Prolonged Transcortical Mixed Aphasia Following Awake Glioma Resection: Functional Language Network Disruption Associated with Persistent Epileptiform Activity

抄録

Aphasia occurring after tumor resection in the language-dominant hemisphere is commonly interpreted as a consequence of irreversible structural injury. In awake craniotomy, intraoperative language mapping enables real-time functional monitoring and is expected to reduce the risk of postoperative aphasia. However, postoperative language impairment is not always attributable to structural damage alone, and functional network disturbances may also contribute.

We report a case of prolonged aphasia following awake glioma resection in the dominant hemisphere, in which epileptiform activity was suspected to underlie a prolonged functional disruption of the language network. Intraoperative language mapping confirmed preserved language function throughout tumor resection. However, during the late intraoperative phase, stimulation-induced after-discharges were observed on electroencephalography, followed by the emergence of unstable language output. Postoperatively, severe aphasia persisted despite the absence of new ischemic or hemorrhagic lesions on neuroimaging. Serial electroencephalography demonstrated sustained epileptiform activity within the interictal–ictal continuum, raising concern for possible aphasic status epilepticus.

Detailed language assessment revealed severe impairment of spontaneous speech and auditory comprehension, with relative preservation of repetition, reading aloud, and writing. This pattern was consistent with transcortical mixed aphasia, classically described as isolation of the speech area, suggesting functional disconnection of the language network despite anatomical preservation of core language cortices. Although electroencephalographic abnormalities gradually attenuated with antiseizure treatment, language impairment remained prolonged.

Prolonged aphasia after awake glioma resection may reflect potentially reversible language network disconnection associated with persistent epileptiform activity rather than structural injury alone, supported by SLTA-confirmed recovery at 6 months.