Clinical Evaluation of Brain Perfusion SPECT with Brodmann Areas Mapping in Early Diagnosis of Alzheimer's Disease.

Abstract

Early diagnosis of Alzheimer's disease (AD) based on clinical criteria alone may be problematic, while current and future treatments should be administered earlier in order to be more effective. Thus, various disease biomarkers could be used for early detection of AD. We evaluated brain perfusion with 99mTc-HMPAO single photon emission computed tomography (SPECT) and Brodmann areas (BAs) mapping in mild AD using an automated software (NeuroGam) for the semi-quantitative evaluation of perfusion in BAs and the comparison with the software's normal database. We studied 34 consecutive patients with mild AD: 9 men, 25 women, mean age 70.9 ± 8.1 years, mean Mini-Mental State Examination 22.6 ± 2.5. BAs 25L, 25R, 38L, 38R, 28L, 28R, 36L, and 36R had the lower mean perfusion values, while BAs 31L, 31R, 19R, 18L, 18R, 17L, and 17R had the higher mean values. Compared with healthy subjects of the same age, perfusion values in BAs 25L, 25R, 28R, 28L, 36L, and 36R had the greatest deviations from the healthy sample, while the lowest deviations were found in BAs 32L, 32R, 19R, 24L, 17L, 17R, 18L, and 18R. A percentage of ≥94% of patients had perfusion values more than -2SDs below the mean of healthy subjects in BAs 38R, 38L, 36L, 36R, 23L, 23R, 22L, 44L, 28L, 28R, 25L, and 25R. The corresponding proportion was less than 38% for BAs 11L, 19R, 32L, 32R, 18L, 18R, 24L, and 17R. In conclusion, brain SPECT studies with automated perfusion mapping could be useful as an ancillary tool in daily practice, revealing perfusion impairments in early AD.