ISSN:0362-2436    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Spinal cord monitoring, as currently practiced, requires a source of sensory stimulus, transmitted through filters and amplifiers, to result in an enhanced signal, which is recorded and studied. Three techniques are under investigation. In one, the stimulation and responses are recorded directly from the dura. In another, the stimulus is applied to a peripheral nerve and the response is gathered from vertebral bone. The third utilizes responses in the form of cortical evoked potentials, with the stimulus applied to peripheral nerves.

ISSN:0362-2436    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

To determine the diagnostic and prognostic significance of evoked spinal potentials (ESPs), reproducible, compressive spinal cord lesions were produced in dogs under ESP monitoring. Both motor recovery and histologic findings were investigated in relation to the amplitude and persistence of the ESPs. Animals that had moderate, anterior compression (51% of canal width) in which the ESP was maintained had considerable motor recovery. Among animals that had submaximal compression (60%), motor recovery was good in those with persistent ESPs. The compression ratio at which ESPs terminated (67%) was termed the “electrophysiologic maximum tolerable compression.” Continuous ESP expiration resulted in irreversible lesions and loss of motor recovery. Compressive spinal cord lesions of reproducible, graded severity were employed for the first time in our study of ESP. Persistence and amplitude were both useful in predicting not only the severity and extent of this type of lesion but also the recovery.

ISSN:0362-2436    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Experimental and clinical studies were performed to measure the segmental spinal evoked potential (SEP) of the cervical cord after stimulation of the median nerve, to determine the location, severity, and outcome of cord lesion in patients who had cervical spondylotic myelopathy. The SEP in control subjects consisted of two waves, the primary reactive R-wave and the secondary reactive N-wave. The R-wave related to both the dorsal root potential and the funiculus posterior potential; the N-wave related to the post-synaptic potential in the spinal cord. In the early stages of cervical spondylotic myelopathy, the N-wave weakens or disappears at the level of lesion. Then, as damage progresses, the R-wave also weakens or disappears.

ISSN:0362-2436    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

A new recording method for continuous spinal cord monitoring has been developed at Rancho Los Amigos Hospital. Using peripheral nerve stimulation, spinal evoked potentials (SEPs) are recorded from cancellous bone of spinous processes. This neurologically noninvasive technique provides a highly reproducible and consistent signal, unaffected by biologic noise and surgical handling of the spinal column. Moreover, the evoked response is extremely sensitive to changes in functional integrity of the spinal cord. In experimental spinal cord injuries, produced by localized distraction of the spine, changes of the evoked responses were well correlated with the change in spinal cord function.

ISSN:0362-2436    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Spinal cord evoked potentials were recorded from spinous processes of the lumbar, thoracic, and cervical levels of the spinal column of normal cats in response to direct stimulation of the sciatic nerve and subcutaneous stimulation of the posterior tibial nerve. The typical primary response was altered by changes in location, magnitude, and frequency of the stimulation. Further changes in the primary response could be associated with spinal level of observation. Reduction in amplitude and decrease in signal complexity with increasing frequency of stimulus indicated the loss of the slower components of the primary response of average evoked potentials. Sharp reduction of signal amplitude and increase in latency was evident as the recording moved from L1 to C3 and C2.

ISSN:0362-2436    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

As part of a study to determine if decompressive surgery benefits patients who have incomplete lesions of the spinal cord, the somatosensory evoked potential (SEP) has been employed as an intraoperative spinal cord monitor. This procedure was used to see if decompression results in any rapid changes in spinal cord conductivity and to correlate these findings with the patient's subsequent clinical course. In addition to trauma, however, other factors also affect the SEP, and these must be recognized if intraoperative monitoring is to be successful. Frequency of stimulation, wakefulness, and anesthetic agents alter the wave-form and amplitude of the SEP. Using nitrous oxide, oxygen, meperidine (or morphine), and a muscle relaxant for anesthesia, and stimulating at frequencies of 1 or 2 per second, 11 patients with cervical or upper thoracic lesions have been monitored. There was no loss or diminution of an SEP and no patient was neurologically poorer afterwards. In 4 patients, the SEP “improved” soon after decompression. Clinical outcome, however, was not related to whether the SEP changed or remained the same. In total, 8 patients subsequently improved functionally and 3 did not.

ISSN:0362-2436    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Four patients underwent transoral resection of the odontoid with utilization of microsurgical technique and spinal cord monitoring of somatosensory cortical evoked responses. All patients improved following surgery, and no operative morbidity or mortality was encountered. Spinal cord monitoring enhances the safety of the procedure and, reapplied at a later date, detects information of prognostic value.

ISSN:0362-2436    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:1979

数据来源: OVID