Focal thinning of the posterior corpus callosum: normal variant or post-traumatic?

Aim: The corpus callosum (CC) can be affected by childhood traumatic brain injury (TBI), through focal lesions, reductions in size and arrested development. Little is known, however, about what constitutes normal CC shape and appearance and how it may be affected in the long-term after early TBI.

Methods: In this study, the appearance of the CC was investigated in individuals with TBI assessed 10 years post-injury (n = 52, mean age = 16.82 years, SD = 3.55 years, 24 male) and compared to age-matched healthy controls (n = 44, mean age = 15.77 years, SD = 1.21 years, 18 male). A simple visual analysis technique was used to code the appearance of the CC according to location of focal thinning and severity of thinning and results between groups were compared using Chi-square analysis.

Results: A significantly higher proportion of patients with childhood TBI had focal posterior thinning of the CC than age-matched controls (p = 0.001).

Conclusions: The findings call into question previous conclusions that focal posterior thinning is a normal variant of development. Instead, attenuations of the posterior portion of the CC in the long-term may reflect altered cortical and callosal development as a result of early brain injury, although the functional significance of this remains to be determined.