An Overlooked Presentation of Alzheimer’s Disease: Posterior Cortical Atrophy

Maryam Mohamed Seddik

MPharm Student, University of Hertfordshire (GAF Campus)

INTRODUCTION

Posterior Cortical Atrophy (PCA) is a rare, progressive neurodegenerative syndrome primarily affecting the occipital and parietal lobes. Although usually underpinned by Alzheimer’s disease (AD) pathology, PCA presents with visuospatial and perceptual deficits rather than the early memory loss typically seen in AD; this atypical presentation often leads to delayed or incorrect diagnosis. This review summarizes recent literature on PCA’s clinical profile, imaging characteristics, and main symptoms.

METHODS

A literature search was conducted using PubMed, NIH, and Google Scholar for studies from 2015–2025. Keywords included “posterior cortical atrophy,” “atypical Alzheimer’s,” and “visual variant AD.” Studies were included if they involved human participants diagnosed with PCA or visual variant AD and reported clinical and/or neuroimaging findings. Case reports involving fewer than three participants, non-English publications, and animal studies were excluded in order to focus on human diagnostic presentation and to improve interpretability of findings. Extracted data included author, publication year, sample size, mean or range of participant age, symptoms, neuroimaging findings and stage of diagnosis. Data was summarized using Microsoft Excel.

RESULTS

Table 1. Key clinical and neuroimaging characteristics of included PCA studies (2017–2024).

Study Type	Sample Size (N)	Mean Age / Range	Imaging Findings	Stage of diagnosis
Intl cohort + IPD meta-analysis4	1092	59.4 yrs (onset)	Amyloid-PET 94%+, Tau-PET 97%+	Symptomatic (diagnosed at first presentation)
Retrospective registry3	38	67.8 yrs (presentation)	Posterior atrophy on MRI; FDG-PET occipitoparietal hypometabolism	Mild–moderate symptomatic
Longitudinal cohort2	117	—	Early occipital/parietal atrophy; longitudinal MRI	Symptomatic (mild-to-moderate dementia stage)
Prospective longitudinal1	12	56 yrs median (48–63)	FDG ↓ parieto-occipital; PiB diffuse cortical amyloid	Symptomatic at diagnosis

  

Four studies (n = 1,259) met inclusion criteria. Across studies, PCA showed early-onset visuospatial impairment with consistent occipital-parietal atrophy and FDG-PET hypometabolism, while memory and language remained relatively preserved in early stages. 

CONCLUSIONS

A rare and underdiagnosed form of Alzheimer's disease, PCA mostly manifests visually and frequently causes a delayed diagnosis.  Improved awareness and use of neuroimaging, alongside multidisciplinary collaboration between neurologists, ophthalmologists, and general practitioners, can support earlier detection. Timely diagnosis enables better symptom management, rehabilitation, and individualized care while patients still retain insight, and may also reduce caregiver burden and healthcare costs. Further research is needed to clarify disease mechanisms and develop targeted, stage-specific treatments.

REFERENCES