Posterior cortical atrophy syndrome: Asian study

Abstract

AbstractBackgroundPosterior cortical atrophy (PCA) syndrome is a rare clinical syndrome occurred in the first several years of several progressive neurodegenerative diseases, of which the manifestations are mainly confined to the impairments in the functions of posterior cerebral cortices. The underlying pathomechanisms may include Alzheimer‘s disease, Lewy body disease, corticobasal degeneration and prion disease. A consensus of the diagnostic procedures for PCA syndrome has been published in 2017, based on cases from Western countries.MethodWe invited behavioral neurologists from five Asian countries to join the study and followed the suggestions of the paper published by Scott and Crutch (2019). Each research participant investigated their cases and submitted the results to chief principal investigator. Data were analyzed and compared with those of Western countries. Moreover, a workshop was held at Tainan, Taiwan in the winter of 2019 for all investigators to reach consensus on the results.ResultA total of 63 cases (26 male) from Taiwan, Thailand, Singapore, Korea and Japan were included. Their mean age was 64.48 (SD 8.26) years, onset age 59.7 (8.37) years, and education 10.76 (5.43) years. 94.9% of the findings of brain MRI and 86.8% of the brain SPECT supported a diagnosis of PCA syndrome. As compared with the results of Crutch et al (2017), the Asian data showed more often in space perception deficits, simultanagnosia, construction dyspraxia, oculomotor apraxia, dressing apraxia, optic ataxia, alexia, left/right disorientation, acalculia, agraphia, finger agnosia, limb rigidity, onset before 65, prominent early memory disturbance, and prominent early language disturbance, while less often in hallucination. The PCA‐plus cases (n=12), as defined by 2017 consensus, were older and more in favor of Lewy body disease. Meanwhile, PCA‐plus cases had more dressing apraxia and more alexia. PCA patients with Parkinsonism had more optic ataxia, dressing apraxia, left/right disorientation, acalculia, more relative spared memory impairment and less relative spared executive dysfunction.ConclusionThe public awareness of PCA syndrome is inadequate, which may delay its timely diagnosis. The differences in clinical features between Asian and Western countries need further investigation.