Plasticity in the developing brain: impact of focal lesions on language network

In this presentation I will review some recent evidence for the impact of focal brain injury in early life on language performance in later childhood and adolescence. I will focus on two broad neural systems: the dorsal and ventral streams in the left hemisphere and the interhemispheric connections. I will also consider the moderating effects of language plasticity (atypical language dominance) on language outcome and will speculate on which factors might promote inter-hemispheric language shifts. I will conclude with examples of how such evidence can help guide neurosurgical resections to eloquent regions in the developing brain. A greater understanding of the neural mechanisms which shape the lateralized patterning of cortical networks remains an important question for future research, as it might offer insights into mechanisms of recovery of function after neurological injury.

Relevant references:
Liégeois, F., Connelly, A., Cross, J. H., Boyd, S., Gadian, D. G., Vargha-Khadem, F., Baldeweg, T. (2004). Language reorganization in children with early-onset lesions of the left hemisphere: an fMRI study. Brain 127(6), 1229-1236.
Pahs G, Rankin P, Cross J, Croft J, Northam G, Liegeois F, Greenway S, Harrison S, Vargha-Khadem F, Baldeweg T. (2013) Asymmetry of planum temporale constrains inter-hemispheric language plasticity in children with focal epilepsy. Brain; 136(Pt 10):3163-75.
Weiss-Croft LJ, Baldeweg T. Maturation of language networks in children: A systematic review of 22years of functional MRI. Neuroimage. 2015 Dec;123:269-81.
Northam GB, Liégeois F, Tournier JD, Croft LJ, Johns PN, Chong WK, Wyatt JS, Baldeweg T. Interhemispheric temporal lobe connectivity predicts language impairment in adolescents born preterm. Brain. 2012 Dec;135(Pt 12):3781-98. doi:10.1093/brain/aws276. Epub 2012 Nov 11.
Northam GB, Adler S, Eschmann KCJ, Chong WK, Cowan FM, Baldeweg T. Developmental conduction aphasia after neonatal stroke. Ann Neurol. 2018 Apr;83(4):664-675. doi: 10.1002/ana.25218.