BRITISH MEDICAL JOURNAL
related to capillary walls. Of those with RA-positive immunofluorescence, 88" developed rheumatoid arthritis, compared with 25",, of those negative by this test. The latex screening test for rheumatoid factor12 correlated poorly with the presence of rheumatoid arthritis. The sheep cell agglutination test was positive in only 25", of those who developed the disease, and in any case it is positive in 6", of the general population.'3 Testing for these factors in synovial fluid added nothing of diagnostic significance. Estimation of IgG concentrations has been advocated as a possible means of reaching a diagnosis in seronegative patients who may have conditions such as psoriatic arthritis,'4 but Hollander and his colleagues did not find this test useful.15 The complement activity in synovial fluid is sometimes low in rheumatoid arthritis, but since such patients also seem to have rheumatoid factor present the test does not further the diagnosis.3 " Other tests such as the white cell count and searching for RA cells in synovial fluid also proved unrewarding in the Perth study. Early diagnosis of rheumatoid arthritis is desirable for both general management and prognosis, but it is doubtful whether it makes much difference to the outcome. This latest investigation was justified on the grounds that the use of immunosuppressive therapy was being considered early in the course of rheumatoid arthritis-an approach contrary to the current views of most clinicians.16 In a disease whose course is so variable noxious remedies should be withheld so long as possible, for over half the patients with rheumatoid arthritis will improve eventually if treated along simple lines.'7 Remissions induced by anti-inflammatory drugs have not been sustained, and the ultimate course of the disease does not appear to have been significantly altered for the better. A controlled trial has shown that a period of complete immobilisation may usefully and safely be applied to control pain and muscle spasm and that it often leads to a decrease in signs of the activity of the disease." The use of analgesic anti-inflammatory drugs at this stage is important but often haphazard. McConkey and his colleagues' have advocated a systematic approach to treatment:2( but in practice one study has shown that only 42"W of patients with rheumatoid arthritis were prescribed salicylates and that 3400 were given an inadequate dose.20 One great need at present is for the multiplicity of analgesic and anti-inflammatory drugs available for treating the disease to be arranged into a scientifically based pecking order. In this simple way we might do much to help our patients. Ropes, M W, et al, Annals of the Rheumiatic Diseases, 1959, 18, 49. Lee, P R, et al, California Medicine, 1960, 93, 125. Bayliss, C E, et al, Annals of the Rheuimatic Diseases, 1975, 34, 395. Mikkelsen, W M, et al, Archives of Internal Medicine, 1958, 102, 977. Rodnan, G P, Yunis, E J, and Totten, R S, Annals of Internal Medicine, 1960, 53, 319. 6 Polley, H F, and Bickel, W H, Annals of the Rheumatic Diseases, 1951, 10, 277. Wilkinson, M, and Jones, B S, Annals of the Rheumatic Diseases, 1963, 22, 100. Caughey, D E, and Highton, T C, New Zealand Medical Journal, 1965, 64, 444. 9 Caughey, D E, and Kulka, J P, New England Jtournal of Medicine, 1972, 286, 416. 1 Parker, R H, and Pearson, C M, Arthritis and Rheumatism, 1963, 6, 172. '1 Schumacher, H R, and Kitridou, R C, Arthritis and Rheumatism, 1972, 15, 465. 12 Bird, R, and Burr, R G, 'ournal of Clinical Pathology, 1962, 15, 472. 13 Kellgren, J H, and Ball, J, British Medical journal, 1959, 1, 523. 14 Howell, F A, et al, Annals of the Rheumatic Diseases, 1972, 31, 129. 15 Tapanes, F J, et al, Arthritis and Rheumatism, 1972, 15, 153. 16 Steinberg, A D, Arthritis and Rheumatism, 1973, 16, 92. 17 Duthie, J J R, in Textbook of the Rheumatic Diseases, ed W S C Copeman, 4th edn, p 259. Edinburgh, Livingstone, 1969. 18 Partridge, R E H, and Duthie, J J R, Annals of the Rheumatic Diseases, 1963, 22, 91. 9 Constable, T J, et al, Lancet, 1975, 1, 1176. 20 Mason. D I R, et al, Health Bulletin, 1975, 33, 72. I
2 3 4 5
923
17 APRIL 1976
Drugs for mentally handicapped children "The advice to those about to prescribe for the mentally handicapped is-when in doubt, don't." This comment comes from a physician with great experience of mental handicap, and it deserves to be considered in the correct context.' The dispute is not about whether a mentally handicapped child with acute tonsillitis should receive penicillin in the same way as a normal child: it is about the different standards of management of behaviour disorders for the normal and for the handicapped child. For the normal child with a sleep disorder or an episode of destructive behaviour the parents and child are likely to get a sympathetic hearing and careful assessment, followed by efforts to change the child's environment or to alter the factors causing the symptom. Drugs would probably not be used, and if they were it would be for a brief period. But the mentally handicapped child with sleep disorder or destructive behaviour is very likely to be given hypnotic or sedative drugs and still be receiving them six months later. We are accustomed to the different standards of management used for acute as opposed to chronic illness and for those with normal intelligence compared with those who have subnormal intelligence. Drug treatment provides another example of this dichotomy-and one that is specially important because of the increased prevalence of behaviour disorders in children with mental handicap: nearly one-third are considered to have a severe behaviour disorder.2 The pattern of disorder is variable. All the problems that may occur in normal children may occur in the handicapped, but for these the difficulties are compounded by secondary problems resulting from the difficulties that the family have in dealing with the handicap. Parental guilt and uncertainty added to the social restrictions that may arise from the chore of caring for a handicapped child cause problems in the rest of the family, and these may increase the behaviour disturbance. In an institution the problems are just as great. Those who care for mentally handicapped children are often doing so in the most difficult circumstances. Old buildings, staff shortages, and overcrowding all tend to reduce the amount of communication and interaction between staff and patient. In one survey a ward of 20 severely retarded children had three staff to look after them and only 60' of staff time was spent in initiating reactions and trying to communicate with the children.' The nursing staff were busy with the housekeeping duties to the virtual exclusion of their role as substitute parent, teacher, organiser, and adviser. In this setting behaviour that is awkward for the institution is likely to get overtreated with drugs. It is easy to see how the needs of the institution may seem to be set before those of the individual,4 yet mental subnormality does not diminish an individual's emotional needs. Drugs are needed for the mentally handicapped as they are for normal children, but they are not necessarily needed in any greater quantity for the mentally handicapped, and in particular should be used with discretion for the treatment of behaviour disturbances. Some apparent behaviour disorders may be caused by conditions demanding drug treatment. The child who is confused and stuporous as a result of repeated epileptic seizures may benefit dramatically from appropriate anticonvulsant treatment. A few children with hyperkinetic behaviour may benefit from drug treatment, but for that condition and most other behaviour disturbances it is more important to look for ways of manipulating the environment to
924
alter the behaviour. This may require changing the child's timetable or his room or ward; it may mean more personal contact with a particular relative or a member of staff. When drugs are given their use should be reconsidered at frequent intervals. When hypnotics or sedatives are prescribed to help in a crisis they should be stopped when the crisis is over. When they are used to tide over a period during which alternative management is introduced they should be stopped soon after the introduction of the new regimen. It may then be possible to see if the changes really are in the best interests of the child. Kirman, B, British Journal of Psychiatry, 1975, 127, 545. 2Department of Health and Social Security, Census of Mentally Handicapped Patients in Hospitals in England and Wales at the End of 1970. London, HMSO, 1972. 3Wright, E, Abbas, K A, and Meredith, C, British Journal of Mental Subnormality, 1974, 20, 14. 4Raynes, N V, and King, R D, in Proceedings of 1st Congress of the International Association for the Scientific Study of Mental Deficiency, 1967, ed B W Richard, p 657. Reigate, Michael Jackson Publishing Co, 1968. I
Surgery for epilepsy Enough time has passed since the introduction of surgical treatment for temporal lobe epilepsy for a very clear picture to have emerged of the indications, results, and morbidity of the operations. Yet opinion still remains uncertain and medical treatment is often continued in spite of poor control of seizures with their associated morbidity and mortality. Is this due to fear of surgery and uncertainty about the outcome or to difficulty in obtaining the necessary advice ? Recently in an attempt to clarify the situation Jensen 1-3 has carried out an extensive analysis of the published results of surgery in the treatment of temporal lobe epilepsy based on the results of 2282 resections carried out between 1928 and 1973. There is almost universal agreement on the conditions (for example, those suggested by Rasmussen4 and Falconer5) which need to be fulfilled before operation should be considered. Firstly, there must have been a failure to respond to a really adequate trial of drug treatment, including monitoring of the blood levels. There must be evidence of a predominantly or wholly unilateral temporal disorder, as shown by inferior or anterior temporal spikes in the electroencephalogram. If these are bilateral they must be at least four times more frequent on the side to be operated upon. The fits must have been established long enough for there to be reasonable certainty that all potentially epileptogenic areas have manifested themselves and that spontaneous regression is unlikely. Finally the patient must have an IQ of at least 60. Patients with tumours, arteriovenous malformations, or abscesses are excluded from consideration in this context; their indications for operation are not based on the control of epilepsy alone. Considering only those series in which these criteria were fulfilled, and in which adequate preoperative and postoperative data were available, Jensen found that 43 6% of 885 patients were entirely free from seizures after operation. In 18% the fits were reduced to less than one-quarter of their former incidence, and in a further 16-5% there were less than half the number of seizures. Analysis of the reports shows rather a wide scatter in the success rates, but a closer look shows that those
BRITISH MEDICAL JOURNAL
17 APRIL 1976
series in which surgery was limited to a superficial or partial removal of the temporal lobe had fewer successful results than those in which the deeper structures-including parts of the amygdalum, uncus, and hippocampus-were removed. In a recent series Van Burent found a success rate of only 60OX for partial operations and 50° 0, for the total removal. Again, inclusion of patients with bilateral abnormalities also reduces the success rate, as was shown by Bailey7 and Bloom8 and their co-workers. The number of patients with psychiatric abnormality varied from one centre to another, but more than 5000 of those who had mental abnormalities preoperatively were improved or returned to normal. Jensen also showed that neither the epileptic nor the psychiatric history affected the outcome of surgery unless there were genetic factors in both parents. If this was so the likelihood of benefit to the fit pattern or the psychiatric outcome was reduced. The mortality from the operations was under 1°0/ and the morbidity was low. Persistent hemiparesis occurred in 2.40/a of the 885 patients studied by Jensen and transient hemiparesis in 4.20/,, but these proportions have fallen slightly in recent years. Minor visual defects, of which the patient was unaware, were quite common, and a complete homonymous hemianopia occurred in 8.30). Temporary dysphasia and diplopia did occur, but they did not persist. A further inquiry was undertaken into the late mortality after operation. The late mortality of 47-6 per 1000 contrasted with an expected mortality of 2-9 per 1000 in a normal population, but the expected mortalitv in a similar group of Danish epileptic patients not treated surgically would be 59 4 per 1000. Most late deaths were in the group of 16-5%K, of patients with less than a 50%/ reduction in their fits: 62%' of these deaths were due to epilepsy, while other causes included suicide in 28% of those who died and who had continued to suffer from their fits after operation. In a Danish investigation by Henriksen et a19 the excess mortality ratio due to suicide among patients with epilepsy was shown to be 30000; it accounted for 20%/ of deaths. This is a measure of suffering, and of the need to use every means to prevent it. Resections of other parts of the cerebral hemispheres for the treatment of epilepsy were shown by Rasmussen'0 and Feindel1 to have a success rate of 30-45%, but the results may be less permanent. Treatment by implanted electrodes and stereotactic lesions has yet to be fully evaluated. But the value of surgery in the treatment of intractable temporal lobe seizures is now clearly established. The presence of demonstrable and eradicable disease is clear. Two-thirds of the patients operated upon will be helped significantly. The prospect of relief should therefore not be denied to those who need it. IJensen, I, Acta Neurologica Scandinavica, 1975, 52, 354. 2 Jensen, I, Acta Neurologica Scandinavica, 1975, 52, 374. 3Jensen, Acta Neurologica Scandinavica, 1975, 52, 381. 4Rasmussen, T, Clinical Neurosurgery, 1969, 16, 288. 5 Falconer, M A, Neurochirurgia, 1965, 8, 161. 6 Van Buren, J M, Marsan, C A, and Mutsuga, N,Journal of Neurosurgery, 1975, 43, 596. 7Bailey, et al, Research Publications Association for Research in Nervous and Mental Disease, 1953, 31, 341. 8 Bloom, D, Jasper, H, and Rasmussen, T, Epilepsia (Amsterdam), 1960, 1, 351. 9 Henriksen, B, Juul-Jensen, P, and Lund, M, Life Assurance Medicine, ed R D C Brackenridge, p 139. London, Pitman, 1970. 10 Rasmussen, T, Advances in Neurology, ed D Purpura, J K Penry, and R D Walter, vol 8, pp 197 and 207. New York, Raven Press, 1975. Feindel, W, Advances in Neurology, ed D Purpura, J K Penry, and R D Walter, vol 8, p 281. New York, Raven Press, 1975.
related to capillary walls. Of those with RA-positive immunofluorescence, 88" developed rheumatoid arthritis, compared with 25",, of those negative by this test. The latex screening test for rheumatoid factor12 correlated poorly with the presence of rheumatoid arthritis. The sheep cell agglutination test was positive in only 25", of those who developed the disease, and in any case it is positive in 6", of the general population.'3 Testing for these factors in synovial fluid added nothing of diagnostic significance. Estimation of IgG concentrations has been advocated as a possible means of reaching a diagnosis in seronegative patients who may have conditions such as psoriatic arthritis,'4 but Hollander and his colleagues did not find this test useful.15 The complement activity in synovial fluid is sometimes low in rheumatoid arthritis, but since such patients also seem to have rheumatoid factor present the test does not further the diagnosis.3 " Other tests such as the white cell count and searching for RA cells in synovial fluid also proved unrewarding in the Perth study. Early diagnosis of rheumatoid arthritis is desirable for both general management and prognosis, but it is doubtful whether it makes much difference to the outcome. This latest investigation was justified on the grounds that the use of immunosuppressive therapy was being considered early in the course of rheumatoid arthritis-an approach contrary to the current views of most clinicians.16 In a disease whose course is so variable noxious remedies should be withheld so long as possible, for over half the patients with rheumatoid arthritis will improve eventually if treated along simple lines.'7 Remissions induced by anti-inflammatory drugs have not been sustained, and the ultimate course of the disease does not appear to have been significantly altered for the better. A controlled trial has shown that a period of complete immobilisation may usefully and safely be applied to control pain and muscle spasm and that it often leads to a decrease in signs of the activity of the disease." The use of analgesic anti-inflammatory drugs at this stage is important but often haphazard. McConkey and his colleagues' have advocated a systematic approach to treatment:2( but in practice one study has shown that only 42"W of patients with rheumatoid arthritis were prescribed salicylates and that 3400 were given an inadequate dose.20 One great need at present is for the multiplicity of analgesic and anti-inflammatory drugs available for treating the disease to be arranged into a scientifically based pecking order. In this simple way we might do much to help our patients. Ropes, M W, et al, Annals of the Rheumiatic Diseases, 1959, 18, 49. Lee, P R, et al, California Medicine, 1960, 93, 125. Bayliss, C E, et al, Annals of the Rheuimatic Diseases, 1975, 34, 395. Mikkelsen, W M, et al, Archives of Internal Medicine, 1958, 102, 977. Rodnan, G P, Yunis, E J, and Totten, R S, Annals of Internal Medicine, 1960, 53, 319. 6 Polley, H F, and Bickel, W H, Annals of the Rheumatic Diseases, 1951, 10, 277. Wilkinson, M, and Jones, B S, Annals of the Rheumatic Diseases, 1963, 22, 100. Caughey, D E, and Highton, T C, New Zealand Medical Journal, 1965, 64, 444. 9 Caughey, D E, and Kulka, J P, New England Jtournal of Medicine, 1972, 286, 416. 1 Parker, R H, and Pearson, C M, Arthritis and Rheumatism, 1963, 6, 172. '1 Schumacher, H R, and Kitridou, R C, Arthritis and Rheumatism, 1972, 15, 465. 12 Bird, R, and Burr, R G, 'ournal of Clinical Pathology, 1962, 15, 472. 13 Kellgren, J H, and Ball, J, British Medical journal, 1959, 1, 523. 14 Howell, F A, et al, Annals of the Rheumatic Diseases, 1972, 31, 129. 15 Tapanes, F J, et al, Arthritis and Rheumatism, 1972, 15, 153. 16 Steinberg, A D, Arthritis and Rheumatism, 1973, 16, 92. 17 Duthie, J J R, in Textbook of the Rheumatic Diseases, ed W S C Copeman, 4th edn, p 259. Edinburgh, Livingstone, 1969. 18 Partridge, R E H, and Duthie, J J R, Annals of the Rheumatic Diseases, 1963, 22, 91. 9 Constable, T J, et al, Lancet, 1975, 1, 1176. 20 Mason. D I R, et al, Health Bulletin, 1975, 33, 72. I
2 3 4 5
923
17 APRIL 1976
Drugs for mentally handicapped children "The advice to those about to prescribe for the mentally handicapped is-when in doubt, don't." This comment comes from a physician with great experience of mental handicap, and it deserves to be considered in the correct context.' The dispute is not about whether a mentally handicapped child with acute tonsillitis should receive penicillin in the same way as a normal child: it is about the different standards of management of behaviour disorders for the normal and for the handicapped child. For the normal child with a sleep disorder or an episode of destructive behaviour the parents and child are likely to get a sympathetic hearing and careful assessment, followed by efforts to change the child's environment or to alter the factors causing the symptom. Drugs would probably not be used, and if they were it would be for a brief period. But the mentally handicapped child with sleep disorder or destructive behaviour is very likely to be given hypnotic or sedative drugs and still be receiving them six months later. We are accustomed to the different standards of management used for acute as opposed to chronic illness and for those with normal intelligence compared with those who have subnormal intelligence. Drug treatment provides another example of this dichotomy-and one that is specially important because of the increased prevalence of behaviour disorders in children with mental handicap: nearly one-third are considered to have a severe behaviour disorder.2 The pattern of disorder is variable. All the problems that may occur in normal children may occur in the handicapped, but for these the difficulties are compounded by secondary problems resulting from the difficulties that the family have in dealing with the handicap. Parental guilt and uncertainty added to the social restrictions that may arise from the chore of caring for a handicapped child cause problems in the rest of the family, and these may increase the behaviour disturbance. In an institution the problems are just as great. Those who care for mentally handicapped children are often doing so in the most difficult circumstances. Old buildings, staff shortages, and overcrowding all tend to reduce the amount of communication and interaction between staff and patient. In one survey a ward of 20 severely retarded children had three staff to look after them and only 60' of staff time was spent in initiating reactions and trying to communicate with the children.' The nursing staff were busy with the housekeeping duties to the virtual exclusion of their role as substitute parent, teacher, organiser, and adviser. In this setting behaviour that is awkward for the institution is likely to get overtreated with drugs. It is easy to see how the needs of the institution may seem to be set before those of the individual,4 yet mental subnormality does not diminish an individual's emotional needs. Drugs are needed for the mentally handicapped as they are for normal children, but they are not necessarily needed in any greater quantity for the mentally handicapped, and in particular should be used with discretion for the treatment of behaviour disturbances. Some apparent behaviour disorders may be caused by conditions demanding drug treatment. The child who is confused and stuporous as a result of repeated epileptic seizures may benefit dramatically from appropriate anticonvulsant treatment. A few children with hyperkinetic behaviour may benefit from drug treatment, but for that condition and most other behaviour disturbances it is more important to look for ways of manipulating the environment to
924
alter the behaviour. This may require changing the child's timetable or his room or ward; it may mean more personal contact with a particular relative or a member of staff. When drugs are given their use should be reconsidered at frequent intervals. When hypnotics or sedatives are prescribed to help in a crisis they should be stopped when the crisis is over. When they are used to tide over a period during which alternative management is introduced they should be stopped soon after the introduction of the new regimen. It may then be possible to see if the changes really are in the best interests of the child. Kirman, B, British Journal of Psychiatry, 1975, 127, 545. 2Department of Health and Social Security, Census of Mentally Handicapped Patients in Hospitals in England and Wales at the End of 1970. London, HMSO, 1972. 3Wright, E, Abbas, K A, and Meredith, C, British Journal of Mental Subnormality, 1974, 20, 14. 4Raynes, N V, and King, R D, in Proceedings of 1st Congress of the International Association for the Scientific Study of Mental Deficiency, 1967, ed B W Richard, p 657. Reigate, Michael Jackson Publishing Co, 1968. I
Surgery for epilepsy Enough time has passed since the introduction of surgical treatment for temporal lobe epilepsy for a very clear picture to have emerged of the indications, results, and morbidity of the operations. Yet opinion still remains uncertain and medical treatment is often continued in spite of poor control of seizures with their associated morbidity and mortality. Is this due to fear of surgery and uncertainty about the outcome or to difficulty in obtaining the necessary advice ? Recently in an attempt to clarify the situation Jensen 1-3 has carried out an extensive analysis of the published results of surgery in the treatment of temporal lobe epilepsy based on the results of 2282 resections carried out between 1928 and 1973. There is almost universal agreement on the conditions (for example, those suggested by Rasmussen4 and Falconer5) which need to be fulfilled before operation should be considered. Firstly, there must have been a failure to respond to a really adequate trial of drug treatment, including monitoring of the blood levels. There must be evidence of a predominantly or wholly unilateral temporal disorder, as shown by inferior or anterior temporal spikes in the electroencephalogram. If these are bilateral they must be at least four times more frequent on the side to be operated upon. The fits must have been established long enough for there to be reasonable certainty that all potentially epileptogenic areas have manifested themselves and that spontaneous regression is unlikely. Finally the patient must have an IQ of at least 60. Patients with tumours, arteriovenous malformations, or abscesses are excluded from consideration in this context; their indications for operation are not based on the control of epilepsy alone. Considering only those series in which these criteria were fulfilled, and in which adequate preoperative and postoperative data were available, Jensen found that 43 6% of 885 patients were entirely free from seizures after operation. In 18% the fits were reduced to less than one-quarter of their former incidence, and in a further 16-5% there were less than half the number of seizures. Analysis of the reports shows rather a wide scatter in the success rates, but a closer look shows that those
BRITISH MEDICAL JOURNAL
17 APRIL 1976
series in which surgery was limited to a superficial or partial removal of the temporal lobe had fewer successful results than those in which the deeper structures-including parts of the amygdalum, uncus, and hippocampus-were removed. In a recent series Van Burent found a success rate of only 60OX for partial operations and 50° 0, for the total removal. Again, inclusion of patients with bilateral abnormalities also reduces the success rate, as was shown by Bailey7 and Bloom8 and their co-workers. The number of patients with psychiatric abnormality varied from one centre to another, but more than 5000 of those who had mental abnormalities preoperatively were improved or returned to normal. Jensen also showed that neither the epileptic nor the psychiatric history affected the outcome of surgery unless there were genetic factors in both parents. If this was so the likelihood of benefit to the fit pattern or the psychiatric outcome was reduced. The mortality from the operations was under 1°0/ and the morbidity was low. Persistent hemiparesis occurred in 2.40/a of the 885 patients studied by Jensen and transient hemiparesis in 4.20/,, but these proportions have fallen slightly in recent years. Minor visual defects, of which the patient was unaware, were quite common, and a complete homonymous hemianopia occurred in 8.30). Temporary dysphasia and diplopia did occur, but they did not persist. A further inquiry was undertaken into the late mortality after operation. The late mortality of 47-6 per 1000 contrasted with an expected mortality of 2-9 per 1000 in a normal population, but the expected mortalitv in a similar group of Danish epileptic patients not treated surgically would be 59 4 per 1000. Most late deaths were in the group of 16-5%K, of patients with less than a 50%/ reduction in their fits: 62%' of these deaths were due to epilepsy, while other causes included suicide in 28% of those who died and who had continued to suffer from their fits after operation. In a Danish investigation by Henriksen et a19 the excess mortality ratio due to suicide among patients with epilepsy was shown to be 30000; it accounted for 20%/ of deaths. This is a measure of suffering, and of the need to use every means to prevent it. Resections of other parts of the cerebral hemispheres for the treatment of epilepsy were shown by Rasmussen'0 and Feindel1 to have a success rate of 30-45%, but the results may be less permanent. Treatment by implanted electrodes and stereotactic lesions has yet to be fully evaluated. But the value of surgery in the treatment of intractable temporal lobe seizures is now clearly established. The presence of demonstrable and eradicable disease is clear. Two-thirds of the patients operated upon will be helped significantly. The prospect of relief should therefore not be denied to those who need it. IJensen, I, Acta Neurologica Scandinavica, 1975, 52, 354. 2 Jensen, I, Acta Neurologica Scandinavica, 1975, 52, 374. 3Jensen, Acta Neurologica Scandinavica, 1975, 52, 381. 4Rasmussen, T, Clinical Neurosurgery, 1969, 16, 288. 5 Falconer, M A, Neurochirurgia, 1965, 8, 161. 6 Van Buren, J M, Marsan, C A, and Mutsuga, N,Journal of Neurosurgery, 1975, 43, 596. 7Bailey, et al, Research Publications Association for Research in Nervous and Mental Disease, 1953, 31, 341. 8 Bloom, D, Jasper, H, and Rasmussen, T, Epilepsia (Amsterdam), 1960, 1, 351. 9 Henriksen, B, Juul-Jensen, P, and Lund, M, Life Assurance Medicine, ed R D C Brackenridge, p 139. London, Pitman, 1970. 10 Rasmussen, T, Advances in Neurology, ed D Purpura, J K Penry, and R D Walter, vol 8, pp 197 and 207. New York, Raven Press, 1975. Feindel, W, Advances in Neurology, ed D Purpura, J K Penry, and R D Walter, vol 8, p 281. New York, Raven Press, 1975.
