Left arcuate fasciculus [Neurosurgery Wiki]

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====== Left arcuate fasciculus ======
 

The [[arcuate fasciculus]] has been considered a major dorsal frontotemporal [[white matter pathway]] linking frontal [[language production]] regions with [[auditory perception]] in the [[superior temporal gyrus]], the so-called [[Wernicke's area]]. In line with this tradition, both historical and contemporary models of [[language function]] have assigned primacy to superior temporal projections of the [[arcuate fasciculus]]. However, classical anatomical descriptions and emerging behavioral data are at [[odds]] with this assumption. On one hand, frontotemporal projections to [[Wernicke's area]] may not be unique to the arcuate fasciculus. On the other hand, dorsal stream [[language]] [[deficit]]s have been reported also for damage to the middle, inferior, and basal [[temporal]] [[gyri]] which may be linked to arcuate [[disconnection]]. These findings point to a reappraisal of arcuate projections in the [[temporal lobe]]. Giampiccolo and Duffau reviewed anatomical and functional [[evidence]] regarding the temporal cortical terminations of the [[left arcuate fasciculus]] by incorporating [[dissection]] and [[tractography]] findings with [[stimulation]] data using cortico-cortical [[evoked potential]]s and [[direct electrical stimulation]] [[mapping]] in [[awake]] patients. Firstly, they discuss the [[fiber]]s of the arcuate fasciculus projecting to the [[superior temporal gyrus]] and the functional rostrocaudal gradient in this region where both phonological encoding and auditory-motor transformation may be performed. Caudal regions within the [[temporoparietal junction]] may be involved in articulation and associated with temporoparietal projections of the third branch of the [[superior longitudinal fasciculus]], while more rostral regions may support encoding of acoustic-phonetic features, supported by arcuate fibers. They then moved to examine clinical data showing that multimodal phonological encoding is facilitated by projections of the arcuate fasciculus to superior, but also middle, inferior, and basal temporal regions. Hence, they discuss how projections of the arcuate fasciculus may contribute to acoustic (middle-posterior superior and middle temporal gyri), visual (posterior inferior temporal/fusiform gyri comprising the visual word form area) and lexical (anterior-middle inferior temporal/fusiform gyri in the basal temporal language area) information in the [[temporal lobe]] to be processed, encoded and translated into a dorsal phonological route to the frontal lobe. Finally, they point out surgical implications for this model in terms of the prediction and avoidance of [[neurological deficit]]
((Giampiccolo D, Duffau H. Controversy over the temporal cortical terminations of the left arcuate fasciculus: a reappraisal. Brain. 2022 Feb 10:awac057. doi: 10.1093/brain/awac057. Epub ahead of print. PMID: 35142842.)).