Effects of taxane-induced peripheral neuropathy on hand dexterity impairment: evaluation of quantitative and subjective assessments.

PURPOSE: Chemotherapy-induced peripheral neuropathy (CIPN) commonly involves hand dexterity impairment. However, the factors affecting hand dexterity impairment are unknown and there is currently no established treatment. The purpose of the current study was to clarify factors influencing hand dexterity impairment in taxane-induced peripheral neuropathy using subjective and objective assessments. METHODS: We assessed patient characteristics, treatment-related factors, subjective symptoms of CIPN (Patient Neurotoxicity Questionnaire [PNQ]), psychological symptoms, and upper limb dysfunction (Quick Disabilities of the Arm, Shoulder and Hand [Quick DASH]). Quantitative assessments were pinch strength, sensory threshold, hand dexterity impairment, and grip force control. Multiple regression analysis was performed using hand dexterity impairment as the dependent variable and age and PNQ, Quick DASH, and control of grip force as independent variables. RESULTS: Forty-three breast cancer patients were included in the analysis. Hand dexterity impairment in taxane-induced peripheral neuropathy patients was significantly correlated with age, grip force control, and PNQ sensory scores (p < 0.008). Multiple regression analysis demonstrated that PNQ sensory scores and grip force control were significantly associated with hand dexterity impairment (p < 0.01). CONCLUSION: Subjective symptoms (numbness and pain) and grip force control contributed to impaired hand dexterity in taxane-induced peripheral neuropathy.

Influence of vibrotactile random noise on the smoothness of the grasp movement in patients with chemotherapy-induced peripheral neuropathy.

Patients with chemotherapy-induced peripheral neuropathy (CIPN) often suffer from sensorimotor dysfunction of the distal portion of the extremities (e.g., loss of somatosensory sensation, numbness/tingling, difficulty typing on a keyboard, or difficulty buttoning/unbuttoning a shirt). The present study aimed to reveal the effects of subthreshold vibrotactile random noise stimulation on sensorimotor dysfunction in CIPN patients without exacerbating symptoms. Twenty-five patients with CIPN and 28 age-matched healthy adults participated in this study. To reveal the effects of subthreshold vibrotactile random noise stimulation on sensorimotor function, participants were asked to perform a tactile detection task and a grasp movement task during random noise stimulation delivered to the volar and dorsal wrist. We set three intensity conditions of the vibrotactile random noise: 0, 60, and 120% of the sensory threshold (Noise 0%, Noise 60%, and Noise 120% conditions). In the tactile detection task, a Semmes-Weinstein monofilament was applied to the volar surface of the tip of the index finger using standard testing measures. In the grasp movement task, the distance between the thumb and index finger was recorded while the participant attempted to grasp a target object, and the smoothness of the grasp movement was quantified by calculating normalized jerk in each experimental condition. The experimental data were compared using two-way repeated-measures analyses of variance with two factors: experimental condition (Noise 0, 60, 120%) × group (Healthy controls, CIPN patients). The tactile detection threshold and the smoothness of the grasp movement were only improved in the Noise 60% condition without exacerbating numbness/tingling in CIPN patients and healthy controls. The current study suggested that the development of treatment devices using stochastic resonance can improve sensorimotor function for CIPN patients.

Effect of experimentally induced plantar pain on trunk posture during gait.

[Purpose] Plantar pain is associated with the prevalence of low back pain. Therefore, it is reasonable to assume that some kind of physical change should be occurring in the trunk due to plantar pain. However, the physical effect of plantar pain on the trunk remains unknown. We evaluated the effect of plantar pain on trunk posture during gait. [Participants and Methods] Ten healthy volunteers participated in the present study. Participants walked under two conditions: without pain and with pain. In the with pain condition, we set pain-inducing devices to the right foot to induce plantar pain during stance phase. By using 3D motion analysis system, the angles of the head, thorax, and pelvis segments, as well as the neck, trunk, bilateral hip, bilateral knee, and bilateral ankle joints, were measured. We analyzed the angle data throughout the gait cycle by using one-dimensional statistical parametric mapping. [Results] The anterior trunk tilt was observed in the right stance phase. [Conclusion] The anterior trunk tilt observed in the with pain condition may be a burden on the trunk. Our results presented one of the possible reasons for increased prevalence of low back pain in the plantar pain patients.

The Effects of Transcranial Direct Current Stimulation Combined with Aerobic Exercise on Pain Thresholds and Electroencephalography in Healthy Adults.

OBJECTIVES: We examined whether transcranial direct current stimulation (tDCS) combined with aerobic exercise (AE) modulated the pressure pain threshold (PPT) and peak alpha frequency (PAF) measured via resting electroencephalography. DESIGN: Single-blind experimental study with a cross-over design. SETTING: Neuro Rehabilitation Research Center, Kio University. SUBJECTS: Ten healthy controls participated in this study. METHODS: Three types of sessions--(i) tDCS, (ii) Sham tDCS/AE, and (iii) tDCS/AE--were tested in this investigation. Anodal stimulation (2 mA, 20 minutes) was applied over the left primary motor cortex. Each session was 20 minutes long. We used the PPT and short-form Profile of Mood States-Brief, as well as PAF measured via resting-electroencephalography, to investigate the effects of tDCS and AE. Heart rate and scores on the Borg scale were used to confirm exercise intensity. PAF was calculated in four regions of interest: frontal, central, parietal, and occipital areas. RESULTS: The change ratio of PPT increased during each session. The maximum change ratio of PPT were tDCS: 40.7%, Sham tDCS/AE: 51.5%, and tDCS/AE: 83.4%. change ratio of PPT was earlier and higher in the tDCS/AE trials compared with the other sessions. Negative mood was improved after session completion. Significant differences in PAF were found in the occipital area in the Sham tDCS/AE and tDCS/AE sessions. CONCLUSIONS: The combined tDCS and AE intervention induced significant changes in PPT in a single session, with a PAF that was earlier and higher than those produced during the Sham tDCS/AE and tDCS sessions.

Direct evidence of EEG coherence in alleviating phantom limb pain by virtual referred sensation: Case report.

Virtual reality (VR) systems have been integrated into rehabilitation techniques for phantom limb pain (PLP). In this case report, we used electroencephalography (EEG) to analyze corticocortical coherence between the bilateral sensorimotor cortices during vibrotactile stimulation in conjunction with VR rehabilitation in two PLP patients. As a result, we observed PLP alleviation and increased alpha wave coherence during VR rehabilitation when stimulation was delivered to the cheek and shoulder (referred sensation areas) of the affected side. Vibrotactile stimulation with VR rehabilitation may enhance the awareness and movement of the phantom hand.

Development of More Precise Measurement to Predict Pain 1 Month Postoperatively Based on Use of Acute Postoperative Pain Score in Patients With Distal Radial Fracture.

BACKGROUND: A method for modeling the acute pain trajectory using the simple linear fit of an individual's pain intensity scores after surgery was developed and affords more precise measurement than conventional pain assessment. However, the method has the disadvantage of using only the slope without considering the intercept. The purpose of this study was to verify our modification of the pain trajectory model including slope and intercept and to identify clusters. METHODS: The pain intensity was measured in 60 patients after surgery, and we calculated their pain trajectories. The pain trajectory normally resolves in intensity over a period of days, and the linear fit of an individual patient's pain intensity score defines the trajectory. In this simple linear model (x axis, days; y axis, pain intensity), each patient's trajectory has the slope and the intercept. A multiple regression analysis model known as structural equation modeling was used to predict postoperative pain at 30 days after surgery. Finally, we performed hierarchical cluster analysis using the pain trajectory. RESULTS: The slope and intercept model was the best fit among the models. Based on cluster analysis results, we created 4 pain trajectory groups (slope and intercept). CONCLUSION: Our results suggest that the pain trajectory using the slope and intercept is quite useful for predicting postoperative pain at 30 days after surgery. Additionally, patients were classified into 4 groups using the slope and intercept. By considering both the slope and intercept, clinicians may be able to detect the risk for prolonged pain earlier than other methods.

Experimental Pain Is Alleviated by Manual Traction Itself Rather than Subjective Bias in the Knee: A Signal Detection Analysis.

BACKGROUND: Manual traction is used for pain relief, but it is not clear whether the pain relief effect of manual traction is due to sensitivity or to subjective bias. The differences between manual traction and touch have also been unclear. OBJECTIVES: We used signal detection theory to investigate whether manual traction and touch were effective for pain relief, and we compared the pain relief effect between manual traction and touch. DESIGN: Repeated measures and single blinding. METHODS: Twenty healthy adult volunteers performed an intensity judgment task immediately before and after each intervention. The intervention was either manual traction or touch for 10 minutes. We measured the intensity judgment task's signal detection measures of hit rates, false alarm rates, sensitivity (d'), and response bias (C) in an Aδ fiber-mediated pain condition and C fiber-mediated pain condition. RESULTS: Manual traction did not provide a significant level of change, but its effect sizes differed. In our comparison of the effect sizes, manual traction tended to reduce the hit rate and altered the sensitivity value rather than the response bias in Aδ fiber-mediated pain. There was no significant difference in the amount of change in the hit rate between touch and manual traction regarding Aδ fiber-mediated pain and C fiber-mediated pain. CONCLUSIONS: In terms of effect sizes, manual traction was effective for the pain relief of the first pain by producing a change in pain sensitivity rather than by subjective bias. Manual traction reduced the first pain, whereas touch reduced the first pain and second pain.

Characteristics of Phantom Limb Pain Alleviated with Virtual Reality Rehabilitation.

OBJECTIVES: Neurorehabilitation techniques using virtual reality (VR) systems have recently become widespread as a rehabilitation method for restoring phantom limb movement and alleviating phantom limb pain (PLP). However, analgesic effects have varied between studies, possibly because of differences in the characteristics of PLP between patients (e.g., cramping, burning, shooting). We aimed to reveal the relationship between VR effects and PLP characteristics using an exploratory factor analysis. METHODS: PLP characteristics of 19 patients were measured using the Short-Form McGill Pain Questionnaire (SF-MPQ), and all PLP patients performed the VR rehabilitation protocol for 20 minutes. During VR rehabilitation, mirror-reversed computer graphic images of an intact arm (the virtual phantom limb) were presented to patients via a head-mounted display, inducing the perception of voluntary execution of movements of their phantom limb when intending bimanual movements. RESULTS: VR rehabilitation significantly restored movement representation (P < 0.0001) quantified using the bimanual coupling effect and significantly alleviated PLP intensity (P < 0.0001). The factor analysis revealed that PLP characteristics could be divided into two factors: "somatosensory-related pain characteristics" and "kinesthesia-related pain characteristics." PLP alleviation via VR rehabilitation was significantly correlated with "kinesthesia-related pain characteristics" (r = 0.47, P = 0.02) but not "somatosensory-related pain characteristics" (r = 0.22, P = 0.17). CONCLUSIONS: The current findings indicate that VR rehabilitation may be particularly effective for PLP associated with distorted phantom limb movement and body representations (e.g., clamping, gnawing), compared with typical neuropathic sensations (e.g., shooting, burning, dysesthesia).

Kinesiophobia modulates lumbar movements in people with chronic low back pain: a kinematic analysis of lumbar bending and returning movement.

PURPOSE: We aimed to kinematically analyze lumbar bending and returning movements and clarify the relationship between fear of movement and kinematic output. METHODS: We recruited 45 participants with CLBP (i.e., > 6 months) and 20 healthy control (HC) participants with no history of CLBP. We used the numerical rating pain scale (NRS), Tampa Scale for Kinesiophobia (TSK-11), and Pain Self-Efficacy Questionnaire (PSEQ-2) as qualitative outcome measurements. CLBP participants were divided into two subgroups (high- and low-fear groups) based on the median split of the total TSK-11 score. In the kinematic recording session, a starting-cue beep signaled participants to bend forward using the lumbar region of their spine and then return to an upright posture, and we used a flexible twin-axis electrogoniometer to record the lumbar movements. The time series of lumbar movements was divided into four phases according to lumbar movement velocity, and we calculated the length (sec) of each phase. RESULTS: Phase 1 (duration prior to cue-induced movement initiation) and phase 3 (switch in the direction of lumbar movement from forward to backward) were significantly longer in the CLBP high-fear group compared with those in the CLBP low-fear group and HC group (p < 0.05). The increased lengths of these two phases were positively correlated with not only pain intensity but also TSK-11 scores (p < 0.05). CONCLUSIONS: These results represent evidence of a particular lumbar movement pattern associated with kinesiophobia. These results might help to identify psychological factors that impact lumbar movement patterns in individuals with CLBP. These slides can be retrieved under Electronic Supplementary Material.

Correction to: Kinesiophobia modulates lumbar movements in people with chronic low back pain: a kinematic analysis of lumbar bending and returning movement.

In the figure 2, "CLBP Low fear" located at the right end of Time of Phase 1 is wrong. The correct statement is "CLBP High fear". The complete correct figure 2 is given below.

Kinematic evaluation for impairment of skilled hand function in chemotherapy-induced peripheral neuropathy.

INTRODUCTION: Chemotherapy-induced peripheral neuropathy (CIPN) usually affects both sensory and motor function of hands and feet, resulting in impaired skilled hand function (e.g., typing a keyboard). However, quantitative and objective evaluations for this condition have not been established. PURPOSE OF THE STUDY: We evaluated skilled hand function using a kinematic analysis and investigated relationships among hand kinematic function and the clinical sensory and motor features of CIPN. STUDY DESIGNS: Clinical measurement. METHODS: Twelve CIPN patients and 12 age-matched control participants were enrolled. We recorded their reach and grasp movements using a three-dimensional measurement system, and calculated the normalized jerk of these movements as quantitative indexes of skilled hand function. Additionally, we used the number of sequential hand grip-release cycles in 10 seconds as an evaluation of clinical motor function. RESULTS: Our kinematic analyses revealed significant difference in normalized jerk of grasp movement (CIPN: 3.7 ± 0.2, control: 3.4 ± 0.1; P = .005), but this was not the case for reach movement (CIPN: 2.5 ± 0.1, control: 2.5 ± 0.2; P = .43), indicating that the distal part of the forearm is particularly affected in CIPN. Such disturbed grasp movement was directly correlated with poor scores on the hand grip-release test and the sensory tests. DISCUSSION: We revealed deficit impaired hand function objectively and quantitatively in CIPN patients using a kinematic analysis. Further, the hand grip test could represent such kinematic abnormality and could be useful for evaluating skilled hand function of CIPN patients. CONCLUSIONS: Our kinematic and clinical measurements objectively and quantitatively evaluate skilled hand function in individuals with CIPN in clinical settings. LEVEL OF EVIDENCE: Cross-sectional observational study.

A "matched" sensory reference can guide goal-directed movements of the affected hand in central post-stroke sensory ataxia.

Patients with central post-stroke sensory ataxia (CPSA) suffer from not only somatosensory dysfunction but also the ataxic movement disorder of the affected limb. These sensory and motor impairments possibly interfere each other, but such interference is still unclear. We evaluated smoothness of grasp movements in CPSA patients using a kinematic analysis, and verified the effect of somatosensory reference from the intact hand on grasp movements. Eight CPSA patients were enrolled. We recorded their reach-and-pinch movements of both affected and intact hands toward the tip of the 3-cm-diameter vertical bar, using a three-dimensional measurement system. When executing these movements of one hand, the patients simultaneously pinched the same diameter bar as the goal tip (matched-reference condition: Matched-Ref) or the 5-cm-diameter thicker bar (mismatched-reference condition: Mismatched-Ref) by the other hand. The normalized jerk index (i.e., movement smoothness) of the affected hand was disturbed compared with the intact hand. The kinematic data of the finger opening and closing phases were also disturbed. These disturbances were partially improved with Matched-Ref but not Mismatched-Ref of the intact hand. We successfully evaluated the features of CPSA, indicating that the somatosensory reference method could be useful for rehabilitation in sensory ataxia.

Effect of illusory kinesthesia on hand function in patients with distal radius fractures: a quasi-randomized controlled study.

OBJECTIVES: We investigated the effects of the illusion of motion through tendon vibration on hand function in patients with distal radius fractures. SETTING: Kawachi General Hospital, Japan. SUBJECTS: A total of 22 patients with distal radius fractures were divided into either an illusory kinesthesia group ( n = 11) or a control group ( n = 11). INTERVENTION: We performed the intervention for seven consecutive days after surgery. Evaluations were performed at one day, seven days, one month, and two months postsurgery. MAIN MEASURES: Data were collected on pain at rest and pain during movement. The Patient-Rated Wrist Evaluation and Pain Catastrophizing Scale were also used. RESULTS: The illusory kinesthesia group showed significantly better scores on Patient-Rated Wrist Evaluation ( p < 0.01) compared with the control group at seven days, one month, and two months postsurgery. The mean (SD) of the Patient-Rated Wrist Evaluation total score was 97.6 (2.2) at one day postsurgery and 9.1 (5.3) at seven days postsurgery in the illusory kinesthesia group, while the Patient-Rated Wrist Evaluation total score was 96.3 (4.4) at one day postsurgery and 20.1 (17.0) at seven days postsurgery in the control group. CONCLUSION: Our results indicate that illusory kinesthesia is an effective postsurgery management strategy not only for pain alleviation, but also hand function in patients with distal radius fractures. Furthermore, the significant improvements persisted for up to two months after intervention in the illusory kinesthesia group, but not in the control group. In addition, patients in the kinesthetic illusions group showed increased use of the affected limb in daily living.

The influence of trait anxiety and illusory kinesthesia on pain threshold.

[Purpose] It has also been reported that decreased activity in the reward pathway causes a decrease in brain activity in the descending pain control system in people with high trait anxiety. Activation of this system is dependent on both the reward pathway and motor areas. Recently, studies have also shown that motor areas are activated by illusory kinesthesia. It was aimed to explore whether anxiety trait modulates the influence of illusory kinesthesia on pain threshold. [Subjects and Methods] The pain threshold and trait anxiety at rest before vibratory tendon stimulation (the task) were measured. After the task, the pain threshold, the illusory kinesthesia angle, and the intensity of illusory kinesthesia for patients with and without illusory kinesthesia were measured. A total of 35 healthy right-handed students participated, among whom 22 and 13 were included in the illusion and no-illusion groups, respectively. [Results] There was a significant increase in the pain threshold after task completion in both groups; however, there was no statistically significant difference between the two groups. Correlational analysis revealed that State-Trait Anxiety Inventory-trait score correlated negatively with the pain threshold in the no-illusion group, but there was no correlation in the illusion group. [Conclusion] The pain threshold improved regardless of the size of trait anxiety in the illusion group, but did not improve merely through sensory input by vibratory stimulation in the no-illusion group. Thus, illusory kinesthesia has effect of increasing the pain threshold.

Influence of illusory kinesthesia by vibratory tendon stimulation on acute pain after surgery for distal radius fractures: a quasi-randomized controlled study.

OBJECTIVES: We investigated the effects of inducing an illusion of motion by tendon vibration on sensory and emotional aspects of pain and range of motion in patients with fractures of the distal radius. DESIGN: A quasi-randomized controlled trial. SETTING: Kawachi General Hospital, Japan. SUBJECTS: A total of 26 patients with fractures of the distal radius were distributed quasi-randomly to either the illusory kinesthesia group (n = 13) or control group (n = 13). INTERVENTION: The intervention was performed on seven consecutive days from postoperative Day 1. Evaluation was performed at seven days, one month, and two months after the surgery. MAIN MEASURES: Data were collected for pain at rest, movement pain, the pain catastrophizing scale, the Hospital Anxiety and Depression Scale, and range of motion. RESULTS: The illusory kinesthesia group reported improved pain at rest (p < 0.001), movement pain (p < 0.001), pain catastrophizing scale (p < 0.001), Hospital Anxiety and Depression Scale (p < 0.01), and range of motion (p < 0.05) compared with the control group at seven days, one month, and two months after the surgery. The mean (SD) score of the visual analogue scale of pain at rest was 51.3 (16.8) at one day and 4.2 (4.7) at seven days in the illusory kinesthesia group, and 56.8 (22.1) at one day and 35.5 (16.2) at seven days in the control group. CONCLUSION: Illusory kinesthesia group improves the sensory and emotion aspects of pain in patients with fractures of the distal radius.

Tactile feedback for relief of deafferentation pain using virtual reality system: a pilot study.

BACKGROUND: Previous studies have tried to relieve deafferentation pain (DP) by using virtual reality rehabilitation systems. However, the effectiveness of multimodal sensory feedback was not validated. The objective of this study is to relieve DP by neurorehabilitation using a virtual reality system with multimodal sensory feedback and to validate the efficacy of tactile feedback on immediate pain reduction. METHODS: We have developed a virtual reality rehabilitation system with multimodal sensory feedback and applied it to seven patients with DP caused by brachial plexus avulsion or arm amputation. The patients executed a reaching task using the virtual phantom limb manipulated by their real intact limb. The reaching task was conducted under two conditions: one with tactile feedback on the intact hand and one without. The pain intensity was evaluated through a questionnaire. RESULTS: We found that the task with the tactile feedback reduced DP more (41.8 ± 19.8 %) than the task without the tactile feedback (28.2 ± 29.5 %), which was supported by a Wilcoxon signed-rank test result (p < 0.05). CONCLUSIONS: Overall, our findings indicate that the tactile feedback improves the immediate pain intensity through rehabilitation using our virtual reality system.

Successful Graded Mirror Therapy in a Patient with Chronic Deafferentation Pain in Whom Traditional Mirror Therapy was Ineffective: A Case Report.

A 43-year-old man had deafferentation pain in his right upper extremity secondary to brachial plexus avulsion from a traffic accident 23 years previously. On our initial examination, he had severe tingling pain with numbness in the right fingers rated 10 on the numerical rating scale. The body perception of the affected third and fourth fingers was distorted in the flexed position. Although he performed traditional mirror therapy (TMT) for 4 weeks in the same methods as seen in previous studies, he could not obtain willed motor imagery and pain-alleviation effect. Therefore, we modified the task of TMT: Graded mirror therapy (GMT). GMT consisted of five stages: (1) observation of the mirror reflection of the unaffected side without imagining any movements of the affected side; (2) observation of the mirror reflection of the third and fourth fingers changing shape gradually adjusted from a flexed position to a extended position; (3) observation of the mirror reflection of passive movement; (4) motor imagery of affected fingers with observation of the mirror reflection (similar to TMT); (5) motor imagery of affected fingers without mirror. Each task was performed for 3 to 4 weeks. As a result, pain intensity during mirror therapy gradually decreased and finally disappeared. The body perception of the affected fingers also improved, and he could imagine the movement of the fingers with or without mirror. We suggested that GMT starting from the observation task without motor imagery may effectively decrease deafferentation pain compared to TMT.

Tactile localization training for pain, sensory disturbance, and distorted body image: a case study of complex regional pain syndrome.

This report presents a case of complex regional pain syndrome. The patient presented with severe pain, sensory disturbance, and distorted body image at the site of initial injury and other body sites. Tactile localization training (TLT) at only the site of initial injury decreased severe pain at the site of initial injury and the secondary affected sites, whereas TLT at secondary affected sites had no effect. These results highlighted the importance of assessing changes in patients' pain processes to determine the part of the body where TLT should be applied.

The effect of virtual visual feedback on supernumerary phantom limb pain in a patient with high cervical cord injury: a single-case design study.

We characterized the effect of virtual visual feedback (VVF) on supernumerary phantom limb pain (SPLP) in a patient with high cervical cord injury. The subject was a 22-year-old man diagnosed with complete spinal cord injury (level C2) approximately 5 years ago. We applied the ABA'B' single-case design and set phases B and B' as intervention phases for comparison. SPLP significantly improved in comparison of phase A with phase B and phase A with phase B'. We suggest that VVF reduces SPLP and the effect lasts after VVF.

[Neurorehabilitation for Neuropathic Pain].

Deafferentation, like as in limb amputation, brachial plexus avulsion injury and spinal cord injury, is usually followed by neuropathic pain. Neuropathic pain is a debilitating condition and it impairs the quality of life profoundly. Based on recent advances in the cognitive neuroscience, we explain intimate relationships among neuropathic pain, reorganization of primary sensory and motor cortices and the sensorimotor integration of the deafferentated limb. From the standpoint of the sensorimotor integration theory for emerging phantom limb pain, we further discuss the analgesic mechanism of neurorehabilitation techniques such as mirror visual feedback treatment and its related neurorobotics advancement for neuropathic pain.