Extensive Cavity Formation in the Central Nervous System, Presumably Due to Bacillus Aerogenes Capsulatus
Boston Medical and Surgical Journal
The so-called Gruyère cheese brain has been the subject of much speculation since 1870. There have been various theoriesy of the nature of these cavities found in the brain. The earliest theory was that the condition is due to dilatation of the perivascular lymph spaces ; later that it is a detention of the network of the neuroglia due to lymph stasis ; again to dilatation of the pericellular spaces of the neuroglia or to absorption of the nerve substance from pressure. The process has been
... rocess has been spoken of as " cystiform degeneration," also quite widely to-day as " cyst formation." The other pathological conditions known generally under the term état criblé could hardly now be mistaken for that produced by the gas bacilli. In genuine cyst formation there is a lining membrane and evidences of a chronic process. At the present time there is no reasonable doubt that the cavity formation is due to the production of gas in the brain substance by gas-forming bacteria. Bacteria have been found in the brain substance in this condition by several observers, but in only three cases has the identity of these bacteria been clearly established. Two of these cases are reported by W. T. Howard, Jr.1 In one of them he identified the bacteria as of the species known as the Bacillus aërogenes capsulatus. In a third case reported by Madison c the Bacillus aërogenes capsulatus and other bacteria were found. The Bacillus aërogenes capsulatus, as first shown by W. H. Welch,8 is characterized by its power of producing gas in the tissues of man and animals. It is the bacterial cause of the majority of the septic and putrefactive conditions accompanied by gas formation in the tissues. It is a common inhabitant of the intestine, and is probably widely distributed outside of the body. The Bacillus mucosus capsulatus is found in certain forms of pneumonia and peritonitis and in various other inflammatory conditions. It is probably a normal inhabitant of the upper air passages. The strain of this bacillus found by Howard in one of his cases was shown by him to be an energetic gas producer, both in culture media and in the bodies of animals. The following case, which occurred at the Mc-Lean Hospital, may here be briefly reported. For the sake of brevity we leave out all detail which has no bearing on the special features to which we wish to call attention. The patient, a man forty-nine years of age, had advanced general paralysis, having' been in the hospital for nine years. He was profoundly demented, with extensive paralytic evidences, and confined to bed. He was well nourished and weighed 1G8 pounds. The patient's condition continued unchanged until ¡i few days before death, when an Increased restlessness was noted. On the morning of the day he died there was discovered a marked abdominal detention, a temperature of 104" and respiration 48-58. He rapidly failed, and died in the evening. Autopsy. The autopsy was made twenty hours after death ; the weather was hot and the body, with ice over the abdomen, had been kept in a cool room. Rigor mortis was present ; the face and body appeared bloated, the abdomen greatly distended and the entire skin of a dark bluish hue. On section there was gaseous emphysema of the subcutaneous tissues in both thorax and abdomen, but none in the scalp, which was very dense and of unusual thickness. Gas escaped on opening the abdominal cavity. The stomach and intestines were greatly distended with gas, and showed red discoloration in places. The blood vessels were very prominent. The liver appeared spongy, pale and puffy, riddled with gas cavities ; the spleen slightly so. In the kidneys and heart muscle no cavities were seen ; but both shovved gas cavities and bacilli on microscopical examination. The heart muscle appeared soft, and on microscopical examination the muscle fibers were much fragmented and the nuclei stained poorly. The kidneys showed in places slight increase of connective tissue. There was no pneumonia, no pleural nor peritoneal exúdate. There were old adhesions at the base of the left lung. The stomach showed several small erosions. The brain presented at the autopsy nothing but the usual condition found in advanced general paralysis ; that is, marked atrophy, especially in the frontal lobes (weight of brain 1070 gin.), thickening of the pia. The vessels appeared unusually large. It was put into formalin in toto and found to float. The formalin was frequently changed. The cord showed unusual thickening of the pia arachnoid from the thoracic region down and a marked dark purplishred discoloration of the membranes. After the brain had been six days in formalin, frontal sections were made. The appearance of these sections was very striking. The whole of the cut surface showed many cavities (Figs 1 and 2) ; these varied in size from 3.5 cm. to the smallest visible to the naked eye ; the shape varied, being usually oval but sometimes round ; a few were slitlike. They were located in both white and gray matter. The portions which had maintained the greatest integrity were the gray matter of the cortex of both cerebral hemispheres and that of the cerebellum. The basal ganglia and brain stem (Fig. 2 ) were equally affected with the medullary portions of the brain. There was present a distinct pigmentation in certain portions of the brain ; it was of a dark slate color and irregularly distributed, being seen outlining some of the convolutions (especially in the temporal lobes) just below a narrow line of unpignieuted cortex. This color was also seen in the gray matter of the cerebellum and irregularly on the cut surface of the pons and medulla. The cord below the medulla did not show this pigmentation microscopically, but in the meninges was seen the same dark slate color uniformly distributed. Miciioscoi'iCAi. Examination of Suctions. Specimens from the cortex were hardened in alcohol and stained by Nissl's method. Other pieces were hardened in formalin and stained by heiuatoxylineosin and by Gram's and various other methods. Specimens from heart and kidney were hardened in Zenker's fluid. The cortex showed the usual changes of general paralysis, which it is not necessary to describe here, The Boston Medical and Surgical Journal as published by The New England Journal of Medicine. Downloaded from nejm.org at SAN DIEGO (UCSD) on July 9, 2016. For personal use only. No other uses without permission. From the NEJM Archive.