Motor versus somatosensory evoked potential changes after acute experimental spinal cord injury in rats

Zılelı, Mehmet; Schramm, Johannes

doi:10.1007/bf01418522

Cited by 26 publications

(12 citation statements)

References 23 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…7,12 Moreover, variability in MEP amplitudes has also been dramatic within studies. 7,9,11,12 In a previous study we have found that controlling the depth of anesthesia will reduce the variability in SEP and BMEP amplitudes. 8 This suggests that varying types and levels of anesthesia may underlie the variability in reported MEP and SEP amplitudes.…”

Section: Introductionmentioning

confidence: 98%

“…7,9,10 One of the reasons for this lack in correlation may be the great variability in the shape and the size (amplitude) of the recorded signals. Indeed, dierent groups have reported electromyographic MEP amplitudes in healthy rats ranging from as low as 50 mV 11 to more than 10 mV. 7,12 Moreover, variability in MEP amplitudes has also been dramatic within studies.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The effect of ketamine/xylazine anesthesia on sensory and motor evoked potentials in the rat

et al. 2002

View full text Add to dashboard Cite

Study design: Experimental laboratory investigation of the eect of anesthesia on evoked potentials in rats. Objectives: To de®ne the optimal ketamine/xylazine anesthesia levels for the recording of dierent evoked potentials. Setting: BioSurgery Preclinical Department, Baxter BioScience, Vienna, Austria. Methods: Rats were implanted with cranial screws that allow stimulation and recording of evoked potentials. Somatosensory evoked potentials (SEPs), brainstem-derived motor evoked potentials (BMEPs) and corticomotor evoked potential (CMEPs) were recorded under dierent levels of anesthesia. The recorded signals were evaluated by measuring their latencies and amplitudes. The level of anesthesia was assessed by scoring the hind limb withdrawal re¯ex. Results: All three signals showed a strong dependency on the level of anesthesia. The observed eects, however, diered between the three signals. SEP amplitudes and latencies declined as animals slowly transgressed from deep to light anesthesia. In contrast, BMEP amplitudes were larger and latencies shorter in light anesthesia than in deep anesthesia. CMEPs ®nally were hard to record under deep anesthesia, but were easily recorded in light anesthesia. BMEPs that were recorded during light anesthesia also showed a signi®cant change in con®guration that was coupled with a notable increase in the variability of its amplitudes. Conclusions: The level of ketamine/xylazine anesthesia aects evoked potentials and thus should be controlled during electrophysiological recording. Our results suggest that SEPs should be best recorded during deep anesthesia, while BMEPs and CMEPs are best recorded during intermediate and light anesthesia.

show abstract

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

The effect of ketamine/xylazine anesthesia on sensory and motor evoked potentials in the rat

et al. 2002

View full text Add to dashboard Cite

show abstract

“…Moreover, Bennett (1983) concluded that monitoring of ascending evoked activity (e.g., SSEPs or aSCEPs) would reflect changes in descending spinal cord conduction for compressive and higher magnitude ischemic spinal cord insults. Despite the controversy, SSEPs seem to be related to the extent of spinal cord lesion and functional recovery of ambulatory capacity and they are being used for predicting outcome in experimental studies and in humans after SCI (Fehlings et al, 1988;Nuwer, 1988;Onishi et al, 1991;Zileli and Schramm, 1991).…”

Section: Scep As An Outcome Parameter For Quantification Of Injurymentioning

confidence: 99%

Long-Term Changes in Spinal Cord Evoked Potentials After Compression Spinal Cord Injury in the Rat

et al. 2006

View full text Add to dashboard Cite

1. After traumatic spinal cord injury (SCI), histological and neurological consequences are developing for several days and even weeks. However, little is known about the dynamics of changes in spinal axonal conductivity. The aim of this study was to record and compare repeated spinal cord evoked potentials (SCEP) after SCI in the rat during a 4 weeks' interval. These recordings were used: (i) for studying the dynamics of functional changes in spinal axons after SCI, and (ii) to define the value of SCEP as an independent outcome parameter in SCI studies. 2. We have used two pairs of chronically implanted epidural electrodes for stimulation/recording. The electrodes were placed below and above the site of injury, respectively. Animals with implanted electrodes underwent spinal cord compression injury induced by epidural balloon inflation at Th8-Th9 level. There were five experimental groups of animals, including one control group (sham-operated, no injury), and four injury groups (different degrees of SCI). 3. After SCI, SCEP waveform was either significantly reduced or completely lost. Partial recovery of SCEPs was observed in all groups. The onset and extent of recovery clearly correlated with the severity of injury. There was good correlation between quantitated SCEP variables and the volumes of the compressing balloon. However, sensitivity of electropohysiological parameters was inferior compared to neurological and morphometric outcomes. 4. Our study shows for the first time, that the dynamics of axonal recovery depends on the degree of injury. After mild injury, recovery of signal is rapid. However, after severe injury, axonal conductivity can re-appear after as long as 2 weeks postinjury. In conclusion, SCEPs can be used as an independent parameter of outcome after SCI, but in general, the sensitivity of electrophysiological data were worse than standard morphological and neurological evaluations.

show abstract

“…In previous studies, a 15–20% decrease in amplitude has been recognized as a significant indicator of SEP variations [1, 22, 23]. Such variations in SEP are measured as extensions of the period of distal latency and decreases in amplitude [24,25,26,27,28,29,30,31,32,33,34]. …”

Section: Discussionmentioning

confidence: 99%

Protective Effect of Sildenafil (Viagra) in Transient Spinal Cord Ischemia

Kıymaz¹,

Yılmaz²,

Mumcu³

et al. 2007

Pediatr Neurosurg

View full text Add to dashboard Cite

Prospective study of the neuroprotective activity of sildenafil in a rat spinal ischemia model. The present study involved 21 male Sprague-Dawley rats. The animals were divided into 3 groups. Physiological serum was administered intraperitoneally to the 8 rats in the control group at the beginning of reperfusion for a period of 20 min after abdominal aortal occlusion. Sildenafil (Viagra®) was administered as a single 10-mg/kg/day intraperitoneal dose to the 8 rats in the sildenafil group at the beginning of reperfusion after 20 min of abdominal aortal occlusion. No occlusion was performed and no agent was administered to the 5 rats in the sham group, but the abdominal aorta was reached by means of surgical intervention. Before the animals were sacrificed, several physiological and biochemical parameters were investigated, preoperative and postoperative motor functions were also assessed, and somatosensory evoked potential (SEP) monitoring and histopathological examinations were carried out. No differences were found between the physiological and biochemical parameters in each of the 3 groups. Neurological scoring performed after reperfusion demonstrated a significant improvement in the neurological results relative to those of the control group over 48 h in subjects that received sildenafil. These animals also showed better 24-hour SEP results, measured in terms of extended latency and decreased amplitude, than the control animals. A histopathological study showed reduced ischemic symptoms in rats that received sildenafil compared with those in the control group. However, no anomalies were observed in the sham group with respect to the histopathological and neurological findings. These results indicate that neurological damage due to spinal-cord ischemia-reperfusion injury can be reduced by sildenafil.

show abstract

Motor versus somatosensory evoked potential changes after acute experimental spinal cord injury in rats

Cited by 26 publications

References 23 publications

The effect of ketamine/xylazine anesthesia on sensory and motor evoked potentials in the rat

The effect of ketamine/xylazine anesthesia on sensory and motor evoked potentials in the rat

Long-Term Changes in Spinal Cord Evoked Potentials After Compression Spinal Cord Injury in the Rat

Protective Effect of Sildenafil (Viagra) in Transient Spinal Cord Ischemia

Contact Info

Product

Resources

About