Clinical Manifestations.

Area of Science:

• Neuroscience
• Neurology
• Radiology

Background:

• Posterior Cortical Atrophy (PCA) is a progressive neurodegenerative disorder impacting visual and posterior cognitive functions.
• While often linked to Alzheimer's Disease (AD) pathology, PCA can also stem from Dementia with Lewy Bodies (DLB), Corticobasal Degeneration (CBD), or Prion disease.
• This study investigates PCA cases in India using established diagnostic criteria.

Purpose of the Study:

• To examine the clinical, etiological, and imaging characteristics of Posterior Cortical Atrophy (PCA) patients in India.
• To evaluate the utility of advanced imaging techniques in characterizing PCA phenotypes.
• To understand the heterogeneity of PCA presentations within the Indian population.

Main Methods:

• A prospective case series of eight PCA patients diagnosed between 2021 and 2024 at a tertiary Indian hospital.
• Analysis of demographic data, neuropsychological assessments, imaging findings (MRI, FDG-PET, Tau-PET), and biomarker studies.
• Classification of patients based on Crutch et al. 2017 consensus criteria for Pure PCA and PCA Plus subtypes.

Main Results:

• PCA presented with early-onset cognitive decline (5th-6th decade) and initial visuospatial/praxis impairments.
• 6 patients (75%) were Pure PCA, 2 (25%) were PCA Plus (including mixed pathologies). Phenotypes included dorsal, ventral, and biparietal variants.
• MRI confirmed posterior cortical atrophy; FDG-PET showed characteristic hypometabolism, with Tau-PET correlating findings in affected regions.

Conclusions:

• Posterior Cortical Atrophy (PCA) is underdiagnosed due to atypical, early-onset presentations.
• This Indian cohort demonstrates significant clinical and imaging heterogeneity in PCA.
• Advanced imaging like FDG/Tau-PET is crucial for phenotype differentiation, guiding future research into biomarkers and therapies.