In nearly half of his cases Kraepelin found apoplectiform attacks appearing without any marked psychosis preceding them. In some instances no mental symptoms appeared for many years. The attacks were, however, immediately followed, usually, by periods of confusion and clouding, sometimes of excitement and violence. The acute disturbance as a rule subsides rather quickly and clears up partially or completely. Usually there remains a memory defect, an increased fatigability and a depressed or irritable mood. These he refers to as cases of apoplectic deterioration or mental enfeeblement. Recurrent apoplectiform seizures may result in excitement, depressions or deliria. Gradual progressive deterioration is the usual picture. As a general rule the cases with marked excitements, depressions and deliria are of short duration and have a bad prognosis.
Kraepelin finds that the arteriosclerotic psychoses appear a decade earlier than the senile psychoses. Less than one per cent developed at the age of forty; 2.7 per cent at forty-five; 3.7 per cent at fifty; 7.4 per cent at fifty-five; twenty-two per cent at sixty; twenty-two per cent at sixty-five; 18.57 per cent at seventy; twelve per cent at seventy-five, etc. In the cases observed at a particularly early age he believes heredity to be a very important factor. Seventy-one and five-tenths per cent of his cases were men. Sixty-two per cent of the men and fifty-three per cent of the women were less than sixty-five years of age. The epileptic and demented forms appear earlier than the apoplectiform variety. Arteriosclerotic involvement of the smaller vessels occurs earlier than that of the larger arteries. Kraepelin found alcoholism more common in the history of his cases than syphilis. He is uncertain whether specific infections can produce a genuine arteriosclerosis or not.
Erb has shown that by the experimental injection of adrenalin into the blood stream artificial arteriosclerosis can be produced, with an increase of blood pressure, splitting of the elastica, thickening of the vessel walls and aneurysm formation. Thoma considers alcohol, tobacco, coffee, tea, and infectious poisons important causes. Cramer found the disease more common in innkeepers, actors, directors, officers, bankers and parliamentarians. Alcohol, syphilis, overwork and high living are important etiological factors. Kraepelin assumes the existence of certain metabolic products in the blood, possibly the result of infections which affect blood pressure and the structure of the vessel walls during a period of lowered resistance.
The pathological changes associated with the arteriosclerotic psychoses are quite clearly demarcated. Clinical differentiations, however, are not so well established. There is some question as to the justification of the separate entities into which Kraepelin would divide the arteriosclerotic processes. For statistical purposes the Association's committee felt that a determination of the frequency of occurrence of the arteriosclerotic group as a whole is all that should be attempted at this time. The following suggestions were offered in the manual as to the delimitations of these conditions:—
"The clinical symptoms, both mental and physical, are varied depending in the first place on the distribution and severity of the vascular cerebral disease and probably to some extent on the mental make-up of the person.
"Cerebral physical symptoms, headaches, dizziness, fainting attacks, etc., are nearly always present, and usually signs of focal brain disease appear sooner or later (aphasia, paralysis, etc.).
"The most important mental symptoms (particularly if the arteriosclerotic disease is diffuse) are impairment of mental tension, i.e., interference with the capacity to think quickly and accurately, to concentrate and to fix the attention; fatigability and lack of emotional control (alternate weeping and laughing), often a tendency to irritability is marked; the retention is impaired and with it there is more or less general defect of memory, especially in the advanced stages of the disease, or after some large destructive lesion occurs.
"Pronounced psychotic symptoms may appear in the form of depression (often of the anxious type), suspicions or paranoid ideas, or episodes of marked confusion.
"To be included in this group are the psychoses following cerebral softening or hemorrhage, if due to arterial disease. (Autopsies in state hospitals show that in arteriosclerotic cases softening is relatively much more frequent than hemorrhage.)
"Differentiation from senile psychosis is sometimes difficult particularly if the arteriosclerotic disease manifests itself in the senile period. The two conditions may be associated; when this happens preference should be given in the statistical report to the arteriosclerotic disorder.