Single photon emission computed tomography perfusion differences in mild cognitive impairment
- 1Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
- 2Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- 3Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts, USA
- 4Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Correspondence to: Dr K A Johnson Departments of Radiology (Nuclear Medicine) and Neurology, Massachusetts General Hospital, Fruit Street, Boston, MA 02114, USA;
- Received 28 April 2006
- Accepted 18 September 2006
- Revised 1 August 2006
- Published Online First 20 October 2006
Objective: To relate cerebral perfusion abnormalities to subsequent changes in clinical status among patients with mild cognitive impairment (MCI).
Methods: Perfusion single photon emission computed tomography (SPECT) images were acquired in 105 elderly patients without dementia with MCI, using 99mTc-HMPAO. Clinical outcome after a 5-year follow-up period was heterogeneous.
Results: Baseline SPECT data differed in those patients with MCI who were later diagnosed with Alzheimer’s disease (the converter group) from those patients with MCI who experienced clinically evident decline but did not progress to a diagnosis of Alzheimer’s disease within the follow-up period (the decliner group), from patients with MCI who had no clinical evidence of progression (the stable group), and from a group of 19 normal subjects (the control group). The most consistent decreases in relative perfusion in converters compared with the normal, stable and decliner groups were observed in the caudal anterior cingulate, and in the posterior cingulate. In addition, converters showed increased relative perfusion in the rostral anterior cingulate in comparison to the stable and decliner groups. A group of patients with Alzheimer’s disease were also included for purposes of comparison. The group of patients with Alzheimer’s disease at baseline differed from each of the other groups, with temporoparietal regions showing the most significant reductions in perfusion.
Conclusions: These results suggest that clinical heterogeneity in MCI is reflected in SPECT perfusion differences, and that the pattern of perfusion abnormalities evolves with increasing clinical severity.
- ANOVA, analysis of variance
- CDR, clinical dementia rating
- CDR-SB, CDR Sum of Boxes
- MCI, mild cognitive impairment
- MMSE, Mini-Mental State Examination
- MRI, magnetic resonance imaging
- MTL, medial temporal lobe
- PET, positron emission tomography
- ROI, regions of interest
- SPECT, single photon emission computed tomography
- SPM, statistical parametric mapping
- TMT, Trailmaking Test
Published Online First 20 October 2006
Funding: This research was supported by grants from the NIA (PO1-AG04953) and the Alzheimer Association (# IRG-99-1515). This research was approved by the Massachusetts General Hospital Human Research Committee (1999-P-005425).
Competing interests: None declared.