A system of practical medicine. By American authors. Vol. 5

by Unknown

The cerebro-spinal fluid is usually more abundant than normal, of a deeper color, cloudy, sometimes tinged with the coloring matter of the blood.

The Brain.—The intimate lesions of the substance of the brain are not yet known. The volume of the encephalon, as a rule, undergoes no change. Occasionally it appears to be swollen, and protrudes with some degree of force through the incision first made in the membranes. More commonly, the brain is throughout or in certain parts atrophied or shrivelled, its convolutions flattened, its surface retracted. This is sometimes the result of the pressure of collections of hemorrhagic or inflammatory products.

The consistence of the cerebral mass is sometimes increased; it becomes harder, more resistant to pressure, and preserves its form when removed from the cranium better than the normal brain. This condition may be present throughout the brain or it may be localized. In the latter case it is usually due to patches of sclerosis. Softening in more or less extensive areas may occur in the advanced stages of the more severe forms of chronic alcoholism. It is found chiefly in the gray substance, where the vessels are more numerous, especially in the cortex and central ganglia. In this as in other affections cerebral softening is the result of obstruction of the circulation in consequence of atheroma, thrombosis, or other change in the arteries. It varies from simple diminution in consistency to diffluence.

The nervous substance of the brain doubtless undergoes changes proportionate to the degree and duration of its exposure to an alcohol-charged blood. What these changes are has not yet been fully determined. The nerve-cells of the cortex have been found rounded and contracted, so that instead of being surrounded by a small lymph-space they seem to be lying in large cavities, and so granular that the nucleus can hardly be made out. Slight increase in the number of the small round cells in the cortex and in the adjoining parts of the white matter has also been observed (Hun). These changes are not, however, constant. Not only has the microscopical morbid anatomy of the lesions of nerve-substance peculiar to chronic alcoholism not yet been worked out, but even macroscopic changes adequate to account for symptoms that were during life serious, persistent, and apparently referable to well-defined lesions, are sometimes absent altogether.

It is important to distinguish the disorders due to the direct action of alcohol, which are often functional or dependent upon lesions too subtle for recognition, from those which are secondary and dependent for the most part upon coarser changes of structure.

In consequence of hyperæmia of the brain and its membranes there not infrequently occur a sense of confusion or dulness, increasing to headache, which may become almost unbearable, mental disturbances of the most varied character, disorders of movement and sensation, and disorders of the special senses.

Cerebral hemorrhage, to which the subjects of chronic alcoholism are, in consequence of the vascular lesions already described, peculiarly prone, manifests itself by the usual primary and secondary phenomena. Meningeal hemorrhage, save in the form of hæmatoma, is rare except in the advanced stages of paretic dementia.

The blood in alcoholic dyscrasia undergoes changes which favor its transudation through the walls of the vessels; hence a tendency to œdema and to accumulations in serous sacs. This tendency implicates the structures of the nervous system in common with the organism at large. The ventricles of the brain become distended with fluid, and the brain-substance itself and the meninges not rarely become œdematous in the last stage of chronic alcoholism, in consequence of grave disturbances of the circulation or as complications of affections of the lungs, heart, or kidneys. These conditions are attended by mental obscuration, somnolence alternating with sleeplessness, delirium, maniacal paroxysms, impairment of muscular power, of general and special sensibility, impaired reflexes, inability to speak, deepening stupor, and death.

2. Spinal Disorders.—Lesions of the spinal cord or its membranes have been rarely discovered. When present they have been invariably associated with similar or corresponding lesions of the brain or its envelopes. Leyden³⁹ states that not only do the cerebral meninges present inflammatory changes in chronic alcoholism, but the meninges of the cord are sometimes found in an analogous condition; that pachymeningitis hæmorrhagica interna spinalis has also been observed, as well as other forms of spinal meningitis, with thickening and discoloration of the pia and dura; and that œdema of the pia has been especially noted. While anatomical lesions of the cord are less frequent than lesions of the brain, nutritive and functional disturbances, as manifested in the general symptomatology, are quite as common in one as in the other.