Posterior cortical atrophy: clinical presentation and cognitive deficits compared to Alzheimer's disease

Posterior cortical atrophy (PCA) is an uncommon dementia syndrome with initial manifestations of visual dysfunction and preservation of memory and language until late in the disease. Since prognosis and management differ from typical Alzheimer's disease (tAD), clinical tests to distinguish PCA from tAD are needed. Fifteen PCA cases and 15 tAD cases, defined by clinical and MRI criteria, were compared by present symptoms and scores on four cognitive tests. Symptoms of visual disturbance and dyslexia were more commonly reported in PCA cases (p = 0.0001 and p = 0.006, respectively), and memory loss was more commonly reported in tAD (p = 0.006). Patients with PCA were less accurate on the Cortical Vision Screening Test (t = 6.0; p < 0.001) and in copying the Rey-Osterreith Complex Figure (t = 6.0; p < 0.001), in comparison to the tAD group. Memory, evaluated by the Rey Auditory Verbal Learning Test, was impaired in both groups; however, delayed recall was more impaired in the tAD group (t = 2.5; p = 0.03). Compared to patients with tAD, patients with PCA are more likely to present to their providers with symptoms of visual dysfunction. Performance on simple tests of visual perception and copying can be used to distinguish the two disorders even a few years after initial symptoms.