HC Deb 20 December 1984 vol 70 cc676-82

Motion made, and Question proposed, That this House do now adjourn.—[Mr. Peter Lloyd.]

12.2 am

Mr. Derek Spencer (Leicester, South)

The phrase "myasthenia gravis" casually dropped during conversation is calculated to bring it to an immediate halt. The inevitable response is, "What on earth is myasthenia gravis"? Had I been faced with the phrase on any date before 11 November this year, my response, too, would have been, "What on earth is myasthenia gravis"? But on that date the phrase intruded into my life out of the blue, in the same way as it has intruded from time to time into the lives of comparatively few families in Britain.

Myasthenia gravis is a serious muscle weakness. In technical terms, it is a neuro-muscular disorder that is due to a defect in the action at the nerve ending. It prevents the brain from effectively controlling several groups of muscles, especially in the face and throat. It is a rare complaint, fortunately. It affects about one in 20,000. In my constituency there should be no more than three or four cases.

Usually a GP will see only one or two cases in his professional life. Fortunately, it is neither contagious nor infectious and it is rare for more than one member of a family to be affected. If by chance the mother should suffer from it when the child is born, within a few weeks the symptoms normally fade away.

It is one of the oddest, most frustrating and infuriating of medical conditions known to mankind. For that reason, my prime purpose is to give publicity to the disorder so that the cloak of ignorance which has shrouded it might be lifted.

The symptoms are usually slight at first, but they gradually become worse. They have a characteristic distribution, starting with drooping eyelids, double vision, difficulty in swallowing or speaking, a general weakness and feeling of fatigue or difficulty in breathing and raising the arms. Many are the symptoms that any hypochondriac might have—especially after an all-night sitting.

The disorder has no respect for age. It is most common at the age of 20 years. For men the peak is between 50 and 60 years. Below that age women usually outnumber men, but among older people men are the principal sufferers.

Delay and inaccuracy in diagnosis is often an insult added to the injury of myasthenia sufferers. The symptoms vary in type and severity. A myasthenic might have one symptom, or a combination of symptoms, but rarely all of them. In the early stages the symptoms are slight and gradual. They become worse in the afternoon or evening and they tend to improve in the morning or after rest.

The symptoms are aggravated by weather changes, by heat, cold or extremes of emotion. No two myasthenic sufferers are alike. Their symptoms are not necessarily the same on different days. They exhibit a variable pattern. With such a wide variety of symptoms suffered by the same person, let alone symptoms shown by different people, it is not surprising that mistakes in diagnosis occur not infrequently. Some cases are not diagnosed at all.

The inability to smile or slurred speech are often diagnosed as depression, neurosis or stress. Patients are often bewildered by the change in their condition. They go to their doctor, rest in the surgery and suddenly feel much better. They are confused and feel fraudulent when they face their GP and try to describe their symptoms. Often the condition leads to the psychiatrist and the speech therapist instead of the neurologist and thoracic surgeon.

Sadly, what is physical is often diagnosed as mental. A simple diagnostic test is now available which shows beyond peradventure that the patient suffers from this condition. A simple injection of the drug tensilon will clear the symptoms and indicate the presence of the disorder. There is a crucial need for the medical profession to be more aware of these difficulties and to identify the disorder earlier.

An experiment was carried out in Essex by interested parties who distributed leaflets in one locality. That little exercise showed that three people formerly not known to be suffering from the condition were diagnosed as myasthenics. Will my hon. Friend the Under-Secretary of State assure the House that his Department is giving sufficient publicity to programmes aimed at general practitioners in particular and the public in general to ensure that there is sufficient knowledge of this condition and to alleviate the unnecessary suffering undergone by some people?

For the people who suffer from the disorder—a child cannot run or play, the smile is suddenly wiped off the face of a young girl, a woman cannot comb her hair and a man cannot hold a razor—the condition is a tragedy, and for their families it is a source of deep sadness. The condition is especially flummoxing because its exact cause is unknown. The evidence points to an immunological disease in which the body's immune system goes wrong and starts rejecting its own tissue. To date, the exact mechanism behind the disease has not been located.

Fortunately, nowadays, there are effective means of treatment— it was not always so. Today, two types of treatment afford considerable improvement, if not complete remission. First, surgery and the removal of the thymus gland, which is located in the upper part of the chest, often completely eliminate the symptons and they substantially improve the condition in about 80 per cent. of cases. It involves a period in intensive care, but most patients are discharged by the end of the second or third week. Fortunately, if that method of treatment is not appropriate, drugs usually are. They can improve the strength of the patient and the affected muscles, although they do not always restore the patient to full power.

One of the many crosses that myasthenics have to bear is the need to ensure that the drugs they take do not aggravate their symptons. Drugs regularly prescribed for heart ailments, barbiturates and some antibiotics have an aggravating effect. I am happy to be able to say that, fortunately, modern treatment has returned most patients to productive lives. This has transformed the position in recent years. Before the last war, 85 per cent. of patients died; the proportion fell to 15 per cent. and it has fallen still further recently. The condition of the vast majority of patients can be substantially improved with drugs or surgery.

Sufferers are entitled to certain benefits. Those benefits are by no means clear. Because of the variety and intensity of the symptons, some myasthenics have problems in persuading the DHSS that their disability entitles them to a mobility allowance. One day they are severely immobile, the next they are completely mobile. I ask my hon. Friend to consider whether myasthenia sufferers are satisfactorily categorised for benefit, particularly mobility allowance.

In the past 10 years research has taken a remarkable step forward. In 1973, Messrs. Patrick and Lindstrom of the Salk institute found that rabbits that were immunised with the electric organ of an electric eel developed a condition that was apparently identical to that of myasthenia sufferers. The rabbits became floppy, but after a time when the symptoms had worn off they became frisky. At about the same time in research into the same disease an advance was made with regard to snake toxins from the venom of the Indian cobra which was found to contain a component which induced, not surprisingly, instantaneous myasthenia in the victim.

Those two separate advances have enabled vast strides to be made in the understanding and treatment of myasthenia in the past 10 years and established what until then had been merely theory—that myasthenia gravis is a disease of the autoimmune system. That showed the importance in this disease as with many other diseases, of properly controlled animal experiments. Will animal libbers please note and take to heart those examples of where there has been considerable relief in human suffering from properly monitored experiments carried out on animals in humane circumstances?

In the next few years we look forward to seeing identified drugs which will be able to control the triggering factors in the disorder. Myasthenia blood cells can now be cultivated in the laboratory so that the human disease can be studied in test tubes. The objective is to find a drug which will be selective in its operation and switch off the unwanted self-destructive response while leaving all the other immune responses intact.

In this, as probably with all other research, the cry is for more money. I hope that my hon. Friend can assure the House, not as to the amount of money but as to its effective use.

The British Association of Myasthenics was set up in 1975 as a branch of the muscular dystrophy group. It is a voluntary organisation. It aims to relieve and comfort those who suffer from this disorder, to bring them together and to promote self help. At present large numbers of myasthenics remain isolated or undiagnosed. The association seeks to educate the public and locate as many myasthenics as possible. It acts as a reminder to the medical profession and the ancillary services of this disorder by improving diagnosis time, treatment and services. It does splendid work with modest resources. I compliment the association on its wholly admirable work, and particularly on its fund-raising for research.

Great work is done at the University College hospital in Gower street and at the Royal Free hospital in London, but it is perhaps invidious to select two out of so many National Health Hospitals as so many medical staffs, many members of the social services and researchers are striving for the day in the not-too-distant future when myasthenia gravis is no longer a conversation stopper, and when myasthenia will no longer be gravis but simply myasthenia.

12.20 am
The Parliamentary Under-Secretary of State for Health and Social Security (Mr. Ray Whitney)

I am grateful to my hon. and learned Friend the Member for Leicester, South (Mr. Spencer), for giving us the opportunity of this debate and for drawing myasthenia gravis to the attention of the House and to a wider public.

As my hon. and learned Friend has said, this is fortunately a comparatively rare disease, and the causes of it are unknown, but it is thought that they are related in some way to a disorder of the thymus gland, which leads to a breakdown in immune tolerance. It is classed as one of the autoimmune diseases, along with multiple sclerosis and muscular dystrophy, which means that the body produces its own antibodies, which then attack healthy tissue. The main symptom is that the muscles tire very quickly so that the patient finds it difficult and sometimes impossible to make normal movements; not just limb movements, as in standing, walking and carrying things, but movements in the face, and throat, which affect talking, chewing and swallowing, and in severe cases breathing. As my hon. and learned Friend said the symptoms of the disease fluctuate in intensity, and there are usually long periods of remission, particularly during the early years.

My hon. and learned Friend correctly said that one of the main problems associated with myasthenia gravis is the difficulty of initial diagnosis. During its early stages the symptoms may occur only as a result of extreme physical activity or emotional stress, and they disappear again after rest. This means that when the patient is examined by the doctor, it will be unlikely that the patient will be exhibiting any symptoms. The doctors will therefore have to rely upon the patient's own accounts and the diagnosis will have to be made retrospectively.

The doctor's initial impression is likely to be that the muscular weakness that the patient describes is either the direct result of exercise that has been somewhat overdone, or, if what precipitated the symptoms was emotional stress, that it is some sort of psychosomatic disorder. It is likely to be only after several consultations that the likelihood of myasthenia gravis is considered.

I am glad to be able to reassure my hon. and learned Friend that all general practitioners learn about neurology during their training, and that in the course of this attention is given to myasthenia gravis, but I would emphasise that, because it is such a rare disease, it is very difficult for general practitioners to build up any expertise. Indeed, it is probable that the majority of general practitioners will not encounter a single instance of the disease during the whole of their careers.

Myasthenia gravis is, of course, not the only disease to encounter such difficulties of early diagnosis. The more common neuromuscular diseases, such as multiple sclerosis and muscular dystrophy, can also present initially "flitting" symptoms; and diagnosis in these patients is often made only after several attacks, and confirmed by referral to a hospital specialist.

We recognise that these are real problems. In retrospect it is easy to cast some blame on doctors for failing to make the right diagnosis, but it is remarkably difficult for them to do so at the time. My hon. and learned Friend asked about the possibility of some special initiative to inform doctors of the symptoms of myasthenia gravis in order to improve diagnosis. I must make it clear that it is the responsibility of individual doctors to ensure that they are adequately informed within their areas of interest, and to keep themselves informed on clinical and scientific developments, so this is a matter for the medical profession rather than for my Department. There are a number of established mechanisms for enabling doctors to keep up to date; for example, through medical journals and scientific papers, through conferences and seminars, and where appropriate through postgraduate training. I have no reason to believe that these mechanisms are inadequate in respect of myasthenia gravis.

Once a diagnosis has been made, the best prospect for a permanent cure is the surgical removal of the affected thymus gland, but that is likely to be effective only if a patient is comparatively young and only if the onset of myasthenia gravis is comparatively recent. Otherwise, the course of the disease is characterised by spontaneous remission of varying but diminishing duration, and the course of treatment at that point is directed towards controlling the symptoms.

Treatment of the symptoms is normally by drug therapy, usually by neostigmine and steroids, and those are usually very successful, though they may need to be administered together with other drugs to control possible side effects. The patient's management of his own lifestyle is an important aspect of keeping the symptoms under control, and patients will be advised to keep fatigue and stress to an absolute minimum.

One recently developed treatment for the relief of very severe myasthenia gravis symptoms is plasmapherisis, which is a process of, in lay language, washing a patient's blood to remove the antibodies that are causing the damage. The plasma content of the patient's blood is removed and then replaced with plasma products collected from the blood given by blood donors. This treatment is indicated only when the patient is seen to be moving towards a paralytic crisis. It is a very effective treatment in the short term, but there is no evidence that the beneficial effects of the treatment are long lasting. It is for health authorities to decide whether or not to make that treatment available, having regard to the other demands on their resources.

Apart from plasmapherisis, facilities for the treatment of the disease are generally available. Facilities for drug therapy and surgical facilities for thymectomy are not limited to a small number for hospitals, and there is no evidence of difficulties in making treatment available once a diagnosis of myasthenia gravis has been made.

My hon. and learned Friend referred to the social security benefits available to people suffering from the disease, and I should like to make some comments on this issue. The main social security benefits and allowances for disabled people are not based on the particular disabling condition, but on the extent to which a person's everyday life is affected. For example, there is attendance allowance for those who need a lot of care and attention, and mobility allowance — to which my hon. and learned Friend specifically referred — for those who are unable, or virtually unable, to walk.

The legislation does not define virtual inability to walk, but the factors to be taken into account are the distance, speed, length of time and manner in which a person can walk without severe discomfort. Each claim is decided according to individual circumstances on the basis of a medical examination. Decisions on claims for mobility allowance are made by the independent adjudicating authorities, and there is a system of appeal for those who are dissatisfied with the decision.

I am not aware that those who suffer from myasthenia gravis are encountering any particular difficulties, but I emphasise that, in view of the independence of the adjudication system, neither Ministers nor officials of the Department can interfere with the decision given on an individual claim.

I was pleased that my hon. and learned Friend raised the matter of research into myasthenia gravis. I was also pleased that he referred to the work of Patrick and Lindstrom, and I should like to add another name to the list of research workers to whom myasthenia gravis sufferers have reason to be grateful, that of Professor Eric Barnard of Imperial college. In myasthenia gravis, the body produces antibodies against acetylcholine receptors, and the effect is that messages passed along the nerves may not reach their destinations, as they are blocked by the antibodies at the nerve endings. That prevents the muscles from working properly. What Professor Barnard has managed to do, supported by the Medical Research Council and the Muscular Dystrophy Group, is to isolate the gene for the acetylcholine receptor. This important advance means that research and work on the fundamental basis of the disease can also be pursued. Research into other autoimmune diseases, and into muscular dystrophy and other genetic disorders, is being pursued in many centres, and this research may well have spin-offs for myasthenia gravis.

I should like to end as I began, by paying tribute to my hon. and learned Friend for bringing this disease to the attention of the House. I assure him that I shall make certain that my colleagues, the Health Ministers at the Department of Health and Social Security, and the officials and specialist experts in our Department, take good note of the points that he made. We shall study carefully all that he has said, and of course we shall be willing to continue our dialogue with him about the disease. Finally, I put on record my appreciation of the scientific work that is being done in identifying the causes of the disease, which is a prerequisite for any permanent cure.

Question put and agreed to.

Adjourned accordingly at twenty-nine minutes past Twelve o'clock.