Kraepelin[192] also refers to the fact that the mental symptoms may precede the choreiform manifestations in appearance, sometimes by a number of years. The patients become forgetful, defective in judgment, somewhat dull, show a poverty of thought and an incapacity for orderly activities. Generally there is an emotional depression, often with irritability and more rarely euphoric symptoms. Delusions gradually develop. These are of a persecutory nature, although ideas of grandeur appear at times. Suicidal tendencies are common. Disturbances of perception and memory may be very pronounced. The relation of the patient to his environment becomes very much confused. In some cases, on the other hand, the mental symptoms are not very striking. Anxious states, outbursts of anger or emotional excitements may appear at times. Appetite and sleep are often interfered with. The pathology of this disease is not characteristic. There may be a chronic meningitis or extensive atrophies. The cells of the third layer of the cortex, according to Kraepelin, are decreased in number with an increase of glia nuclei. The remaining cells are shrunken with deeply staining processes, and there is a considerable loss of tangential fibres. Sclerotic changes with thickened walls are noted in the blood vessels. Hyaline degeneration and miliary hemorrhages have been observed, although Nissl and Alzheimer found no vascular lesions worthy of note. The cortical changes, according to Räcke, are more pronounced in the central convolutions, being much less conspicuous in the frontal and occipital regions. Alzheimer found the corpus striatum particularly involved. Here he noted a striking cell loss, with glia proliferation but no vascular changes. D'Ormea, according to Kraepelin, traced the disease through five generations in one family and Browning went as far back as two hundred years in another. The observations on the subject of Huntington's chorea in the statistical manual of the American Psychiatric Association are as follows:— "Mental symptoms are a constant accompaniment of this form of chorea and as a rule become more marked as the disease advances. Although the disease is regarded as being hereditary in nature, a diagnosis can be made on the clinical picture in the absence of a family history. "The chief mental symptoms are those of mental inertia and an emotional change, either apathy and silliness or a depressive irritable reaction with a tendency to passionate outbursts. As the disease progresses the memory is affected to some extent, but the patient's ability to recall past events is often found to be surprisingly well preserved when the disinclination to cooperate and give information can be overcome. Likewise the orientation is well retained even when the patient appears very apathetic and listless. Suspicions and paranoid ideas are prominent in some cases."