Bilateral effects of unilateral cerebellar lesions as detected by voxel based morphometry and diffusion imaging

PLoS ONE, 2017 · DOI: 10.1371/journal.pone.0180439 · Published: July 10, 2017

Simple Explanation

The study investigates how damage to one side of the cerebellum affects the brain. Using advanced imaging techniques, the researchers looked at the microstructure of white matter in patients with lesions in one side of the cerebellum. They found that even though the damage was only on one side, both sides of the cerebellum showed changes. This suggests that a lesion in one side of the cerebellum can impact brain areas beyond the directly affected side. Researchers found alterations in cerebral regions linked to the cerebellum, supporting the idea that damage to one side of the cerebellum can affect cognitive functions not strictly linked to the lesion side.

Study Duration

2012 and 2016

Participants

9 patients with left cerebellar lesions and 25 healthy subjects

Evidence Level

Not specified

Key Findings

1
Unilateral cerebellar lesions are associated with bilateral microstructural changes in the middle and superior cerebellar peduncles (MCP and SCP).
2
Radial Diffusivity (RD) and Mean Diffusivity (MD) increased in both ipsilateral and contralateral MCP and SCP, while Fractional Anisotropy (FA) decreased only in the ipsilateral MCP.
3
Patients with unilateral cerebellar lesions showed a widespread pattern of regional gray matter (GM) loss, involving both cerebral hemispheres, including the contralateral thalamus and ipsilateral caudate and putamen.

Research Summary

This study aimed to describe the white matter alterations associated with unilateral cerebellar lesions by reconstructing the MCP and SCP using diffusion-based tractography. The most intriguing finding was that, in spite of the unilaterality of the lesion, microstructural changes were present bilaterally in MCP and SCP at least at group level. Present findings indicate that, in face of a unilateral cerebellar lesion, bilateral changes in the cerebellar peduncles microstructure can be observed. Consistently, cerebral GM reduction can be found without lateralization.

Practical Implications

Understanding Cerebellar-Cerebral Interplay

The findings may impact our understanding of cerebro-cerebellar interplay, questioning the interpretation of functional and structural alterations observed in the cerebral cortex after unilateral damage of the cerebellar efferents.

Insights into CNS Disease

The structural observations may provide important insights into understanding cerebro-cerebellar interaction in health and disease, especially considering the increasing interest in cerebellar neuromodulation to treat different CNS diseases.

Reinterpreting Functional and Structural Alterations

The presence of bilateral microstructural changes questions the interpretation of functional and structural alterations observed in the cerebral cortex after unilateral damage of the cerebellar efferents.

Study Limitations

1
Small sample size limits direct correlation between GM changes, WM structural alterations, and cognitive performances.
2
Most patients had a lesion in the left cerebellum, limiting the generalization of findings to right-side lesions.
3
The precise mechanism inducing bilateral abnormalities in MCP and SCP is still unclear.

Your Feedback

Was this summary helpful?

Back to Neurology