PRIMARY POSTERIOR CORTICAL ATROPHY DISORDER: BEHAVIORAL AND PSYCHIATRIC SYNDROME

Abstract

The diagnosis of posterior cortical atrophy (PCA), as an unique dementia disorder, is rarely made by general practitioners because patients only present vague visual symptoms in the beginning. When the PCA patients finally receive the proper diagnosis made by dementia specialists, they often present behavioral and psychiatric symptoms related to the visuospatial/visuoperceptual deficits. These symptoms range from anxiety to visual hallucinations. Recent research indicates, although the underlying causes can include a variety of neuropathololgies, majority of PCA patients actually have Alzheimer's disease. In this study, the behavioral and psychiatric symptoms of PCA are surveyed in a tertiary dementia clinic and treatment responses are discussed. The medical records of all patients seen at the clinic from January 1st 2011 to December 31 2013 were reviewed. Nine patients were identified according to the published diagnostic criteria of PCA. The data collected included clinical problems of visits, laboratory results, volumetric MRI data of all patients and cerebrospinal fluid (CSF) amyloid/tau assays, if available. One patient had an AmyVid PET/CT study. Among all patients (n=372) seen in three years, only nine patients were diagnosed with PCA and followed regularly at the clinic. The most salient presentation in the first two years of onset were visuosperceptual and visuospatial deficits. The brain MRI studies showed outstanding cortical atrophy of association cortices of bilateral occipitoparietal lobes. Regarding the neuropsychiatric symptoms, all reported anxiety and depression. Furthermore, the longer the disease last, the more depressive symptoms developed because the patients were decapitated by visual deficits. When PCA progressed, two patients presented cortical blindness. One patient showed Capgras syndrome; he was unable to recognize his wife. One patient displayed vivid visual hallucinations. Amyloid/tau in CSF were tested in two patients; the results suggested Alzheimer profiles. One patient had a positive AmyVid PET/CT study. All patients did not respond to treatments, including cholinesterase inhibitors, memantine, antidepressants and antipsychotics. Patients with PCA can present unique behavioral and psychiatric symptoms; they are often not recognized by clinicians. In the early stage, they all have preserved insights into their cognitive difficulties, which cause significant psychological burden on themselves and their caregivers. Despite that Alzheimer's disease is the most common underlying pathology of PCA, the treatments available for Alzheimer's disease are not effective for visual deficits. The commonly prescribed psychiatric treatments are not beneficial as well.