Vascular distribution of glioblastoma multiforme at diagnosis.

Treatment of high-grade gliomas with selective intra-arterial (IA) administration of chemotherapies has been proposed, and utilized as a therapeutic modality. This approach offers the conceptual benefit of providing maximal delivery of the agent to the tumor bed, while potentially reducing systemic exposure to the agent. This retrospective study was designed to determine the vascular distribution of glioblastoma multiforme (GBM) at the time of diagnosis in an effort to determine what proportion of patients would likely be candidates for this approach. The preoperative MRI scans of 50 patients with GBM were analyzed and compared to published normative data of intracranial vascular distribution. Vascular distribution was determined by analyzing post-gadolinium axial and coronal T1 images, axial T2 images, and axial T2 images with an additional 1 cm margin (T2 + 1 cm) added in all dimensions. T1 analysis demonstrated 60% of tumors in a single vascular distribution. T2 analysis of these tumors reduced that number to 34%. When the T2 + 1 cm margin was utilized, only 6% of tumors were in a single vascular distribution. 66% of tumors were limited to the anterior circulation on T1 imaging but only 34% on T2 + 1 cm imaging. 30% of tumors were also within the distribution of the anterior choroidal artery. These findings suggest that the use of selective IA administration of agents is necessarily limited to a fraction of presenting patients or will require administration via multiple cerebral arteries.

Progression of regional neuropathology in Alzheimer disease and normal elderly: findings from the Nun study.

Although diffuse plaques in the neocortex may represent an early stage in the evolution of neuritic plaques, plaques in the striatum and cerebellum retain their predominantly diffuse nature in Alzheimer disease (AD), regardless of disease duration. We had the opportunity to explore the progression of these regional features by using autopsy brain specimens from 15 cognitively normal and five AD subjects, all Catholic sisters enrolled in the Nun Study, a longitudinal study on aging and AD. Neuropathologic changes were assessed in the temporal cortex, striatum, and cerebellum without knowledge of clinical status. We found diffuse plaques in the striatum in six (40%) and cerebellar plaques in none of the brains from the non-demented subjects. Striatal plaques were present in all five and cerebellar plaques in four of the five AD cases. In the 20 cases overall, the presence of striatal plaques generally paralleled the occurrence of neuritic plaques in neocortex and correlated with lower scores on several neuropsychologic tests assessing memory. Our findings suggest that striatal diffuse plaques occur relatively early in the progression of AD pathology and coincide with neocortical pathology and cognitive changes. Thus, it is unlikely that temporal factors alone account for regional differences in progression of AD neuropathology.