Clinical Scorecard: Localization of Language Functions in Subcortical Areas During Awake Craniotomy for Resection of Dominant Posterior Temporal Glioma in a Patient with Hearing Impairment

At a Glance

Key Highlights

• First reported case of awake language mapping testing both sign language and spoken language modalities in a post-lingual deaf patient.
• Preoperative functional MRI and diffusion tensor imaging (DTI) used to localize language areas and critical white matter tracts (arcuate fasciculus and inferior fronto-occipital fasciculus) near the tumor.
• Subcortical stimulation elicited phonemic paraphasias, guiding the extent of tumor resection while preserving language function.

Guideline-Based Recommendations

Diagnosis

• Use MRI with T1, T2, and FLAIR sequences to characterize tumor and involvement of eloquent cortex.
• Perform preoperative task-based functional MRI to lateralize language and identify activation near lesions.
• Use diffusion tensor imaging tractography to delineate critical language white matter pathways.

Management

• Consider awake craniotomy with intraoperative direct cortical and subcortical stimulation for maximal safe resection of tumors near language areas.
• Test both spoken and sign language modalities intraoperatively when applicable, with collaboration from neuropsychology and sign language interpreters.
• Use neuromonitoring and neuronavigation integrated with preoperative imaging to guide resection boundaries.

Monitoring & Follow-up

• Monitor language function intraoperatively using direct stimulation and naming tasks with visual stimuli.
• Observe for language errors such as phonemic paraphasias to identify functional language pathways during resection.

Risks

• Risk of postoperative language deficits if eloquent cortex or subcortical language tracts are damaged.
• Potential challenges in intraoperative language testing in hearing-impaired patients requiring tailored approaches.

Patient & Prescribing Data

Post-lingual deaf patient with profound sensorineural hearing loss and bilingual communication in American Sign Language and English.

Awake craniotomy with intraoperative mapping can be successfully performed in hearing-impaired patients using both spoken and sign language stimuli to preserve language function.

Clinical Best Practices

• Integrate preoperative fMRI and DTI tractography to plan surgical approach and anticipate language pathway locations.
• Use awake craniotomy with direct cortical and subcortical stimulation to maximize tumor resection while preserving language.
• Collaborate with neuropsychology and sign language interpreters for intraoperative testing in bilingual and hearing-impaired patients.
• Employ naming tasks with visual stimuli for both spoken and sign language during mapping.
• Use intraoperative neuro-navigation combined with stimulation findings to define safe resection margins.

References

• Intraoperative direct cortical stimulation for language mapping
• Awake mapping in deaf patients using sign language
• Functional MRI and DTI in language lateralization and tractography