2. General symptoms with third nerve paralysis.
3. General symptoms with localizing signs of facial paralysis.
4. General symptoms with localizing signs extending down to the cord.
5. General symptoms with polyneuritic involvements.
6. Mild and abortive cases.
Autopsies have shown meningeal and cortical congestion, degeneration of the nerve cells, and thickening of the vessels with endothelial proliferation of the glia. Venous thrombosis and multiple hemorrhages also occur. In a study of the cerebrospinal fluid Boveri[210] found the pressure slightly greater in many cases with an increase in the albumen and globulin content and a mild lymphocytosis in occasional cases. The findings are not characteristic or of great diagnostic value. Efforts to isolate the organism responsible for this disease have so far been unsuccessful.
The mental symptoms associated with encephalitis lethargica have been studied recently by Abrahamson[211]. He finds that the patient can be aroused from the initial lethargy and responds quickly and coherently to questions, relapsing again into an apparent sleep. Some irritability is shown. The attitude "expresses a desire to be left alone." If the somnolence disappears it is usually followed by a period of depression. The patient complains of weariness and inability to sleep. Choreic manifestations sometimes occur. The somnolence may terminate, on the other hand, in a profound stupor resembling a drug intoxication with a restless delirium. Even then the patient can be roused momentarily. Responses are automatic with no evidences of emotional disturbance. Flexibilitas cerea is often present. This condition may be followed by a period of confusion, disorientation and amnesia suggesting Korsakow's disease. There is usually a period of mental depression with poverty of thought. Occasional hallucinations were also observed.
An exceedingly important contribution to the literature of encephalitis lethargica is an analysis recently made of the symptoms shown in eighteen cases by Kirby and Davis.[212] "The psychic disturbances of epidemic encephalitis present the general characteristics of an acute organic type of mental reaction, corresponding more specifically to a toxic-infectious psychosis. In the acute stages of the disease, psychic torpor and delirium are the most frequently observed mental disturbances although other clinical pictures may be encountered, as the Korsakoff syndrome or more complex mental disorders in which various affective and trend reactions give a special cast to the psychotic disturbance." They report two types of sleep disturbance, hypersomnia and hyposomnia. The former is characterized by drowsiness, lethargy, stupor or coma, depending entirely on the degree reached. In the latter the patient is sleepless at night and somnolent during the daytime. Usually delirium was present at some time in both types of the disease. Often there was a brief period showing a mild depression or anxiety, following lethargy or delirium. Euphoria was observed in a number of instances. In the unrecovered cases they often found residuals—"depressive affects, emotional elevations, irritability, explosive reactions, stubbornness, apathy, etc." Their findings may be summarized perhaps in the statement that "definitely formulated and persistent trends are infrequent in epidemic encephalitis ... we have found much evidence of persisting emotional alteration with little evidence of organic mental defects or dementia."
A review of the statistics of American institutions shows that psychoses associated with brain and nervous diseases other than Huntington's chorea and brain tumor, which have already been discussed, are exceedingly rare. The percentage of cases reported in the New York hospitals was .95, in the Massachusetts institutions, 1.02, and in twenty-one other hospitals only 1.56. In a total of 70,987 first admissions there were only 787 cases (1.1 per cent). The relative frequency of the various forms is illustrated by the statistics of the admissions to the New York state hospitals during a period of eight years. Of 462 cases, 160 were diagnosed as psychoses due to cerebral embolism; twelve, to meningitis; twenty, to multiple sclerosis; thirty-eight, to tabes; thirty-four, to acute chorea; and 163, to other conditions not specified. These figures are astonishing when the fact that 49,640 patients were admitted during that time is taken into consideration.