Association of microstructural lesions of the corpus callosum with cognitive impairment in patients with high grade glioma

Purpose

Glioblastoma is one of the most common malignant brain tumors. To ensure a treatment that does not only lengthen survival, but also improves preservation of neurocognitive functions, reliable methods to measure changes in neurocognitive abilities at an early stage are necessary. The most direct way to objectify neurocognitive properties is neuropsychological testing. Neurocognitive decline is often based on lesions of the connectome. We take the corpus callosum (CC) as a reliable structure to identify decline of white matter (WM) integrity. We hypothesized a relation between compromised structural integrity in specific regions of the CC and neurocognitive deficits in glioma patients.

Methods

We included 28 patients with high-grade glioma who underwent a neuropsychological test battery and MRI with Diffusion tensor imaging (DTI) preoperatively. MRI data was processed using the software fsl, Oxford. Neuropsychological parameters were correlated with the fractional anisotropy (FA) in three parts of the CC.

Results

Preoperatively, most of the neuropsychological parameters correlated significantly with FA of at least one of the CC volumes. Higher FA-values were associated with better focus, memory, speed and speech fluency. Different tests examined the same neuropsychological parameter and then correlated with the same region of the CC.

Conclusions

We consider the FA of the CC for an adequate parameter to examine the influence of distant lesions on neurocognitive abilities.