Clinical, genetic, and neuropathologic characteristics of posterior cortical atrophy

Abstract

PCA is a distinctive dementia syndrome in which the most pronounced pathologic involvement is in the occipitoparietal regions independent of the specific underlying pathology. AD was the most common pathologic cause, but its regional distribution differed from typical AD.

Imaging correlates of posterior cortical atrophy

“…The aim of the study was not to collect data on the prevalence of clinical features in PCA but to perform a detailed anatomical assessment of the patterns of atrophy on MRI and assess correlations with clinical features. Detailed clinical features on nine of these cases were previously reported [48]. Only one case in this series had come to autopsy and was found to have NFT and neuritic plaques in a distribution typical of PCA [34,48].…”

“…Detailed clinical features on nine of these cases were previously reported [48]. Only one case in this series had come to autopsy and was found to have NFT and neuritic plaques in a distribution typical of PCA [34,48]. A subset of 19 PCA cases also had a single voxel 1 H MRS study acquired from the posterior cingulate gyrus.…”

“…Inclusion criteria were as follows: 1) insidious onset of symptoms; 2) a chief complaint of at least two prominent symptoms referable to the occipital, parietal or posterior temporal lobes that has been liked to PCA; 3) no primary ocular disease accounting for the compliant after ophthalmologic evaluation by an ophthalmologist, 4) an evaluation by at least one behavioral neurologist and 5) progression of symptoms. The list of prominent symptoms linked to PCA include visuospatial deficit, visual perceptual deficit, visual agnosia, environmental disorientation, prosopagnosia, body schema distortion, or any feature suggestive of the Balint's or Gerstmann syndromes [4,39,48]. Patients were excluded if there was early loss of insight, or prominent cognitive impairment affecting language fluency, behavior, or episodic memory that preceded the onset of visual impairment, or exceeded the severity of the visual complaint at onset.…”

“…These early clinical features differ from those of typical Alzheimer's disease (AD) in which memory impairment is an early feature, although as both diseases progress there is considerable overlap. In addition, the most frequent pathological findings of PCA are neurofibrillary tangles (NFT) and neuritic plaques characteristic of typical AD [48], although distributed differently, leading some authors to suggest that PCA is simply an atypical presentation of AD [19]. These differences and similarities beg the question of whether PCA is a distinct entity from typical AD.…”

CSF neurogranin or tau distinguish typical and atypical Alzheimer disease

“…Participants included 68 patients with amnestic AD according to International Working Group 2 (IWG‐2) criteria14 with an AD‐indicative CSF AD biomarker profile (T‐tau/Aβ 42 >0.52)15; 19 patients with PCA, also with a CSF T‐tau/Aβ 42 >0.52, according to Tang‐Wai criteria and fulfilling the latest international criteria for diagnosis of “PCA‐AD”16, 17; and 27 controls who were spouses or friends of patients with no history or symptoms of neurodegenerative disease at the time of lumbar puncture (LP). These healthy individuals underwent a thorough neurological examination, as well as a standardized neuropsychological assessment using the Mattis Dementia Rating Scale 18, 19.…”