Longitudinal cerebellar diffusion tensor imaging changes in posterior fossa syndrome.

Area of Science:

• Neuroscience
• Neurosurgery
• Radiology

Background:

• Posterior fossa syndrome (PFS) is a significant postsurgical complication following cerebellar tumor resection, characterized by transient language deficits.
• The underlying pathophysiology and anatomical basis of PFS remain incompletely understood, leading to ongoing debate.

Purpose of the Study:

• To investigate the white matter microstructural changes associated with PFS using diffusion tensor imaging (DTI).
• To identify potential pre-operative radiographic markers that predict the risk of developing PFS after cerebellar tumor surgery.

Main Methods:

• A retrospective analysis of cerebellar tumor resections performed between 2010 and 2015 at Seattle Children's Hospital.
• Diffusion tensor imaging (DTI) data from patients were analyzed and categorized based on post-operative language function: intact, mild deficit, and PFS.
• White matter integrity was assessed using fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD) in various cerebellar regions.

Main Results:

• Patients with PFS exhibited significant reductions in FA in the left and right superior cerebellar peduncle (SCP) post-resection, persisting at 1-year follow-up.
• These SCP white matter changes in PFS patients were more pronounced than in other cerebellar regions.
• Prior to surgery, PFS patients showed distinct differences in MD and RD, but not FA, compared to control groups, suggesting pre-operative risk factors.

Conclusions:

• Posterior fossa syndrome is associated with demonstrable white matter microstructural abnormalities in the superior cerebellar peduncle, detectable with DTI.
• These DTI-derived white matter changes in the SCP are a key feature of PFS and persist long-term.
• Pre-operative alterations in mean and radial diffusivity may serve as radiographic markers for identifying patients at higher risk of developing post-operative language deficits.