The most characteristic degenerative changes met with in chronic alcoholism are fatty change and atrophy of the parenchyma, with a corresponding increment of connective tissue. These changes, as might be expected, are generally most pronounced in the alimentary tract and in the liver, but no tissue is exempt from them. Their distribution varies in different subjects : sometimes the liver is most affected, sometimes the nervous system, sometimes, again, it is the cardio-vascular system - a fact which lends support to the view that the changes in question are produced, not by the direct action of the alcohol only, but by the indigestion toxaemia which it sets up, the exact nature of this toxaemia differing, we may suppose, in different subjects.
The liver in the chronic alcoholic tends in the first instance to become congested. Later, fibrosis occurs, together with fatty degeneration of the liver cells, though it is doubtful whether fibrosis culminating in "hob-nailed liver" is so characteristically associated with deep potations as has been thought. Not only is its occurrence among hard drinkers infrequent, but it is met with in those who have led perfectly healthy lives.
The heart of the alcoholic tends to undergo fatty degeneration and frequently exhibits fibroid change. It has also been definitely shown that excessive drinking favours arterial sclerosis.
While chronic alcoholism predisposes the kidneys, in common with all other organs and tissues, to inflammatory affections, it cannot be regarded as more than a subsidiary factor in the causation of granular kidney.
The nervous system is peculiarly susceptible to the action of alcohol, and tends in the inebriate to degenerate throughout its entire extent. The changes may be acute, as in peripheral neuritis, or, as more frequently happens, chronic. In the latter case the neurons atrophy, their place being taken by fibrous tissue. One of the first changes observable in the body of the neurons is a diminution in the number of their dendrites, and this interferes not only with the more organic aspects of neural function, such as muscular co-ordination and vaso-motor action, but with the proper association of ideas on which memory, judgment, and all the higher operations of mind depend. These dendritic changes are accompanied and followed by changes in the body of the neuron : the nucleus travels towards the periphery, the protoplasm ceases to take up stains in the normal way, and finally, the whole cell shrinks, becoming the mere ghost of its former self. In addition to these parenchymatous changes an abundant fibrosis occurs throughout the brain and spinal cord, while an inflammatory thickening of the meninges - especially those of the brain - is often met with.