Double dissociation between conduction aphasia and conduction agraphia supports a ventro-dorsal partition of the left arcuate fasciculus.

We identified in two awake surgery cases a postoperative double dissociation between phonological and graphemic output buffer deficits. Using lesion-symptom mapping from ischaemic mini-strokes and preoperative tractography, we demonstrated that the phonological (resp. graphemic) disorder fitted with ventral (resp. dorsal) damage to the AF. Further studies are needed to confirm our hypothesis of a ventro-dorsal functional organization within the AF for phonological versus graphemic processing.