Time jitter of somatosensory evoked potentials in recovery from hypoxic–ischemic brain injury

Ma, Ying; Hu, Yong; Valentin, Nicolas S.; Geocadin, Romergryko G.; Thakor, Nitish V.; Jia, Xiaofeng

doi:10.1016/j.jneumeth.2011.08.025

Cited by 14 publications

(16 citation statements)

References 36 publications

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“…While the general trends in SSEP alterations following injury are consistent with previous work in animal models, 23 , 25 , 26 , 46 in the present study, we were able to identify time-domain alterations in the SSEP in finer detail. The most prominent SSEP peaks—N1, P1, and N2—exhibited differing alterations after injury, some of which are consistent with the known anatomical correlates of time-domain waveform.…”

Section: Discussionsupporting

confidence: 91%

Alterations in neurovascular coupling following acute traumatic brain injury

et al. 2017

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Following acute traumatic brain injury (TBI), timely transport to a hospital can significantly improve the prognosis for recovery. There is, however, a dearth of quantitative biomarkers for brain injury that can be rapidly acquired and interpreted in active, field environments in which TBIs are frequently incurred. We explored potential functional indicators for TBI that can be noninvasively obtained through portable detection modalities, namely optical and electrophysiological approaches. By combining diffuse correlation spectroscopy with colocalized electrophysiological measurements in a mouse model of TBI, we observed concomitant alterations in sensory-evoked cerebral blood flow (CBF) and electrical potentials following controlled cortical impact. Injury acutely reduced the peak amplitude of both electrophysiological and CBF responses, which mostly recovered to baseline values within 30 min, and intertrial variability for these parameters was also acutely altered. Notably, the postinjury dynamics of the CBF overshoot and undershoot amplitudes differed significantly; whereas the amplitude of the initial peak of stimulus-evoked CBF recovered relatively rapidly, the ensuing undershoot did not appear to recover within 30 min of injury. Additionally, acute injury induced apparent low-frequency oscillatory behavior in CBF ([Formula: see text]). Histological assessment indicated that these physiological alterations were not associated with any major, persisting anatomical changes. Several time-domain features of the blood flow and electrophysiological responses showed strong correlations in recovery kinetics. Overall, our results reveal an array of stereotyped, injury-induced alterations in electrophysiological and hemodynamic responses that can be rapidly obtained using a combination of portable detection techniques.

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Section: Discussionsupporting

confidence: 91%

Alterations in neurovascular coupling following acute traumatic brain injury

et al. 2017

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“…We found no reliable evidence of sensory transmission from the tibial nerve to the cortex despite evidence of motor connectivity, which causes us to question technical aspects of SSEP acquisition. After SCI, techniques of time-locked ensemble averaging may not be optimal if the signals are small or they vary in latency as may axons undergoing spontaneous repair ( 144 ). A second-order blind source technique ( 145 ) or a time-frequency analysis might be better suited to characterize signals exhibiting variable time and amplitude ( 146 , 147 ).…”

Section: Discussionmentioning

confidence: 99%

Neurophysiological Changes in the First Year After Cell Transplantation in Sub-acute Complete Paraplegia

et al. 2021

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Neurophysiological testing can provide quantitative information about motor, sensory, and autonomic system connectivity following spinal cord injury (SCI). The clinical examination may be insufficiently sensitive and specific to reveal evolving changes in neural circuits after severe injury. Neurophysiologic data may provide otherwise imperceptible circuit information that has rarely been acquired in biologics clinical trials in SCI. We reported a Phase 1 study of autologous purified Schwann cell suspension transplantation into the injury epicenter of participants with complete subacute thoracic SCI, observing no clinical improvements. Here, we report longitudinal electrophysiological assessments conducted during the trial. Six participants underwent neurophysiology screening pre-transplantation with three post-transplantation neurophysiological assessments, focused on the thoracoabdominal region and lower limbs, including MEPs, SSEPs, voluntarily triggered EMG, and changes in GSR. We found several notable signals not detectable by clinical exam. In all six participants, thoracoabdominal motor connectivity was detected below the clinically assigned neurological level defined by sensory preservation. Additionally, small voluntary activations of leg and foot muscles or positive lower extremity MEPs were detected in all participants. Voluntary EMG was most sensitive to detect leg motor function. The recorded MEP amplitudes and latencies indicated a more caudal thoracic level above which amplitude recovery over time was observed. In contrast, further below, amplitudes showed less improvement, and latencies were increased. Intercostal spasms observed with EMG may also indicate this thoracic “motor level.” Galvanic skin testing revealed autonomic dysfunction in the hands above the injury levels. As an open-label study, we can establish no clear link between these observations and cell transplantation. This neurophysiological characterization may be of value to detect therapeutic effects in future controlled studies.

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“…Besides, N13 abnormalities have predicted good surgical outcomes. SEPs have been found useful in outcome prediction in many studies [37,38].…”

Section: Diagnostic Tests For Csmmentioning

confidence: 99%

Cervical Spondylotic Myelopathy: Natural Course and the Value of Diagnostic Techniques –WFNS Spine Committee Recommendations

et al. 2019

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ObjectiveThis study presents the results of a systematic literature review conducted to determine most up-to-date information on the natural outcome of cervical spondylotic myelopathy (CSM) and the most reliable diagnostic techniques. MethodsA literature search was performed for articles published during the last 10 years. ResultsThe natural course of patients with cervical stenosis and signs of myelopathy is quite variable. In patients with no symptoms, but significant stenosis, the risk of developing myelopathy with cervical stenosis is approximately 3% per year. Myelopathic signs are useful for the clinical diagnosis of CSM. However, they are not highly sensitive and may be absent in approximately one-fifth of patients with myelopathy. The electrophysiological tests to be used in CSM patients are motor evoked potential (MEP), spinal cord evoked potential, somatosensory evoked potential, and electromyography (EMG). The differential diagnosis of CSM from other neurological conditions can be accomplished by those tests. MEP and EMG monitoring are useful to reduce C5 root palsy during CSM surgery. Notable spinal cord T2 hyperintensity on cervical magnetic resonance imaging (MRI) is correlated with a worse outcome, whereas lighter signal changes may predict better outcomes. T1 hypointensity should be considered a sign of more advanced disease. ConclusionThe natural course of CSM is quite variable. Signal changes on MRI and some electrophysiological tests are valuable adjuncts to diagnosis.

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Time jitter of somatosensory evoked potentials in recovery from hypoxic–ischemic brain injury

Cited by 14 publications

References 36 publications

Alterations in neurovascular coupling following acute traumatic brain injury

Alterations in neurovascular coupling following acute traumatic brain injury

Neurophysiological Changes in the First Year After Cell Transplantation in Sub-acute Complete Paraplegia

Cervical Spondylotic Myelopathy: Natural Course and the Value of Diagnostic Techniques –WFNS Spine Committee Recommendations

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