912

sone) to raise a warning voice and to emphasise that it isessential to continue, along with newer forms of treat-ment, what a group of workers at the Mayo Clinic havecalled a basic " conservative program, including physicalmedicine, adequate rest, diet, simple analgesics and othergeneral supportive measures." 1The comparison made by this group between 34

patients treated with a basic regime including physicalmedicine and 54 patients treated with cortisone inaddition is of great topical interest, particularly so sinceit emanates from the Mayo Clinic. They found that 85%of the cortisone group showed objective improvement,as against 80% of those treated similarly but withoutcortisone-a difference which on testing statistically forsignificance is found to be negligible. The groups weresimilar in most respects, but the cortisone group containeda larger proportion of chronic cases (63% with a durationof 5 years or more, compared with 47% in the controlgroup), and it is stated that this type of case shows lessimprovement with conservative treatment than cases

in which symptoms have been present for a lesser time.Even in this type of long-standing disease, however,the difference between the cortisone-treated and controlgroup does not reach significant levels : the observeddifference in the numbers improved in the two treatmentgroups (62% and 85%) gives a value for x.2 of 2-1 andmight occur by chance alone in more than 1 out of 10therapeutic trials if the treatments were absolutely thesame. The use of such statistical checks would improvea lot of the papers appearing on this subject, but manyaspects of treatment cannot be put into figures. Thosewho have had some experience in the use of cortisonein cases of rheumatoid arthritis will agree with theauthors’ modest statement that " Cortisone is an

important adjuvant to the treatment programme of

many patients with active rheumatoid arthritis."

1. Martin, G. M., Polley, H. F., Anderson, T. P. J. Amer. med.Ass. 1952, 148, 525.

2. Cooper, I. S., Kernohan, J. W., Craig, W. McK. Arch. Neurol.Psychiat. 1952, 67, 269.

TUMOURS OF THE MEDULLA OBLONGATA

- INTRINSIC tumours of the medulla are uncommon,but a report from the Mayo Clinic reviews 15 casesin which the tumour was confined to the medulla or inwhich extension into the pons or spinal cord was minimal.In 14 of these cases the extent of the tumour was verifiedat necropsy, and in the 15th the site of the tumour wasconfirmed at operation. Despite the crowding of cranialnerve nuclei and ascending and descending fibre tractsin the small space of the medulla, the clinical pictureof these tumours is far from uniform and there may be

very few neurological signs. The reason is the relativeresistance of axis-cylinders and ganglion cells to pressurefrom an infiltrating glioma. Pathologically 11 of thetumours were gliomas—7 astrocytomas, 2 glioblastomas,1 ependymoma, and 1 oligodendroglioma-while the

remaining 4 were hoemangio-endothelioinas. The com-mon early symptoms were : ataxia, partly of cerebellarorigin and partly due to disturbance of proprioceptionfrom involvement of the cuneate and gracile nuclei ;headache, chiefly in the occipital region ; and weaknessof the limbs. This weakness was due to pyramidaltract involvement, but in contrast to gliomas of the pons,where pyramidal involvement is usual, it was presentin only 9 of the medullary tumours-probably becausethe pyramidal fibres are more diffuse and widespreadin the pons than in the medulla, where they are groupedon the ventral aspect, and the majority of the tumoursoccur in the dorsal two-thirds. Cranial nerve dysfunctionwas found in 7 of the patients, and often more than onenerve was involved ; there was facial weakness in all7 cases and sixth nerve paresis in 6. In some of the

patients the sixth nerve was compressed by the enlarged

medulla as it passed between the pons and medulla, butthe Ma,yo Clinic workers do not explain the unexpectedfrequency of facial nerve involvement by tumours

apparently confined to the medulla. Of the lowercranial nerves the twelfth was involved in 3 patients,the eleventh in 2, and the ninth and tenth in 4. Therewas raised intra,cranial pressure in only 6 of the patients;and hiccup was a prominent feature in 5 cases, in 2 ofwhich this was an early symptom. A surprising featurein 2 cases was epileptic fits, and no definite explanationfor this was found.

There is considerable difficulty in the clinical diagnosisof intrinsic tumours of the medulla oblongata, owingto the great variability of the symptoms and physicalsigns. In these patents there is a real danger of suddenunexpected death from acute respiratory failure.

1. Thorn, G. W., Koepf, G. F., Clinton, M. jun. New Engl. J.Med. 1944, 231, 76.

2. Sawyer, W. H., Solez, C. Ibid, 1949, 240, 210.3. Nussbaum, H. E., Bernhard, W. G., Mattia, V. D. jun. Ibid,

1952, 246, 289. 4. Platt, R. Lancet, 1951, i, 1239. 5. Bull, G. M., Joekes, A. M., Lowe, K. G. Clin. Sci. 1950,

9, 379.

"SALT-LOSING NEPHRITIS"

IN 1944, Thorn et al.1 described two cases in whichelectrolyte disturbances due to advanced chronic renaldisease gave rise to a clinical picture akin to that ofAddison’s disease with crisis. This diagnostic difficultyhas since been reported by Sawyer and Solez 2 in a caseof nephrocalcinosis, and by Nussbaum et al.3 in a case ofchronic pyelonephritis. In these patients the absenceof hypertension or preceding acute renal disease, togetherwith the absent or very slight albuminuria, delayedrecognition of the underlying renal disease; and theraised blood-urea and sodium depletion were attributedat first to adrenocortical insufficiency. Subsequently,failure of the blood-urea to fall to normal after thesodium depletion was corrected by adequate salt intake,and such findings as normal glucose tolerance, normal17-ketosteroid excretion, and normal suppression of

eosinophils by A.C.T.H., led to recognition of the renaldisease.

In chronic nephritis minor degrees of dehydration arecommon, and care has to be taken to ensure an adequatesodium intake.

Platt 4 conceives of the failing kidney as one with areduced number of nephrons working under conditionsof osmotic diuresis due to the high blood-urea andtherefore failing to conserve sodium. Generally patientswith chronic renal disease remain in fair balance forsodium and potassium even with quite a large range ofintake of these ions. On the other hand, some of themshow a tendency to excessive sodium loss, and Plattdescribes these as potential cases of " salt.losingnephritis." The overt case of sodium depletion withvasomotor collapse is probably only the extreme exampleof this failure to conserve sodium. Just as sodium

depletion from any cause can bring about renal insuf-ficiency in the absence of organic renal disease, so it canfurther reduce function in an already diseased kidney.A vicious cycle is then set up ; and it is understandablethat azotæmia, weight-loss, vomiting, and vasomotorcollapse may stimulate an Addisonian crisis. In suchcases the tubules may perhaps be more severely damagedthan the glomeruli, and the resulting glomerulotubularimbalance may account for the failure of ion conservation.This recalls the ion-depletion states that readily arisein the early diuretic phase of acute tubular necrosis.5Gross sodium or potassium deficiency may thenarise unless enough of these elements is ingested tobalance the uncontrolled urinary losses occurringwhile the tubules are being relined with immatureepithelium.

913

With sodium depletion of renal origin, treatment

consists simply in quantitative replacement of sodium,usually as a mixture of sodium chloride and sodiumlactate intravenously, followed by a liberal intake of

salt in the diet. In the case reported by Nussbaum et al.,despite the presence of polyuria, hyperpotasssemiaaccompanied the sodium depletion. Adrenocortico-

tropic and adrenocortical hormones did not appreciablyaffect the renal losses of sodium; but possiblythey protected against the harmful effects of

hyperpotassæmia. In Nussbaum’s patient sudden

unexpected death, probably due to hyperpotassæmia,followed the cessation of cortisone therapy duringtreatment with sodium acetate to counteract the acidosisof renal failure. Despite the lowering of the plasma-potassium level, death was attributed to potassiumpoisoning; and Nussbaum cites experimental evidencethat alkalinising salts promote death from hyper-potassæmia, whereas adrenal hormones increase toleranceof it.

1. Lancet, 1951, i, 333.2. Barnett, S. A. Surgo, 1952, 18, 111.3. Davis, D. E. Amer. J. publ. Hlth, 1951, 41, 158.4. Barnett, S. A., Bathard, A. H., Spencer, M. M. Ann. appl.

Biol. 1951, 38, 444.5. Calhoun, J. B. Ann. N.Y. Acad. Sci. 1950, 51, 1113.6. Barnett, S. A. Ann. appl. Biol. 1947, 34, 297.

CONTROL OF RAT POPULATIONS

RAT control, even by the newest methods of poisoning,remains exceedingly difficult and very expensive.12 2Davis 3 has suggested that a solution may be found, notin new poisons or baiting methods, but in the study of thebehaviour of rat populations. If a few rats begin tobreed in a favourable area their rate of increase will beslow at first, then more rapid ; but as the area fills upincrease will slow down until a maximum number isreached.3 4 One implication is that reduction of such apopulation by about half (a common result of attemptedcontrol) merely brings it to the level at which it increasesmost rapidly. When, in Baltimore, half a rat populationwas caught by trapping, the survivors rapidly gained inweight, and within two months the pregnancy-rate haddoubled.The decline in population growth, and the final

equilibrium are due to adverse factors whose effectsincrease with the density of the population. The morerats there are, the greater will be

" predation " by man,dogs, and hawks ; the greater will be the pressure onnesting sites ; and the less food there will be for each rat.Calhoun 5 has shown that rats which were able to nestnear food were more fertile and grew more rapidly thanthose farther away-evidently because the latter, whenon their way to food, were attacked by the others.From facts of this sort Davis concludes that " pre-dation," including poisoning and trapping, is not

profitable, and he advocates instead action to " increasecompetition " among the rats themselves. He claimsthat, by reducing access to food and clearing awayharbourage, the rat population of Baltimore was

reduced from about 400,000 in 1944 to about 65,000in 1949.

Meanwhile, however, methods of direct destruction willcontinue to be used ; and for these, too, knowledge ofpopulation changes is needed. An authority with limitedresources needs to know the most economical way of

applying them. This requires : (a) a knowledge of theeffects on rat populations of particular methods ofcontrol, and (b) quantitative information on rat-popula-tion levels and the amount of disease or food destructionthey cause. During the late war the use of the pre-baitingmethod, with carefully tested poisons, brought, ratinfestation of Government food stores to a very lowlevel. 6 On the other hand, little impression seems tohave been made on the rat population of rural areas.4

To investigate food losses, Barnett egposed bagged wheat.to small numbers of rats for 12-28 weeks : the total loss.was 18% of the original value of the wheat plus sacks,but nearly two-thirds of this loss was due to damage to thesacks. It is sometimes said that rats cause more loss offood by fouling than by eating it; but in these experi-ments, although 70% of the wheat was fouled, it was alldeemed fit for human consumption after cleaning.Barnett 2 concludes that a rational scheme of rat control

requires much fuller information, both ecological andeconomic, than has yet been brought to light.

7. Barnett, S. A. J. Hyg., Camb. 1951, 49, 22.

CONFINEMENT IN HOSPITAL ?

AT last week’s Margate congress of the Royal SanitaryInstitute one of the sections had a useful session on

Hospital Midwifery versus Domiciliary Midwifery. Theopening speakers were an obstetrician (Mr. RufusThomas), a medical officer for maternal and child health(Dr. Elspeth Warwick), a superintendent of midwives(the Hon. Eve Chetwynd), and a general practitioner(Dr. Talbot Rogers), and they agreed that hospital anddomiciliary midwifery should be complementary services;and therefore need coordination. The extent of hospitalprovision varies widely in different areas, and it is rarelyplanned in concert with the local health authority. How-ever many maternity beds are provided they seem to begenerally full, and though the demand for them is oftenbased on social rather than medical needs, it appearsslikely to continue so long as shortage of houses obligesso many young couples to begin their married lifewithout proper homes. Both Dr. Warwick and MissChetwynd regarded the domiciliary midwife as thebest judge of the social indications for hospitalconfinement. Both thought, too, that the Ministry’scircular last year on the Selection of Maternity Cases forAdmission to Hospital advocated too strongly theadmission of primigravidæ and of multigravidae withmore than four children. Mr. Rufus Thomas listed aseries of types of medical and obstetric difficulty thatshould always qualify for admission ; and he wouldalso admit all primigravidæ aged over 35 and all elderlymultigravidae. -

In 1946 the Royal College of Obstetricians recom-mended that hospital beds should be provided for 70%of confinements. Lack of money and other resourceshas made this impracticable, and Dr. Warwick and MissChetwynd alike believed that something much less=probably about 50%-is quite enough, so long as theselection of cases is satisfactory. Dr. Rogers argued thatthe two factors governing the proportion of cases admittedare (1) long-standing local custom, and (2) the number ofbeds. The demand for beds is high and will remain so.The Ministry’s circular has done nothing to increase thenumber or proportion of domiciliary confinements ;nor is there evidence that admission is being grantedonly to mothers who can show medical or social need.He believed that all the maternity beds provided willalways be used ; that with, a falling birth-rate the

proportion of hospital deliveries will rise ; that this willmean a higher proportion of uncomplicated cases inhospital; and that many of these cases will not requirespecialised help. He therefore favoured setting aside,in hospital, beds where women being confined could becared for by their own doctors and midwives. Mr.Rufus Thomas, though approaching the problemdifferently, came to not dissimilar conclusions ; for he

sought to cure underemployment of midwives, andunderestablishment and overworking of trained hospitalstaff, by bringing the midwife into the hospital for partof her time. He would also like to see the G.P.-obstet-riciaii " fitted into the hospital structure in such a wayas to bring him into close relationship with the con-sultant staff."