TY - JOUR
T1 - Non-Invasive Functional Evaluation of the Human Spinal Cord by Assessing the Peri-Spinal Neurovascular Network with near Infrared Spectroscopy
AU - Valenzuela, Felipe
AU - Rana, Mohit
AU - Sitaram, Ranganatha
AU - Uribe, Sergio
AU - Eblen-Zajjur, Antonio
N1 - Funding Information:
The work of Felipe Valenzuela was supported by the Scholarship under Grant Comisión Nacional de Investigacion Cientifica y Tecnologica (CONICYT)-21171608. The work of Mohit Rana and Ranganatha Sitaram was supported in part by the Comisión Nacional de Investigacion Cientifica y Tecnologica (CONICYT) through the Fondo Nacional de Desarrollo Cientifico y Tecnológico (Fondecyt) Post-Doctoral Grant under Grant 3100648, in part by the Fondecyt Regular under Project 1171313 and Project 117132, and in part by the CONICYT Programa de Investigación Asociativa (PIA)/Anillo de Investigación en Ciencia y Tecnología under Grant ACT172121. The work of Sergio Uribe and Antonio Eblen-Zajjurwas supported in part by the Fondo de Fomento al Desarrollo Cientifico y Tecnologico (FONDEF) under Grant ID18I0064, in part by the Fundación COPEC-UC under Grant 2018R.1030, in part by the Global-UC under Grant 2018-IV, and in part by the Patentar-Pontificia Universidad Católica de Chile under Grant 2018-DTD-UC.
Publisher Copyright:
© 2001-2011 IEEE.
PY - 2021
Y1 - 2021
N2 - Current medical care lacks an effective functional evaluation for the spinal cord. Magnetic resonance imaging and computed tomography mainly provide structural information of the spinal cord, while spinal somatosensory evoked potentials are limited by a low signal to noise ratio. We developed a non-invasive approach based on near-infrared spectroscopy in dual-wavelength (760 and 850 nm for deoxy- or oxyhemoglobin respectively) to record the neurovascular response (NVR) of the peri-spinal vascular network at the 7th cervical and 10th thoracic vertebral levels of the spinal cord, triggered by unilateral median nerve electrical stimulation (square pulse, 5-10 mA, 5 ms, 1 pulse every 4 minutes) at the wrist. Amplitude, rise-time, and duration of NVR were characterized in 20 healthy participants. A single, painless stimulus was able to elicit a high signal-to-noise ratio and multi-segmental NVR (mainly from Oxyhemoglobin) with a fast rise time of 6.18 [4.4-10.4] seconds (median [Percentile 25-75]) followed by a slow decay phase for about 30 seconds toward the baseline. Cervical NVR was earlier and larger than thoracic and no left/right asymmetry was detected. Stimulus intensity/NVR amplitude fitted to a 2nd order function. The characterization and feasibility of the peri-spinal NVR strongly support the potential clinical applications for a functional assessment of spinal cord lesions.
AB - Current medical care lacks an effective functional evaluation for the spinal cord. Magnetic resonance imaging and computed tomography mainly provide structural information of the spinal cord, while spinal somatosensory evoked potentials are limited by a low signal to noise ratio. We developed a non-invasive approach based on near-infrared spectroscopy in dual-wavelength (760 and 850 nm for deoxy- or oxyhemoglobin respectively) to record the neurovascular response (NVR) of the peri-spinal vascular network at the 7th cervical and 10th thoracic vertebral levels of the spinal cord, triggered by unilateral median nerve electrical stimulation (square pulse, 5-10 mA, 5 ms, 1 pulse every 4 minutes) at the wrist. Amplitude, rise-time, and duration of NVR were characterized in 20 healthy participants. A single, painless stimulus was able to elicit a high signal-to-noise ratio and multi-segmental NVR (mainly from Oxyhemoglobin) with a fast rise time of 6.18 [4.4-10.4] seconds (median [Percentile 25-75]) followed by a slow decay phase for about 30 seconds toward the baseline. Cervical NVR was earlier and larger than thoracic and no left/right asymmetry was detected. Stimulus intensity/NVR amplitude fitted to a 2nd order function. The characterization and feasibility of the peri-spinal NVR strongly support the potential clinical applications for a functional assessment of spinal cord lesions.
KW - fNIRS
KW - functional test
KW - nerve stimulation
KW - neuro-vascular coupling
KW - neuro-vascular response
KW - spinal cord
UR - http://www.scopus.com/inward/record.url?scp=85118554868&partnerID=8YFLogxK
U2 - 10.1109/TNSRE.2021.3123587
DO - 10.1109/TNSRE.2021.3123587
M3 - Article
C2 - 34705650
AN - SCOPUS:85118554868
SN - 1534-4320
VL - 29
SP - 2312
EP - 2321
JO - IEEE Transactions on Neural Systems and Rehabilitation Engineering
JF - IEEE Transactions on Neural Systems and Rehabilitation Engineering
ER -