tests has been called into question. In 105 patients with proved tumours we found tone decay in 25 (24%), abnormal loudness balance in 71 (68%), and abnormal speech audiometry in 49 (47%). Although better, the stapedial reflex threshold and decay parameters were normal in 17 (16%) of these patients. Even the auditory brainstem response has its limitations. In most series it has been found to be a sensitive test (only 2% of these patients had a normal auditory brainstem response), but Lai et al recently reported an incidence of 24% normal or equivocal auditory brainstem responses in patients with proved tumours.3 Furthermore, the specificity of the test is very poor. Radiological diagnosis is now highly reliable. Computed tomography with contrast will show most intracranial lesions. Magnetic resonance imaging enhanced with gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) will reveal all tumours regardless of size.4 We believe that there is an overwhelming case for all patients with unilateral audiovestibular symptoms for which there is no other plausible explanation to be examined with computed tomography or magnetic resonance imaging. Computed tomography is now available in most parts of Britain, and the same will soon be true of magnetic resonance imaging, which is the optimal tool for neuro-otological diagnosis. Our final point concerns cost. Financial audit in such matters is a firmament full of black holes. We accept the calculations of Drs Swann and Gatehouse, but there are certain omissions. Moffat et al5 made the point that the failure to diagnose a small tumour may make the difference between a patient who rapidly returns to work and one who is in need of state support for years. Lastly, we cannot ignore the medicolegal climate. An increasing number of suits are being filed for failed diagnosis of acoustic neuroma. Health authorities will have to consider this cost with as much concern as the cost of neuroradiological imaging

techniques. RICHARD RAMSDEN RICHARD LYE JOHN DUTTON

Departments of Otolaryngology and Neurosurgery, Manchester Royal Infirmary, Manchester M13 9WL 1 Swann IRC,Gatehouse S. Clinical and financial audit of diagnostic

protocols for lesions of the cerebellopontine angle. BMJ 1991;302:701-4. (23 March.) 2 Dutton JEM, Ramsden RT, Lye RH, et al. Acoustic neuroma (schwannoma)-surgery 1978-1990. 7 Laryngol Otol 1991;105:

165-73. 3 Lai D, Gibson W, Scrivener B. Prognostic factors for facial nerve function after acoustic neuroma surgery. journal of the Otolaryngology Society of Australia 1991-5:414-8. 4 Stack JP, Ramsden RT, Antoun NM, Lye RH, Isherwood I, Jenkins JPR. Magnetic resonance imaging of acoustic neuromas: the role of gadolinium-DTPA. Br I Radiol

1988;61:800-5. 5 Moffat DA, Hardy DG, Baguley DM. Strategy and benefits of acoustic neuroma searching.J Laryngol Otol 1989;103:51-9.

Terodiline for treating detrusor instability in elderly people SIR,-Terodiline has anticholinergic (selectively antimuscarinic) and calcium channel blocking activity and has been advocated for the treatment of urinary frequency and urge incontinence. Although it is widely prescribed, Dr Penelope Wiseman and colleagues could not show that it had any advantages over placebo in elderly patients with detrusor instability. ' In the past 12 months we have treated two patients, aged 76 and 78, who were referred for consideration of permanent pacing; each was receiving terodiline 12-5 mg twice daily for urge incontinence. In each case 24 hour Holter monitoring showed prolonged episodes of atrioventricular dissociation with ventricular rates of 30-40 beats/ minute. After terodiline was stopped repeat 24 hour recordings showed sinus rhythm through-

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out with only marginal prolongation of the PR interval and left axis deviation in each case. The manufacturer's datasheet lists tachycardia but not bradycardia among the side effects,2 although bradycardia and hypotension are described as features of overdosage, being attributed to predominance of the drug's calcium antagonist effects over its anticholinergic actions. It is important to appreciate that even standard doses of terodiline may precipitate atrioventricular dissociation in elderly patients who already have some features of conducting system disease. This may further alter the balance of possible risks to benefits to be considered when prescribing this drug. S W DAVIES S J BRECKER R N STEVENSON London Chest Hospital, London E2 9JX 1 Wiseman PA, Mialone-Lee J, Rai GS. Terodiline with bladder retraining for treating detrusor instability in elderly people. BMJ 1991;302:994-6. (27 April.) 2 Association of the British Pharmaceutical Industry. Data sheet compendium 1990-1991. London: Datapharm Publications, 1990:786.

Referral for suspected glaucoma SIR,-Messrs Maurice W Tuck and Ronald P Crick raise again the problem of direct referral of patients with suspected glaucoma from an optometrist to an ophthalmologist. ' Many patients with raised intraocular pressures are referred initially by their optometrist.2 The alarmed patient then has to trudge wearily and increasingly nervously to the general practitioner to obtain a further referral (often just a signature on the sight test form) to the local ophthalmologist. The system is clearly flawed, causing distress to the patient and wasting the general practitioner's time. A sensible solution, hinted at by Messrs Tuck and Crick, would be to permit direct referral provided that the optometrist has performed all three main tests for glaucoma- tonometry, ophthalmoscopy, and perimetry-and that he or she notifies the general practitioner independently. The present system of referral through the general practitioner would otherwise apply. This would have the benefit of providing the ophthalmologist with an initial or "baseline" set of investigations, and would provide an incentive to optometrists to equip themselves adequately and to perform these tests routinely. With greater competition among high street optometrists, providing such services is likely to become increasingly important. Close cooperation locally would allow quicker referral for the patient, enhanced professional responsibility for optometrists, better information for the ophthalmologist, and a reduction of the general practitioner's workload. D R TREW

Eye Unit, Sutton Hospital, Sutton SM2 5NF 1 Tuck MW, Crick RP. Efficiency of referral for suspected glaucoma. BMJ 1991;302:998-1000. (27 April.) 2 Harrison RJ, Wild JM, Hobley AJ. Referral patterns to an ophthalmic outpatient clinic by general practitioners and ophthalmic opticians and the role of these professionals in screening for ocular disease. BMJ 1988;297:1162-7.

No blood, no drug SIR,-Dr Fred Charatan detailed the recent developments in the United States concerning the Clozaril Patient Management System (CPMS), and this news item was followed by a brief footnote on the situation in Britain.' The United Kingdom Clozaril Patient Monitoring Service is completely separate from the monitoring system in the United

States (though sharing the same safety objective of prompt detection of blood dyscrasia) and has been codeveloped by Sandoz Pharmaceuticals (UK) and leading representatives of the psychiatric and pharmacological professions in accordance with the requirements of health care services in the United Kingdom. As a fully licensed medicine, Clozaril (clozapine) was first introduced into the United Kingdom in January 1990 for schizophrenia resistant to treatment, accompanied by the centralised safety service that individually registers all psychiatrists and pharmacists who prescribe clozapine and also each patient for whom treatment is intended. After an initial screening patients are formally monitored throughout the duration of their treatment with clozapine. The service provides the necessary materials to send regular blood samples (weekly at first and fortnightly after 18 weeks of treatment) to the. CPMS laboratory for the standardised safety analysis (including white blood cell differential count). Where this screening detects an abnormal result the patient's care team is immediately notified to ensure that clozapine treatment stops and any necessary supportive measures are promptly instituted. A full 24 hour expert back up advisory service is provided. If a patient is withdrawn from clozapine the monitoring continues for a further four weeks. The monitoring service helps ensure that a patient is not inadvertently rechallenged with clozapine after withdrawal due to a blood abnormality. In addition to the safety that this assurance provides for individual patients, the Clozaril Patient Monitoring Service enables the full safety profile of clozapine to be continuously observed by the appropriate professional bodies, including the drug safety regulatory authorities. RICHARD M NOYELLE

Sandoz Pharmaceuticals, Camberley. Surrey GU 16 5SG I Charatan FB. No blood, no drug. BMJ7 1991;302:1041-2. (4 May.)

What is a normal upper gastrointestinal tract? SIR,-Drs D G Colin-Jones and P L Golding averred that "a normal upper gut does what is asked of it without complaint."' Were the behaviour ofthe lower gastrointestinal tract included, for continuity's sake, then the normal gastrointestinal tract could be regarded as that least susceptible, at the extreme, to gastric cancer and to chronic bowel diseases, including appendicitis, diverticular disease, and colorectal cancer. In this respect, rural Africans can claim merit. Until very recently gastric disease was rare and bowel diseases nearly absent. In 1986 at Murchison Hospital, Natal, of 136 patients with malignancies from a rural Zulu population of a quarter of a million there was one case of stomach cancer and were no cases of colorectal cancer.2 Even in cities, although dyspepsia and gastritis are becoming increasingly common, gastric cancer remains uncommon; moreover, the incidence of chronic bowel diseases has risen only slightly'which is puzzling because the diet of urban black people now includes 25-35% of energy from fat, and fibre intake, now 10-15 g daily, has fallen considerably. What is inhibiting rises in gastrointestinal- diseases? Regarding chronic bowel diseases, a large proportion of ingested starch from maize, the staple cereal, reaches the colon, ferments, and hence contributes to inhibit disease development.4 Faecal pH value has scarcely risen, thereby also conferring a measure of protection." Early local studies indicated absence of polyps in

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the large bowel and found that they did not give rise to malignancies.' At Baragwanath Hospital, colonoscopy studies (over 100 a year) confirm absence of polyps; the colons even of elderly black patients have the same appearance and elasticity as those of young white patients.8 Conceivably, any population subsisting on a diet high in foods containing fibre could be similarly protected. In the early 1.800s rural Scots ate oat porridge three times a day, seven days a week, with a thick vegetable soup at night.9 In England, rural farm workers consumed a huge amount of bread, several times our present consumption,'0 but virtually all were active physically. Perhaps their gastrointestinal tracts resembled those of rural Africans in their lesser proneness to disease. Present dietary guidelines, however vehemently urged, will never cause the gastrointestinal tract to revert to its pattern in former times. A R P WALKER B F WALKER

Human Biochemistry Research Unit, Department of Tropical Pathology, School of Pathology of the University of the Witwatersrand, Johannesburg, South Africa I SEGAL Gastroenterology Unit, Baragwanath Hospital and University of the Witwatersrand, Johannesburg, South Africa I Colin-Jones DG, Golding PL. What is a normal upper gastrointestinal tract? BMJ7 1991;302:742. (30 March.) 2 Gilpin TP, Walker ARP, Walker BF, Evans JA. Admissions of rural black patients to Murchison Hospital, Port Shepstone, Natal: causes of admissions and prospects of improvements. S Afr3' Food Sci Nutr 1989;1: 11-5. 3 Segal I, Walker ARP. Low fat intake with falling fiber intake commensurate with rarity of noninfective bowel diseases in blacks in Soweto, Johannesburg, Souith Africa. Nutr Cancer 1986;8: 185-91. 4 Segal I, Walker ARP, Naik I, Riedel L, Daya B, De Beer M. Absorption of carbohydrate food by blacks in Soweto, South Africa. S Afr Med7 (in press). 5 Walker ARP, Walker BF, Walker AJ. Faecal pH, dietary fibre intake, and proneness to colon cancer in four South African

populations. Brj Cancer 1986;53:489-95. 6 Thornton JR. High colonic pH promotes colorectal cancer.

Lancet 1981 ;i: 1083-7. 7 Bremner CG, Ackerman LV. Polyps and carcinoma of the large bowel in the South African Bantu. Cancer 1970;26:991-9. 8 Segal I, Cooke SA, Hamilton DG, Ou Tim L. Polyps and colorectal cancer in South African blacks. Gut 1981;22:653-7. 9 Kitchin AH, Passmore R. The Scotman's food. Edinburgh: Livingstone, 1949. 10 Anonymous. Brown bread versus white [editorial]. BMJ

1937;ii:752.

Waiting lists out, booking systems in SIR,-Miss Linda Beecham describes a "revolutionary" new system for booking patients in for operations. I was appointed consultant surgeon in West Berkshire in 1977 with outpatient clinics at Battle Hospital, Reading, and Newbury District Hospital. All patients seen at Battle Hospital have their operations there; most patients seen at Newbury Hospital can have their operations there, but those with more major problems are admitted to Battle Hospital. From the date of my appointment I ran a diary system at both hospitals, every patient needing surgery being given a date for admission and operation. I still continue this practice at Newbury Hospital. At Battle Hospital, however, in August 1989 a management decision resulted in 18 beds and three operating lists being taken away from the two consultant firms on which I work. I was forced to start a waiting list. During the past 18 months, from having no patients on the waiting list at Battle Hospital I now have 97, 25 of whom have been waiting for more than six months. Even if the beds and operating sessions that were taken away were returned there are now too many patients on the waiting list for the diary system to be reintroduced. Proposals such as those suggested by South Western Regional Health Authority are

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excellent in theory but fail to take into account those patients already on the waiting list. There are two prerequisites before waiting lists can be abolished: firstly, an initiative has to be taken to create over a defined period extra beds, operating sessions, and staff to work off the existing waiting list; and, secondly, adequate facilities (beds, operating time, and staff) must be made available to maintain a booking system. I doubt whether the political will and the finance will ever be made available to achieve these two prerequisites. R G FABER Battle Hospital, Reading, Berkshire RG3 lAG I Beecham L. Waiting lists out, booking system in. BMJ 1991; 302:929. (20 April.)

DRAMS scheme

ramp with a gradient of 1 in 10 may be easier to accommodate (in terms of space) and to use than a longer ramp with the traditionally recommended gradients of I in 12 to 1 in 20. The short ramp required a short burst of energy, whereas the longer ramp required a slower, sustained energy expenditure. These results confirmed the findings of a study by the Disabled Living Foundation that recommended, for wheelchair users who propel themselves, a gradient of 1 in 10 on a 3 m ramp.6 G M SWEENEY A K CLARKE

Roval National Hospital for Rheumatic Diseases, Bath BA I I RL 1 Travers AF. Ramps and rails. B13J 1991;302:951-4. (20 April.) 2 Sweeney GM, Clarke AK, Harrison RA, Bulstrode SJ. An evaluation of portable ramps. British Journal of- Occupational Therapy 1989;52:473-5. 3 Sweeney GM, Harrison RA, Clarke AK. Portable ramps for wheelchair users-an appraisal. Int Disabil Stud 1989;11: 6870. 4 British Standards Institute. Code ofJ practice for access Jor the disabled to buildings. London: BSI, 1979. (BS 5810.)

5 American National Standards Institute. Specifications for making

SIR,-We wish to clarify the Health Education Authority's position about the DRAMS (drinking reasonably and moderately with self control) scheme, which was developed in Scotland by the Scottish Health Education Group (now the Health Education Board for Scotland). ' The Health Education Authority is the statutory body charged with health education and health promotion in England. It has agreed to introduce the DRAMS pack to general practitioners and others together with a range of materials, such as the COD (cut down on your drinking) pack, which we and others are currently developing for those working in primary health care. These materials address the issue of sensible drinking in a variety of ways. Our intention is to acquaint general practitioners, trainers, and other staff with this range of materials and the different approaches through a series of introductory workshops. We hope that this will encourage general practitioners and regional advisers to make informed choices about alcohol training and support materials appropriate to their needs and the needs of their patients. We are confident that the incentives contained in the general practice contract will help achieve the widest practicable dissemination of DRAMS, COD, and other materials beyond these initial workshops. We will be happy to supply further details of our plans to anyone who contacts us. RAY EARWICKER TARA WOLFF

Health Education Authority, London WClH 9TX

buildings and facilities accessible to and usable by physically handicapped people. New York: ANSI, 1980. (Al17.1.) 6 Walters F. Four architectural movemett studies for the wheelchair and ambulant disabled. Part 3. Ramp gradients. London: Disabled Living Foundation, 1971.

Brain, mind, insanity, and the law SIR,-In his editorial on sane and insane automatism Dr P B C Fenwick repeats the canard that when a defendant is found to be suffering from insane automatism the judge must inevitably send him to a secure hospital.' This is not so. These defendants may be, and indeed are, sent to ordinary psychiatric hospitals, and the Home Secretary is by no means inflexible about their management. Thus in his research on the insanity defence and its consequences Mackay describes three cases in which the defendants were found to be insane, were sent to local hospitals, and were discharged within six weeks.2 One of these was a person with epileptic automatism. This does not mean that the 1964 act is altogether satisfactory, only that it can be operated humanely, and the Criminal Procedure (Insanity and Unfitness to Plead) Bill now before parliament will definitely be an improvement as it will make the proper disposal in these cases much easier. As an addendum, I should like to hear from Dr Fenwick when and where defendants suffering from anxiety are found to be insane. Mackay did not come across this diagnosis in any of those found insane in the years 1975-88. D TIDMARSH

I Nettleton B. DRAMS scheme. BMJ 1991;302:967. (20 April.)

Broadmoor Hospital,

Crowthorne, Berkshire RG I 1 7EG

Gradients of portable ramps SIR,-We found Dr A F Travers's article on ramps and rails interesting,' having recently evaluated commercially available portable ramps for the Department of Health2 and completed a separate study that aimed to establish gradients that could be negotiated by wheelchair users on two different lengths (1 m and 1-8 m) of otherwise identical portable ramps.3 In the light of the findings of the second study, we would query Dr Travers's recommendation that a ramp's gradient should not exceed 1 in 12 and should ideally be 1 in 20. Indeed, both the British Standards Institute and the American National Standards Institute recommend gradients of 1 in 12 or shallower,45 but we found that gradients of 1 in 8 and 1 in 6 could be negotiated on both lengths of ramp by a significant number of subjects in our study. A gradient of 1 in 10 on the 1 m ramp could be negotiated with relative ease by most of the subjects, and we concluded that a short

1 Fenwick PBC. Brain, mind, insanity, and the law. BMJ 1991;302:979-80. (27 April.) 2 Mackay RD. Fact and fiction about the insanity defence.

Crtminal Law Review 1990;37:247-55.

Been to Africa SIR,-Recently a wealth of material has been published testifying to the benefits of an elective period spent practising clinical medicine in the developing world. ` I agree with these sentiments, having recently returned from working as a lecturer in surgery in Nigeria. Clinical skills, operative experience, and management skills are all enhanced in a way that is not possible in the United Kingdom. Ms Alison Fiander, however, identifies a very real problem when she states that "unsupervised tropical experience is largely overlooked."6 Given the benefits attested to by so many, is it not time that formal links between clinical and 1277