Abstract for presentation at 38th Annual Scientific Meeting of the Australian and New Zealand Society of Nuclear Medicine 2008

Bilateral Precuneus Hypometabolism is an Important Diagnostic Feature of Early Dementia

  • Dr Simon Gruenewald, Department of Nuclear Medicine, P.E.T. and Ultrasound, Westmead Hospital, Sydney, Australia
  • Dr George Larcos, Department of Nuclear Medicine, P.E.T. & Ultrasound Westmead Hospital, Sydney, Australia
  • Kevin Choong, Department of Nuclear Medicine, P.E.T. and Ultrasound, Westmead Hospital, Sydney, Australia
  • Rochelle McCredie, Department of Nuclear Medicine, P.E.T. and Ultrasound, Westmead Hospital, Sydney, Australia
  • Scott Evans, Department of Nuclear Medicine, P.E.T. & Ultrasound Westmead Hospital, Sydney, Australia

    • Over a one year period, neurological PET studies were performed in 28 patients who presented with either cognitive decline at age 65 or less (n=15, mean 52.5 years) or over 65 but with atypical clinical findings (n=13, mean 70.8 years).

    The referring clinicians were asked for their assessment of the value of the PET scan and for their final diagnosis established by neuropsychological findings, genetic testing, CT, MRI and PET imaging.

    The improved resolution of PET allowed the accurate evaluation of both the right and left precuneus and posterior cingulate regions. These have been reported to be the earliest areas abnormal in Alzheimers disease. Three experienced Nuclear Medicine physicians blinded to patient information and diagnosis, reviewed the scans to determine which region correlated best with the final diagnosis. Data were also analysed using a 3 dimensional stereotactic surface projection technique (3D-SSP).

    Of the 12 patients with a final diagnosis of Alzheimers disease, 9 had bilateral symmetrical precuneus hypometabolism but posterior cingulate changes were far more variable. Of the 16 non-Alzheimers patients, 12 had normal bilateral precuneus metabolism and only 1 patient with suspected Lewy Body disease had bilateral symmetrical precuneus hypometabolism.

    In conclusion, bilateral precuneus hypometabolism appears superior to the posterior cingulate gyrus abnormality in the early diagnosis of Alzheimers disease.

    Conference Organiser - ICMS Pty Ltd