835

Nutrition: The Changing Scene

The third of four extracts from a discussion paper prepared forthe National Advisory Committee on Nutrition Education, to bemade available by the Health Education Council on Oct 10.

PROPOSALS FOR NUTRITIONAL GUIDELINESFOR HEALTH EDUCATION IN BRITAIN

DIETARY FIBRE: HEALTHY FUNCTION AND DISORDERS OF

THE LARGE BOWEL

This aspect of diet in relation to health also received verylittle attention from official bodies in the UK until the recent

report on the medical aspects of dietary fibre of the RoyalCollege of Physicians.1Burkitt attributed low faecal weights and associated

diseases to lack of dietary fibre. Recent developmentssuggest that dietary fibre should be thought of in thecontext of the carbohydrate content of the diet as a whole,2since the bulk of fibre is polysaccharide, with lignincomprising less than 1% of human foods. The average Britishdiet, for instance, contains about 285 g carbohydrate, ofwhich 20 g is dietary fibre. Preliminary data suggest that fibreintake is low in the UK at present: fibre intakes of 50-120

g/day are estimated for Africans living in rural communities.In the UK during the war 32-40 g fibre/day was the averageintake and British vegetarians at present consume on average42 g fibre/day.3Metabolic studies have shown that dietary fibre is a

constituent of diet with marked effects on faecal weight,cereal fibre having a greater effect than fruit or vegetablefibres.4 By diluting intestinal contents and shortening transittime, fibre may also reduce intraluminal pressure and couldreduce carcinogen contact with the intestinal wall. Thesesuggestions are less firmly based than the clear physiologicalevidence relating fibre intakes to laxation.

Optimum Intakes

Dietary fibre intakes of 30 g or more are associated with alower prevalence of diverticular disease in vegetarians,3 andare used with beneficial effect in the treatment of constipationand diverticular disease. Although there is a suggestion thatincreased cereal and vegetable consumption will reducemineral absorption, the added cereals and vegetablesthemselves increase the intake of minerals (eg, trace elements)and thereby limit any deleterious effects on mineral status ofthe phytate or fibre associated with these foods.

5

It is recommended that the intakes should be increased toan average of about 30 g dietary fibre/day for adults. (Thisvalue was suggested by Dr J. H. Cummings in a papersubmitted to the DHSS panel on Nutritional Aspects ofBread and Floury and based on an analysis of physiologicaland epidemiological data.) Cereal fibre in particular shouldbe increased, because it is more effective in increasing faecalweight than fruit or vegetable fibre.4 In practice healtheducators should encourage the consumption of fruit andvegetables as well as cereals while recognising that in the UKintakes of cereal fibre have declined greatly this century. Forthis trend to be reversed will obviously take time and it seemsreasonable to expect such a change to occur over 15 years,with perhaps an increase in average fibre intakes to

23 g/head/day in the short term.

It is suggested that this dietary fibre might best be derivedfrom foods, not from either dietary fibre preparations orfoods to which bran and other fibres have been added. This

approach is more likely to ensure that the whole grain productwill be used, which is more likely to ensure increased intakesof minerals, trace elements, and other micronutrients;element malabsorption is also then less likely. Thisrecommendation is therefore, like the other proposals, anassessment of the balance of current evidence on the potentialadvantages and disadvantages of these changes. Further workon mineral absorption is clearly needed but the health benefitlikely to accrue from an increase in cereal fibre consumptionis widely accepted. 1,6,7The importance of adequate labelling of food, for health

education as well as for regulation, is evident here, as

throughout this field. 6

DIETARY FAT AND CORONARY HEART DISEASE

A subcommittee of the Committee on Medical Aspects ofFood Policy is at present reconsidering the question of diet inrelation to cardiovascular disease. The proposals set out inthis document may have to be revised when the new reportbecomes available.Death rates for coronary heart disease (CHD) in the UK are

among the highest in the world, Scotland and Finland sharing anunenviable position at the top of the international league table.8 InEngland and Wales in 1980 31% of deaths from coronary arterydisease (ICD 410-414) occurred in men under the age of 65 years.Compared with other western nations, the UK has a poor record inthe prevention of CHD, the rates in recent years showing only avery slight decline compared with those in the USA, Belgium,Australia, Finland, Canada, and the Netherlands.9Many national and international professional and government

committees have reviewed the evidence relating to the causes ofCHD. Their reports show a strong consensus of opinion that CHDcan be prevented by the reduction of total fat in the diet to 30-35%total energy. The DHSS report 10 recommended a decrease in thetotal fat content of the diet but did not specify the average level forwhich health educators should aim. The report of the Royal Collegeof Physicians and the British Cardiac Societyl I recommended areduction in fat intake to 35% of the energy intake. Since mentionwas made in that report of a current fat intake exceeding 40%, it isclear that the committee of the RCP was considering the amount offat in the diet in terms of non-alcohol energy, not total energy.Reference to other reports shows that this distinction between total

energy and alcohol-free energy is rarely made, which may explainthe variation in the choice of 30% or 35% as the goal for fat intakesadvocated by different committees. It seems best to consider averageintakes on a population basis as referring to total energy intakesincluding alcohol and when dealing with diets for specific groups(eg, children) to readjust the figures. This document will not discussthe frequently published analyses on which these recommendationsare based.Recent but relatively small surveys have suggested that

approximately 38% of total energy is derived from fats in men livingin south-east England,12 and in Scotland, where the rates of heartdisease are high.13 These figures take account of alcohol

consumption which contributes 4% and 9%, respectively, to totalenergy intakes in these two regions. When alcohol is not included inthe figures for total energy intake, the proportions derived from fatare 40% for south-east England and 4107o for Scotland.Analyses of the relation between fat intakes and the average

plasma cholesterol concentration of a population suggests that anintake of 3007o total energy from fat will be needed to bring averagecholesterol concentrations down towards 200 mg/dl (5 - 2 mmol/1),the lowest value considered likely to be achieved in the UK. Therecent WHO report gives an average value below 200 mg/dl asappropriate, a view which has received additional support.14 Aplasma cholesterol concentration of 160-180 mg/dl (4-4 - 5 mmol/1)is associated with a very low risk of coronary heart disease, 15 but this

836

does not mean that reducing the serum cholesterol to these levels inpopulations in developed countries would necessarily be of anygreater benefit. The ability to reduce the concentration of totalplasma cholesterol by limiting total fat and saturated fatty acidintakes has been widely demonstrated in patients with hyper-cholesterolaemia.

Reduction in Total Saturated Fatty Acid Intakes

The DHSS reportl° advocates a reduction in total saturatedfatty acid intake but does not specify a goal for the UK. Manyother committees (eg, the WHO committee 14) suggest a valueof 10% of energy from saturated fatty acids. In the absence ofconflicting official advice, it is suggested that this figure of10% should be considered as a proportion of total energyintake including alcohol. A similar value is proposed in thejoint recommendations of the International Society andFederation of Cardiology Scientific Councils on Arterio-sclerosis, Epidemiology, Prevention and Rehabilitationwhich were concerned mainly with secondary prevention.l6There is a striking degree of agreement among diversecommittees in the western world who have examined thisissue that a marked reduction in saturated fatty acid intake isindicated.

Increase in Polyunsaturated Fatty Acid Intakes

On this point a variety of options have been expressed.The DHSS reportl° did not recommend a substitutionfor polyunsaturated for saturated fatty acids, whereasother committees did recommend some increase in

polyunsaturated fatty acid intake. The evidence suggests thata P/S ratio of 2 or more is not conducive to a reduction in total

mortality rates even though the rate of coronary heart diseasemay decline. Additional risks ensue with a highpolyunsaturated fatty acid intake. An increase in the currentvery low dietary P/S ratio to a value of about 1’ 0 is likely to bebeneficial, but it should be remembered that the highest ratioin free-living populations is 0 - 6-0 - 8 (in parts of the USA andin parts of south-east Europe). An increase in the P/S ratio canbe achieved by reducing saturated fatty acid intake, byincreasing polyunsaturated fatty acid intake, or by a

combination of both measures. In the present circumstancesit is unwise for health educators to recommend an increase in

polyunsaturated fatty acid intake as a specific measure initself beneficial to health. For practical dietary purposes,however, a modest increase in polyunsaturated fatty acids as asubstitute for some of the saturated fatty acids is recognised asan acceptable measure in devising a more healthy andpalatable diet.The problem then becomes one of achieving both a

reduction in fat intake to 30% of total energy and a fall insaturated fatty acid intake to 10% (ie, to a third of the total fat).In practice this combination of recommendations may not beachieved without substituting different types of oils and fats,some of which will be high in polyunsaturated fatty acids. Inhealth education terms therefore the aim will be to reducesaturated fatty acid intake, but in practice there is likely to be agreater consumption of both polyunsaturated andmonounsaturated fatty acids. If total fat consumption isreduced to 30% of total dietary energy in the UK, it is

unlikely that the P/S ratio will remain at its current level ofabout O. 28 (1983 figure provided by Ministry of Agriculture,Fisheries and Food), because most commonly consumed fattyproducts in the UK have a low P/S ratio, and their

consumption will have to be reduced for total fat

consumption to decline to an acceptable level. There areobviously many ways in which total fat can be reduced, but

some are easier to implement than others. Data from theMinistry of Agriculture’s National Food Survey suggest thattotal dairy fat provides about a third of total fat intakes, andmeat fat approximately 27%. With a reduction in these twosources of fat, the P/S ratio will tend to increase. This increasewill be enhanced if the suggested rise in cereal, beans, andother vegetable consumption materialises. Manufacturingtechniques which also lead to a partial substitution of

polyunsaturated fatty acids for saturated fatty acids are

unlikely to be harmful since this would lead to only moderateincreases in the intake of polyunsaturated fatty acids.Dietary Cholesterol

Neither the DHSS10 nor the RCP" made anyrecommendations specifically to reduce dietary cholesterol,although the RCP did advise that egg consumption should bereduced and the WHO committee recommended limitingdietary cholesterol to less than 300 mg/day.Given the variation in current scientific opinion, the

limitation of dietary cholesterol should not be incorporated asa key feature of dietary advice for the UK, and accordingly nospecific recommendations have been made. The practicalimplications of other dietary recommendations would,however, result in reduced levels in the UK diet. It is

important to recognise, however, that the tendency for peopleto buy cholesterol-free mixed vegetable oils may well reflecttheir desire to achieve a healthier diet. This link between "no

cholesterol", "vegetable oil", and "health" is misleading,,since many of the oils have a high saturated fatty acid content.

These changes in total fat and fatty acid intake cannot beachieved rapidly. A combination of measures will be

required, some of which have been noted in the section onexcess weight and obesity. If the proposed changes wereachieved over a period of 15 years with a third of theadjustment being made, for example, in 5 years, this shouldbe considered very satisfactory progress.Other factors (eg, dietary deficiencies of selenium and fibre)

have been linked to the development of CHD but evidencefor these being important is neither convincing nor ofsufficient substance to have been considered in any depth byexpert committees.

SALT AND BLOOD PRESSURE

This subject has recently assumed greater significance inpublic discussion but has not been considered by expertcommittees dealing with food and health policy in the UK.(The WHO reportl4 does, however, consider it.) A moredetailed assessment of the problem will therefore be given.Estimates of the prevalence of hypertension are influenced by the

definition chosen, by the age of the sample, and by the nature of thepopulation considered. About a quarter of a sample of 3000 Scots(aged 45-64) studied by Hawthorne et all? had diastolic (phase v)blood pressures above 95 mm Hg. 39-8% of this sample haddiastolic pressures above 90 mm Hg (the lower limit for entry intothe current Medical Research Council trial on the treatment of mild

hypertension.18 Population studies in the USA have shown that10-15% of adults aged 35-64 have both systolic blood pressuresgreater than 160 mm Hg and diastolic pressures greater than

90 mm Hg.19Prospective epidemiological studies are consistent in finding that

hypertension is a major risk factor in the development of bothischaemic heart disease and cerebrovascular disease, and a reductionin blood pressure, either through antihypertensive therapy orthrough weight loss, improves outcome in terms of mortality. It hasbeen estimated that a small reduction (2-3 mm) in mean bloodpressure in the population, if the distribution remained similar tothe present distribution of blood pressures, would result in a majorbenefit in terms of mortality and a shift of this magnitude would be

837

References commued overleaf

comparable to the benefit currently achieved by antihypertensivetherapy.20 This estimated benefit seems applicable to mild as well assevere hypertension.Not all populations display hypertension. In many groups

hypertension is unknown and the rise in blood pressure with agecharacteristic of westernised populations is not seen. These groupsare tribal societies living indigenous ways of life, such as theYanomamo Bushmen and Samburu. Many other groups show amuch lower prevalence of hypertension than that in England andWales and these are often populations in transition between

indigenous and westernised ways of life. The Japanese, certainIndian groups, and others show very high prevalence rates ofhypertension and high rates of cerebrovascular disease.

Characteristics of groups with low or zero prevalences of

hypertension are the lack of obesity, high levels of physical activity,diets low in animal fat, a high dietary intake of potassium, and lowintakes of sodium, Obesity is clearly related to hypertension on bothan individual and a population basis. Population studies that havetaken this into account have shown that part, but not all, of thedifferences in blood pressure between groups can be explained bydifferences in body mass. Animal experiments have suggested thatfat intake, particularly of saturated fat, is related to blood pressure,and mechanisms by which increased saturated fat intakes may leadto a rise in blood pressure have been proposed. Fat intake is unlikelyto be the single major determinant of international differences ofhypertension and stroke, however, since Japan with its high rateshas a low fat intake and, as fat intakes are rising in this population,stroke rates are falling. 21Experiments in animals have shown that very high intakes of

sodium lead to high levels of blood pressure and that modest intakesof sodium (though still above those naturally occurring in theanimals’ food) can lead to hypertension in genetically susceptibleanimals.22 The maintenance of a high potassium intake minimisesthe effects of sodium, so the sodium/potassium ratio appears to bemore important in determining blood pressure than the absoluteintake of sodium. 23 Metabolic experiments in human beings havedemonstrated a fall in blood pressure when subjects are fed low-sodium diets. 24-2’ A fall in blood pressure also occurs innormotensive relatives of hypertensive parents on a high-sodiumdiet when additional potassium is given.The comparison of mean population blood pressures and mean

salt intakes in 27 populations has shown convincing linear relationsfor both systolic and diastolic blood pressures. 27 There are fewdocumented intervention studies, but Farquhar28 was able to

demonstrate a 5 mm Hg reduction in mean systolic blood pressurebya modest reduction in salt intake in a sample of the population butnot in a control group in which no reduction of salt intake had taken

place. No satisfactory demonstration of a low-salt-eating populationwith hypertension or of a high-salt-eating population withouthypertension has emerged, and until either of these cases is

satisfactorily demonstrated the salt hypothesis cannot be discarded.However, the assessment of sodium intake in such studies hasusually been inadequate to characterise accurately the individualsinvolved.

Although a relation can be demonstrated for blood pressure withsalt intake between populations, most studies within populationshave failed to show this relation. However, individuals are likely tovary in their susceptibility to salt-induced hypertension, so a failureto distinguish between susceptible and non-susceptible individualsmay explain the poor relation between mineral intake and bloodpressure within a population. One study, which has used improvedmethods and has attempted to group subjects into susceptible andnon-susceptible categories (on the basis of family history), has founda relation between salt intake and blood pressure.29Optimum Range of IntakeThe present evidence is sufficient for the WHO committee

to suggest that exposure to a high sodium/low potassiumintake may be a cause of hypertension in susceptibleindividuals. The proportion of such individuals in the

population is unknown but may be 20%. A group of expertsfor the American Society of Clinical Nutrition considered salt

and hypertension to be the clearest link between diet and thediseases of affluence. 30 Other committees, when dealing withboth paediatric and adult medicine,3o,31 have advocated areduction in salt intake, but the limits previously set (eg, bythe McGovern Committee32) were not argued on a scientificbasis and no objective in hypotensive effect was identified.On the basis of the WHO report’4 and the general advice inEating for Health’ it is considered appropriate to encourageindividuals towards a lower salt intake.The present estimated average intake of salt in the UK

amounts to 12 g/day, if allowances are made for additionsmade in cooking and at table, but only 8’ 1 g if reliance isplaced on the National Food Survey estimate of salt infoods.2o,33 A salt intake of 12 g/day is far in excess of thatrequired even by physically active individuals and a gradualreduction to a half or even a quarter of this level is unlikely tobe associated with any danger to health. Such a drasticreduction, however, would necessitate major changes in foodmanufacture and marketing. The group calculated fromGlieberman’s data27 relating salt intake to mean populationblood pressure that a reduction in mean salt (not sodium)intake of 3 g/day would lead to a reduction in mean systolicblood pressures (in men aged 50-59) of 5 mm Hg. This fallwould substantially lower the prevalence rate of hypertensionand therefore the mortality resulting from this disease andassociated pathology.

If intake is closer to 12 g/day, the value suggested by WHOof 5 g could mean a substantial reduction. Clearly, more workis needed to define actual intakes in the UK and the

adjustment in sodium intake should be considered, as withthe other recommendations, as being capable of achievementover 15 years. Thus, an average decline in salt intake of1 g/head/day within the next 5 years should be the goal ofhealth educators. At present, an individual can reduce his saltintake only by limiting the use of cooking and table salt. Asubstantial amount of salt is ingested in manufactured foodsand it would help if some simple system of labelling could bedeveloped to aid the choice of products with a lower saltcontent.

REFERENCES

1. Royal College of Physicians of London. Report on the medical aspects of dietary fibre1981

2. Bingham S, Cummings JH. Sources and intakes of dietary fiber in man. In Spiller GA,Kay RM. Medical aspects of dietary fiber New York: Plenum, 1980 261-82

3. Gear JSS, Fursdon P, Nolan DJ, et al. Symptomless diverticular disease and intake ofdietary fibre. Lancet 1979; i: 511-14.

4. Cummings JH, Branch W, Jenkins DJA, Southgate DAT, Houston H, James WPT.Colonic response to dietary fibre from carrot, cabbage, apple, bran, and guar gum.Lancet 1978, i. 5-9.

5. James WPT Dietary fiber and mineral absorption In: Spiller GA, Kay RM, eds.Medical aspects of dietary fiber. New York: Plenum, 1980: 239-59

6. Department of Health and Social Security. Committee on Medical Aspects of FoodPolicy. Nutritional aspects of bread and flour. Rep Health Soc Subj 1981; 23.

7. Department of Health and Social Security Prevention and health-Eating for health.London HM Stationery Office, 1978.

8. Department of Health and Social Security Prevention and health: avoiding heartattacks. London HM Stationery Office, 1981.

9 Editorial. Why the American decline in coronary heart disease? Lancet 1980; i. 183-84.10. Department of Health and Social Security. Report on health and social subjects, no 7.

Diet and coronary heart disease. London: HM Stationery Office, 1974.11. Royal College of Physicians of London and British Cardiac Society. Prevention of

coronary heart disease. J Roy Coll Phys 1976, 10: 213-75.12. Bingham S, McNeil NI, Cummings JH The diet of individuals: a study of a randomly

chosen cross-section of British adults in a Cambridgeshire village. Br J Nutr 1980;45: 23-35

13. Thomson M, Logan RL, Sharman M, Lockerbie L, Riemersura RA, Oliver MF.Dietary survey in 40-year old Edinburgh men. Hum Nutr 1982; 36A: 272-80.

14. WHO Expert Committee. Prevention of coronary heart disease. WHO Techn Rep Ser1982; 678.

15. Conference on the health effects of blood lipids. optimal distributions for populations.American Health Foundation. Prev Med 1979, 8: 612-78.

16. International Society and Federation of Cardiology Scientific Councils on

Arteriosclerosis, Epidemiology, Prevention and Rehabilitation. Br Med J 1981;282: 894-96.

838

17. Hawthorne VM, Greaves DA, Beevers DG Blood pressure in a Scottish town. Br MedJ 1974; iii: 600-03

18. Medical Research Council Working Party on Mild to Moderate Hypertension.Randomised controlled trial of treatment for mild hypertension: design and pilottrial. Br Med J 1977; i: 1437-40.

19. US Department of Health, Education and Welfare. Blood pressure levels of persons6-74 years, United States 1971-1974. Washington DC: USDHEW (Publ No[HRA] 78-1648). Series Ll No 203. 1977

20. Marmot MG Diet, hypertension and stroke. In: Turner MR, ed. Nutrition and health.London: British Nutrition Foundation, MTP Press, 1982: 243-54.

21. Keys A. Seven Countries. A multivariate analysis of death and coronary heart diseaseCambridge, Massachusetts. Harvard University Press, 1980

22. Dahl LK, Heine M, Tassinari L Effects of chronic excess salt ingestion: evidence thatgenetic factors play an important role in susceptibility to experimentalhypertension. J Exp Med 1962; 115: 1173-90.

23. Meneely GR, Ball COT. Experimental epidemiology of chronic sodium chloridetoxicity and the protective effect of potassium chloride. Am J Med 1958, 25:713-25.

24. Morgan T, Gillies A, Morgan G, Adam W, Wilson M, Carney S. Hypertension treatedby salt restriction Lancet 1978; i. 227-30.

25. MacGregor GA, Markandu N, Best F, et al. Double-blind randomised crossover trial ofmoderate sodium restriction in essential hypertension. Lancet 1982; i: 351-55.

26. Skrabal F, Aubock J, Hortnagl H. Low sodium/high potassium diet for prevention ofhypertension, probable mechanism of action Lancet 1981, ii, 895-900.

27. Gleibermann L. Blood pressure and dietary salt in human populations. Ecol Food Nutr1973; 2: 143-56

28. Farquhar JW, Wood RD, Haskell WL, Williams P, Fortmann SP Relationship ofurinary sodium/potassium ratio to systolic blood pressure the Stanford-three-

Community study. In: Abstracts of the 18th Annual Conference on CardiovascularDisease Epidemiology March 13-16, 1978. Orlando, Florida. Dallas, Texas.American Heart Association, CVD Epidemiology Newsletter No 25.

29. Pietinen PI, Wong O, Altschul AM Electrolyte output blood pressure and familyhistory of hypertension. Am J Clin Nutr 1979; 32: 997-1005.

30 Tobian L, et al. Dietary salt (sodium) and hypertension. In: Report of the Task Force onthe evidence relating six dietary factors to the nation’s health. Am J Clin Nutr 1979;32: 2659-62

31. Committee on Nutrition. Salt intake and eating patterns of infants and children inrelation to blood pressure. Paediatrics 1974; 53: 115-21

32. US Senate Select Committee on Nutrition and Human Needs. Dietary goals for theUnited States Washington DC Government Printing Office, 1977.

33. Bull NL, Buss DH. Contribution of foods to sodium intake. Proc Nutr Soc 1980; 39:30A.

Occasional Survey

"BALTIC" MYOCLONUS EPILEPSY:HEREDITARY DISORDER OF CHILDHOOD

MADE WORSE BY PHENYTOIN

ROSWELL ELDRIDGEROBERT STERN

MATTI IIVANAINENTHELMA KOERBER

B. J. WILDERClinical Neurogenetics Studies, Neuroepidemiology Section, NationalInstitute of Neurological and Communicative Disorders and Stroke,

National Institutes of Health, Bethesda, Maryland, USA;Department of Neurology, University of Helsinki, Finland; and Beth

Israel Hospital, Boston, Massachusetts; and VeteransAdministration Medical Center, Gainesville, Florida, USA

Summary A survey of 15 families in the USA withBaltic myoclonus epilepsy showed that the

27 individuals who were affected had the following clinicalpicture from about the age of 10: photosensitive, occasionallyviolent, myoclonus, usually worse upon waking; generalisedtonic-clonic seizures, sometimes associated with absence

attacks; and light-sensitive, generally synchronous, spike-and-wave discharges on EEG that preceded clinical manifes-tations. Necropsy revealed marked loss of Purkinje cells ofthe cerebellum, but no inclusion bodies. Since the disease wasconfined to sibs and consanguinity was present in two fami-lies, autosomal recessive inheritance is probable. The diseaseprogressed more rapidly in these families than it did in theearly cases, seen in the Baltic region. This difference could be

due to a toxic effect of phenytoin because phenytoin givenalone or with other antiepileptic drugs was associated withprogressive motor and intellectual deterioration, markedataxia, and even death. Treatment with valproic acid, and theconcomitant reduction or elimination of phenytoin, has beenassociated with marked improvement in at least 8 patients.Baltic myoclonus epilepsy must be distinguished from Laforabody disease, which is invariably fatal and discernible onclinical grounds.

INTRODUCTION

THE hereditary disorders characterised by myoclonusepilepsy have not been classified clearly. The tendency inrecent years has been to group together the type with onset inyouth, as described from Estonial and from EasternSweden, 2-3 with Lafora disease, a fatal type associated withhighly characteristic intraneuronal inclusion bodies.4 Lack ofprecise biochemical definition of either disorder and a

generally poor prognosis for both in the past 30 years havecontributed to this tendency. 5

In the past 20 years a concentration of Finnish cases

exhibiting myoclonus epilepsy, autosomal recessive inheri-tance,6-9 and favourable prognosis with valproate sodiumtreatmentl° has been reported. These seem to be similar tothose described earlier from neighbouring Estonia andEastern Sweden and differ from Lafora disease in age at onset,symptom complex, and natural history.This report is based on clinical and genetic studies of 15

families in the United States in which one or more membershave had spontaneous onset of myoclonus epilepsy in youth,but do not have inclusion bodies of the Lafora type. Becauseof the similarity in age at onset, clinical picture, andinheritance pattern between these families and families

reported from the Baltic (fig 1) region, 1,2,7-8 we suggest theterm "Baltic" myoclonus epilepsy for this disorder. It differsfrom Lafora disease by earlier age at onset, lack of inclusionbodies, and most importantly, far slower progression withproper management.

Pot AND

Fig I-Distribution of 127 cases about the Baltic Sea.

8 patients from Estonia,’ 18 from Sweden,=" and 101 from Finland’