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malformations. They found that patients with AWMtended to present with a large bleed, causing headache andsubarachnoid haemorrhage. Those with AOVM were morelikely to have an evolving or episodic disturbance, leading toan incorrect diagnosis of multiple sclerosis in some patients.We are not told whether there was any supportive evidencefor the clinical diagnosis of demyelination; such

misdiagnosis has been reported by others.5 Nor is it clearhow often MRI was the only investigation that revealed anabnormality but probably it was seldom. Usually the CTscan showed a hyperdense lesion and the differential

diagnosis for this is between haemorrhage, calcification,astrocytoma, oligodendroglioma, and granuloma. Less

commonly an area of reduced density was seen. MRI candistinguish between haemorrhage and the others.One reason for distinguishing AOVM from non-vascular

lesions is that surgery may have something to offer topatients with vascular malformation. In those with

brainstem malformations surgery is often not feasible, butvarious radiotherapeutic measures, including stereotacticprocedures, are now being evaluated.Vascular malformations are classified neuro-

pathologically as capillary telangiectases, cavernous

angiomas, and (arterio-)venous malformations. Capillarytelangiectases are a cluster of dilated capillary channels andare a common incidental finding at necropsy; they are mostfrequently over the pons and the cerebral cortex. Cavernousangiomas are thin-walled blood-filled spaces and are usuallylarger than capillary telangiectases. Arteriovenousmalformations consist of a tangle of vessels, usually arteriesand veins in which the former have excess elastic tissue andthe latter walls thickened by collagen. Abe et al did not haveenough histological data to classify their malformations, butit is possible that the capillary telangiectases and cavernousangiomas, which are low pressure and low flow systems,do not present with large haemorrhages and are

angiographically occult.

WHICH ORTHOSIS?

CONSIDERABLE media attention has lately been focusedon the problems of getting young paraplegic patients towalk. The high technology approach-ie, use of electricalimpulses to stimulate coordinated muscle function andthereby permit ambulation-has been emphasised. Thesetechniques are still experimental and are available only inspecialist centres. However, the difficulties faced by youngparaplegics are very real; any help that can be given to thisgroup of people to allow them to walk will not only facilitatean independent existence and improve their self-esteem butalso may well decrease the costs to the community in lookingafter them.Two orthoses have lately been developed to help young

paraplegic people to walk. The hip guidance orthosis

(HGO) is British and designed along classical NationalHealth Service lines, with substantial leather and metalcomponents and a regard for utility rather than cosmesis.The reciprocating gait orthosis (RGO) is American andmakes use of lightweight plastics. Unlike the HGO, theRGO is designed to be worn under clothing and is thereforecosmetically more acceptable.

5. Britt RH, Connor WS, Enzmann DR. Occult arteriovenous malformation of the brainstem simulating multiple sclerosis. Neurology 1981; 31: 901-04.

A comprehensive prospective trial was carried out toevaluate these two orthoses by the then Department ofHealth and Social Security.1 Unfortunately, few childrencould be recruited, so the study was undertaken withtwenty-two adults. Variables assessed included ease of

measurement; fabrication and fitting of the orthoses;training that was required to achieve competence in theiruse; clinical, ergonomic, and biochemical differences;psychological aspects associated with their use; relative cost;and acceptability to the patients.

In many ways the two orthoses were very similar. Most

patients were fitted fairly easily, although considerableattention to detail was required to achieve a satisfactoryresult. The RGO failed in two patients whereas nostructural failure was recorded with the more substantialHGO. The RGO took twice as long to manufacture and cost£ 1772 vs C 1116 for the HGO. Results of ergonomic testingwere evenly split, the HGO being quicker to doff and donand the RGO allowing for more rapid standing. Thedifferences in the times to doff and don the orthoses are

mainly related to the fact that the HGO is worn over theclothes and the RGO under them. Videotape and gaitanalysis showed no significant difference in walking qualityand only minor differences in gait. Energy consumption wassimilar for both appliances.Comparison between the two orthoses ultimately comes

down to consumer preference, with twelve patients optingfor the RGO and four for the HGO. The remaining sixpatients were either unable or did not wish to use an orthosisafter the trial. Cosmesis undoubtedly played a major part inthe choice of orthosis; it is interesting that psychologicalanalysis showed that highly anxious people might not besuitable for the HGO.

AUTONOMIC NEUROPATHY IN LIVERDISEASE

AUTONOMIC nervous dysfunction is an important causeof morbidity and mortality in diabetes mellitus2 andalcoholism.3 Its presence in other diseases of metabolism hasnot been fully assessed. The autonomic neuropathy ofdiabetes is characterised by an unremitting course.

Widespread subclinical nerve damage can precede themanifestations of disordered carbohydrate metabolism;4 4both parasympathetic and sympathetic nerves are involved,with the brunt of the damage being borne by the vagus nerveand splanchnic sympathetics. Complications such as

orthostatic hypotension can be ameliorated but continue topfogress. The 5-year mortality rate in diabetic patients oncea symptomatic neuropathy has developed is 56 %P Inchronic alcoholics the 7-year mortality is between 20 and34%; the lower figure is nonetheless 10-20% above that fornon-alcoholic controls. Autonomic neuropathy fromalcohol abuse differs from diabetic neuropathy in that fewerpatients have sympathetic dysfunction. Moreover, withcontinued abstinence, chronic alcoholics with vagal

1. A comparative evaluation of the hip guidance orthosis (HGO) and the reciprocatinggait orthosis (RGO). Health Equipment Information 192. DH, NHS ProcurementDirectorate, 14 Russell Square, London WC1B 5EP.

2. Ewing DJ, Campbell IW, Clarke BF. The natural history of diabetic autonomicneuropathy. Quart J Med 1980; 49: 95-105.

3. Johnson RH, Robinson BJ Mortality in alcoholics with autonomic neuropathy.J Neurol Neurosurg Psychiatry 1988; 51: 476-80.

4. Rundles RW Diabetic neuropathy. Medicine 1945, 24: 110-60

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neuropathy may show an improvement in their vagalfunction tests.5

Recognition of an even higher frequency of autonomicneuropathy in older female alcoholic patients with

peripheral neuropathy and established liver disease led tospeculation about a direct link between the liver conditionand autonomic dysfunction. With alcoholic cirrhosis thefrequency of vagal neuropathy is 64% ;6 hyponatraemia ismore common, and effective intravascular volume may bereduced with an increased risk of stroke. If it were true thatsome damage to the autonomic nervous system is caused bythe liver disease rather than by a direct toxic effect of alcohol,other forms of cirrhosis would also be likely to give rise toautonomic dysfunction. This hypothesis has been examinedby Thuluvath and colleagues in Sheffield.8

Evaluation of the autonomic nervous system is never easy.Symptoms are a poor guide to the presence or absence ofautonomic neuropathy.6 The symptoms that suggestimpairment-eg, dizziness, dryness of the mouth and eyes,dysphagia, abnormal sweating, impotence, and

constipation-are shared by many real and imagineddisorders, and such signs as can be found on routineexamination are seldom recorded. However, Ewing andClarke9 and othersl° have provided standardised batteries oftests of autonomic function that quantify the changes inheart rate and blood pressure during the Valsalva

manoeuvre, with deep breathing or alterations of posture,and with sustained hand grip.

In the Sheffield study, patients were excluded if they hada history of ischaemic heart disease or an abnormal

electrocardiogram; diabetes or an abnormal blood sugarprofile; or if they had been taking drugs that could affect theautonomic nervous system or its tests. Alcoholic patientswere included only if they had been abstaining from alcoholfor at least 2 weeks. 64 patients with biopsy-proven liverdisease and 29 age-matched controls were enrolled. Thenutritional state of the cirrhotic patients was worse than thatof controls, but there were no essential differences innutrition between the various types of cirrhosis. In a

preliminary survey of symptoms, 54% of patients withalcoholic liver disease and 45 % with non-alcoholic liverdisease volunteered symptoms consistent with autonomic

dysfunction compared with 7% of controls. Peripheralneuropathy was investigated clinically but not byneurophysiological tests, so it is likely that the true

frequency of peripheral abnormalities was underestimated.Peripheral neuropathy was present in 45% of patients

with alcoholic liver disease and 22% with non-alcoholic

disease; the overall frequency of autonomic neuropathiesdiffered only marginally between the 20 alcoholic patientsand the 42 patients with non-alcoholic liver disease.

Parasympathetic abnormalities were recorded in 45% ofalcoholic and 43% of non-alcoholic patients, with

sympathetic dysfunction in 11% and 12%, respectively.Damage to the peripheral, sympathetic, and

5. Tan ETH, Johnson RH, Lambie DG, Whiteside EA. Alcoholic vagal neuropathyrecovery following prolonged abstinence. J Neurol Neurosurg Psychiatry 1984; 47:1335-37.

6. Barter F, Tanner AR. Autonomic neuropathy in an alcoholic population. PostgradMed J 1987; 63: 1033-36.

7. Decaux G, Cauchie P, Soupart A, Kruger M, Delwiche F Role of vagal neuropathy inthe hyponatraemia of alcoholic cirrhosis. Br Med J 1986; 293: 1534-37

8. Thuluvath PJ, Triger DR. Autonomic neuropathy in chronic liver disease. Quart JMed 1989; 72: 737-47.

9. Ewing DJ, Clarke BF. Diagnosis and management of diabetic autonomic neuropathy.Br Med J 1982; 285: 916-18.

10. Bannister R. Autonomic failure. Oxford: Oxford University Press, 1983

parasympathetic systems occurred independently of oneanother. Liver function was well preserved in most patients,so there was no discernible correlation between severity ofliver damage and prevalence of autonomic neuropathy.Alcoholic subjects with autonomic neuropathy were

significantly older than those without, but among the 20with primary biliary cirrhosis there was no such difference.Patients with chronic active hepatitis fell into two distinctgroups-women with autoimmune chronic active hepatitis,who had an average age of 58-7 years (5 of the 9 had anautonomic neuropathy), and a much younger all male cohortof 9 HBsAg-positive patients of average age 39 7 years (1 of 9had an autonomic neuropathy). Two main conclusionsemerge from the study. First, there is a high frequency ofautonomic dysfunction associated with both alcoholic andnon-alcoholic liver disease, and, secondly, in both disordersthe parasympathetic system is affected more commonly thanthe sympathetic system.

UK MEDICAL RESEARCH HANDBAGGEDAGAIN

THE proposed merger of the Medical Research Council(MRC) Clinical Research Centre at Northwick Park withthe Royal Postgraduate Medical School at HammersmithHospital on the Hammersmith site, to create a nationalcentre for clinical research in Britain, may have beenblighted early after conception but the abortion is a

remarkably protracted affair. When, after lengthydeliberations, the Advisory Board for the Research Councils(ABRC) and the MRC decided on the Hammersmith sitefor the new establishment they could hardly have envisagedthat over two years later the Government, mindful of theTreasury, would send them reeling back to square one andforce on them another options appraisal. Accordingly theABRC met on Tuesday to survey the field, Hammersmithstill being the front runner, but other options includedtwo-site working and a move to another university site suchas Cambridge, Birmingham, or Edinburgh. The last-mentioned idea apparently accords with generalGovernment policy against "centralisation".

Ultimately the Clinical Research Centre will almost

certainly close, leaving Northwick Park as a rather specialdistrict hospital, and presumably the spoils will bedistributed elsewhere, with a fair chunk for the RoyalPostgraduate Medical School. Mrs Thatcher, who

personally ambushed a major study of sexual behaviour inthe UK only a week ago (Sept 16, p 696), seems to havehandbagged yet another project; any talk of housewifelythrift must surely be tempered by the knowledge that theplanning stages of both projects had already madeconsiderable demands on the public purse.

Earlier this year Dr Dai Rees, Secretary of the MRC,gently chastised The Lancet for referring to the Council aslacklustre with respect to its ability to inspire importantchanges in official policy-in effect, to put medical researchin the UK firmly on the agenda.l He proudly announcedthat an additional z4 million had been provided to theMRC as a result of the allocation of the science vote for1989-90. While we are happy to congratulate Dr Rees andhis team on such success, those inextricably bound-up withthe new national centre may have good cause to doubt DrRees’s confidence that "the struggle ... availeth".

1. Rees DA. Medical research funding. Lancet 1989; i: 442.