Use of peripheral electrical stimulation on healthy individual and patients after stroke and its effects on the somatosensory evoked potentials. A systematic review

Characterization of somatosensory evoked potentials through fine intrafascicular stimulation via flexible carbon nanotube yarn electrodes under different isoflurane anaesthetics

BACKGROUND

While most current studies have focused on the effects of transcutaneous and extrafascicular stimulation on SEPs, intrafascicular stimulation offers a more advantageous alternative. By providing closer access to target afferent fibers, it allows for lower stimulation currents and greater nerve fiber selectivity, making it a promising approach for achieving fine tactile feedback. New method This study employed intrafascicular stimulation with carbon nanotube yarn (CNTy) electrodes to explore its impact on tactile feedback under different levels of isoflurane anaesthesia in rats. Bipolar and monopolar stimulation were applied to stimulate tibial nerves and the SEPs were recorded to analyse quantitatively.

RESULTS

The stimulation current threshold increased with increasing anaesthetic concentration for both bipolar and monopolar stimulation for each rat. As the anaesthesia concentration increased, the amplitude progressively decreased (P < 0.001, 1.0% vs 2.0%, monopolar; P < 0.01, 1.0% vs 2.0%, bipolar), the latency was prolonged (P < 0.01, 1.0% vs 2.0%, monopolar; P < 0.05, 1.0% vs 2.0%, bipolar), and the spectral power of early and late components significantly decreased (P < 0.01, 1.0% vs 2.0%, monopolar, Pearly; P < 0.05, 1.0% vs 2.0%, monopolar, Plate).

COMPARISON WITH EXISTING METHODS

For the first time, this study utilized CNTy electrodes via intrafascicular stimulation to investigate the characteristics of SEPs under varying isoflurane concentrations.

CONCLUSIONS

This study provides a solid foundation for quantifying tactile feedback of intrafascicular stimulation during rat experiments, and reveals among the three anesthetic concentrations tested, 1.0% exerted the minimal impact on all measured SEP characteristics in rats.

Somatosensory-Evoked Potentials and Clinical Assessments of Sensory Function Over Time in Patients With Subacute Stroke

Objective: To demonstrate the utility of somatosensory evoked potentials (SEPs) following median nerve stimulation for chronological assessment of sensory function in patients with subacute stroke during rehabilitation. Design: Retrospective study. Patients: Forty-seven patients with hemiparesis due to stroke during the subacute phase. Methods: We screened 363 patients who underwent SEP measurements at a rehabilitation hospital. Among them, 47 who underwent SEP measurements within 1 week after admission and at least 2 weeks after the initial assessment were included in this study. Sensorimotor assessments, including the Semmes-Weinstein monofilament test (SWMT), pain sensation, position sensation, two-point discrimination, and Stroke Impairment Assessment Set (SIAS) motor tests simultaneously with SEP measurements were available for 20 of the 47 patients. The relationship between the SEP peak count and each sensorimotor assessment was examined. Results: SEP amplitudes and latencies showed no significant differences between the initial and second assessments (paired t-test, p  > 0.05). However, the counts of SEP peaks after NI (N20) increased (Wilcoxon signed-rank test, p  < 0.05), indicating changes in the SEP waveform. Furthermore, strong correlations were observed between SEP peak counts, stage, and all functional assessments (counts and SWMT, RS = -0.77, p < 0.001; counts and pain sensation, RS = -0.71, p < 0.001; counts and position sensation, RS = 0.75, p < 0.001; counts and two-point discrimination, RS = -0.74, p < 0.001; stage and SWMT, RS = -0.74, p < 0.001; stage and pain sensation, RS = -0.69, p < 0.001; stage and position sensation, RS = 0.74, p < 0.001; and stage and two-point discrimination, RS = -0.75, p < 0.001; all Spearman's rank correlation coefficients). Conclusion: Despite the limitations of the retrospective study design, our study highlights the utility of SEPs for evaluating sensory function in patients with subacute stroke, setting the foundation for further investigations on the use of SEPs to assess functional changes in patients with subacute stroke undergoing rehabilitation.

A scoping review on examination approaches for identifying tactile deficits at the upper extremity in individuals with stroke

PURPOSE

Accurate perception of tactile stimuli is essential for performing and learning activities of daily living. Through this scoping review, we sought to summarize existing examination approaches for identifying tactile deficits at the upper extremity in individuals with stroke. The goal was to identify current limitations and future research needs for designing more comprehensive examination tools.

METHODS

A scoping review was conducted in accordance with the Joanna Briggs Institute methodological framework and the PRISMA for Scoping Reviews (PRISMA-ScR) guidelines. A database search for tactile examination approaches at the upper extremity of individuals with stroke was conducted using Medline (Ovid), The Cochrane Library (Wiley), CINAHL Plus with Full Text (Ebsco), Scopus (Elsevier), PsycInfo (Ebsco), and Proquest Dissertations and Theses Global. Original research and review articles that involved adults (18 years or older) with stroke, and performed tactile examinations at the upper extremity were eligible for inclusion. Data items extracted from the selected articles included: if the examination was behavioral in nature and involved neuroimaging, the extent to which the arm participated during the examination, the number of possible outcomes of the examination, the type(s) of tactile stimulation equipment used, the location(s) along the arm examined, the peripheral nerves targeted for examination, and if any comparison was made with the non-paretic arm or with the arms of individuals who are neurotypical.

RESULTS

Twenty-two articles met the inclusion criteria and were accepted in this review. Most examination approaches were behavioral in nature and involved self-reporting of whether a tactile stimulus was felt while the arm remained passive (i.e., no volitional muscle activity). Typically, the number of possible outcomes with these behavioral approaches were limited (2-3), whereas the neuroimaging approaches had many more possible outcomes ( > 15 ). Tactile examinations were conducted mostly at the distal locations along the arm (finger or hand) without targeting any specific peripheral nerve. Although a majority of articles compared paretic and non-paretic arms, most did not compare outcomes to a control group of individuals who are neurotypical.

DISCUSSION

Our findings noted that most upper extremity tactile examinations are behavioral approaches, which are subjective in nature, lack adequate resolution, and are insufficient to identify the underlying neural mechanisms of tactile deficits. Also, most examinations are administered at distal locations of the upper extremity when the examinee's arm is relaxed (passive). Further research is needed to develop better tactile examination tools that combine behavioral responses and neurophysiological outcomes, and allow volitional tactile exploration. Approaches that include testing of multiple body locations/nerves along the upper extremity, provide higher resolution of outcomes, and consider normative comparisons with individuals who are neurotypical may provide a more comprehensive understanding of the tactile deficits occurring following a stroke.

Effectiveness of Proprioceptive Body Vibration Rehabilitation on Motor Function and Activities of Daily Living in Stroke Patients with Impaired Sensory Function

Stroke patients experience impaired sensory and motor functions, which impact their activities of daily living (ADL). The current study was designed to determine the best neurorehabilitation method to improve clinical outcomes, including the trunk-impairment scale (TIS), Berg balance scale (BBS), Fugl-Meyer assessment (FMA), and modified Barthel index (MBI), in stroke patients with impaired sensory function. Forty-four stroke survivors consistently underwent proprioceptive body vibration rehabilitation training (PBVT) or conventional physical therapy (CPT) for 30 min/session, 5 days a week for 8 weeks. Four clinical outcome variables-the FMA, TIS, BBS, and MBI-were examined pre- and post-intervention. We observed significant differences in the FMA, BBS, and MBI scores between the PBVT and CPT groups. PBVT and CPT showed significant improvements in FMA, BBS, TIS, and MBI scores. However, PVBT elicited more favorable results than CPT in patients with stroke and impaired sensory function. Collectively, this study provides the first clinical evidence of optimal neurorehabilitation in stroke patients with impaired sensory function.

Effects of acupuncture synchronized rehabilitation therapy on upper limb motor and sensory function after stroke: a study protocol for a single-center, 2 × 2 factorial design, randomized controlled trial

Background

Upper limb function reconstruction has been an important issue in the field of stroke rehabilitation. Due to the complexity of upper extremity dysfunction in stroke patients, the clinical efficacy produced by central or peripheral stimulation alone is limited. For this reason, our group has proposed acupuncture synchronized rehabilitation therapy (ASRT), i.e., simultaneous scalp acupuncture and intradermal acupuncture during rehabilitation. Pre-experiments results showed that this therapy can effectively improve the motor and sensory functions of upper limbs in post-stroke patients, but the clinical efficacy and safety of ASRT need to be further verified, and whether there is a synergistic effect between scalp acupuncture and intradermal acupuncture also needs to be studied in depth. Therefore, we designed a randomized controlled trial to compare the efficacy and safety of different therapies to explore a more scientific "synchronous treatment model."

Methods

This is a single-center, randomized controlled trial using a 2 × 2 factorial design. We will recruit 136 stroke survivors with upper extremity dysfunction and randomize them into four groups (n = 34). All subjects will undergo routine treatment, based on which the Experimental Group 1: rehabilitation training synchronized with intradermal acupuncture treatment of the affected upper limb; Experimental Group 2: rehabilitation training of the affected upper limb synchronized with focal-side scalp acupuncture treatment, and Experimental Group 3: rehabilitation training synchronized with intradermal acupuncture treatment of the affected upper limb synchronized with focal-side scalp acupuncture treatment; Control Group: rehabilitation training of the affected upper limb only. The intervention will last for 4 weeks, 5 times a week. Both acupuncture treatments will be performed according to the Revised Standards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA). The primary outcome indicators for this trial are Fugl-Meyer Assessment-Upper Extremity and Somatosensory Evoked Potential. Secondary outcome indicators include Wolf Motor Function Test, Upper Extremity Function Test, revised Nottingham Sensory Assessment Scale, Diffusion Tensor Imaging, and Modified Barthel Index. The incidence of adverse events will be used as the indicator of safety.

Discussion

The study will provide high-quality clinical evidence on whether ASRT improves upper limb motor and sensory function and activities of daily living (ADL) in stroke patients, and determine whether scalp acupuncture and intradermal acupuncture have synergistic effects.

Clinical trial registration

https://www.chictr.org.cn/, Chinese Clinical Trial Registry [ChiCTR2200066646].

Efficacy of functional electrical stimulation in rehabilitating patients with foot drop symptoms after stroke and its correlation with somatosensory evoked potentials-a crossover randomised controlled trial

OBJECTIVE

The connectivity between somatosensory evoked potentials (SEPs) and cortical plasticity remains elusive due to a lack of supporting data. This study investigates changes in pathological latencies and amplitudes of SEPs caused by an acute stroke after 2 weeks of rehabilitation with functional electrical stimulation (FES). Furthermore, changes in SEPs and the efficacy of FES against foot drop (FD) stroke symptoms were correlated using the 10-m walk test and foot-ankle strength.

METHODS

A randomised controlled two-period crossover design plus a control group (group C) was designed. Group A (n = 16) was directly treated with FES, while group B (n = 16) was treated after 2 weeks. The untreated control group of 20 healthy adults underwent repeated SEP measurements for evaluation only.

RESULTS

The repeated-measures ANOVA showed a decrease in tibial nerve (TN) P40 and N50 latencies in group A after the intervention, followed by a decline in non-paretic TN SEP in latency N50 (p < 0.05). Moreover, compared to groups B and C from baseline to 4 weeks, group A showed a decrease in paretic TN latency P40 and N50 (p < 0.05). An increase in FD strength and a reduction in step cadence in group B (p < 0.05) and a positive tendency in FD strength (p = 0.12) and step cadence (p = 0.08) in group A were observed after the treatment time. The data showed a moderate (r = 0.50-0.70) correlation between non-paretic TN latency N50 and step cadence in groups A and B after the intervention time.

CONCLUSION

The FES intervention modified the pathological gait in association with improved SEP afferent feedback. Registered on 25 February 2021 on ClinicalTrials.gov under identifier number: NCT04767360.