MRI morphometry of mamillary bodies, caudate nuclei, and prefrontal cortices after chemotherapy for childhood leukemia: Multivariate models of early and late developing memory subsystems

Neurotoxic intrathecal chemotherapy for childhood acute lymphoblastic leuke mia (ALL) affects developing structures and functions of memory and learnin g subsystems selectively. Results show significant reductions in magnetic r esonance imaging morphometry of mamillary bodies, components of the cortico limbic-diencephalic subsystem subserving functionally later developing, sin gle-trial memory, nonsignificant changes in bilateral heads of the caudate nuclei, components of the corticostriatal subsystem subserving functionally earlier developing, multitrial learning, significant reductions in prefron tal cortical volume, visual and verbal single-trial memory deficits, and vi suospatial, but not verbal, multitrial learning deficits. Multiple regressi on models provide evidence for partial dissociation and connectivity betwee n the subsystems, and suggest that greater involvement of caudate may compe nsate for inefficient corticolimbic-diencephalic components.