The cognitive profile of posterior cortical atrophy

Abstract

PCA is predominantly a dorsal stream syndrome, distinct from typical DAT, which involves occipitotemporal regions over time.

Posterior kortikal atrofi

“…Neglekt, og det at pasienten bare oppfatter visuelle stimuli i den ene halvdelen av synsfeltet når to stimuli presenteres samtidig i hvert synshalvfelt (visuell ekstinksjon), kan vaere vanskelig å påvise ved tidlig posterior kortikal atrofi på grunn av ledsagende manglende evne til gjenkjennelse/forståelse av visuelle inntrykk (visuell agnosi), til tross for bevart synsskarphet. I senere stadier av sykdommen kan neglekt og visuell ekstinksjon vaere mer fremtredende (1,6,14,17).…”

Focal Cortical Presentations Genetically Proven Alzheimer Disease

“…Occipito-temporal syndrome presented with alexia, aperceptive agnosia and some degree of prosopagnosia. In visual variants, there is a primary visual failure and failure of perceptual abilities (32). The immense majority of the patients with PCA do have AD with lewy body disease, prion disease, and aupathies as major differential diagnosis (21).…”

Posterior Cortical Atrophy

“…However, Snowden et al found that that 5% of 523 patients with AD presenting to a single specialist cognitive disorders centre had a visual presentation (also labelled posterior cortical atrophy) 18 . Age at onset tends to be much earlier in PCA than in typical amnestic AD, with most studies reporting PCA symptom onset in patients' mid 50s and early 60s 17,19 although some studies have reported a wider age spread (45-74 years 20 , 40-86 years 21 ). In terms of gender distribution, some studies have reported no difference in the prevalence based on gender 15,17,19 , whereas others have reported an over-representation among women 18,[20][21][22][23][24] .…”

“…The most frequently cited neuropsychological deficits in PCA are visuospatial and visuoperceptual impairments, alexia and features of Balint's syndrome (simultanagnosia, oculomotor apraxia, optic ataxia, environmental agnosia) and Gerstmann's syndrome (acalculia, agraphia, finger agnosia, left/right disorientation) 15,17,[19][20][21][25][26][27][28][29][30][31] . Working memory deficits and limb apraxia have also been emphasised 20 .…”