Notable volume loss occurs in the corpus callosum in Parkinson's disease (PD), with specific neuroanatomic distributions in PD with dementia (PDD) and relationships of regional atrophy to different cognitive domains, a recent study found. 100 patients with PD and 24 healthy controls underwent clinical and neuropsychological evaluations and structural MRI brain scans. Participants with PD were classified as cognitively normal (PD-NC; n=28), having mild cognitive impairment (PD-MCI; n=47), or PDD (n=25) by Movement Disorder Society criteria. Researchers found:

• Participants with PD had reduced corpus callosum volumes in mid-anterior and central regions compared to healthy controls.
• Participants with PDD demonstrated decreased callosal volumes involving multiple subsections spanning anterior to posterior compared to participants with PD-MCI and PD-NC.
• Regional callosal atrophy predicted cognitive domain performance such that central volumes were associated with the attention/working memory domain; mid-posterior volumes with executive function, language, and memory domains; and posterior volumes with memory and visuospatial domains.