The reversed clock drawing test phenomenon in Alzheimer's disease: A perfusion SPECT study

A. Brugnolo, S. Morbelli, B. Dessi, N. Girtler, D. Mazzei, F. Famà, P. Barbieri, G. Cabassi, P. M. Koulibaly, G. Sambuceti, G. Rodriguez, F. Nobili

Research output: Contribution to journalArticle

Abstract

Aim: To unveil a brain single photon emission computed tomography (SPECT) pattern in Alzheimer's disease (AD) patients, showing a reversed clock drawing test (CDT) phenomenon. Patients and Methods: Among 1,005 consecutive subjects, 9 AD patients who drew a reversed CDT (AD-R) underwent SPECT, which was analysed (SPM2) versus a group of 10 AD patients performing the CDT correctly (AD+) and versus 15 controls (CTR). Brain SPECT in 11 AD patients who mistook the CDT in a common way (AD-) was compared with AD+ and CTR groups. Results: Relative hypoperfusion was found in AD-R versus CTR in right medial frontal, parahippocampal and subcallosal gyri, and in left insula and superior temporal gyrus. Hypoperfusion was found in AD-R versus AD+ in the right uncus, superior temporal and parahippocampal gyri. In the AD- versus CTR comparison, hypoperfusion was found in left hippocampus, parahippocampal gyrus and superior parietal lobule. In AD-R versus AD+ and CTR merged together, the analysis showed hypoperfusion in the right parahippocampus, medial frontal gyrus, superior temporal gyrus and uncus, in the left insula and superior temporal gyrus. Conclusion: Fronto-temporal dysfunction, especially in the right hemisphere, plays a role in the reversed CDT phenomenon in AD patients, whereas matched AD patients mistaking the CDT in a common way show left posterior temporo-parietal hypoperfusion.

Original languageEnglish
Pages (from-to)1-10
Number of pages10
JournalDementia and Geriatric Cognitive Disorders
Volume29
Issue number1
DOIs
Publication statusPublished - Feb 2010

Keywords

  • Alzheimer's disease
  • Apraxia
  • Brain single photon emission computed tomography
  • Reversed clock

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Geriatrics and Gerontology
  • Cognitive Neuroscience

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    Brugnolo, A., Morbelli, S., Dessi, B., Girtler, N., Mazzei, D., Famà, F., Barbieri, P., Cabassi, G., Koulibaly, P. M., Sambuceti, G., Rodriguez, G., & Nobili, F. (2010). The reversed clock drawing test phenomenon in Alzheimer's disease: A perfusion SPECT study. Dementia and Geriatric Cognitive Disorders, 29(1), 1-10. https://doi.org/10.1159/000270898