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APOPLEXIES OR TUMOURS OR ARTERIAL DEG...

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Originally appearing in Volume V14, Page 607 of the 1911 Encyclopedia Britannica.
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APOPLEXIES OR TUMOURS OR ARTERIAL DEGENERATION. (a) Traumatic Insanity.—Insanity following blows on the head is divided into (I) the forms in which the insanity immedi- ately follows the accident; (2) the form in which there Traumatic innsanit is an intermediate prodromal stage characterized by . strange conduct and alteration in disposition; and (3) in which the mental symptoms occur months or years after the accident, which can have at most but a remote pre-disposing causal relation to the insanity. The cases which immediately succeed injuries to the head are in all respects similar to confusional insanity after operations or after fevers. There is generally a noisy incoherent delirium, accompanied by hallucinations of sight or of hearing, and fleeting unsystematized delusions. The physical symptoms present all the features of severe nervous shock. In those cases in which there is an intervening prodromal condition, with altered character and disposition, there is usually a more or less severe accidental. implication of the cortex cerebri, either by depression of bone or local hemorrhage, or meningitic sub-inflammatory local lesions. Most of the cases during the prodromal stage are sullen, morose or suspicious, and indifferent to their friends and surroundings. At the end of the prodromal stage there most usually occurs an attack of acute mania of a furious impulsive kind. The cases which for many years after injury are said to have remained sane will generally be found upon examination and inquiry to exhibit symptoms of hereditary degeneration or of acquired degeneracy, which may or may not be a consequence of the accident. The most common site of vascular lesion is one of the branches of the middle cerebral artery within the sylvian fissure, or of one of the smaller branches of the same artery which go directly to supply the chief basal ganglia. When an artery like the middle cerebral or one of its branches becomes either through rupture or blocking of its lumen, incapable of performing its function of supplying nutrition to important cerebral areas, there ensues devitality of the nervous tissues, frequently followed by softening and chronic inflammation. It is these secondary changes which give rise to and maintain those peculiar mental aberrations known as post-apoplectic insanity. Various characteristic physical symptoms, depending upon the seat of the cerebral lesion, are met with in the course of this form of insanity. These consist of paraplegias, hemiplegias and muscular contractures. Speech defects are very common, being due either to the enfeebled mental condition, to paralysis of the nerve supplying the muscles of the face and tongue,or to aphasia caused by implication of those parts of the cortex which are intimately associated with the faculty of speech. Mental symptoms vary considerably in different cases and in accordance with the seat and extent of the lesion. There is almost always present, however, a certain degree of mental enfeeblement, accompanied by loss of memory and of judgment, often by mental confusion. Another very general mental symptom is the presence of emotionalism which leads the patient to be affected either to tears or to laughter upon trifling and inadequate occasions. Cerebral tumours do not necessarily produce insanity. Indeed it has been computed that not one half of the cases become insane. When insanity appears it is met with in all degrees varying from slight mental dulness up to complete dementia, and from mere moral perversion up to the most intense form of maniacal excitement. On the physical side the various symptoms of cerebral tumour such as Loma, ataxia, paralysis, headache, vomiting, optic neuritis and epileptiform convulsions are met with. All forms of so-called moral changes and of changes of disposition are met with as mental symptoms and all the ordinary forms of insanity may occur in varying in-tensity; but by far the most common mental change occurring in connexion with cerebral tumour is a progressive enfeeblement of the intelligence, unattended with any more harmful symptoms than mental deterioration which ends in complete dementia. (b) Arterial Degeneration.—Arterial degeneration is a common cause of mental impairment, especially of that form insanity of mental affection known as " Early " dementia. due to It also predisposes to embolism and thrombosis, Arterial which often results in the paralytic and aphasicDegeneragroups of nerve disturbance, and which are always Don. accompanied by more or less marked interference with normal cerebral action. The commonest seat for atheroma of the cerebral vessels is the arteries at the base of the brain and their main branches, especially the middle cerebral. As a general rule the other arteries of the cerebrum are not implicated to the same extent, although in a not inconsiderable number of cases of the disease all the arteries of the brain may participate in the change. When this is so, we obtain those definite symptoms of slowly advancing dementia commencing in late middle life and ending in complete dementia before the usual period for the appearance of senile dementia. The same appearances are met within certain patients who have attained the age in which senile changes in the arteries are not unexpected. As a rule atheroma in the cerebral vessels is but a part of a general atheroma of all the arteries of the body. Atheroma is common after middle life and increases in frequency with age. The chief causes are syphilis, alcoholism, the gouty and rheumatic diatheses and above all Bright's disease of the kidneys. Perhaps certain forms of Bright's disease, owing to the tendency to raise the blood pressure, are of all causes the most common. It is not easy to say to what extent, alone, the arteriosclerosis is effectual in inducing the gradual failure of the mental powers, and to what extent it is assisted in its operation by the action on the brain-cells of the general toxic substances which give rise to the arterial atheroma. In any case there can be no question that the gradual mechanical diminution of the blood-supply to the cortex caused by the occlusion of the lumen of the arteries is a factor of great importance in the production of mental incapacity.
End of Article: APOPLEXIES OR TUMOURS OR ARTERIAL DEGENERATION
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