Disruption of the Frontal Aslant Tract is Not Associated with Long-Term Postoperative Language Deficits: A Case Report

Abstract Background and Importance: The frontal aslant tract (FAT) is a white matter fiber pathway connecting the superior frontal gyrus to Broca area. This tract in the dominant hemisphere has been shown to play a role in speech initiation and production, and direct subcortical stimulation can induce stuttering and speech arrest in a patient. However, controversy remains as to whether disruption of this pathway will lead to a permanent language deficit and if it is even necessary to map this tract during tumor resections of the dominant frontal lobe. Clinical Presentation Here, we report a case of a patient with a lower grade diffuse glioma invading the dominant FAT that was removed with an asleep craniotomy. In the immediate postoperative state, the patient had a transcortical motor dysphasia and was unable to initiate speech. These immediate language deficits quickly recovered, and the patient was neurological intact at the time of discharge a few days after surgery. Conclusion Given the high likelihood for a complete neurological recovery including transient aphasia, we propose that awake mapping for the purpose of identifying the dominant FAT is unnecessary during tumor resection and that disruption of this tract is not associated with any long-term language deficits.