Medial Temporal Atrophy in Posterior Cortical Atrophy and Its Relationship to the Cingulate Island Sign

Kennedy A. Josephs, Nha Trang Thu Pham, Jonathan Graff-Radford, Mary M. MacHulda, Val J. Lowe, Jennifer L. Whitwell

Research output: Contribution to journalArticlepeer-review


Background: It has been hypothesized that medial temporal sparing may be related to preserved posterior cingulate metabolism and the cingulate island sign (CIS) on [18F]fluorodeoxyglucose (FDG) PET in posterior cortical atrophy (PCA). Objective: To assess the severity of medial temporal atrophy in PCA and determine whether the presence of a CIS is related to medial temporal sparing. Methods: Fifty-five PCA patients underwent MRI and FDG-PET. The degree and symmetry of medial temporal atrophy on MRI was visually assessed using a five-point scale for both hemispheres. Visual assessments of FDG-PET coded the presence/absence of a CIS and whether the CIS was symmetric or asymmetric. Hippocampal volumes and a quantitative CIS were also measured. Results: Medial temporal atrophy was most commonly mild or moderate, was symmetric in 55% of patients, and when asymmetric was most commonly worse on the right (76%). Older age and worse memory performance were associated with greater medial temporal atrophy. The CIS was observed in 44% of the PCA patients and was asymmetric in 50% of these. The patients with a CIS showed greater medial temporal asymmetry, but did not show lower medial temporal atrophy scores, compared to those without a CIS. Hippocampal volumes were not associated with quantitative CIS. Conclusion: Mild medial temporal atrophy is a common finding in PCA and is associated with memory impairment. However, medial temporal sparing was not related to the presence of a CIS in PCA.

Original languageEnglish (US)
Pages (from-to)491-498
Number of pages8
JournalJournal of Alzheimer's Disease
Issue number1
StatePublished - 2022


  • Cingulate island sign
  • MRI
  • hippocampus
  • visual assessment

ASJC Scopus subject areas

  • General Neuroscience
  • Clinical Psychology
  • Geriatrics and Gerontology
  • Psychiatry and Mental health


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