CHAPTER XX. Morbid Phenomena of Sensation. THE sensibility is very frequently affected in organic disease of the brain, and exalted, depressed, or perverted states of this important function are to be found among the early and premonitory symptoms of all cerebral affections. The sensation may be, a. Exalted. B. Impaired or lost. EXALTATION OF SENSATION (HYPERESTHESIA). In many affections of the nervous system unconnected with organic disease of the brain, the sensibility exhibits great acuteness; and to such a degree do we occasionally witness this state of morbid exaltation, that the slightest touch of the skin, or puff of cold air, has been known to throw the patient into a paroxysm of convulsive agony. In hydrophobia this condition of acute sensibility is observed, perhaps, in its highest degree of development, and it is frequently seen to exhibit itself for some time after death has apparently taken place. In these cases, such is the morbid peripheral acuteness of sensibility, that the minimum portion of cold wind, or even a faint puff of air from the mouth, coming in contact with the cutaneous surface of the hydrophobic patient, has often induced a fearful paroxysm of spasmodic suffering. In cases of acute visceral inflammation involving some of the ganglia of the great sympathetic nerve, the general sensibility has become keenly acute. In certain hysterical affections of women the sensation is often intensely manifested. To such a degree has this hyperæsthesia been observed, that patients have been known to scream violently when the skin has been only touched. The faintest whisper, sudden opening of a door, or ruffle of a newspaper has been known, in such cases, to induce severe conditions of violent convulsive spasm. It is difficult satisfactorily to explain this phenomenon, but as described here, it is frequently observed in practice. Occasionally, in the incipient stage of inflammation. of the encephalon, an exalted condition of sensation is noticed. The same phenomenon is apparent in cases of tumours interfering with the corpora restiformia, pons varolii, processus cerebelli, and corpora quadragemina. An exaltation of sensibility, both special and general, has been frequently observed in diffused neuralgic conditions, and when connected with cephalalgia of long continuance, and associated with morbid psychical phenomena, it should always command attention in cases of supposed disease of the brain and spinal cord.* Hyperæsthesia of the special sensorial ganglia will be more particularly referred * Spinal softening is often connected with a profound pain occupying the depth of the limb or following the course of the great nervous trunks. Exalted sensibility is, as Andral observes, liable to be mistaken for neuralgia. In other cases these pains do not exist. The limb is merely benumbed, the extreme parts are cold and less sensible than they should be. The patient, says Andral, treats these incipient symptoms with neglect, but the disease marches on, the engourdissement and insensibility gradually increase, and then paralysis ensues. Andral refers to the particulars of a case in which the chief symptom for two consecutive months was nothing more than a sensation of cold—of intense cold-occupying the extremities of the fingers and toes. This symptom continued without any change for eight weeks. It was suddenly changed to a pricking kind of feeling in the same part. After a short time the extremities were seized with a brusque convulsive movement, "des mouvements saccadés." These latter symptoms continued to progress until followed by characteristic signs of spinal softening, to when I proceed to a consideration of the exaltations of special sensibility, viz. :— a. Vision. B. Hearing. 8. Touch. Epileptic Vertigo.-Physiologists have described various types of vertigo. 1. When the body appears to move backwards and forwards. 2. In which the movement seems to be on one side. 3. When the illusory sensation is rotatory. It is not my intention to consider in detail these various phases of vertiginous sensation. In all affections of the brain, the sensation of illusory movements, termed vertigo, or giddiness, stand prominently forward among the significant and important incipient symptoms. In some respects it is more characteristically diagnostic of serious cerebral disease, organic and functional, than that of headache, even in its more acute form of manifestation. If the vertigo be clearly an idiopathic encephalic affection, and not, as is often the case, symptomatic of some form of stomach, heart, hepatic, visceral, renal, or blood disease, we may infer that the state of the brain is entitled to careful pathological analysis, and earnest therapeutic consideration. This phase of disordered sensibility, when not obviously arising from the above causes, or connected with states of poisoned blood, resulting from retained excretions, or presence of a toxic agent in the vital fluid, generally indicates serious disturbance of the cranial circulation, and is frequently dependent upon a want of normal balance in the amount of blood distributed to the various sinuses as well as to the venous and arterial cerebral vessels. The cerebral type of vertigo is easily diagnosed by the absence of those affections of other organs which sympathetically disorder the brain, such as gastric and hepatic derangement, loss of blood, and long-continued, exhausting discharges from various parts of the body.* The most important form of vertigo is undoubtedly that associated with obscure and often hidden types of epilepsy, and it is to this form of neurosis of sensibility I am particularly desirous of directing special attention. * "Vertigo, or giddiness," says Dr. Clutterbuck, "though unattended with pain, is, in general, of a more dangerous nature than the severest headache. Vertigo consists in a disturbance of the voluntary power, and in some degree of sensation, especially of vision; and thus it shows itself to be an affection of the brain itself; while mere pain in the head does not necessarily imply this, it being for the most part an affection of the membranes only. In vertigo, objects that are fixed appear to be in motion, or to turn round, as the name implies. The patient loses his balance, and is inclined to fall down. It often is followed immediately by severe headache. Vertigo is apt to recur, and thus often becomes frequent and habitual. After a time the mental powers become impaired, and complete idiocy often follows, as was the case in the celebrated Dean Swift. It frequently terminates in apoplexy or palsy, from the extension of disease in the brain. "Vertigo is induced by whatever is capable of disturbing suddenly the circulation of the brain, whether in the way of increase or diminution: thus the approach of syncope, whether produced by loss of blood, or a feeling of nausea ; blows on the head, occasioning a concussion of the brain; stooping; swinging; whirling; or other unusual motions of the body, as in sailing, are the ordinary exciting causes of the disease. Vertigo is exceedingly frequent at an advanced period of life, and generally indicates the approach and formation of disease in the brain. Accordingly, it is a frequent forerunner of apoplexy and palsy. "The immediate or proximate cause of giddiness, or vertigo, that is, the actual condition of the brain at the moment, is probably some partial disturbance in the circulation there; which all the occasional causes mentioned are obviously calculated to produce. It is more or less dangerous, according to the cause inducing it, and the state of the brain itself, which may be sound or otherwise. And as this cannot be certainly known, nor the extent of it when actually present, the event is of course uncertain. At all times, your prognosis should be guarded; because vertigo seldom occurs under favourable circumstances of age and general health; uniess when produced by so slight a cause as bloodletting, or a trifling blow upon the head. Whenever vertigo recurs frequently, and at an advanced period of life, and more particularly when it is accompanied with drowsiness, weakness of the voluntary muscles, impaired memory or judgment, or, in short, any other disturbance or imperfection in the state of the sensorial functions, an unfavourable result is to be expected; because all these afford decisive evidence of a considerable degree and extent of disease in the brain." This type of epilepsy has been termed by the French pathologists, the Petit-mal, and, by English writers, epileptic vertigo. It is observed, at all periods of life, in various degrees of severity. It is a common affection of childhood, and often, before its existence is suspected, fatally damages the bodily health and undermines the intelligence. Much of the defective and enfeebled intellect observed among children, associated with great disorder of the general health and impaired vital and nerve force arises from this subtle and mischievous phase of epilepsy. In the majority of cases, particularly in adults, these attacks of pseudo epilepsy are unassociated with any form of convulsive action. The patient never falls down in a characteristic fit, neither is he deprived for any length of time of consciousness. The malady exhibits itself at all periods of the day, and in all possible positions of the body. The fit occurs in the middle of the night, during the transition state between sleeping and waking, early in the morning on first rising, during meals, whilst engaged in conversation, and when walking in the streets. The patient, for a second or two, and occasionally for a longer period, is seized with severe vertigo, and momentarily loses his consciousness. This disorder of sensation often developes itself whilst the patient is actively engaged in his accustomed vocation. I have known clergymen attacked whilst preaching in the pulpit, merchants when engaged at the desk, or on the Stock Exchange, barristers whilst addressing courts of law. I have in many cases traced the malady back for a period of some years, manifesting itself under all conceivable physical and mental conditions. This affection is rarely considered of an important character, until the bodily health and mental condition of the patient begin to be affected. It is then dis |