The pain most usually attacks the temples, the supra-orbital and the occipital regions, the parts within the orbit, and more rarely the top of the head. It is more or less paroxysmal, sometimes occurring with comparative regularity, but frequently arising after a period of anxiety, care, worry, or excitement. In many cases the pain is continuous, and paroxysms consist simply of increase of the ordinary suffering. In the majority of females examined who have been habitual sufferers from headache, there has been found habitual pain at the origin of the trapezius muscles, at the point over the extremity of the spinous process of the seventh cervical vertebra, and at the lower angles of the scapulæ. Less common, but quite characteristic pains accompanying headache are between the angles of the scapulæ and at the lower part of the dorsal region. It is worthy of observation that in general, if pain is habitually experienced at the lower angles of the scapulæ, it is rarely found at the point over the spinous processes of the vertebræ situated between those points; and, again, if pain is habitual over the spinous process of the seventh cervical vertebra, it may be presumed to exist, although it is not invariably found, at one of the other locations below it. These pains occur much less frequently in men, who, more than women, suffer from dull pains at the occipital region. This occipital pain, which is invariably located in the scalp and occipital muscle, is very frequently and incorrectly spoken of, sometimes even in medical literature, as "pain at the base of the brain."

Other sympathetic pains are, at the turn of the shoulders and along the course of the triceps muscle, and in the upper portion of the chest.

Patients suffering from headaches are frequently dyspeptics; they often suffer from insomnia, and habitual constipation is also a not infrequent attendant condition.

To the various conditions just named, the headaches are often attributed, and many patients feel sure that they can account for their headaches as of stomachic origin, because they habitually suffer from disturbance of the stomach at the time of, or just before, the paroxysm of headache. That these are simply attendant symptoms and not causative influences, will be seen as we advance, and the fact that an indiscretion in diet, or an enforced loss of sleep, may act as an immediate cause, will be found to be explained on the principle of increased demand upon nervous energies already rendered inadequate to the ordinary demands of the system, and that this increased demand acts in the same manner as would other calls upon the nervous energies.

Habitual sufferers from headaches, although often persons of highest mental culture and of superior intellectual endowments, are liable to suffer from chronic lassitude and inaptitude to set themselves about any employment, especially if it demands much mental exercise. In some cases a confusion of ideas is so conspicuous a symptom that patients express fears of approaching insanity. There is, in a large proportion of instances, a general nervous irritabil

ity, inability to continuous exertion, and mental depression. Still other cases are so characterized by general impaired functional activity, that the principal local manifestation, the headache, is apparently a secondary subject of attention. Such patients exhibit symptoms varying in a considerable degree, according to the sex of the individual, and the cases are known as spinal irritation, neurasthenia, etc., conditions to which attention will be presently directed.

Chronic headaches are common among those who inherit a neuropathic tendency; by far the greatest number of subjects acquiring the predisposition by inheritance. Certain collateral influences modify the disease in a marked degree. Thus, a residence in a malarial district may give to the complaint a more distinctly periodical tendency, and subjects of headache passing an active life in the open air will, in general, experience less of the associated neuralgic pains in the back and sides than persons of sedentary habits.

The most important facts relating to the etiology of the complaint may be briefly recapitulated as follows: It is an exceedingly chronic disorder, often relieved temporarily, but rarely, if ever, permanently cured by medicines. It is often traceable to the earliest years of the patient. The tendency is frequently, if not generally, hereditary. It is usually intermitting, and demands upon the nervous energies, slightly in excess of those ordinarily required, act as immediate causes. We also find that other symptoms of nervous disturbance, such as insomnia, dyspepsia, and

pains in various localities, are frequent attendant disorders.

These facts lead to the conclusion that the cause is permanent, and in most cases commensurate with the life of the patient; that the irritation or exhaustion affects the nervous centers and is reflected to various parts at a distance from the head as well as to the head itself. Hence, the manifestations of nervous exhaustion or irritation are interchangeable. Thus it is that one in whom the irritation may have been for a long time exhibited as habitual headache may, from some reason, assignable or otherwise, afterward suffer from dyspepsia, neuralgia, or other forms of nervous disorder from the same irritation, and such a change in the form of disorder does not indicate a cure of the first disease, but only a different manifestation of the same trouble from the same cause.

We also find that certain modifying influences, such as the manner of life, the location of residence, and the occupation of the individual, contribute to lend certain characteristics to the complaint.

We are, then, applying all these facts, to search for some cause which shall most generally answer to all these conditions. It must be permanent, often inherited. It is not of necessity situated at the seat of pain, and is as capable of inducing pain or distress in one part as in another. Such a cause must be anatomical, and it is reasonable to assume that it acts by causing inordinate demand upon the nervous energies in the performance of some function or functions, thus reducing the ordinary standard of nervous power in

such a manner that slight additional demands cause marked irregularity of nervous action, permitting agencies which might not otherwise induce disease in the individual to become under these circumstances, capable of exerting important modifying influences. It may be said in general that any anatomical condition which would render the execution of an important and constantly performed function difficult might, by so reducing the amount of nervous energy, become a neuropathic predisposition.

This principle being established, it remains to determine, if possible, whether difficulties in performing any one function more often act as such predisposition, than those attending the performance of other functions.

This question can not be satisfactorily settled upon theoretical principles independently of practical results. If it should theoretically appear probable that this irritating or exhausting influence is to be found more frequently located in one organ or set of organs than another, and should assistance in the performance of the functions of that organ or set of organs be quite uniformly followed by a relief from the disturbances previously experienced, a reasonable ground would exist for concluding that the most general cause had been discovered.

It has already been shown that, in the performance of the visual act, difficulties of no insignificant character are very frequently encountered. These difficulties are often permanent, and are to a great extent hereditary. The nervous strain arising from visual