Axonal Injury Is Accentuated in the Caudal Corpus Callosum of Head-Injured Patients

Abstract

Amyloid precursor protein (APP) accumulation is a sensitive marker for the axonal damage that is commonly seen in the brain as the result of head injury. This form of damage is particularly associated with midline structures such as the corpus callosum, although it is not clear whether some areas are more susceptible than others. The aim of this study was to determine if there was a differential distribution of axonal injury throughout the corpus callosum after head injury in an unselected group of cases. Coronal tissue sections from eight cases were taken at different levels through the corpus callosum, including the genu, body, and splenium. The sections were immunostained with an antibody to APP, and the amount of axonal damage at the different levels was quantified using computer image analysis to build up a rostro-caudal profile for each case. The profiles revealed a significantly higher APP load in caudal parts of the corpus callosum. This supports previous nonquantitative reports in the literature and has important implications in terms of choosing where tissue should be sampled to maximize the chance of detecting axonal injury post mortem.

Mechanism of Injury to the Corpus Callosum, With Particular Reference to the Anatomical Relationship Between Site of Injury and Adjacent Brain Structures

“…3,11,14) Injury to the corpus callosum predominantly occurs in the posterior half, particularly at the bodysplenium junction in MR imaging studies, but not in postmortem studies. 4,8,10,11,14,16,21,22) In the present study, lesions in the posterior part of the body and the splenium accounted for 56.4% of corpus callosum injuries, and 80% of lesions were located in the posterior half of the corpus callosum.…”

Diffusion Tensor Imaging Characteristics of the Corpus Callosum in Mild, Moderate, and Severe Traumatic Brain Injury

“…Conventional imaging and pathologic-anatomic study have indicated that the posterior corpus callosum is more susceptible to fiber disruption than the anterior corpus callosum. [2][3][4]24 In consequence, it may be hypothesized that the DTI pattern we observed in the splenium is associated with more irreversible traumatic lesions than the DTI pattern in the genu, which in turn may reflect more reversible abnormalities. This should be investigated in a longitudinal study.…”

Hemispheric and executive influences on low-level language processing after traumatic brain injury

“…It is also sometimes referred to as traumatic axonal injury (TAI)-a moniker which sidesteps the problem that this injury is not actually diffuse, but rather multifocal, with common sites of occurrence found in multiple studies. Most frequently affected are the corpus callosum and the dorsolateral part of the midbrain (e.g., LeClercq, McKenzie, Graham, & Gentleman, 2001). A tiered grading system set forth by Adams and Gennarelli and colleagues describes a grade 1 injury as affecting the hemispheric white matter, a grade 2 as having additional involvement of the corpus callosum, and a grade 3 as showing additional lesions in the superior cerebellar peduncle (Adams, Doyle, Ford, Gennarelli, Graham, & Mclellan, 1989;Gennarelli, Thibault, Adams, Graham, Thompson, & Marcincin, 1982).…”