Holper Lisa, Biallas Martin, Wolf Martin
Institute of Neuroinformatics, University of Zurich and ETH Zurich, Zurich, Switzerland.
Neuroimage. 2009 Jul 15;46(4):1105-13. doi: 10.1016/j.neuroimage.2009.03.027. Epub 2009 Mar 21.
Hand motor tasks are frequently used to assess impaired motor function in neurology and neurorehabilitation. Assessments can be varied by means of hand laterality, i.e. unimanual or bimanual performance, as well as by means of task complexity, i.e. different degrees ranging from simple to complex sequence tasks. The resulting functional activation in human primary motor cortex (M1) has been studied intensively by traditional neuroimaging methods. Previous studies using functional near-infrared spectroscopy (fNIRS) investigated simple hand motor tasks. However, it is unknown whether fNIRS can also detect changes in response to increasing task complexity. Our hypothesis was to show that fNIRS could detect activation changes in relation to task complexity in uni- and bimanual tasks. Sixteen healthy right-handed subjects performed five finger-tapping tasks: unimanual left and right, simple and complex tasks as well as bimanual complex tasks. We found significant differences in oxy-hemoglobin (O(2)Hb) and deoxy-hemoglobin (HHb) concentration in the right hemisphere over M1. Largest O(2)Hb concentration changes were found during complex (0.351+/-0.051 micromol/l) and simple (0.275+/-0.054 micromol/l) right hand tasks followed by bimanual (0.249+/-0.047 micromol/l), complex (0.154+/-0.034 micromol/l) and simple (0.110+/-0.034 micromol/l) left hand tasks. Largest HHb concentration changes were found during bimanual (-0.138+/-0.006 micromol/l) tasks, followed by simple right hand (-0.12+/-0.016 micromol/l), complex left (-0.0875+/-0.007 micromol/l), complex right (-0.0863+/-0.005 micromol/l) and simple left (-0.0674+/-0.005 micromol/l) hand tasks. We report for the first time that fNIRS detects oxygenation changes in relation to task complexity during finger-tapping. The study aims to contribute to the establishment of fNIRS as a neuroimaging method to assess hand motor function in clinical settings where traditional neuroimaging methods cannot be applied.
手部运动任务常用于评估神经病学和神经康复中受损的运动功能。评估可以通过手部偏好性来进行，即单手或双手执行任务，也可以通过任务复杂性来进行，即从简单到复杂序列任务的不同程度。人类初级运动皮层（M1）中由此产生的功能激活已通过传统神经成像方法进行了深入研究。先前使用功能近红外光谱（fNIRS）的研究调查了简单的手部运动任务。然而，尚不清楚fNIRS是否也能检测到因任务复杂性增加而产生的变化。我们的假设是，fNIRS能够检测到单手和双手任务中与任务复杂性相关的激活变化。16名健康的右利手受试者执行了五项手指敲击任务：单手的左手和右手任务、简单和复杂任务以及双手复杂任务。我们发现M1上方右半球的氧合血红蛋白（O₂Hb）和脱氧血红蛋白（HHb）浓度存在显著差异。在复杂的（0.351±0.051微摩尔/升）和简单的（0.275±0.054微摩尔/升）右手任务中发现了最大的O₂Hb浓度变化，其次是双手（0.249±0.047微摩尔/升）、复杂的（0.154±0.034微摩尔/升）和简单的（0.110±0.034微摩尔/升）左手任务。在双手任务（-0.138±0.006微摩尔/升）中发现了最大的HHb浓度变化，其次是简单的右手（-0.12±0.016微摩尔/升）任务、复杂的左手（-0.0875±0.007微摩尔/升）任务、复杂的右手（-0.0863±0.005微摩尔/升）任务和简单的左手（-0.0674±0.005微摩尔/升）任务。我们首次报告，fNIRS在手指敲击过程中检测到了与任务复杂性相关的氧合变化。该研究旨在有助于将fNIRS确立为一种神经成像方法，用于在无法应用传统神经成像方法的临床环境中评估手部运动功能。
