Acute and chronic brain syndromes due to intracranial neoplasms (tumors). These neoplasms, or “new growths,” are of unknown origin and vary greatly in size. They may be either benign or malignant. Some tumors remain small and relatively harmless, depending on their location. Others may reach the size of an orange and do extensive damage by exerting pressure on brain tissue. Malignant tumors cause damage by direct destruction of cells.Brain tumors occur most frequently in adults between the ages of forty and sixty, but are also occasionally seen in children. Although about 1 per cent of the population are afflicted, brain tumor patients account for only about .1 per cent of first admissions to mental hospitals since they seldom develop serious and chronic mental symptoms.The clinical picture in brain tumor disorders is a varied one since the symptoms are due not only to the size, location, and rapidity of growth of the tumor, but to the pre-illness personality and insight of the patient. There is probably no disorder in which the individual’s reactions are so dependent on his degree of maturity, stability, and tolerance for stress. In fact, these factors frequently outweigh the physical effects of the tumor itself in determining the symptom picture. Some patients undergo noticeable changes in personality and attitude even when the physical symptoms are not severe. They may become easily upset, indifferent toward work, neglectful of personal appearance, or shameless in their behavior. Others are able to endure even the most intense suffering with courage, determination, and a refusal to admit defeat.The most common early symptoms are absentmindedness, fatigability, drowsiness, and mild confusion. As the disorder advances, memory, concentration, reasoning, and sensation become increasingly affected. Patients who have some awareness of their condition often become depressed and apprehensive; those who do not understand what is wrong with them may become euphoric or jocular, in an unconscious effort to deny that it is anything serious.The specific symptoms depend largely on the area affected. Temporal lobe tumors frequently produce disagreeable taste and smell sensations, strange dreamlike states, transient feelings of fear or dread, or “Lilliputian” hallucinations in which they see small animals crawling around. In some cases automatic, irrational actions are carried out suddenly and without recollection later on. Tumors of the frontal lobe lead to absentmindedness, memory impairment, and inability to concentrate. These patients also develop personality changes, often becoming apathetic about their personal appearance, indifferent toward their work, suspicious and uninhibited in their behavior. Occipital lobe tumors are most frequently associated with simple visual hallucinations such as flashes of colored light, or auditory hallucinations such as ringing, buzzing, or roaring sounds. Tumors of the corpus callosum (the tissue joining the two hemispheres of the brain) are accompanied by impairment of concentration and thinking processes. In general, mental symptoms are less likely to occur if the intracranial pressure builds up slowly than if it develops rapidly.Brain tumor cases usually require surgery where this is feasible. Its success depends on the size and location of the tumor, the damage it has already done, and the amount of tissue that must be sacrificed in removing it. Early and accurate diagnosis is essential, although some tumors, particularly the benign type, grow so slowly that it is hard to discover them in their early stages. An estimated 40 per cent of cases are completely curable; 20 per cent can be relieved for five or more years, but may involve some impairment of physical or mental functions; the remainder are fatal within a relatively short period. There are no known methods of prevention.A twenty-five-year-old mechanic grew very dull mentally. His reactions slowed and his facial expression became dull and stupid. He was unable to grasp simple matters. For example, when he expected an out-of- town visitor, he would ask how the guest would travel and how long he would stay; he was unable to figure out where the visitor would sleep. He became more and more forgetful, even forgetting where he put his tools. He failed to complete jobs, and, when criticized for it, did not know what he had done wrong. A mental examination showed that he had memory disturbances and slight intellectual impairment. His physical examination showed neither general nor local symptoms of brain tumor, but the encephalogram showed partial obliteration of the ventricles. On the basis of this, a tumor in both frontal lobes was diagnosed. It was removed surgically, the patient recovered fully and has been well for ten years. (Mas- low and Mittelmann, 1951)