Differential Diagnosis of Late Onset Psychosis Using Neuropsychological Assessment and Neuroimaging Techniques
Date of Submission
Doctor of Psychology (PsyD)
Arthur Freeman, Ed.D., ABPP
Katherine J. Miller, Ph.D., Chairperson
David Castro-Blanco Ph.D., ABPP
Nancie B. Wolfe, Ph.D.
Few references in the literature have been made with respect to the diagnosis of late onset psychosis by the use of behavioral observations coupled with neuropsychological and neuroimaging techniques. This is a report of the case of a 68-year-old woman who experienced a sudden onset of psychotic illness characterized by delusions and confabulation. As part of her neurobehavioral evaluation, a SPECT scan revealed right frontal and left anterior temporal lobe hypoperfusion. Serial neuropsychological evaluations demonstrated decline on tests of executive control (monitoring, allocation of attention, perseveration) and visuospatial abilities, whereas performance in other areas of cognitive functioning remained close to the normal range for the patient's age and educational level. Over the same period of time MRI and neurological examinations were within normal limits. Thus, there was little evidence to diagnose dementia. The patient did not have a fundamental disorder of thinking or profound deterioration in mental or social functioning, so a diagnosis of late life onset schizophrenia was not made. It is suggested that impairment in executive control with a diminished capacity to process perceptual information can give rise to psychotic behavior characterized by late onset psychosis. The review of the literature provides a nosology for late onset psychosis, which follows a succinct neuroanatomical review of the frontal, temporal, and parietal lobe function found to be involved with the psychotic underpinnings of the disorder. This work culminates with a research study wherein specific neuropsychological and neuroirnaging tests sensitive to late onset psychosis would be delivered to three elderly cohort groups to aid in early detection and differential diagnosis of late onset psychosis. It is expected that proficiency on neuropsychological tests sensitive to visuospatial organization will be compromised for individuals having late onset psychosis. It is also expected that these individuals will demonstrate a low total score on a neuropsychiatric inventory scale. It is postulated that MRI will demonstrate subcortical white matter intensities not found in late life onset schizophrenia or frontotemporal dementia. Additionally, it is hypothesized that the SPECT scan of individuals having late onset psychosis will demonstrate hypoperfusion to the right frontal, right parietal, and anterior left temporal regions.
Ball, Susan Fralick, "Differential Diagnosis of Late Onset Psychosis Using Neuropsychological Assessment and Neuroimaging Techniques" (1999). PCOM Psychology Dissertations. 6.