Slope analysis of somatosensory evoked potentials in spinal cord injury for detecting contusion injury and focal demyelination.
In spinal cord injury (SCI) research there is a need for reliable measures to determine the extent of injury and assess progress due to natural recovery, drug therapy, surgical intervention or rehabilitation. Somatosensory evoked potentials (SEP) can be used to quantitatively examine the functionality of the ascending sensory pathways in the spinal cord. A reduction of more than 50% in peak amplitude or an increase of more than 10% in latency are threshold indicators of injury. However, in the context of injury, SEP peaks are often obscured by noise. We have developed a new technique to investigate the morphology of the SEP waveform, rather than focusing on a small number of peaks. In this study, we compare SEP signals before and after SCI using two rat models: a contusion injury model and a focal experimental autoimmune encephalomyelitis model. Based on mean slope changes over the signal, we were able to effectively differentiate pre-injury and post-injury SEP values with high levels of sensitivity (83.3%) and specificity (79.2%).
Department of Biomedical Engineering, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Traylor 710B, Baltimore, MD 21205, USA.
Gracee
G
Agrawal
David
D
Sherman
Anil
A
Maybhate
Michael
M
Gorelik
Douglas A
DA
Kerr
Nitish V
NV
Thakor
Angelo H
AH
All
D000818:Animals; D003288:Contusions / Q000175:diagnosis / Q000503:physiopathology*; D003711:Demyelinating Diseases / Q000175:diagnosis / Q000503:physiopathology*; D004195:Disease Models, Animal; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000175:diagnosis / Q000503:physiopathology; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D013119:Spinal Cord Injuries / Q000503:physiopathology*