OBSERVATIONS ON EVOKED SPINAL POTENTIALS IN EXPERIMENTAL ACUTE SPINAL CORD TRAUMA
- VernacularTitle:实验性急性脊髓损伤时的脊髓诱发电位观察
- Author:
Juliang BAO
- Publication Type:Journal Article
- From:
Academic Journal of Second Military Medical University
1983;0(S1):-
- CountryChina
- Language:Chinese
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Abstract:
The evoked spinal potentials (ESPs) of cats were observed in this experiment. 29 animals weighing 2 to 3.5kg were Used, and divided into three groups:I, control and general observations; II, acute contusion of spinal cord; III, spinal cord compression and decompression. In each mode of trauma. the intensity of traumatizing factor included three different levels.The normal lumbar segmental ESPs consist of two predominant components: N1 and N2 wave, within the first 20 msec after stimulation artefact. Preceding to N1 was a positive wave P1. From a series of tests, it was suggest N1 is related to the activity of dorsal part of cord and N2 is related to the activity of dorsal as well asventral part of cord.After the transection of spinal cord at L4-5, the ESPs recorded rostral to that site disappeared and were replaced by a single positive wave, the so called "killed end" potential.Immediately after cord contusion, the P1-N1 components of ESPs of traumatized portion disappeared and were replaced by a single positive wave, and simu-1 tenously, the N2 diminished or flattend. If the impacting energy level was lower, the N1 or both N1 and N2 reappeared, and gradually increased their amplitude with the improvement of peak latency of N1 which was abnormally prolonged in the earlier hours of recovery.During cord compression both N1 and N2 of ESPs at the compressed portion decreased their amplitude with the peak latency of N1 prolonged. N2 disappeared earlier than N1 and finally only a single positive wave was left. If the compression time was shorter, both N1 and N2 might reappear after decompession, and the trend of recovering their original amplitude and peak latency was shown.Data proved that changes of ESPs may be used as the indicator of the viability of the traumatized spinal cord. The transient disappearance of ESPs would not indicate that the cord function coud not get recovery. On the other hand dying out of ESPs for several hours or even longer might reflect the serious-damage of cord function.The results of this experiments also suggested that N1 and N2 have different implications in reflecting the mechanisms of injuries.
