Blunting of sensibility to pain is a beneficent process, suggesting that with the gradual process of involution and approach to a physiological death the need for the warning normally conveyed by symptoms is no longer needed. This is connected with the simultaneous atrophy of the nervous tissues which look after the conduction, perception, and reference of pain. The latency of disease, as shown by an absence of the characteristic symptoms observed in earlier adult life, is often remarkable in the aged. Thus death may occur suddenly from extensive but entirely unsuspected pneumonia; the passage of biliary or urinary calculi may be unaccompanied by the violent colic of these events in ordinary cases, and extensive malignant disease may exist without any definite localizing discomfort. This failure in the power to react is also shown in fevers and infections (_vide_ p. 142).

Cutaneous sensation is little affected, and indeed the aged are very sensitive to cold. Taste and smell are impaired, and presbyopia is due to changes in the crystalline lens. The pupils are contracted and the iris sluggish. From weakness of the orbicularis palpebrarum muscle ectropion and epiphora may noticeably change the facial appearance. With advancing years hearing commonly becomes less acute from various causes, and after 60 there is a successive decrease in the number of persons with normal hearing. According to Albert Gray[182] there is probably a characteristic form of deafness for the higher notes of Galton’s whistle in all old people, even when for all practical purposes there is no obvious defect or tinnitus; this he regards as due to progressive atrophy of the ligamentum spirale. Chronic progressive labyrinthine deafness, due to atrophy of the auditory nerve and fibrosis of the ductus cochleariae, is the most common condition in persons over 60. Fixation of the stapes frequently causes deafness, and the sequels of middle-ear disease accumulate with advancing years. Gouty eczema of the external auditory meatus and collections of wax may seriously interfere with hearing. Tinnitus in the elderly is commonly associated with high blood pressure and arteriosclerosis.

_Appetite_ for food is sometimes capricious; old people may eat excessively, possibly because the pleasures of the table are the only ones to which they feel equal.

_Muscular movement_ is slow and somewhat uncertain, and the reflexes are diminished except in the presence of sclerosis of the spinal cord. According to Moebius the _knee-jerk_ is often absent in normal old persons, but Sternberg, by employing methods of reinforcement not available in Moebius’ time, found that it was invariably present even in the tenth decade.

The _sleep_ of the aged is less continuous, and from interruptions often appears to them to be much less than it really is. There is often a tendency to irregularity, bad and good nights alternating. But too much attention to disturbed sleep in the aged must be avoided, as hypnotics are inadvisable, and it has been urged by Sir Hermann Weber and others that too much sleep is more harmful than too little.

In old age the _mental condition_ varies in different individuals according to their previous character and their present physical state. Freedom from sexual and other perturbations often renders the minds of old people calm, tolerant, less susceptible to disappointed ambition, and philosophic when the part of spectator has been accepted in place of that of actor in life’s drama. In what may be regarded as normal old age psychical activity diminishes; not only do initiative, elasticity, and originality fail, but new ideas and fresh lines of thought are assimilated with difficulty; hence the old are commonly conservative and _laudatores temporis acti_. Mental fatigue occurs more readily and the power of concentration and attention is impaired so that the old may appear deaf; the mind begins to show disintegration and a return to the primitive condition in which each act demands individual care; it has indeed been said that old age is nothing but progressive fatigue. A less agile memory for names is commonly one of the early symptoms of senescence, and long precedes the characteristic loss of memory for recent events while that for the remote past remains, as if the nerve cells were photographic plates which in course of time have all become occupied with impressions. With commencing failure of memory there is often a tendency to make the same remark or tell the same story repeatedly, to mislay things, and unconsciously to become careless about personal appearance and habits. As a kind of protest against the inevitable there may, in the early stage of old age, be a tendency to ape the young and to conceal the true age; thus a man may remove the date of his birth from _Who’s Who_ and books of reference, and a mother may delay the “coming-out” of her daughter. On the other hand, at a later stage there may be the opposite desire to appear a wonderful prodigy of senescence. The old are notoriously less subject to feel the loss of relatives and friends by death; they become more self-centred; this may be because retirement from active work switches their minds on to their own feelings, and possibly in part depends on loss of touch with the external world, resulting from failure of the sense organs. This when exaggerated develops into selfish dependence and demands on relatives. Senile vanity is not uncommon, and Eden Phillpotts[183] remarks that all old people love to be in the centre of the stage, one of the pathetic things in life being that they are seldom allowed to be there. The ego-centric frame of mind may lead to hypochondriasis with fads and meticulous attention to details of personal health and to experiments in diet and patent medicines. Loss of control, due to failure of the higher centres, engenders restlessness, garrulity, emotional weakness, and peevishness. There may be considerable variation in the moods, so that the deep depression of one day may vanish the next, and irritability and apathy may alternate.

Regression, which closely corresponds to the “devolution” of Hughlings Jackson, who argued that in disease the organism tends to retrace the steps of its development, accounts for the phenomena of “the second childhood.” Thus the old are prone to nervous apprehension, and liable to suggestion and to hysteria which Rivers[184] defined as a protective mechanism representing a recrudescence of the reaction to danger in an early stage of animal development. Will power, like their gait, becomes hesitant and uncertain. This devolutionary change progresses partially and not universally; memory for personal names, as mentioned above, is often the first to fail, because, like the mathematical faculty, it has from the attendant difficulty a high place in the order of mental processes; hence forgetfulness of personal names is a criterion of psychical fatigue and neurasthenia (Dupuis[185]).