Quite characteristic of the senile brain is the occurrence of the miliary plaques or "drusen" described by Redlich in 1898. Fischer in 1907 reached the conclusion that these "drusen" were pathognomonic of presbyophrenia, as he did not find them in senile dementia, in other psychoses or in normal brains. Hübner, however, noted them in alcoholics and "circular" cases as well as in normal individuals. Oppenheim also found them in the brains of the aged when no psychoses were observed. The interior of the plaque is a homogeneous, dark-staining, structureless mass. Sometimes there is a clear space around this center, with club- or spindle-shaped bodies in the periphery, representing remnants probably of neurones, glia cells or axis cylinders. The whole structure is encapsulated in glia fibres. These so-called plaques were spoken of by Fischer as "miliare Nekrosen" and by Redlich as "miliare Sclerosen." Kraepelin is of the opinion that they are associated either with senile cases showing arteriosclerotic changes or presbyophrenia. Alzheimer has described a senile atrophy of the brain with wedgeshaped areas showing cell loss. This is due to a gradual occlusion of the smaller vessels extending down from the meninges into the cortex, and may result in a hemorrhage, a softening or merely an atrophic area characterized by an absence of ganglion cells. He has also described another group of cases showing characteristic cell changes. This condition has been given the name "Alzheimer's disease" by Kraepelin.[160] It is marked clinically by a gradual senile deterioration with organic brain changes. These eases show some thought defect, loss of memory, confusion, and clouding. Later they become restless, talkative, sing and laugh, etc. Aphasic disturbances develop early, with paraphasia or apraxia. There are speech disturbances ending in a senseless jargon and writing becomes impossible. An advanced deterioration ensues. Physically there is a general weakness and uncertain gait, sometimes with epileptiform attacks. The pupillary reaction may be lost and evidences of arteriosclerosis usually appear. The disease may last for many years. At autopsy "drusen" are common in the cortex and almost a third of the nerve cells are found to be destroyed. These are replaced by darkly-staining fibril bundles. There is marked neuroglia reaction, particularly around the "drusen" and retrogressive changes are found in the vessel walls. This disease usually appears about the fortieth year and may be looked upon, Kraepelin says, as a "senium praecox," although its significance is not clear.