54
with an absorption spectrum similar to that of yellow soft paraffin alone. Emulsifying ointment dissolved in chloroform had an E (1%, 1 cm) of 1 at 310 nm, increasing to 4-5 at 260 nm, largely because of the yellow soft paraffin component. Thus emulsifying ointment has a major sunscreen activity in clinically normal skin, in accord with Lowe and Ferguson’s2 findings for emollients. The sunscreen effect of salicylic acid3 could not be detected although the absorption ofUVB by salicylic acid in vitro was about twenty times greater than by emulsifying ointment. The concentration of salicylic acid for topical application was only 2%, and any effect was presumably insignificant compared with that of the ointment base. No important anti-inflammatory effect of salicylic acid could be detected although it has been reported to reduce UVB-induced erythema.4 Emulsifying ointment should not be used before phototherapy or in phototesting procedures. Department of Dermatology, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP, UK
NEIL H. COX GRAHAM SHARPE
1 Farr PM, Diffey BL. Quantitative studies on cutaneous erythema induced by ultraviolet radiation. Br J Dermatol 1984; 111: 673-82. 2. Lowe JG, Ferguson J. Which emollients should be used during phototherapy (UVB)/photochemotherapy (PUVA) for psoriasis? A study of emollient effect on minimal erythema (MED) and phototoxic (MPD) doses. Br J Dermatol 1988; 119 (suppl 33): 52-53. 3. Weirich EG. Dermatopharmacology of salicylic add I: range of dermatotherapeutic effects of salicyclic acid. Dermatologica 1975; 151: 268-73. 4. Weirich EG, Longauer J, Kirkwood AH. Dermatopharmacology of salicylic acid III: topical contrainflammatory effect of salicylic add and other drugs in animal experiments. Dermatologica 1976; 152: 87—99.
Peroperative bupivacaine for pyloromyotomy pain SIR,-Pyloromyotomy is generally a very safe procedure1 but there is a reluctance to provide narcotic analgesia for these children because of the risk of dangerous respiratory depression 2 Anaesthesia usually consists of nitrous oxide, with an added inhalational agent, ventilation being controlled by muscle relaxation. Mild oral analgesics such as paracetamol may not be sufficient to control pain.3,4 Anand et all have shown that the stress response in newborn babies undergoing major surgery (thoracotomy) can be modified by adding fentanyl. For some time we have been using bupivacaine, injected intraoperatively, to control pain after pyloromyotomy. To see if this practice affected postoperative behaviour and clinical and metabolic responses we have done a randomised controlled study in 17 children, with ethical committee and parental consent. Preoperatively, pulse, BP, respiratory rate, Sa02 and glucose were noted and there were no significant differences between the two groups. Atropine 15-20 Ilg/kg was injected intramuscularly 1 h before the operation and anaesthesia was induced with thiopentone 3-5 mg/kg, followed by vecuronium 80 ug/kg. Patients were intubated and given 70% nitrous oxide and oxygen. Halothane 1 % was added until the anterior rectus sheath was incised then reduced to z5 % (enflurane was used for 1 patient in each group). One group then had bupivacaine 0-25% plus adrenaline injected under the anterior rectus sheath on either edge of the wound, to a maximum dose of 15 mg/kg. Postoperatively intravenous quarter-strength saline in 5% dextrose was given at a rate of 4 ml/kg/h. 14 patients were monitored in the recovery room by an independent observer immediately after the child had settled and at 10, 30 and 60 min postoperatively. Indices monitored were behaviour (sleep, wakefulness, crying, grimacing, moving legs), pulse, blood pressure, respiration, and Sa02. At 6 and 24 h postoperatively pulse, blood pressure, respiratory rate, and Sa02 were recorded. Glucose was measured 6 h postoperatively and urine urea was collected for 3 days for 3-methylhistidine/creatinine ratios. There were no signficant differences for age or weight between controls (n 6) and the bupivacaine group (n 8). (A further 3 controls had urine taken for 3 days.) All but 2 children in the bupivacaine group were asleep or comfortably awake at all observation times; a 5-week-old boy was noticed to be crying and a 10-week-old boy to be grimacing, both 30 =
=
t and respiratory rates from preoperative values in firstpost perative days.
Changes in 4
Significance as *p=0 306,"). =024, and ***p=0 05 for heart rate as *p< 0.03 for respiratory rate.
and
min postoperatively. 4 children in the control group were sleeping immediately after surgery, but only 2 were asleep at 10 and 30 min, and none was asleep at 60 min (p < 0 001, p < 0,01, and p < 0.001 for the three times, respectively). In the controls the heart rate tended to increase from baseline level while in the bupivacaine group it fell (figure). Differences were significant at 30 min, 60 min, and 24 h. Respiratory rates increased in controls and fell in the bupivacaine group, differences being significant at 10,30, and 60 min (figure). There were no significant differences between the two groups for changes in blood pressure or
Sa02. Both groups showed a mild hyperglycaemic response at 6 h of 0-85 (SE 0-74) mmol/1 in the controls and 0-7 (0-59) mmol/1 in the
bupivacaine group. Urinary 3-methylhistidine/creatinine ratios did differ on any of the postoperative days and all values were
not
normal. Pain and analgesic requirements in infants are difficult to assess. Crying, grimacing, and body movements are regarded as indicating that a child is in pain/-9 and changes in pulse and respiratory rates are associated with pain. However, these changes may reflect hunger, for example, rather than pain, and some children may react to pain by remaining unduly quiet. 10 Nonetheless the differences we found do suggest that the controls had more pain than the bupivacaine group, and the pulse and respiration rates support that view. The postoperative hyperglycaemic response and changes in 3-methylhisitdine excretion, which have been shown to reflect the stress response in infants,,6 were not different in the two groups The minor hyperglycaemic response seen after inhalational anaesthesiawas not modified by bupivacaine. Our findings suggest that infants undergoing pyloromyotorr under general anaesthesia with an inhalational agent and no oth form of analgesia show behavioural changes and alterations in heat and respiratory rates which can be modified by the injection of
55
bupivacaine 1mg/kg deep to the anterior rectus sheath during the operation. Had we also injected bupivacaine deep to the muscle, between it and the rectus sheath, a more complete block might have
pharmaceutical industry has been encouraging cholesterol testing in primary care. We believe that this practice may fail to conform with the ABPI Code of Practice for the pharmaceutical industry.2
resulted.
National Forum for Coronary Heart Disease Prevention, London WC1
IMOGEN SHARP
Coronary Prevention Group, 60 Great Ormond Street, London WC1 N 3HR, UK
MIKE RAYNER
L. R. MCNICOL Department of Anaesthesia, and Biochemistry Royal Hospital for Sick Children, Glasgow G3 8SJ, UK
C. S. MARTIN N. G. SMART R. W. LOGAN
NJ, Fitzpatrick GJ, Moore KP, et al. Anaesthesia for congenital hypertrophic pyloric stenosis: a review of 350 patients. Br J Anaesth 1987; 59:
1. MacDonald
B, Hutton J. Changing medical practice: a study of reflotron use in general practice. York: Centre for Health Economics Consortium, 1989. 2. Association of the British Pharmaceutical Industry. Code of practice for the pharmaceutical industry. London: ABPI, 1988. 1. Leese
672-77.
Purcell-Jones G, Dorman F, Sumner E. The use of opioids in neonates: a retrospective study of 933 cases. Anaesthesia 1987; 42: 1316-20. 3. Hatch DJ. Analgesia in the neonate. Br Med J 1987; 294: 920. 4. Booker PD. Post-operative analgesia for neonates? Anaesthesia 1987; 42: 343-45. 5. Anand KJS, Sippell WG, Aynsley-Green A. Randomised trial of fentanyl in pre-term babies undergoing surgery: effects on the stress response. Lancet 1987; i: 243-47. 6. Anand KJS, Sippell WG, Schofield NM, Aynsley-Green A. Does Halothane 2.
anaesthesia decrease the metabolic and endocrine stress response of newborn infants undergoing operation? Br Med J 1988; 296: 668-72. 7. Owens ME. Pain in infancy: conceptual and methodological issues. Pain 1984; 20: 213-30. 8. Anand KJS, Hickey PR. Pain and its effects in the human neonate and fetus. N Engl J Med 1987; 317: 1321-29. 9. McGrath PA. An assessment of children’s pain: a review of behavioural, physiological and direct scaling techniques. Pain 1987; 31: 147-76 10. Marshall RE, Stratton WC, Moore JA, Boxerman SB. Circumcision I: Effects upon newborn behaviour. Infant Behav Devel 1980; 3: 1-14.
Cholesterol testing with desk-top machines SIR,-Research on the relation between serum cholesterol concentration and coronary risk may have encouraged the growing interest in cholesterol testing as a means of assessing an individual’s risk of coronary heart disease (CHD). The development of desk-top measuring machines could now be allowing more tests to be carried out. The pharmaceutical industry may also be encouraging cholesterol testing to increase the prescription of cholesterol-
Psychotic symptoms in basal ganglia sclerosis SIR,-Your Nov 18 editorial on psychotic symptoms in Alzheimer’s disease mentions the association of delusions with basal ganglia calcification. This association has been repeatedly emphasised, but never statistically proven.12 We have evaluated cranial computed tomographic scans and neuropsychiatric symptoms in patients with unilateral or bilateral basal ganglia calcificationFahr’s syndrome3--and a random sample of patients without calcification, at the same time. The table shows patients’details. We showed in a log-linear model4 that the clinical disturbances and diagnoses were largely determined by the patients’ age and by atrophic brain disorders, which were more prevalent in the Fahr’s syndrome group. After correction for these confounding variables, the odds ratios did not support an increased rate of dementia in patients with basal ganglia sclerosis. However, the odds ratios for paranoid or affective syndromes, classified clinically as organic or non-organic disorders, was slightly increased in patients with basal ganglia calcification (odds ratios below 2).5 These differences were
significant (p < 0’05).
lowering drugs.
AGE AND DIAGNOSIS OF PATIENTS WITH BASAL GANGLIA CALCIFICATION AND CONTROLS
biennial conference of AC’. ;anticipatory care teams working for the prevention- et cardiovascular disease), delegates were asked about their practice with respect to cholesterol testing. A total of 220 questionnaires were completed by general practitioners, practice nurses, and health visitors, of whom 209 (95%) were doing cholesterol testing as. paÌ1: of their programme of risk assessment for CHD. 33 (15%) respondents were mainly using a desk-top measuring machine to measure cholesterol concentrations in blood samples, and the remainder were using their local hospital laboratory. 64% (21/33) of those using a desk-top machine were testing blood cholesterol in all their patients participating in a CHD prevention programme, compared with 33% (58/174) of those who were mainly using their local hospital At the
recent
laboratory to assess samples. We asked about how desk-top measuring machines had been acquired and the results were: No of
findings agree with the hypothesis that basal ganglia are implicated in sensory gating, cognition, and affect.6 This weak Our
association, however, should not encourage the notion that there was a clinically distinct Fahr’s syndrome of a specific of specific clinical symptoms, such as delusions. This weak statistical association cannot account for the various neuropsychiatric disturbances in individuals, which should be investigated in every case.
neuropathological aspect
-
-
-
HANS FORSTL
Departments of Psychiatry, Biostatistics, and Neuroradiology, Central Institute of Mental Health, 6800 Mannheim 1, West Germany
had
The primary health care professionals questioned a particular interest in CHD prevention, and therefore it was not unexpected that most were undertaking some cholesterol testing as part of their preventive work. Surprisingly few (only 1 in 7) of the respondents were using a desk-top measuring device, but such use seemed to increase the number of cholesterol tests done. The least expensive desk-top machine costs more than L4000-a non-reimbursable expense which must inhibit their widespread use in general practice. On the other hand the loan or gift of a machine by a pharmaceutical company is one way in which the
SILKE EDEN BERTRAM KRUMM KNUT KOHLMEYER
Cummings JL. Organic delusions: phenomenology, anatomical correlations and review Br J Psychiatry 1985; 146: 184-97. 2. Konig P. Psychopathological alterations in cases of symmetrical bilateral basal ganglia sclerosis. Biol Psychiatry 1989; 25: 459-68. 3. Fahr T Idiopathische Verkalkung der Hirengefässe. Centralbl Allg Pathol Pathol 1
Anat 1930; 50: 129-33. Fienberg SE The analysis of cross-classified categorical data. Cambridge, Mass: MIT Press, 1980. 5. Sandercock P The odds ratio: a useful tool in neurosciences. J Neurol Neurosurg Psychiatry 1989; 52: 817-20. 6. Schneider JS. Basal ganglia role in behaviour: importance of sensory gating and its relevance to psychiatry. Biol Psychiatry 1984; 19: 1693-710 4.
with an absorption spectrum similar to that of yellow soft paraffin alone. Emulsifying ointment dissolved in chloroform had an E (1%, 1 cm) of 1 at 310 nm, increasing to 4-5 at 260 nm, largely because of the yellow soft paraffin component. Thus emulsifying ointment has a major sunscreen activity in clinically normal skin, in accord with Lowe and Ferguson’s2 findings for emollients. The sunscreen effect of salicylic acid3 could not be detected although the absorption ofUVB by salicylic acid in vitro was about twenty times greater than by emulsifying ointment. The concentration of salicylic acid for topical application was only 2%, and any effect was presumably insignificant compared with that of the ointment base. No important anti-inflammatory effect of salicylic acid could be detected although it has been reported to reduce UVB-induced erythema.4 Emulsifying ointment should not be used before phototherapy or in phototesting procedures. Department of Dermatology, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP, UK
NEIL H. COX GRAHAM SHARPE
1 Farr PM, Diffey BL. Quantitative studies on cutaneous erythema induced by ultraviolet radiation. Br J Dermatol 1984; 111: 673-82. 2. Lowe JG, Ferguson J. Which emollients should be used during phototherapy (UVB)/photochemotherapy (PUVA) for psoriasis? A study of emollient effect on minimal erythema (MED) and phototoxic (MPD) doses. Br J Dermatol 1988; 119 (suppl 33): 52-53. 3. Weirich EG. Dermatopharmacology of salicylic add I: range of dermatotherapeutic effects of salicyclic acid. Dermatologica 1975; 151: 268-73. 4. Weirich EG, Longauer J, Kirkwood AH. Dermatopharmacology of salicylic acid III: topical contrainflammatory effect of salicylic add and other drugs in animal experiments. Dermatologica 1976; 152: 87—99.
Peroperative bupivacaine for pyloromyotomy pain SIR,-Pyloromyotomy is generally a very safe procedure1 but there is a reluctance to provide narcotic analgesia for these children because of the risk of dangerous respiratory depression 2 Anaesthesia usually consists of nitrous oxide, with an added inhalational agent, ventilation being controlled by muscle relaxation. Mild oral analgesics such as paracetamol may not be sufficient to control pain.3,4 Anand et all have shown that the stress response in newborn babies undergoing major surgery (thoracotomy) can be modified by adding fentanyl. For some time we have been using bupivacaine, injected intraoperatively, to control pain after pyloromyotomy. To see if this practice affected postoperative behaviour and clinical and metabolic responses we have done a randomised controlled study in 17 children, with ethical committee and parental consent. Preoperatively, pulse, BP, respiratory rate, Sa02 and glucose were noted and there were no significant differences between the two groups. Atropine 15-20 Ilg/kg was injected intramuscularly 1 h before the operation and anaesthesia was induced with thiopentone 3-5 mg/kg, followed by vecuronium 80 ug/kg. Patients were intubated and given 70% nitrous oxide and oxygen. Halothane 1 % was added until the anterior rectus sheath was incised then reduced to z5 % (enflurane was used for 1 patient in each group). One group then had bupivacaine 0-25% plus adrenaline injected under the anterior rectus sheath on either edge of the wound, to a maximum dose of 15 mg/kg. Postoperatively intravenous quarter-strength saline in 5% dextrose was given at a rate of 4 ml/kg/h. 14 patients were monitored in the recovery room by an independent observer immediately after the child had settled and at 10, 30 and 60 min postoperatively. Indices monitored were behaviour (sleep, wakefulness, crying, grimacing, moving legs), pulse, blood pressure, respiration, and Sa02. At 6 and 24 h postoperatively pulse, blood pressure, respiratory rate, and Sa02 were recorded. Glucose was measured 6 h postoperatively and urine urea was collected for 3 days for 3-methylhistidine/creatinine ratios. There were no signficant differences for age or weight between controls (n 6) and the bupivacaine group (n 8). (A further 3 controls had urine taken for 3 days.) All but 2 children in the bupivacaine group were asleep or comfortably awake at all observation times; a 5-week-old boy was noticed to be crying and a 10-week-old boy to be grimacing, both 30 =
=
t and respiratory rates from preoperative values in firstpost perative days.
Changes in 4
Significance as *p=0 306,"). =024, and ***p=0 05 for heart rate as *p< 0.03 for respiratory rate.
and
min postoperatively. 4 children in the control group were sleeping immediately after surgery, but only 2 were asleep at 10 and 30 min, and none was asleep at 60 min (p < 0 001, p < 0,01, and p < 0.001 for the three times, respectively). In the controls the heart rate tended to increase from baseline level while in the bupivacaine group it fell (figure). Differences were significant at 30 min, 60 min, and 24 h. Respiratory rates increased in controls and fell in the bupivacaine group, differences being significant at 10,30, and 60 min (figure). There were no significant differences between the two groups for changes in blood pressure or
Sa02. Both groups showed a mild hyperglycaemic response at 6 h of 0-85 (SE 0-74) mmol/1 in the controls and 0-7 (0-59) mmol/1 in the
bupivacaine group. Urinary 3-methylhistidine/creatinine ratios did differ on any of the postoperative days and all values were
not
normal. Pain and analgesic requirements in infants are difficult to assess. Crying, grimacing, and body movements are regarded as indicating that a child is in pain/-9 and changes in pulse and respiratory rates are associated with pain. However, these changes may reflect hunger, for example, rather than pain, and some children may react to pain by remaining unduly quiet. 10 Nonetheless the differences we found do suggest that the controls had more pain than the bupivacaine group, and the pulse and respiration rates support that view. The postoperative hyperglycaemic response and changes in 3-methylhisitdine excretion, which have been shown to reflect the stress response in infants,,6 were not different in the two groups The minor hyperglycaemic response seen after inhalational anaesthesiawas not modified by bupivacaine. Our findings suggest that infants undergoing pyloromyotorr under general anaesthesia with an inhalational agent and no oth form of analgesia show behavioural changes and alterations in heat and respiratory rates which can be modified by the injection of
55
bupivacaine 1mg/kg deep to the anterior rectus sheath during the operation. Had we also injected bupivacaine deep to the muscle, between it and the rectus sheath, a more complete block might have
pharmaceutical industry has been encouraging cholesterol testing in primary care. We believe that this practice may fail to conform with the ABPI Code of Practice for the pharmaceutical industry.2
resulted.
National Forum for Coronary Heart Disease Prevention, London WC1
IMOGEN SHARP
Coronary Prevention Group, 60 Great Ormond Street, London WC1 N 3HR, UK
MIKE RAYNER
L. R. MCNICOL Department of Anaesthesia, and Biochemistry Royal Hospital for Sick Children, Glasgow G3 8SJ, UK
C. S. MARTIN N. G. SMART R. W. LOGAN
NJ, Fitzpatrick GJ, Moore KP, et al. Anaesthesia for congenital hypertrophic pyloric stenosis: a review of 350 patients. Br J Anaesth 1987; 59:
1. MacDonald
B, Hutton J. Changing medical practice: a study of reflotron use in general practice. York: Centre for Health Economics Consortium, 1989. 2. Association of the British Pharmaceutical Industry. Code of practice for the pharmaceutical industry. London: ABPI, 1988. 1. Leese
672-77.
Purcell-Jones G, Dorman F, Sumner E. The use of opioids in neonates: a retrospective study of 933 cases. Anaesthesia 1987; 42: 1316-20. 3. Hatch DJ. Analgesia in the neonate. Br Med J 1987; 294: 920. 4. Booker PD. Post-operative analgesia for neonates? Anaesthesia 1987; 42: 343-45. 5. Anand KJS, Sippell WG, Aynsley-Green A. Randomised trial of fentanyl in pre-term babies undergoing surgery: effects on the stress response. Lancet 1987; i: 243-47. 6. Anand KJS, Sippell WG, Schofield NM, Aynsley-Green A. Does Halothane 2.
anaesthesia decrease the metabolic and endocrine stress response of newborn infants undergoing operation? Br Med J 1988; 296: 668-72. 7. Owens ME. Pain in infancy: conceptual and methodological issues. Pain 1984; 20: 213-30. 8. Anand KJS, Hickey PR. Pain and its effects in the human neonate and fetus. N Engl J Med 1987; 317: 1321-29. 9. McGrath PA. An assessment of children’s pain: a review of behavioural, physiological and direct scaling techniques. Pain 1987; 31: 147-76 10. Marshall RE, Stratton WC, Moore JA, Boxerman SB. Circumcision I: Effects upon newborn behaviour. Infant Behav Devel 1980; 3: 1-14.
Cholesterol testing with desk-top machines SIR,-Research on the relation between serum cholesterol concentration and coronary risk may have encouraged the growing interest in cholesterol testing as a means of assessing an individual’s risk of coronary heart disease (CHD). The development of desk-top measuring machines could now be allowing more tests to be carried out. The pharmaceutical industry may also be encouraging cholesterol testing to increase the prescription of cholesterol-
Psychotic symptoms in basal ganglia sclerosis SIR,-Your Nov 18 editorial on psychotic symptoms in Alzheimer’s disease mentions the association of delusions with basal ganglia calcification. This association has been repeatedly emphasised, but never statistically proven.12 We have evaluated cranial computed tomographic scans and neuropsychiatric symptoms in patients with unilateral or bilateral basal ganglia calcificationFahr’s syndrome3--and a random sample of patients without calcification, at the same time. The table shows patients’details. We showed in a log-linear model4 that the clinical disturbances and diagnoses were largely determined by the patients’ age and by atrophic brain disorders, which were more prevalent in the Fahr’s syndrome group. After correction for these confounding variables, the odds ratios did not support an increased rate of dementia in patients with basal ganglia sclerosis. However, the odds ratios for paranoid or affective syndromes, classified clinically as organic or non-organic disorders, was slightly increased in patients with basal ganglia calcification (odds ratios below 2).5 These differences were
significant (p < 0’05).
lowering drugs.
AGE AND DIAGNOSIS OF PATIENTS WITH BASAL GANGLIA CALCIFICATION AND CONTROLS
biennial conference of AC’. ;anticipatory care teams working for the prevention- et cardiovascular disease), delegates were asked about their practice with respect to cholesterol testing. A total of 220 questionnaires were completed by general practitioners, practice nurses, and health visitors, of whom 209 (95%) were doing cholesterol testing as. paÌ1: of their programme of risk assessment for CHD. 33 (15%) respondents were mainly using a desk-top measuring machine to measure cholesterol concentrations in blood samples, and the remainder were using their local hospital laboratory. 64% (21/33) of those using a desk-top machine were testing blood cholesterol in all their patients participating in a CHD prevention programme, compared with 33% (58/174) of those who were mainly using their local hospital At the
recent
laboratory to assess samples. We asked about how desk-top measuring machines had been acquired and the results were: No of
findings agree with the hypothesis that basal ganglia are implicated in sensory gating, cognition, and affect.6 This weak Our
association, however, should not encourage the notion that there was a clinically distinct Fahr’s syndrome of a specific of specific clinical symptoms, such as delusions. This weak statistical association cannot account for the various neuropsychiatric disturbances in individuals, which should be investigated in every case.
neuropathological aspect
-
-
-
HANS FORSTL
Departments of Psychiatry, Biostatistics, and Neuroradiology, Central Institute of Mental Health, 6800 Mannheim 1, West Germany
had
The primary health care professionals questioned a particular interest in CHD prevention, and therefore it was not unexpected that most were undertaking some cholesterol testing as part of their preventive work. Surprisingly few (only 1 in 7) of the respondents were using a desk-top measuring device, but such use seemed to increase the number of cholesterol tests done. The least expensive desk-top machine costs more than L4000-a non-reimbursable expense which must inhibit their widespread use in general practice. On the other hand the loan or gift of a machine by a pharmaceutical company is one way in which the
SILKE EDEN BERTRAM KRUMM KNUT KOHLMEYER
Cummings JL. Organic delusions: phenomenology, anatomical correlations and review Br J Psychiatry 1985; 146: 184-97. 2. Konig P. Psychopathological alterations in cases of symmetrical bilateral basal ganglia sclerosis. Biol Psychiatry 1989; 25: 459-68. 3. Fahr T Idiopathische Verkalkung der Hirengefässe. Centralbl Allg Pathol Pathol 1
Anat 1930; 50: 129-33. Fienberg SE The analysis of cross-classified categorical data. Cambridge, Mass: MIT Press, 1980. 5. Sandercock P The odds ratio: a useful tool in neurosciences. J Neurol Neurosurg Psychiatry 1989; 52: 817-20. 6. Schneider JS. Basal ganglia role in behaviour: importance of sensory gating and its relevance to psychiatry. Biol Psychiatry 1984; 19: 1693-710 4.
