Garcia Vences EE1, Ceballos-Zavala J1, Figueroa-Varelo J1, Calvo-Carrion S2, Herrero Gallego P2, De la Cruz Castillo E1, Ibarra A1
1Anahuac University Mexico, Health Sciences Faculty, Mexico, Mexico, 2San Jorge University, Health Sciences, Zaragoza, Mexico
Background: Spinal cord injury (SCI) results from trauma to the spinal cord with associated impairments such as muscle paralysis, spasticity, atrophy and pain. These impairments are triggered by the activation of molecular mechanisms that promote the release of acetylcholine into neuromuscular end-plates as a consequence of spinal cord denervation, leading to increasing calcium levels and depolarization of cell membrane. This injury cascade results in myofibrillar destruction and activation of inflammatory molecules as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNFα) and decrease in acetylcholinesterase (AChS).
Purpose: Dry needling (DN) is an innovative strategy that may promote the reduction of a sustained muscle contraction. However, molecular and electrophysiological mechanisms have not been well investigated. The goal of this study was to analyze the motor, electrophysiological and molecular changes associated with DN inside spastic gastrocnemius muscle in a chronic SCI (cSCI) model in rats.
Methods: Adult female Sprague-Dawley rats (13-14 weeks old, 200-220 g) were supplied by Anahuac University Mexico. After anesthesia induction, the rats were subjected to SCI transection (n=20) at T9. Twenty days after injury (chronic SCI:cSCI) the animals were randomly allocated into five groups: 1. Sham surgery, n=4; 2 and 3. cSCI without DN, n=10 (3 hours and 7 days n=5/group); 4. cSCI + DN, 3 hrs, n=5 and 5. cSCI + DN 7 days n=5.
A motor recovery test with Basso, Beattie and Bresnahan scale was performed each 7 days from SCI until 28 days after. The DN was applied to gastrocnemius muscles with previous localization of the trigger points analyzing its effects at 3 hrs and 7 days. Electrophysiological changes by electromyography (EMG) at different recruitment thresholds (umbral, 1.2 and 1.5 folds) and the gene expression of iNOS, COX-2, IL-1β, TNFα and AChS by qRT-PCR in gastrocnemius was assessed.
Results: The cSCI + DN 7 days group animals showed a significant increased motor recovery compared with other groups (5.6 +/- 2.6 SD vs 2.1 +/- 0.81 SD, Mann Whitney U test, p≤0.05). A non-significant decrease in amplitude and latency was seen in the EMG in SCI + DN 7 days group in comparison to other groups. In relation to gene expression, the SCI + DN 3 hrs group iNOS, COX-2 and AChS were significantly down-regulated (p ≤0.05); however, at 7 days this genes were up-regulated comparing with the cSCI without DN group (U de Mann Withney, p ≤0.05). The other genes didn´t show significant differences between groups at 3 hrs and 7 days after DN.
Conclusion(s): DN may induce the up-regulation of AChS, iNOS and COX-2 at 7 days after cSCI that promotes the reduction of the sustained muscle contraction and vasodilatation of the muscle fiber, possibly supporting a trend to motor recovery.
Implications: DN may set up a focal inflammatory response that could promote decreased reduction in chronic inflammation of trigger points in gastrocnemius muscles.
Keywords: dry needling, electromyography, spinal cord injury
Funding acknowledgements: Grant of CONACYT num 178544.
Purpose: Dry needling (DN) is an innovative strategy that may promote the reduction of a sustained muscle contraction. However, molecular and electrophysiological mechanisms have not been well investigated. The goal of this study was to analyze the motor, electrophysiological and molecular changes associated with DN inside spastic gastrocnemius muscle in a chronic SCI (cSCI) model in rats.
Methods: Adult female Sprague-Dawley rats (13-14 weeks old, 200-220 g) were supplied by Anahuac University Mexico. After anesthesia induction, the rats were subjected to SCI transection (n=20) at T9. Twenty days after injury (chronic SCI:cSCI) the animals were randomly allocated into five groups: 1. Sham surgery, n=4; 2 and 3. cSCI without DN, n=10 (3 hours and 7 days n=5/group); 4. cSCI + DN, 3 hrs, n=5 and 5. cSCI + DN 7 days n=5.
A motor recovery test with Basso, Beattie and Bresnahan scale was performed each 7 days from SCI until 28 days after. The DN was applied to gastrocnemius muscles with previous localization of the trigger points analyzing its effects at 3 hrs and 7 days. Electrophysiological changes by electromyography (EMG) at different recruitment thresholds (umbral, 1.2 and 1.5 folds) and the gene expression of iNOS, COX-2, IL-1β, TNFα and AChS by qRT-PCR in gastrocnemius was assessed.
Results: The cSCI + DN 7 days group animals showed a significant increased motor recovery compared with other groups (5.6 +/- 2.6 SD vs 2.1 +/- 0.81 SD, Mann Whitney U test, p≤0.05). A non-significant decrease in amplitude and latency was seen in the EMG in SCI + DN 7 days group in comparison to other groups. In relation to gene expression, the SCI + DN 3 hrs group iNOS, COX-2 and AChS were significantly down-regulated (p ≤0.05); however, at 7 days this genes were up-regulated comparing with the cSCI without DN group (U de Mann Withney, p ≤0.05). The other genes didn´t show significant differences between groups at 3 hrs and 7 days after DN.
Conclusion(s): DN may induce the up-regulation of AChS, iNOS and COX-2 at 7 days after cSCI that promotes the reduction of the sustained muscle contraction and vasodilatation of the muscle fiber, possibly supporting a trend to motor recovery.
Implications: DN may set up a focal inflammatory response that could promote decreased reduction in chronic inflammation of trigger points in gastrocnemius muscles.
Keywords: dry needling, electromyography, spinal cord injury
Funding acknowledgements: Grant of CONACYT num 178544.
Topic: Neurology: spinal cord injury; Musculoskeletal: lower limb; Disability & rehabilitation
Ethics approval required: Yes
Institution: Anahuac University
Ethics committee: CICUAL
Ethics number: MR06170900616
All authors, affiliations and abstracts have been published as submitted.
