Psychogenic changes in the field of vision. Associated with tumors of the frontal lobe of the brain.

It is a well-recognized fact that defects in the field of vision may be caused by psychogenic factors. In these cases it is pre­ sumed that no organic involvement of the visual pathways exists, but rather that the functional efficiency and symbolic meaning of the neurologic stimuli have been lost. The most common of the psychogenically etermined field defects are those of con­ centric contraction and spiraling. Bizarre and unusual field defects are recognized as being characteristic of a poorly adjusted person. To assume, however, that a patient showing such deficiency is not also suffering from an organic neurologic lesion may be frought with error, for the apparently psychogeni­ cally determined defect may be superimposed on a neoplastic or vascular disease process. Patients who have tumors involving a frontal lobe of the brain may exhibit fields of vision which are contracted or which spiral on the tangent screen. Whether this effect may be due to impairment of cerebra­ tion or whether it may be a result of physical discomfort and consequent inattention may be difficult to assess in the individual case. The possibility that these field changes are secondary to physiologic interruption of some visual association pathway must also be con­ sidered, for contracted fields may be re­ stored to normalcy with the evacuation of a frontal cyst or removal of a tumor of a frontal lobe. Again, however, this filling out of the fields may simply be an expression of the heightened responses consequent to relief