Pre-Operative Mapping of Language Regions Using rsFMRI in Gliomas: A Feasibility Study
Creators: name: Upadhyayula, Sai Koundinya
name: C N, Ajavindu
name: BrainSight Techology
Publisher: name: Zenodo
Year: 2024
Subjects: subject: Neurology/statistics &amp; numerical data
subject: Computational neuroscience
subject: Neurosciences
subject: FOS: Clinical medicine
subject: Cognitive Neuroscience
subject: Cognitive neuroscience
subject: Functional Neuroimaging

description:  

Pre-Operative Mapping of Language Regions Using rsfMRI in Gliomas: A Feasibility Study

Introduction:The pre-operative mapping of language regions in glioma patients is crucial for preserving functional integrity during surgical resection. Traditional intraoperative mapping via direct cortical stimulation requires patient cooperation, which can prolong surgery and introduce variability. This study explores the feasibility of using resting-state functional MRI (rsfMRI) as an alternative for pre-operative language mapping, allowing for more accurate and efficient neurosurgical planning.

Methods:The study employs rsfMRI to analyze the resting-state connectivity of language regions, particularly Broca’s and Wernicke’s areas. Functional networks are mapped using Independent Component Analysis (ICA) and aligned to a functional atlas via nonlinear registration (‘syn’ transformation). Thresholding and Z-score normalization are applied to refine functional segmentation. Additionally, volumetric loss in language regions is quantitatively analyzed to correlate with functional impairment, assessed via the Addenbrooke’s Cognitive Examination III (ACE-III).

Key Findings:



Volume loss in language regions correlates with cognitive decline. A case of Broca’s area volume loss (10,457 mm³) was associated with a fluency score of 8/14, while Wernicke’s area showed no volume loss and had a comprehension score of 24/26.

Severe functional displacement in glioma patients. The patient with the largest midline shift (11 mm) also exhibited the greatest functional shift (Hausdorff distance = 24 mm, Dice = 0.08).

Functional changes are non-linear. More than 70% volume loss is needed before functional impairment becomes apparent, suggesting a threshold effect.

Resting-state fMRI can detect functional reorganization. One patient with better bilateral language representation showed less correlation between volume loss and functional decline, indicating neuroplasticity.


Clinical Relevance:Using rsfMRI for language mapping offers several advantages over traditional intraoperative stimulation:



Patient-independent mapping: Eliminates the need for awake cooperation during surgery.

Pre-operative functional planning: Allows for better localization of eloquent cortex regions, reducing post-operative deficits.

Neuro-navigation integration: Functional shifts due to tumor mass effect can be accounted for, enhancing surgical precision.


Conclusion:This feasibility study demonstrates the potential of rsfMRI in glioma surgery planning. While further validation with larger datasets is required, the approach offers a non-invasive, patient-friendly, and efficient method for mapping language networks. Future studies may refine this methodology to improve functional preservation and post-surgical outcomes in neurosurgical oncology.