Introduction

Diseases of the nervous system are roughly divisible into two great classes, organic and functional. In the former, there is a definite morbid change in the affected structures, which is usually the result of inflammation, haemorrhage, or chronic degeneration; in the latter, a careful examination of the nervous system fails to reveal any pathological change, and the condition is therefore spoken of as functional. A good example of a so-called functional disease of the nervous system is neurasthenia. Diet is an important factor in the treatment of both functional and organic disease of the nervous system. It is of special importance in the former (see Neurasthenia), but it is also important in the latter, as it is probable that a chronic defect in dietetics plays a more important role in the causation of some chronic nervous affections than is commonly supposed. We have conclusive evidence that certain articles of food and drink are, for all practical purposes, the causes of certain well-established " nervous " diseases. Thus pellagra, a chronic disease of the spinal cord, is known to be the result of a poison present in unripe maize; the lesions of the posterior columns of the spinal cord in diabetes may also be cited as a nervous affection intimately asbociated with diet; and in alcoholic peripheral neuritis we have a clear example of a disease resulting from dietetic error. In connection with the last named there is a point of some importance which must be noted. There is reason to believe that the deleterious effects of alcohol on the tissues have a more complex origin than is at first sight apparent. They are in all probability due, not only to the direct effects of the alcohol on the tissues, but to its indirect influence in promoting an abnormal bacterial activity in the intestinal canal, with resulting absorption of toxins. This point is one of much practical importance. The etiology of such diseases as disseminated sclerosis, combined sclerosis, and the like is unknown; all we know is that they are the result of some toxic condition of the blood. If alcohol can act in the manner indicated above, it is possible that other defects in the diet may be a factor of importance in the production of the toxic condition of the blood, which is undoubtedly the cause of these chronic inflammatory affections of the nervous system.

The possibility of the correctness of this view is suggested by the following clinical facts. In many of these nervous disorders the clinical history shows that marked gastrointestinal disturbance preceded the development of the nervous symptoms. This disturbance usually took the form of troublesome flatulence, constipation, diarrhoea, or bilious attacks. Further, examination of the stools of these patients frequently shows them to be ill-formed and very foetid, which indicates an unusually septic condition of the alimentary tract. And lastly, an inquiry into the dietetic history of the patient frequently shows that the diet has been defective, and radically so, having been of a nature which conduces to abnormal bacterial activity in the intestinal canal. The same remarks apply to some chronic mental diseases, which are regarded as the result of a chronic auto-intoxication.

According to this view a defective diet is a factor of some importance in the causation of some chronic nervous diseases, in virtue of its unfavourable influence on the bacteria in the digestive tract. The role of diet is thus an indirect one. This much is certain. In many of these cases an examination of the stools shows a degree of fcetor and other abnormality which is pathological. This condition is either a causal factor or an incidental complication of the nervous disease, and in cither case it is advisable to correct it if possible, such correction being largely a question of diet.

General Principles Of Treatment. In Organic Disease

The general principles of treatment can be clearly defined. In the first place, the diet must be arranged so as to promote a normal state of intestinal secretion and excretion, as revealed by an examination of the stools; and secondly, the diet must be adapted to improve the general nutrition of the patient, which is frequently unsatisfactory. In this connection it is important to bear in mind that the administration of a generous diet to patients with foetid stools may be attended by much less satisfactory results from the point of view of general nutrition, than a diet which contains less than one-half the nutritive value of the "generous" diet.

We seek to give effect to these general principles in the following way. We first of all determine from the patient's dietetic history in what direction, if any, the diet has been such as to predispose to abnormal fermentation, with increased bacterial activity in the intestinal canal. Thus we may find that the patient has had five or six meals a day, consisting too largely of tea, bread foods, and starchy foods. If so, the meals must be reduced in number, and altered in quality so as to diminish the foodstuffs prone to fermentation, the protein foods being proportionately increased. In other instances the diet is found to be of too liberal a character in other directions, rich animal protein foods being taken in large amount twice or thrice daily, in addition to excess in other foodstuffs. Here the diet has to be reduced in amount, the animal protein being specially reduced, and the diet has to be simplified so as to throw less strain on the digestive secretions. By these means the production and absorption of toxins in the intestinal canal is reduced, with advantage to the patient. In rarer cases we find that the diet has actually been deficient in amount, the patient being in a state of malnutrition; as a rule, in these patients the quality of the food has been equally defective from the point of view of maintaining a healthy state of the alimentary tract. Reference may be made to the great importance of attention being directed to the state of the teeth, and to thorough mastication, as prophylactic and therapeutic measures intimately connected with the subject of diet.