Changes in Corticospinal Excitability Following Adaptive Modification to Human Walking.

Changes in corticospinal excitability following adaptive modification to human walking.

Exp Brain Res. 2013 Mar 15;
Zabukovec JR, Boyd LA, Linsdell MA, Lam T

Locomotor adaptations to a novel environment can be measured through changes in muscle activity patterns and lower limb kinematics. The location and mechanisms underlying these adaptive changes are unknown. The purposes of the current study were (1) to determine whether corticospinal tract (CST) excitability is altered by resisted walking and (2) to ascertain whether changes in cortical excitability are muscle specific. Forty healthy participants walked with a robotic gait device (Lokomat) that applied a velocity-dependent resistance against hip and knee movements during walking. CST excitability was assessed by quantifying motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation immediately before and after baseline and resisted walking. MEPs were measured in either the biceps femoris (BF) or the rectus femoris (RF). Recruitment curves were collected by stimulating in 5 % increments from 105 to 145 % of active motor threshold. Results demonstrated a significant increase in MEP amplitude in the BF following baseline walking in the Lokomat. The RF did not demonstrate these changes. There was no further change in MEP size following resisted walking in either muscle group. These results suggest that locomotion increases CST excitability in a muscle-specific fashion. As such, it may be important for determining how to enhance the central nervous system’s ability to integrate adaptive strategies during walking. HubMed – rehab


Effect of electroacupuncture on the pathomorphology of the sciatic nerve and the sensitization of P2X3 receptors in the dorsal root ganglion in rats with chronic constrictive injury.

Chin J Integr Med. 2013 Mar 15;
Cheng RD, Tu WZ, Wang WS, Zou EM, Cao F, Cheng B, Wang JZ, Jiang YX, Jiang SH

OBJECTIVE: To explore the effect of electroacupuncture (EA) on the pathomorphology of the sciatic nerve and the role of P2X3 receptors in EA analgesia. METHODS: The chronic constriction injury (CCI) model was adopted in this study. A total of 32 rats were randomly divided into four groups: sham CCI, CCI, CCI plus contralateral EA (CCI + conEA) and CCI plus ipsilateral EA (CCI + ipsEA). Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured. EA began at day 7 after the CCI operation and was applied to the Zusanli (ST 36) and Yanglingquan acupoints (GB 34). At day 14, the pathomorphologic changes of the operated sciatic nerve were demonstrated by hematoxylin and eosin staining. In addition, dorsal root ganglion (DRG) neurons isolated from rats were examined by electrophysiological recording to determine if the P2X3 receptor agonists, adenosine 5′-triphosphate disodium (ATP) and ?,?-methylen-ATP (?,?-meATP) evoked inward currents. RESULTS: Pain thresholds in the CCI group were obviously decreased post CCI surgery (P<0.01). In the EA groups, thermal and mechanical threshold values were increased after the last EA treatment P<0.05, P<0.01). There was no significant difference in light microscopic examination among the four groups P>0.05). Current amplitude after application of ATP and ?,? -meATP in DRG neurons were much larger in the CCI group compared to those obtained in sham CCI (P<0.05). ATP and ?, ?-meATP invoked amplitudes in the CCI + EA groups were reduced. There was no significant difference between the CCI + conEA group and the CCI + ipsEA group (P>0.05). CONCLUSION: EA analgesia may be mediated by decreasing the response of P2X3 receptors to the agonists ATP and ?,?-meATP in the DRG of rats with CCI. No pathological changes of the sciatic nerve of rats were observed after EA treatment. HubMed – rehab


The association of compensation and long term health status for people with severe traumatic injuries.

J Rehabil Med. 2013 Mar 14;
Schaafsma FG, Middleton J, De Wolf AC, Tate RL, Cameron ID

Objective: It was hypothesized that, for people with severe traumatic injuries, no association between long term health status and receiving financial compensation would be detected. Design: Two prospective cohort studies. Subjects: A group of people with severe traumatic brain injury (n?=?132) and a group of people with traumatic spinal cord injury (n?=?58). Methods: Health status and functioning were measured at baseline and at 5 years follow-up for both injury groups. Results per group were compared between those who received compensation and those who were non-compensable. Results: In the brain injury cohort those receiving financial compensation showed a significantly worse Disability Rating Scale score after 5 years compared to the non-receiving group (p?=?0.01). Financial compensation was a modest predictor for being disabled (scores ??4) after 5 years (Exp (B)?=?2.47, 95% confidence interval 1.03 to 5.93). In the spinal cord injury cohort those receiving financial compensation scored significantly lower with the Short-Form 36 General Health Survey/Physical Component Summarise scores after 5 years than those who did not (p?=?0.04). Again, receiving financial compensation had a modest predictive value for the Short-Form 36/Physical Component Summarise scores after 5 years (B?=?-4.72, SE?=?2.16, 95% confidence interval -9.05 to -0.38). Conclusion: Financial compensation may have a small negative association with recovery, even for people with severe traumatic injury. HubMed – rehab