Marchiafava and Celli observed in several cases the vessels of the brain filled with non pigmented parasites. This explains the occurrence of cerebral pernicious fevers without pigmentation of the brain (Plate VII, Fig. 39).
In addition to the melanemia we must not forget the hemorrhages which are frequently found in different varieties of cerebral pernicious fevers. These are usually punctate and sometimes very numerous. According to Bastianelli and Bignami, they are situated about the very small arteries in the white matter of the brain and spinal cord; less commonly, at the border between it and the gray matter. These arterioles are often thrombosed, and show, as a result, degeneration of the endothelium. The extravasated blood corpuscles never contain parasites. Bastianelli and Bignami assume that the punctate hemorrhages arise by a diapedesis through the injured vessel walls.
According to Blanc, the majority of hemorrhages are to be found within or near the cortex. This writer also reports an interesting case of apoplectic malaria in which, in addition to numerous capillary hemorrhages, a large subcortical hemorrhage was found that had broken through the cortex. Such hemorrhages, however, seem to be very rare.
Maillot observed two cases with red softening in the lower dorsal portion of the spinal cord. Marchiafava reported in one case with bulbar symptoms degenerative changes in the ganglion cells of the medulla.
The retina was studied postmortem in ten cases of pernicious fever by Guarnieri. He found the retinal vessels, veins, capillaries, and arteries considerably dilated; the first irregularly, in that normal and dilated areas alternated. The perivascular lymph spaces were also distended as a result of edema. The capillaries were filled almost exclusively by infected blood corpuscles, while the veins and arteries showed also healthy erythrocytes. The latter occupied the middle of the vessel, while the infected blood corpuscles, as seen previously in the cerebral vessels, lay along the walls.
In the choroidal vessels the large number of mononuclear melaniferous phagocytes, in places thrombosing the vessels, was striking.
In two cases small hemorrhages were found, which took in all the external layers of the retina. The extravasated blood corpuscles were, without exception, healthy, analogously to similar conditions in the brain. The vessel walls showed only slight alterations. Here and there the capillary endothelium was swollen, fatty degenerated, or necrotic.
In reference to pigmentation of the lymph glands, we have nothing to add to our former remarks. Enlargement of the glands does not occur.