Comparative analysis between thoracic spinal cord and sacral neuromodulation in a rat spinal cord injury model: a preliminary report of a rat spinal cord stimulation model.
OBJECTIVE
The purpose of this study is to compare a neuroprotective effect of thoracic cord neuromodulation to that of sacral nerve neuromodulation in rat thoracic spinal cord injury (SCI) model.


METHODS
Twenty female Sprague Dawley rats were randomly divided into 4 groups: the normal control group (n=5), SCI with sham stimulation group (SCI, n=5), SCI with electrical stimulation at thoracic spinal cord (SCI + TES, n=5), and SCI with electrical stimulation at sacral nerve (SCI + SES, n=5). Spinal cord was injured by an impactor which dropped from 25mm height. Electrical stimulation was performed by the following protocol: pulse duration, 0.1ms; frequency, 20 Hz; stimulation time, 30 minutes; and stimulation duration at thoracic epidural space and S2 or 3 neural foramina for 4 weeks. Locomotor function, urodynamic study, muscle weights, and fiber cross sectional area (CSA) were investigated.


RESULTS
All rats of the SCI + TES group expired within 3 days after the injury. The locomotor function of all survived rats improved over time but there was no significant difference between the SCI and the SCI + SES group. All rats experienced urinary retention after the injury and recovered self-voiding after 3-9 days. Voiding contraction interval was 25.5±7.5 minutes in the SCI group, 16.5±5.3 minutes in the SCI+SES group, and 12.5±4.2 minutes in the control group. The recovery of voiding contraction interval was significant in the SCI + SES group comparing to the SCI group (p<0.05). Muscle weight and CSA were slightly greater in the SCI + SES than in the SCI group, but the difference was not significant.


CONCLUSIONS
We failed to establish a rat spinal cord stimulation model. However, sacral neuromodulation have a therapeutic potential to improve neurogenic bladder and muscle atrophy.
Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Seung-Jae
SJ
Hyun
Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Chang-Hyun
CH
Lee
Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Ji Woong
JW
Kwon
Department of Urology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Cheol-Yong
CY
Yoon
Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Jae-Young
JY
Lim
Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Ki-Jeong
KJ
Kim
Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Tae-Ahn
TA
Jahng
Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Hyun-Jib
HJ
Kim
Electrical stimulation; Neuromodulation; Neuroprotection; Spinal cord injury