Single photon emission computed tomography perfusion differences in mild cognitive impairment.

Area of Science:

• Neuroimaging
• Neurology
• Geriatrics

Background:

• Mild cognitive impairment (MCI) represents a heterogeneous clinical state.
• Predicting clinical progression in MCI is crucial for patient management and therapeutic development.

Purpose of the Study:

• To investigate the relationship between baseline cerebral perfusion abnormalities and subsequent clinical status changes in patients with MCI.
• To differentiate perfusion patterns associated with different MCI progression trajectories.

Main Methods:

• Perfusion single photon emission computed tomography (SPECT) using 99mTc-HMPAO was performed on 105 elderly patients with MCI.
• Clinical outcomes were assessed over a 5-year follow-up period, categorizing patients into converter, decliner, and stable groups.
• A control group of normal subjects and a group of Alzheimer's disease patients were included for comparison.

Main Results:

• SPECT data revealed distinct perfusion patterns among MCI subgroups and controls.
• Patients who converted to Alzheimer's disease showed decreased perfusion in the caudal anterior cingulate and posterior cingulate.
• Converters also exhibited increased perfusion in the rostral anterior cingulate compared to stable and decliner groups.

Conclusions:

• Clinical heterogeneity in MCI is mirrored by differences in SPECT perfusion.
• The observed patterns of perfusion abnormalities appear to evolve with increasing clinical severity in MCI.