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CONTROL OF ANTICOAGULANT THERAPY
383 PERTHES’ DISEASE annotation last week on Perthes’ disease is SiR,ņYour call it the attention of the medical for welcome, may the restricted field of orthopxdic profession beyond this condition. towards Nevertheless, it does not surgeons mention a factor which may be of decisive importance in its aetiologyņnamely, that with individual and very probably racial variations, from the age of three to eight years the blood-supply of the proximal femoral epiphysis comes through the small group of lateral epiphyseal vessels without complementary supply from the round ligament or the metaphyseal vessels. This precarious system of blood-flow occurs, at least in the white child, until or before the age of eight years, while the children of African origin seem to preserve the fcetel circulation through the vessels of the ligamentum teres throughout childhood. Perhaps for this reason the Negro child appears to be immune to Perthes’, or at least seems to be only exceptionally affected by it as compared with the European
child. As to the late consequences of Perthes’ disease, in our analysis of over 125 cases we found that, as was to be expected, the only hips suffering from osteoarthritis in adulthood were those left by the early osteochondritis either misshaped or incongruent, or both. Thus, to prevent this possible calamity all precautions should be taken; among them, for the moment, bed recumbency during the period when the dead bone is replaced by soft, malleable new
cartilage.
Nuffield Orthopædic Centre, Oxford.
J. TRUETA.
CONTROL OF ANTICOAGULANT THERAPY
SiR.ņThe isolated sentence from our paper quoted by Professor Quick (Jan. 30) was meant in no way to detract from the basic physiological and practical diagnostic merits of the one-stage prothrombin-time technique. Still less could the sentence be construed as having any relevance to very different procedures like the thromboplastin generation test; the reasons for this cannot be given here, and no-one is more aware of them than Professor Quick. Indeed, the offending sentence has little meaning at all except within the context of anticoagulant therapy, which was the subject of our discussion. acknowledged virtues of Professor Quick’s test, deby us as a landmark in the physiology of coagulation, are too great to be seriously impugned by the recognition of certain limitations within a given context. We specified and discussed the shortcomings we had in mind: they refer only The scribed
the
to
use
of the unmodified
test
in the routine control of anti-
coagulant therapy and are not mentioned in Professor Quick’s letter, while he appears to rebuke us for criticisms we did not make. Surely he would not deny that unduly severe depression of true prothrombin and of factor ix can exist unrevealed by the one-stage test, and that bleeding does occur, though not often, when the clotting-time is within the therapeutic range. With plasma from patients under coumarin treatment (though more doubtfully in the case of isolated deficiencies) thrombotest is sensitive to variations in all four factors concerned. Unlike the one-stage test it has been tailored to meet the requirements of anticoagulant control, successfully so far as we can judge though more extended trial should settle this question. One
at
least of Professor
blood-vessels-was misfired,
Quick’s shafts-the glass-lined whether through misreading
his part or obscure writing on ours. We did not list insensitivity to the contact factor as a shortcoming of the Quick test, but sensitivity to it as a disadvantage of thrombotest. Dr. Laurie is quite right in his statement (Jan. 23) of a much higher price for commercially supplied thrombotest on
reagent than the 4d. per test suggested in our paper (Dec. 26). This over-modest figure was innocently based on the value given for Customs purposes added to the duty chargedamounting in fact to 3½d. per test. We have since confirmed that the present cost per test of purchased reagent would be about Is. 6d., a price at which thrombotest, with all its technical virtues, would be unjustifiably dear for routine use in this country. It is doubtful whether any test costing more than 6d. for the reagent is worth while. A way of reducing the cost of thrombotest may be found-e.g., by using smaller volumes of blood and reagent, though so far our own experience with small volumes is not encoiir.9gingDepartment of Pharmacology and Therapeutics, W. WALKER Queen’s College, M. MATTHEWS.
J.
Dundee.
THE SIGN OF BABINSKI
SiR.ņIn your leading article last week, reviewing the history and significance of this sign-of which Walshe has writtenthat "there is perhaps no more important physical sign in clinical neurology "-you fail to mention the curious but surely relevant fact that the Babinski reflex can be demonstrated in many hypnotic subjects when regressed to infancy. This is difficult to explain on the information available, unless there were some evidence of concurrent neurological or biochemical changes as a result of regression or the hypnotic trance itself. But there is to date no such evidence. This phenomenon was investigated in America by GidroFrank and Buch,2who found that the change of response from plantar to extensor was accompanied by what they described as a reversal of the flexor-extensor chronaxie ratio, which, it was claimed, is normally the case in the truly infantile condition. Later True and Stephenson3 confirmed the presence of this reflex in subjects regressed to infancy, but showed that the E.E.G. was nevertheless of the adult form. However, the genuineness of the phenomenon is still debated on both sides of the Atlantic and is, indeed, very difficult to prove, although most deep-trance hypnotic subjects will produce the response. Gidro-Frank and Buch claimed that their subjects had no knowledge of the reflex or the intention of the investigators, but for my part I have not yet discovered a suitable subject of whom it could be said with certainty that there was no such knowledge. But one subject, a student nurse in her first year, when deliberately misinformed and told with authority (as a temporary, experimental measure) that she had got it muddled and that the infantile response was flexor, nevertheless provided a first-class demonstration of the extensor reaction when repressed to the ase of five months. Lower Beeding, Horsham, Sussex
STEPHEN BLACK.
SIR, Your interesting editorial mentions instances of a temporary Babinski sign, rapidly reverting to normal. A more gradual reversion can also occur in cerebral vascular disease.
Examples of this were seen when 125 patients with hemiplegia, following cerebral vascular accident, were examined at fortnightly intervals for six months. Some 53 of these cases showed an up-going toe on both sides: the remaining 72 had a positive sign on one side only. Out of these 178 responses, no less than 41 (25%) had returned to normal within six months. Such reversion took less than two months in 8 patients; from two to four months in 14 patients; and more than four months in 17 patients. 1 patient with bilateral Babinski signs showed reversion in one week the right side. Queen’s Hospital, Croydon. 1. 2. 3.
on
the left side and three months
on
TREVOR H. HOWELL.
Walshe, F. M. R. Diseases of the Nervous System. Edinburgh, 1940. Gidro-Frank, K., Buch, M. K. B. J. nerv. ment. Dis. 1948, 107, 443. True, R. M., Stephenson, C. W. Personality, 1951, 1, 252.
child. As to the late consequences of Perthes’ disease, in our analysis of over 125 cases we found that, as was to be expected, the only hips suffering from osteoarthritis in adulthood were those left by the early osteochondritis either misshaped or incongruent, or both. Thus, to prevent this possible calamity all precautions should be taken; among them, for the moment, bed recumbency during the period when the dead bone is replaced by soft, malleable new
cartilage.
Nuffield Orthopædic Centre, Oxford.
J. TRUETA.
CONTROL OF ANTICOAGULANT THERAPY
SiR.ņThe isolated sentence from our paper quoted by Professor Quick (Jan. 30) was meant in no way to detract from the basic physiological and practical diagnostic merits of the one-stage prothrombin-time technique. Still less could the sentence be construed as having any relevance to very different procedures like the thromboplastin generation test; the reasons for this cannot be given here, and no-one is more aware of them than Professor Quick. Indeed, the offending sentence has little meaning at all except within the context of anticoagulant therapy, which was the subject of our discussion. acknowledged virtues of Professor Quick’s test, deby us as a landmark in the physiology of coagulation, are too great to be seriously impugned by the recognition of certain limitations within a given context. We specified and discussed the shortcomings we had in mind: they refer only The scribed
the
to
use
of the unmodified
test
in the routine control of anti-
coagulant therapy and are not mentioned in Professor Quick’s letter, while he appears to rebuke us for criticisms we did not make. Surely he would not deny that unduly severe depression of true prothrombin and of factor ix can exist unrevealed by the one-stage test, and that bleeding does occur, though not often, when the clotting-time is within the therapeutic range. With plasma from patients under coumarin treatment (though more doubtfully in the case of isolated deficiencies) thrombotest is sensitive to variations in all four factors concerned. Unlike the one-stage test it has been tailored to meet the requirements of anticoagulant control, successfully so far as we can judge though more extended trial should settle this question. One
at
least of Professor
blood-vessels-was misfired,
Quick’s shafts-the glass-lined whether through misreading
his part or obscure writing on ours. We did not list insensitivity to the contact factor as a shortcoming of the Quick test, but sensitivity to it as a disadvantage of thrombotest. Dr. Laurie is quite right in his statement (Jan. 23) of a much higher price for commercially supplied thrombotest on
reagent than the 4d. per test suggested in our paper (Dec. 26). This over-modest figure was innocently based on the value given for Customs purposes added to the duty chargedamounting in fact to 3½d. per test. We have since confirmed that the present cost per test of purchased reagent would be about Is. 6d., a price at which thrombotest, with all its technical virtues, would be unjustifiably dear for routine use in this country. It is doubtful whether any test costing more than 6d. for the reagent is worth while. A way of reducing the cost of thrombotest may be found-e.g., by using smaller volumes of blood and reagent, though so far our own experience with small volumes is not encoiir.9gingDepartment of Pharmacology and Therapeutics, W. WALKER Queen’s College, M. MATTHEWS.
J.
Dundee.
THE SIGN OF BABINSKI
SiR.ņIn your leading article last week, reviewing the history and significance of this sign-of which Walshe has writtenthat "there is perhaps no more important physical sign in clinical neurology "-you fail to mention the curious but surely relevant fact that the Babinski reflex can be demonstrated in many hypnotic subjects when regressed to infancy. This is difficult to explain on the information available, unless there were some evidence of concurrent neurological or biochemical changes as a result of regression or the hypnotic trance itself. But there is to date no such evidence. This phenomenon was investigated in America by GidroFrank and Buch,2who found that the change of response from plantar to extensor was accompanied by what they described as a reversal of the flexor-extensor chronaxie ratio, which, it was claimed, is normally the case in the truly infantile condition. Later True and Stephenson3 confirmed the presence of this reflex in subjects regressed to infancy, but showed that the E.E.G. was nevertheless of the adult form. However, the genuineness of the phenomenon is still debated on both sides of the Atlantic and is, indeed, very difficult to prove, although most deep-trance hypnotic subjects will produce the response. Gidro-Frank and Buch claimed that their subjects had no knowledge of the reflex or the intention of the investigators, but for my part I have not yet discovered a suitable subject of whom it could be said with certainty that there was no such knowledge. But one subject, a student nurse in her first year, when deliberately misinformed and told with authority (as a temporary, experimental measure) that she had got it muddled and that the infantile response was flexor, nevertheless provided a first-class demonstration of the extensor reaction when repressed to the ase of five months. Lower Beeding, Horsham, Sussex
STEPHEN BLACK.
SIR, Your interesting editorial mentions instances of a temporary Babinski sign, rapidly reverting to normal. A more gradual reversion can also occur in cerebral vascular disease.
Examples of this were seen when 125 patients with hemiplegia, following cerebral vascular accident, were examined at fortnightly intervals for six months. Some 53 of these cases showed an up-going toe on both sides: the remaining 72 had a positive sign on one side only. Out of these 178 responses, no less than 41 (25%) had returned to normal within six months. Such reversion took less than two months in 8 patients; from two to four months in 14 patients; and more than four months in 17 patients. 1 patient with bilateral Babinski signs showed reversion in one week the right side. Queen’s Hospital, Croydon. 1. 2. 3.
on
the left side and three months
on
TREVOR H. HOWELL.
Walshe, F. M. R. Diseases of the Nervous System. Edinburgh, 1940. Gidro-Frank, K., Buch, M. K. B. J. nerv. ment. Dis. 1948, 107, 443. True, R. M., Stephenson, C. W. Personality, 1951, 1, 252.