Neuroprotective effects of sacral epidural neuromodulation following spinal cord injury : an experimental study in rats.
OBJECTIVE
The purpose of this study is to evaluate neuroprotective effect of sacral neuromodulation in rat spinal cord injury (SCI) model in the histological and functional aspects.


METHODS
Twenty-one female Sprague Dawley rats were randomly divided into 3 groups : the normal control group (CTL, n=7), the SCI with sham stimulation group (SCI, n=7), and the SCI with electrical stimulation (SCI+ES, n=7). Spinal cord was injured by dropping an impactor from 25 mm height. Sacral nerve electrical stimulation was performed by the following protocol : pulse duration, 0.1 ms; frequency, 20 Hz; stimulation time, 30 minutes; and stimulation duration, 4 weeks. Both locomotor function and histological examination were evaluated as scheduled.


RESULTS
The number of anterior horn cell was 12.3±5.7 cells/high power field (HPF) in the CTL group, 7.8±4.9 cells/HPF in the SCI group, and 6.9±5.5 cells/HPF in the SCI+ES group, respectively. Both the SCI and the SCI+ES groups showed severe loss of anterior horn cells and myelin fibers compared with the CTL group. Cavitation and demyelinization of the nerve fibers has no significant difference between the SCI group and the SCI+ES group. Cavitation of dorsal column was more evident in only two rats of SCI group than the SCI+ES group. The locomotor function of all rats improved over time but there was no significant difference at any point in time between the SCI and the SCI+ES group.


CONCLUSIONS
In a rat thoracic spinal cord contusion model, we observed that sacral neuromodulation did not prevent SCI-induced myelin loss and apoptosis.
Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Chang-Hyun
CH
Lee
Seung-Jae
SJ
Hyun
Cheol-Yong
CY
Yoon
Jae-Young
JY
Lim
Tae-Ahn
TA
Jahng
Ki-Jeong
KJ
Kim
Electrical stimulation; Neuromodulation; Neuroprotection; Sacral nerve; Spinal cord injury