title: An animal study to examine the effects of the bilateral, epidural cortical stimulation on the progression of amyotrophic lateral sclerosis.
abstract: BACKGROUND
  We examined the effects of the unilateral cortical stimulation on the survival of neurons showing degenerative changes and compared those in delaying the progression of amyotrophic lateral sclerosis (ALS) between the unilateral cortical stimulation and the bilateral one in an animal experimental model using mice.
  
  
  METHODS
  We used 19 G93A transgenic mice and randomly divided into three groups: the control group (n=6) (the implantation of electrodes in the bilateral motor cortex without electrical stimulation), the unilateral stimulation group (n=7) (the implantation of electrodes in the unilateral motor cortex with a 24-hour cortical stimulation) and the bilateral stimulation group (n=6) (the implantation of electrodes in the bilateral motor cortex with a 24-hour cortical stimulation).
  
  
  RESULTS
  The mean survival period was significantly longer in the bilateral stimulation group as compared with the control group (124.33 ± 11.00 days vs. 109.50 ± 10.41 days) (P<0.05). In addition, on postoperative weeks 11, 12, 13, 14 and 15, the mean Rota-rod score was significantly higher in the unilateral stimulation group as compared with the control group (P<0.05). Furthermore, despite a lack of statistical significance, it was the lowest in the bilateral stimulation group on postoperative weeks 13, 14, 15 and 17. On postoperative weeks 11, 12, 13, 14 and 16, the mean score of paw-grip endurance was significantly higher in the unilateral stimulation group as compared with the control group (P<0.05). Furthermore, despite a lack of statistical significance, it was the lowest in the bilateral stimulation group on postoperative weeks 13, 14, 15 and 17.
  
  
  CONCLUSIONS
  In conclusion, our results indicate that the bilateral epidural cortical stimulation might have a treatment effect in a murine model of ALS. But it is the limitation that we examined a small number of experimental animals. Further studies are therefore warranted to establish our results and to identify the optimal parameters of the epidural cortical stimulation in a larger number of experimental animals.
authors.forename: Hyojoon
authors.initials: H
authors.lastname: Kim
authors.forename: Hyoung-Ihl
authors.initials: HI
authors.lastname: Kim
authors.forename: Yun-Hee
authors.initials: YH
authors.lastname: Kim
authors.forename: Soo-Yeon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Rehabilitation Medicine & Institute of Medical Science, Pusan National University School of Medicine, Busan, South Korea. rmshin01@gmail.com.
authors.forename: Yong-Il
authors.initials: YI
authors.lastname: Shin
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology*; D000818:Animals; D004195:Disease Models, Animal; D018450:Disease Progression; D004388:Dura Mater; D004599:Electric Stimulation Therapy / Q000379:methods*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009044:Motor Cortex