Infratentorial white matter integrity as a potential biomarker for post-stroke aphasia

Area of Science:

• Neuroimaging
• Neurology
• Speech-Language Pathology

Background:

• Traditional neuroimaging for post-stroke aphasia focuses on supratentorial regions, which are often distorted by lesions.
• This limitation challenges the identification of reliable neuroimaging biomarkers for language recovery.
• Exploring alternative biomarkers in less affected infratentorial regions is crucial.

Purpose of the Study:

• To investigate infratentorial white matter regions as potential biomarkers for post-stroke aphasia severity.
• To correlate diffusion tensor imaging (DTI) metrics with language function scores in chronic aphasia.
• To identify robust neuroimaging targets below the tentorium, circumventing lesion-related analytical issues.

Main Methods:

• Diffusion tensor imaging (DTI) was performed on 55 participants with chronic post-stroke aphasia.
• Correlations were analyzed between Western Aphasia Battery-Revised (WAB-R) scores and fractional anisotropy (FA) in infratentorial white matter regions.
• The intersection volume of lesions with the left arcuate fasciculus was also correlated with WAB-R scores, followed by linear regression analyses.

Main Results:

• Positive correlations were found between FA in the middle cerebellar peduncle and multiple WAB-R scores (aphasia quotient, spontaneous speech, auditory verbal comprehension, naming, repetition).
• FA in the left inferior cerebellar peduncle and left corticospinal tract also showed significant positive correlations with specific language subscores.
• Lesion intersection volume with the left arcuate fasciculus negatively correlated with aphasia quotient and repetition scores.

Conclusions:

• Infratentorial white matter regions, particularly the middle cerebellar peduncle, serve as significant predictors of aphasia severity and specific language impairments.
• These findings highlight the cerebellum's role in language processing and recovery post-stroke.
• Focusing on sub-tentorial white matter provides a more reliable approach for identifying biomarkers and therapeutic targets in post-stroke aphasia.