Study of Prefrontal Blood Flow in Dementia Patients Using Near‐Infrared

SUMMARY The category frequency task has become one of the most important tools for measuring brain function. In this investigation, we used near-infrared spectroscopy to examine the prefrontal blood flow in the brain, using a category fluency task function test to determine if this method can be used to diagnose dementia in the early stages. We examined 21 healthy volunteer students (age 21.0±1.4; 11 males and 10 females) and 50 patients with dementia (age 83.3±6.7; 12 males and 38 females; mini mental status: 0–22). The category fluency task required the subjects to produce nouns belonging to the category of vegetables. Our results showed that the healthy volunteer students had an increase in the blood flow while performing this task. On the other hand, the dementia patients did not show any relevant increase in blood flow while performing this task. The results suggest that the combination of the category fluency task and near-infrared spectroscopy could be used as one more tool for the diagnosis of dementia.