Localizing apraxia in corticobasal syndrome: a morphometric MRI study

Area of Science:

• Neuroscience
• Neurology
• Neuroimaging

Background:

• Apraxia localization typically relies on lesion-symptom mapping in stroke patients.
• Neural substrates of apraxia in neurodegenerative disorders remain understudied.

Purpose of the Study:

• To investigate the neural substrates of various apraxia manifestations in corticobasal syndrome (CBS) using cortical thickness analysis.
• To differentiate apraxia mechanisms in neurodegeneration from those in vascular lesions.

Main Methods:

• Cross-sectional study of 26 CBS patients.
• Utilized the Goldenberg apraxia test (GAT) and 3D-T1-weighted MRI.
• Applied vertex-based multivariate General Linear Model analysis with Freesurfer 6.0 for cortical thickness correlation.

Main Results:

• Imitation deficits in meaningless gestures correlated with bilateral superior parietal, angular, and supramarginal gyrus atrophy, predominantly left-sided.
• Finger imitation primarily involved superior parietal lobes.
• Hand imitation critically engaged left angular/supramarginal gyri and superior parietal lobes.

Conclusions:

• Widespread bilateral atrophy in CBS-related apraxia suggests different pathophysiological mechanisms than in vascular lesions.
• Findings have implications for understanding praxis and developing rehabilitation strategies for apraxia in neurodegenerative diseases.