Description:
Response variability between individuals (interindividual variability) and within individuals (intraindividual variability) is an important issue in the transcranial magnetic stimulation (TMS) literature. This has raised questions of the validity of TMS to assess changes in corticospinal excitability (CSE) in a predictable and reliable manner. Several participant-specific factors contribute to this observed response variability with a current lack of consensus on the degree each factor contributes. This highlights a need for consistency and structure in reporting study designs and methodologies. Currently, there is no summarized review of the participant-specific factors that can be controlled and may contribute to response variability. This systematic review aimed to develop a checklist of methodological measures taken by previously published research to increase the homogeneity of participant selection criteria, preparation of participants before experimental testing, participant scheduling, and the instructions given to participants throughout experimental testing to minimize their effect on response variability. Seven databases were searched in full. Studies were included if CSE was measured via TMS and included methodological measures to increase the homogeneity of the participants. Eighty-four studies were included. Twenty-three included measures to increase participant selection homogeneity, 21 included measures to increase participant preparation homogeneity, while 61 included measures to increase participant scheduling and instructions during experimental testing homogeneity. These methodological measures were summarized into a user-friendly checklist with considerations, suggestions, and rationale/justification for their inclusion. This may provide the framework for further insights into ways to reduce response variability in TMS research.
Description:
Noninvasive brain stimulation (NIBS) modifies corticospinal excitability (CSE) historically in a predictable manner dependent on stimulation parameters. Researchers, however, discuss high degrees of variability between individuals, either responding as expected or not responding as expected. The explanation for this interindividual variability remains unknown with suggested interplay between stimulation parameters and variations in biological, anatomical, and physiological factors. This systematic review and meta-analysis aimed to investigate the effect of variation in inherent factors within an individual (biological and anatomical factors) on CSE in response to NIBS of the primary motor cortex. Twenty-two studies were included investigating genetic variation (n=7), age variation (n=4), gender variation (n=7), and anatomical variation (n=5). The results indicate that variation in brain-derived neurotrophic factor genotypes may have an effect on CSE after NIBS. Variation between younger and older adults also affects CSE after NIBS. Variation between age-matched males and females does not affect CSE after NIBS, but variation across the menstrual cycle does. Variation between skull thickness and brain tissue morphology influences the electric field magnitude that ultimately reaches the primary motor cortex. These findings indicate that biological and anatomical variations may in part account for interindividual variability in CSE in response to NIBS of the primary motor cortex, categorizing individuals as responding as expected (responders) or not responding as expected (nonresponders).
Description:
Background: The brain motor control assessment (BMCA) for the upper limb has been developed to add resolution to the clinical evaluation in patients with spinal cord injury (SCI). BMCA is a surface electromyography (sEMG)-based measure of motor output from the central nervous system during a variety of reflex and voluntary motor tasks performed under strictly controlled conditions. Method: Nine participants were recruited and assessed four times over a period of 1 year in a prospective cohort study design. The sEMG of 15 muscles (7 muscles from each upper limb and rectus abdominis) were recorded throughout the following stages of the BMCA protocol: (i) relaxation, (ii) reinforcement maneuvers, (iii) voluntary tasks, (iv) tendon-tap reflex responses, (v) vibration responses. Results: Similarity index (SI) values were significantly lower in the SCI group for unilateral shoulder abduction (P = 0.006) and adduction (P = 0.021), elbow extension (P = 0.038), wrist flexion/extension with palm up (P < 0.001 P < 0.001) and wrist flexion with palm down (P = 0.016). sEMG magnitudes were also significantly lower in the SCI group for wrist flexion/extension with palm up (P < 0.001 P = 0.042). SI changes over time were significant for tasks related to wrist joint (P = 0.002). Conclusion: Clinicians who are involved in rehabilitation of patients with SCI can use the BMCA to assess their patients' motor control abilities and monitor their progression throughout their rehabilitation process. The results of this type of neurophysiological assessment might be useful to tailor therapeutic strategies for each patient.
Description:
The Brain Motor Control Assessment (BMCA) is a surface electromyography (sEMG)-based measure of motor output from the central nervous system during a variety of reflex and voluntary motor tasks. The aim of this study was to assess the pattern of voluntary movements in patients with spinal cord injury (SCI) to investigate whether BMCA could add more resolution to clinical assessments and the recovery path of these patients. Ten participants were recruited from the Royal Talbot Rehabilitation Centre as part of a multicenter randomized controlled trial. Four participants received usual care while the other 3 participants received usual care plus an intensive task-specific hand training program in conjunction with functional electrical stimulation for 8 weeks. BMCA assessments were completed for 7 participants at this center 4 times over a period of 1 year. Generalized linear model analysis showed a significant main effect of task ( < .001) and assessment time ( = .003) on the Similarity Index. However, there were no significant interactions among the factors ( > .05). Based on ARAT or summed upper limb strength scores, some participants showed significant improvement after 8 weeks of rehabilitation, however this improvement was not reflected in the pattern of muscle activation that was captured by BMCA. The quantifiable features of BMCA through surface EMG may increase the resolution of SCI characterization by adding subclinical details to the clinical picture of lesion severity and progression during rehabilitation.
Description:
Summary Objective To investigate the effect of cathodal transcranial direct‐current stimulation (c‐tDCS) on seizure frequency in patients with drug‐resistant temporal lobe epilepsy (TLE). Method Twenty‐nine patients with drug‐resistant TLE participated in this study. They were randomized to experimental or sham group. Twenty participants (experimental group) received within‐session repeated c‐tDCS intervention over the affected temporal lobe, and nine (sham group) received sham tDCS. Paired‐pulse transcranial magnetic stimulation was used to assess short interval intracortical inhibition (SICI) in primary motor cortex ipsilateral to the affected temporal lobe. SICI was measured from motor evoked potentials recorded from the contralateral first dorsal interosseous muscle. Adverse effects were monitored during and after each intervention in both groups. A seizure diary was given to each participant to complete for 4 weeks following the tDCS intervention. The mean response ratio was calculated from their seizure rates before and after the tDCS intervention. Results The experimental group showed a significant increase in SICI compared to the sham group (F = 10.3, p = 0.005). None of the participants reported side effects of moderate or severe degree. The mean response ratio in seizure frequency was −42.14% (standard deviation [SD] 35.93) for the experimental group and −16.98% (SD 52.41) for the sham group. Significance Results from this pilot study suggest that tDCS may be a safe and efficacious nonpharmacologic intervention for patients with drug‐resistant TLE. Further evaluation in larger double‐blind randomized controlled trials is warranted.
Description:
Cluster analysis and other subgrouping techniques have risen in popularity in recent years in non-invasive brain stimulation research in the attempt to investigate the issue of inter-individual variability - the issue of why some individuals respond, as traditionally expected, to non-invasive brain stimulation protocols and others do not. Cluster analysis and subgrouping techniques have been used to categorise individuals, based on their response patterns, as responder or non-responders. There is, however, a lack of consensus and consistency on the most appropriate technique to use. This systematic review aimed to provide a systematic summary of the cluster analysis and subgrouping techniques used to date and suggest recommendations moving forward. Twenty studies were included that utilised subgrouping techniques, while seven of these additionally utilised cluster analysis techniques. The results of this systematic review appear to indicate that statistical cluster analysis techniques are effective in identifying subgroups of individuals based on response patterns to non-invasive brain stimulation. This systematic review also reports a lack of consensus amongst researchers on the most effective subgrouping technique and the criteria used to determine whether an individual is categorised as a responder or a non-responder. This systematic review provides a step-by-step guide to carrying out statistical cluster analyses and subgrouping techniques to provide a framework for analysis when developing further insights into the contributing factors of inter-individual variability in response to non-invasive brain stimulation.
Description:
Objective: To compare the effects of anodal trans-cranial direct current stimulation (a-tDCS) over primary motor and dorsolateral prefrontal cortices on Fatigue Severity Scale and its lasting effect on fatigue reduction and improvement in quality of life in patients with multiple sclerosis. Design: A randomized, double-blinded, sham-controlled parallel clinical trial study. Setting: Neurological physiotherapy clinics. Subjects: Thirty-nine participants were randomly assigned to three groups: dorsolateral prefrontal cortex a-tDCS, primary motor a-tDCS (experimental groups) and sham a-tDCS. Finally, 36 participants completed the whole study (n = 12 in each group). Interventions: Participants in the experimental groups received six-session a-tDCS (1.5 mA, 20 minutes) during two weeks (three sessions per week). The sham group received six sessions of 20-minute sham stimulation. Main measures: The Fatigue Severity Scale and quality of life were assessed before, immediately and four weeks after the intervention. Results: Findings indicated a significant reduction in the Fatigue Severity Scale and a significant increase in the quality of life in both experimental groups, immediately after the intervention (P < 0.001), while Fatigue Severity Scale and quality of life changes were not significant in the sham a-tDCS group (P > 0.05). In addition, improvement of the variables remained four weeks after the intervention in dorsolateral prefrontal cortex a-tDCS (mean differences (95% confidence interval): 0.03 (−0.63 to 0.68) as compared to primary motor (−0.62 (−0.11 to −1.14) and sham a-tDCS groups (−0.47 (−1.37 to 0.43)). Conclusion: Both primary motor and dorsolateral prefrontal cortex a-tDCS as compared to sham intervention can immediately improve fatigue and quality of life. However, the effects last up to four weeks only by the dorsolateral prefrontal cortex a-tDCS.
Description:
Several methods can be used to determine the resting motor threshold (RMT) and by that recording transcranial magnetic stimulation (TMS) induced motor evoked potentials (MEPs). However, no research has compared the test retest reliability of these methods. Thus, the aim of this study was to determine intra‐ and inter‐session reliability of Rossini–Rothwell (R–R) and parameter estimation by sequential testing (PEST) methods on TMS‐induced MEPs and comparison of these two methods on RMT. Twelve healthy individuals participated in this study three times (T1, T2 and T3) over two days. TMS was applied using both R–R and PEST to estimate RMT and average of 25 MEPs were acquired at each of the three time points. The intra‐class correlation coefficient indicated high intra‐session reliability in the MEP amplitudes for both methods (0.79 and 0.88, R–R and PEST respectively). The RMT and MEP amplitudes had higher inter‐session reliability in both methods (0.99 and 0.998, R–R and PEST respectively 0.84 and 0.76, R–R and PEST respectively). There was no significant difference between methods for RMT at both T1 (maximum stimulator output of R–R vs. PEST, 33.7% ± 7.7% vs. 33.8% ± 7.6%, p = 0.75) and T3 (maximum stimulator output of R–R vs. PEST, 33.5% ± 7.3% vs. 33.7% ± 7.3%, p = 0.19). There was a significant positive correlation between the methods' estimates of RMT, with PEST requiring significantly fewer stimuli. This study shows that the R–R and PEST methods have high intra‐and inter‐session reliability and the same precision, with PEST having the advantage over R–R in speed of estimation of RMT. R–R and PEST methods are highly reliable for finding RMT, and that there is no difference between TMS‐induced MEPs derived with the methods when measured on two occasions on the same day or between days.
Description:
[Display omitted] •Two-week postural training alone is not sufficient for improving posture in patients with LBP.•M1 a-tDCS can induce efficiency of postural training for improving balance in LBP patients.•Lasting effects of M1 a-tDCS and postural training on balance have shown in LBP patients. Changes in different regions of the brain due to postural disturbances were found in patients with chronic low back pain (LBP). The aims of the current study were to investigate the short- and long-term enhancing effects of concurrent postural training and primary motor cortex (M1) anodal transcranial direct current stimulation (a-tDCS) on balance, postural stability and pain in chronic LBP patients with postural impairment. In this clinical trial study, thirty eight patients with chronic LBP were randomly assigned to a-tDCS and training, sham a-tDCS and training,and training only groups. All groups received identical postural training for 20 min, three sessions per week for two weeks. The length of stimulation, which used concurrent with postural training in the active a-tDCS group was also 20 min. Before, immediately and one-month after the interventions, postural stability, balance and pain were assessed using Biodex Balance System, Berg Balance Scale (BBS) and Visual Analog Scale (VAS), respectively. The postural stability indices, BBS and VAS scores significantly improved immediately and one-month after the intervention in the a-tDCS and training group (P < 0.001), while there were significant differences between active a-tDCS and other two groups (P < 0.001). Postural stability indices, the BBS and VAS scores were not significantly different between the sham and training only groups after the interventions (P > 0.05). M1 a-tDCS significantly improves the effects of postural training on postural stability, balance and pain in patients with chronic LBP. Two-week postural training alone cannot improve postural impairment in patients with chronic LBP.
Description:
Crossover designs are used by a high proportion of studies investigating the effects of transcranial direct current stimulation (tDCS) on motor learning. These designs necessitate attention to aspects of data collection and analysis to take account of design-related confounds including order, carryover, and period effects. In this systematic review, we appraised the method sections of crossover-designed tDCS studies of motor learning and discussed the strategies adopted to address these factors. A systematic search of 10 databases was performed and 19 research papers, including 21 experimental studies, were identified. Potential risks of bias were addressed in all of the studies, however, not in a rigorous and structured manner. In the data collection phase, unclear methods of randomization, various lengths of washout period, and inconsistency in the counteracting period effect can be observed. In the analytical procedures, the stratification by sequence group was often ignored, and data were treated as if it belongs to a simple repeated-measures design. An inappropriate use of crossover design can seriously affect the findings and therefore the conclusions drawn from tDCS studies on motor learning. The results indicate a pressing need for the development of detailed guidelines for this type of studies to benefit from the advantages of a crossover design.
Determination of anodal tDCS intensity threshold for reversal of corticospinal excitability: an investigation for induction of counter-regulatory mechanisms
Description:
Transcranial direct current stimulation is applied to modulate activity, and excitability of the brain. Basically, LTP-like plasticity is induced when anodal tDCS (a-tDCS) is applied over the primary motor cortex. However, it has been shown that specific parameters of a-tDCS can induce a plasticity reversal. We aimed to systematically assess the intensity threshold for reversal of the direction of plasticity induced by a-tDCS, monitored by corticospinal excitability (CSE), and explored mechanisms regulating this reversal. Fifteen healthy participants received a-tDCS in pseudo-random order for 26 min with four intensities of 0.3, 0.7, 1, and 1.5 mA. To measure CSE changes, single-pulse TMS was applied over the left M1, and motor evoked potentials of a contralateral hand muscle were recorded prior to a-tDCS, immediately and 30-min post-intervention. Paired-pulse TMS was used to evaluate intracortical excitation and inhibition. CSE increased significantly following a-tDCS with an intensity of 0.7 mA however, the expected effect decreased and even reversed at intensities of 1 and 1.5 mA. ICF was significantly increased while SICI and LICI decreased at 0.7 mA. On the other hand, a significant decrease of ICF, but SICI and LICI enhancement was observed at intensities of 1, and 1.5 mA. The present findings show an intensity threshold of ≥ 1 mA for 26 min a-tDCS to reverse LTP- into LTD-like plasticity. It is suggested that increasing stimulation intensity, with constant stimulation duration, activates counter-regulatory mechanisms to prevent excessive brain excitation. Therefore, stimulation intensity and plasticity induced by a-tDCS might non-linearly correlate in scenarios with prolonged stimulation duration.
Description:
Transcranial direct current stimulation is applied to modulate activity, and excitability of the brain. Basically, LTP-like plasticity is induced when anodal tDCS (a-tDCS) is applied over the primary motor cortex. However, it has been shown that specific parameters of a-tDCS can induce a plasticity reversal. We aimed to systematically assess the intensity threshold for reversal of the direction of plasticity induced by a-tDCS, monitored by corticospinal excitability (CSE), and explored mechanisms regulating this reversal. Fifteen healthy participants received a-tDCS in pseudo-random order for 26 min with four intensities of 0.3, 0.7, 1, and 1.5 mA. To measure CSE changes, single-pulse TMS was applied over the left M1, and motor evoked potentials of a contralateral hand muscle were recorded prior to a-tDCS, immediately and 30-min post-intervention. Paired-pulse TMS was used to evaluate intracortical excitation and inhibition. CSE increased significantly following a-tDCS with an intensity of 0.7 mA however, the expected effect decreased and even reversed at intensities of 1 and 1.5 mA. ICF was significantly increased while SICI and LICI decreased at 0.7 mA. On the other hand, a significant decrease of ICF, but SICI and LICI enhancement was observed at intensities of 1, and 1.5 mA. The present findings show an intensity threshold of ≥ 1 mA for 26 min a-tDCS to reverse LTP- into LTD-like plasticity. It is suggested that increasing stimulation intensity, with constant stimulation duration, activates counter-regulatory mechanisms to prevent excessive brain excitation. Therefore, stimulation intensity and plasticity induced by a-tDCS might non-linearly correlate in scenarios with prolonged stimulation duration.
Description:
Research is being conducted on the use of transcranial direct current stimulation (tDCS) for therapeutic effects, and also on the mechanisms through which such therapeutic effects are mediated. A bottleneck in the progress of the research has been the large size of the existing tDCS systems which prevents subjects from performing their daily activities. To help research into the principles, mechanisms, and benefits of tDCS, reduction of size and weight, improvement in simplicity and user friendliness, portability, and programmability of tDCS systems are vital. This paper presents a design for a low-cost, light-weight, programmable, and portable tDCS device. The device is head-mountable and can be concealed in a hat and worn on the head by the subject while receiving the stimulation. The strength of the direct current stimulation can be selected through a simple user interface. The device is constructed and its performance evaluated through bench and in vivo tests. The tests validated the operation of the device in inducing neuromodulatory changes in primary motor cortex, M1, through measuring excitability of dominant M1 of resting right first dorsal interosseus muscle by transcranial magnetic stimulation induced motor evoked potentials. It was observed that the tDCS device induced comparable neuromodulatory effects in M1 as the existing bulky tDCS systems.
Description:
•This systematic review indicates that the effects of different type of cerebellar noninvasive brain stimulation (NIBS) on the Corticospinal Excitability (CSE) is different.•This review showed cerebellar PAS 6, a-tDCS + PAS25, and cTBS decrease the CSE level.•This review showed there is an increase in the CSE after using cerebellar PAS 2, PAS 21.5 + a-tDCS, and 1 Hz rTMS.•This review gives a good understanding of the effects of different cerebellar NIBS techniques affect the CSE, and help us to select the best NIBS technique for researches in cerebellar stimulation field, based on the effects that we need. Numerous studies have indicated that non-invasive brain stimulation (NIBS) of the cerebellum could modulate corticospinal excitability (CSE) in young healthy individuals. However, there is no systematic review and meta-analysis that clarifies the effects of cerebellar NIBS on CSE. The aim of this study was to provide a meta-analytic summary of the effects of cerebellar NIBS on CSE. Seven search engines were used to identify any trial evaluating CSE before and after one session of cerebellar NIBS in healthy individuals up to June 2018. Twenty-six studies investigating the corticospinal responses following cerebellar NIBS were included. Meta-analysis was used to pool the findings from included studies. Effects were expressed as mean differences (MD) and the standard deviation (SD). Risk of bias was assessed with the Cochrane tool. Meta-analysis found that paired associative stimulation (PAS) with 2 ms interval, a combination of PAS with 21.5 ms interval and anodal transcranial direct current stimulation, and repetitive transcranial magnetic stimulation with a frequency of < 5 Hz increase CSE (P PAS2 < 0.00001, P PAS21.5 +a-tDCS = 0.02, P rTMS = 0.04). However, continuous theta burst stimulation, a combination of PAS with 25 ms interval and anodal transcranial direct current stimulation, and PAS with a 6 ms interval decreased CSE (P PAS6 < 0.00001, P cTBS < 0.00001, P PAS25 +a-tDCS = 0.003). The results of this review show that cerebellar NIBS techniques are a promising tool for increasing CSE.
Description:
Numerous studies have explored the effects of transcranial electrical stimulation (tES) – including anodal transcranial direct current stimulation (a‐tDCS), cathodal transcranial direct current stimulation (c‐tDCS), transcranial alternative current stimulation (tACS), transcranial random noise stimulation (tRNS) and transcranial pulsed current stimulation (tPCS) – on corticospinal excitability (CSE) in healthy populations. However, the efficacy of these techniques and their optimal parameters for producing robust results has not been studied. Thus, the aim of this systematic review was to consolidate current knowledge about the effects of various parameters of a‐tDCS, c‐tDCS, tACS, tRNS and tPCS on the CSE of the primary motor cortex (M1) in healthy people. Leading electronic databases were searched for relevant studies published between January 1990 and February 2017 126 articles were identified, and their results were extracted and analysed using RevMan software. The meta‐analysis showed that a‐tDCS application on the dominant side significantly increases CSE (P < 0.01) and that the efficacy of a‐tDCS is dependent on current density and duration of application. Similar results were obtained for stimulation of M1 on the non‐dominant side (P = 0.003). The effects of a‐tDCS reduce significantly after 24 h (P = 0.006). Meta‐analysis also revealed significant reduction in CSE following c‐tDCS (P < 0.001) and significant increases after tRNS (P = 0.03) and tPCS (P = 0.01). However, tACS effects on CSE were only significant when the stimulation frequency was ≥140 Hz. This review provides evidence that tES has substantial effects on CSE in healthy individuals for a range of stimulus parameters. tES has significant effect on corticospinal excitability (CSE) in healthy individuals. Among tES techniques, application of a‐tDCS on non‐dominant side primary motor cortex produces significant effect on CSE. Future studies should focus the effect of tPCS on CSE.
Description:
Background: Mechanical injury in patients with spinal cord injury (SCI) rarely transects the cord completely, even when the injury is classified as complete. These patients can show sub-clinical evidence of spared motor connections, which might be amenable to targeted rehabilitation. Neurophysiological evaluations can complement the clinical evaluation by providing objective data about conduction across the SCI site. Case Description: A twenty-four year old patient with SCI was admitted to a rehabilitation centre 49 days post traumatic SCI. His injury was categorized as motor and sensory complete (AIS A) with a neurological level of C4. The strength of his triceps bilaterally was recorded 0/5 repeatedly by his therapists during the five-month period post-injury. As a result, no training was provided for these muscles during the rehabilitation program. Neurophysiological Assessment: Motor evoked potentials (MEPs) were recorded from his left triceps with transcranial magnetic stimulation (TMS) which confirmed the existence of spared corticospinal connections to this muscle post-injury. Intervention: He completed a series of active-assisted exercises with an EMG-triggered neuromuscular stimulation (NMS) device for his left triceps comprising 20-minutes elbow extension (15 trials), three times per day for 4 weeks. Outcome: The strength of his left triceps gradually improved to 2/5. Discussion: Neurophysiological evaluation can be useful in identifying residual function below the level of injury, which can, in turn, be enhanced through appropriate rehabilitation strategies.
Description:
Noninvasive brain stimulation (NIBS) techniques could induce changes in corticospinal excitability (CSE) and neuroplasticity. These changes could be affected by different factors, including having a session of stimulation called the 'priming' protocol before the main stimulation session called the 'test' protocol. Literature indicates that a priming protocol could affect the activity of postsynaptic neurons, form a neuronal history, and then modify the expected effects of the test protocol on CSE indicated by the amplitude of transcranial magnetic stimulation-induced motor-evoked potentials. This prior history affects a threshold to activate the necessary mechanism stabilizing the neuronal activity within a useful dynamic range. For studying the effects of this history and related metaplasticity mechanisms in the human primary motor cortex (M1), priming-test protocols are successfully employed. Thirty-two studies were included in this review to investigate how different priming protocols could affect the induced effects of a test protocol on CSE in healthy individuals. The results showed that if the history of synaptic activity were high or low enough to displace the threshold, the expected effects of the test protocol would be the reverse. This effect reversal is regulated by homeostatic mechanisms. On the contrary, the effects of the test protocol would not be the reverse, and at most we experience a prolongation of the lasting effects if the aforementioned history is not enough to displace the threshold. This effect prolongation is mediated by nonhomeostatic mechanisms. Therefore, based on the characteristics of priming-test protocols and the interval between them, the expected results of priming-test protocols would be different. Moreover, these findings could shed light on the different mechanisms of metaplasticity involved in NIBS. It helps us understand how we can improve the expected outcomes of these techniques in clinical approaches.
Description:
The aim of this scoping review was to critically review and synthesize the evidence concerning the relationship between traumatic peripheral lesions and cognitive impairments. Five electronic databases (Medline, Cinahl, Psycinfo, Embase, and Cochrane Library) were searched in their entirety using the two key words “cognition” and “trauma”. An additional manual search was conducted. All inclusion criteria comprised English language, an assessment of cognition, and the study participants experienced acute peripheral lesion or physical trauma and were aged between 18 and 65 years. The articles were screened for eligibility by two independent reviewers. Disagreements were resolved by discussion or consensus with a third author. A total of 11737 records were identified, of which 10 met the inclusion criteria. Whiplash injury, brachial plexus injury, soft tissue injury around the cervical spine, and fracture were found to be associated with cognitive impairments. The earliest cognitive assessment time point was one-month post injury, while the latest counterpart was 444 months. Cognition was assessed using 20 unique instruments, targeting nine distinct cognitive domains. An overall positive association was found between traumatic peripheral lesions and cognitive impairments. Therefore, further longitudinal research is needed to monitor the changes in cognitive functions post physical trauma.