Olfactory assessment using near-infrared spectroscopy

Objective olfactory test is rare. Recently, near-infrared spectroscopy has been used to study functional activations of the brain. We used multi-channel near-infrared spectroscopy to monitor the activity of the frontal cortex as mirrored by hemodynamic responses subjected to olfactory stimulation. The aim of this study is to establish the objective olfactory Assessment using Multichannel near-infrared spectroscopy. This study was conducted on 19 healthy subjects and 36 subjects who had disease. Isovaleric acid was used as odor stimulation. The changes in concentrations of total hemoglobin measured by Multichannel near-infrared spectroscopy were independently related to total recognition threshold of T&T olfactometory. The usefulness of near-infrared spectroscopy as objective olfactory test is suggested.