Callosal atrophy correlates with temporal lobe volume and mental status inAlzheimer's disease

Background: Recent studies have reported significant atrophy of the corpus callosum (CC) in Alzheimer's Disease (AD), However. it is currently unknown whether CC atrophy is associated with specific cortical volume changes in AD. Moreover, possible atrophy in extra-callosal commissures has not been e xamined to date, The purpose of the present study was to quantify atrophy i n two cerebral commissures [the CC and the anterior commissure (BC)I, to co n,elate this measure with cognitive status, and to relate commissural size to independent measures of temporal lobe volume in AD patients. Methods: A sample of AD patients and of age- and education-matched normal control subj ects (NCs) underwent MRI and a cognitive test battery including the Dementi a Rating Scale and Mini Mental State examination. Mid-sagittal regional are as within CC and AC were measured along with superior, middle and inferior temporal lobes volumes. Results: Alzheimer's Disease patients had significa ntly smaller callosa than did NCs, The callosal regions most affected in AD included the midbody, isthmus and genu. The isthmus and midbody areas of t he CC were positively correlated with cognitive performance and with superi or temporal lobe volume in AD patients. The mid-sagittal area of the AC and the superior temporal volumes did not differ between AD patients and NCs. Conclusions: The study demonstrated that the regional morphology of the CC correlates with current cognitive status and temporal lobe atrophy in AD. A s well, the lack of difference for the AC suggests that commissural atrophy in AD is regionally specific.