What are the diagnostic criteria and treatment options for posterior cortical atrophy?

From the Guidelines

Posterior cortical atrophy (PCA) is diagnosed based on progressive visual and spatial processing deficits with preserved memory and language in early stages, and the most recent guideline recommends a syndromic diagnosis approach, considering the nature of the cognitive and/or behavioral domain most prominently impacted 1. The diagnostic criteria for PCA include early symptoms like difficulty reading, judging distances, and recognizing objects, along with neuroimaging showing atrophy in the posterior brain regions (occipital, parietal, and posterior temporal lobes) 1. Some key points to consider in the diagnosis of PCA include:

• Progressive visuospatial dysfunction, often with limb apraxia, alexia, agraphia, acalculia, and related cognitive dysfunction localizable to posterior cortical regions 1
• Neuropsychological testing typically reveals deficits in visuospatial processing, while biomarkers like amyloid and tau proteins in cerebrospinal fluid may support diagnosis as PCA is often an atypical presentation of Alzheimer's disease 1
• The relationship between syndromic diagnosis and etiologic diagnosis is probabilistic, not deterministic, and AD neuropathologic changes can be associated with many clinical syndromes 1 Treatment for PCA focuses on symptom management, as there is no cure. Some treatment options include:
• Cholinesterase inhibitors like donepezil (5-10 mg daily), rivastigmine (1.5-6 mg twice daily), or galantamine (4-12 mg twice daily) may provide modest cognitive benefits 1
• Memantine (5-10 mg twice daily) might be added in moderate to severe cases 1
• Non-pharmacological approaches, such as occupational therapy to develop compensatory strategies for visual deficits, environmental modifications with high-contrast items and consistent object placement, and psychological support for both patients and caregivers, are crucial 1 Early diagnosis is important to implement appropriate interventions and support systems that can help maintain quality of life despite progressive symptoms 1.

From the Research

Diagnostic Criteria for Posterior Cortical Atrophy

• The diagnosis of posterior cortical atrophy (PCA) is primarily based on the presence of slowly progressing deterioration of visual processing, corresponding to atrophy in the posterior parietal and occipital cortices, with less prominent memory loss than in other forms of dementia such as Alzheimer's Disease (AD) 2.
• The specific localization of cortical atrophy, slow progression characterized by visual processing deficits, and relatively preserved memory are the main criteria for the diagnosis of PCA 2.
• Recent multi-centre consensus recommendations provide PCA criteria with implications for different management strategies, emphasizing the preponderance of primary or co-existing Alzheimer's disease (AD) pathology underpinning PCA 3.
• Examination of higher visual functions, neuropsychological testing, and neuroimaging contribute to the diagnosis of PCA 4.

Treatment Options for Posterior Cortical Atrophy

• Current treatment of PCA is symptomatic, including pharmacological and non-pharmacological approaches, with the use of most treatment options based on small studies or expert opinion 3.
• Recommendations for non-pharmacological approaches include interdisciplinary management tailored to the PCA clinical profile, rather than memory-led, and psychosocial implications 3.
• Practical measures such as the aid of social care workers, telephones with large keypads, computers with voice recognition software, and audiobooks can be useful in managing PCA symptoms 4.
• Emerging disease-modifying treatments have not been tested in PCA, but an accurate and timely diagnosis of PCA and determining underlying pathology is of increasing importance in the advent of disease-modifying therapies for AD and other rare causes of PCA 3.

Challenges in Diagnosing Posterior Cortical Atrophy

• PCA diagnosis is frequently delayed, and people are likely to receive misdiagnoses of ocular or psychological conditions 3.
• Mood or psychotic symptoms that emerge, escalate, or change dramatically at later ages merit further workup to evaluate for underlying neurodegenerative disorders such as PCA 5.
• The disease can present with nonspecific visual disturbances that are often misinterpreted as ophthalmological, which can delay the diagnosis 4.