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The following is a summary of “Cortical Tau Aggregation Patterns Associated With Apraxia in Patients With Alzheimer Disease,” published in the December 2024 issue of Neurology by Bischof et al.      

Researchers conducted a prospective study exploring the relationship between tau aggregation in praxis-related brain regions and apraxia severity in individuals with Alzheimer’s disease (AD).  

They recruited individuals with biomarker-confirmed AD as well as a sample of cognitively unimpaired (CU₁) individuals. Both groups underwent assessments for apraxia using the Dementia Apraxia Screening Test. Positron emission tomography (PET) imaging with the [18F]PI-2620 tracer assessed tau pathology in individuals with AD. To investigate the relationship between apraxia severity and regional tau pathology, the PET data from the AD group were compared with data from an independent sample of amyloid-negative cognitively intact individuals (CU₂), Z-score deviation maps were generated, and the maps were analyzed using voxel-based multiple regression analysis.  

The results showed 120 participants (39% female) with a mean age of 67.9 (9.2) years (AD = 33; CU₁ = 33; CU₂ = 54). A significant correlation was found between tau aggregation in praxis-related brain regions (including the parietal (angular gyrus), temporal, and occipital areas) and the severity of apraxia in individuals with AD. No significant correlations were found between tau tracer uptake in the primary motor cortex or subcortical brain regions and apraxia (P>0.05).  

They concluded that tau deposition in specific cortical praxis-related regions may contribute to the severity of apraxia in individuals living with AD.  

Source: neurology.org/doi/10.1212/WNL.0000000000210062