Exploring Hemispheric Vulnerability in Crossed Cerebellar Diaschisis: A Systematic Review and Meta-Analysis.

Area of Science:

• Neuroscience
• Neurology
• Radiology

Background:

• The cerebellum plays a key role in motor, cognitive, and affective functions.
• Crossed cerebellar diaschisis (CCD) involves reduced cerebellar activity contralateral to a supratentorial lesion, leading to functional deficits.
• Understanding lesion lateralization and its impact on CCD hemispheric distribution is crucial for clinical relevance.

Purpose of the Study:

• To systematically review and meta-analyze the distribution of crossed cerebellar diaschisis (CCD) between cerebellar hemispheres.
• To estimate the pooled proportion of left-sided CCD and assess potential hemispheric laterality.
• To evaluate the clinical relevance of hemispheric involvement in CCD.

Main Methods:

• A systematic literature search was conducted in PubMed and EBSCO databases.
• Seventeen studies with 328 patients diagnosed with CCD via neuroimaging were included in a random-effects proportion meta-analysis.
• Statistical heterogeneity and publication bias were assessed using standard methods (Cochran's Q, I², Egger's regression test).

Main Results:

• The meta-analysis revealed a pooled proportion of 0.45 for left-sided CCD (95% CI: 0.39-0.51), indicating no significant hemispheric preference.
• Low statistical heterogeneity was observed (I² = 0.0%), though moderate heterogeneity could not be entirely excluded.
• No statistically significant publication bias was detected, but the small sample size limited statistical power.

Conclusions:

• This meta-analysis found no evidence supporting a preferential distribution of crossed cerebellar diaschisis (CCD) between cerebellar hemispheres.
• Moderate variability exists across studies, highlighting the need for larger, more homogeneous investigations.
• Further well-powered research is essential to clarify potential hemispheric patterns in CCD and their clinical significance.