Assessment of small sensory fiber function in myotonic dystrophy type 1.

BACKGROUND: Myotonic dystrophy type 1 (DM1) is a multisystem disorder affecting the peripheral nervous system. However, studies evaluating somatic small fiber sensory nerve function, which may contribute to pain in DM1, are lacking. METHODS: Using quantitative sensory testing of the hand and foot, we evaluated Aδ and C-fiber function. Of 20 adult DM1 patients recruited, 16 were analyzed. Their results were compared with those of 32 age- and sex-matched controls. RESULTS: No DM1 patient had diabetes mellitus or clinical evidence of small fiber neuropathy. In DM1, hand (P < .01) and foot (P = 0.02) warm detection thresholds were higher than those of controls. Cool detection thresholds were lower in the foot (P < .001). CONCLUSIONS: Subclinical small sensory fiber dysfunction occurs in DM1 patients without large fiber neuropathy. Further research with other modalities is required to characterize these disturbances as disease modifying therapies are developed.

What Role Does Positive Psychology Play in Understanding Pain Intensity and Disability Among Patients with Hand and Upper Extremity Conditions?

BACKGROUND: A large body of research shows that psychologic distress and ineffective coping strategies substantially contribute to more severe pain and increased physical limitations among patients with orthopaedic disorders. However, little is known about the relationship between positive psychology (constructs that enable individuals to thrive and adapt to challenges) and pain and physical limitations in this population. QUESTIONS/PURPOSES: (1) Which positive-psychology factors (satisfaction with life, gratitude, coping through humor, resilience, mindfulness, and optimism) are independently associated with fewer upper-extremity physical limitations after controlling for the other clinical and demographic variables? (2) Which positive-psychology factors are independently associated with pain intensity after controlling for relevant clinical and demographic variables? METHODS: In a cross-sectional study, we recruited patients presenting for a scheduled appointment with an orthopaedic surgeon at a hand and upper-extremity clinic of a major urban academic medical center. Of 125 approached patients, 119 (44% men; mean age, 50 ± 17 years) met screening criteria and agreed to participate. Patients completed a clinical and demographic questionnaire, the Numerical Rating Scale to assess pain intensity, the Patient-reported Outcomes Measurement Information System (PROMIS) Upper Extremity Physical Function computerized adaptive test to assess physical limitations, and six measures assessing positive-psychology constructs: The Satisfaction with Life Scale, the Gratitude Questionnaire, the Coping Humor Scale, the Brief Resilience Scale, the Cognitive and Affective Mindfulness Scale-Revised, and the Life Orientation Test-Revised. We first examined bivariate associations among physical limitations, pain intensity, and all positive-psychology factors as well as demographic and clinical variables. All variables that demonstrated associations with physical limitations or pain intensity at p < 0.05 were included in two-stage multivariable hierarchical regression models. RESULTS: After controlling for the potentially confounding effects of prior surgical treatment and duration since pain onset (step1; R total = 0.306; F[7,103] = 6.50), the positive-psychology variables together explained an additional 15% (R change = 0.145, F change [5, 103] = 4.297, p = 0.001) of the variance in physical limitations. Among the positive-psychology variables tested, mindfulness was the only one associated with fewer physical limitations (ß = 0.228, t = 2.293, p = 0.024, 4% variance explained). No confounding demographic or clinical variables were found for pain intensity in bivariate analyses. All positive-psychology variables together explained 23% of the variance in pain intensity (R = 0.23; F[5,106] = 6.38, p < 0.001). Among the positive-psychology variables, satisfaction with life was the sole factor independently associated with higher intensity (ß = -0.237, t = -2.16, p = 0.033, 3% variance explained). CONCLUSIONS: Positive-psychology variables explained 15% of the variance in physical limitations and for 23% of the variance in pain intensity among patients with heterogenous upper extremity disorders within a hand and upper extremity practice. Of all positive-psychology factors, mindfulness and satisfaction with life were most important for physical limitations and pain intensity, respectively. As positive-psychology factors are more easily modifiable through skills-based interventions than pain and physical limitations, results suggest implementation of such interventions to potentially improve outcomes in this population. Skills-based interventions targeting mindfulness and satisfaction with life may be of particular benefit. LEVEL OF EVIDENCE: Level II, prognostic study.

Six-Month Assessment of a Hand Prosthesis with Intraneural Tactile Feedback.

OBJECTIVE: Hand amputation is a highly disabling event, which significantly affects quality of life. An effective hand replacement can be achieved if the user, in addition to motor functions, is provided with the sensations that are naturally perceived while grasping and moving. Intraneural peripheral electrodes have shown promising results toward the restoration of the sense of touch. However, the long-term usability and clinical relevance of intraneural sensory feedback have not yet been clearly demonstrated. METHODS: To this aim, we performed a 6-month clinical study with 3 transradial amputees who received implants of transverse intrafascicular multichannel electrodes (TIMEs) in their median and ulnar nerves. After calibration, electrical stimulation was delivered through the TIMEs connected to artificial sensors in the digits of a prosthesis to generate sensory feedback, which was then used by the subjects while performing different grasping tasks. RESULTS: All subjects, notwithstanding their important clinical differences, reported stimulation-induced sensations from the phantom hand for the whole duration of the trial. They also successfully integrated the sensory feedback into their motor control strategies while performing experimental tests simulating tasks of real life (with and without the support of vision). Finally, they reported a decrement of their phantom limb pain and a general improvement in mood state. INTERPRETATION: The promising results achieved with all subjects show the feasibility of the use of intraneural stimulation in clinical settings. ANN NEUROL 2019;85:137-154.

Assessment of Conduit-Assisted Primary Nerve Repair Strength With Varying Suture Size, Number, and Location.

Background: Outcomes following digital nerve repair are suboptimal despite much research and various methods of repair. Increased tensile strength of the repair and decreased suture material at the repair site may be 2 methods of improving biologic and biomechanical outcomes, and conduit-assisted repair can aid in achieving both of these goals. Methods: Ninety-nine fresh-frozen digital nerves were equally divided into 11 different groups. Each group uses a different combination of number of sutures at the coaptation site and number of sutures at each end of the nerve-conduit junction, as well as 2 calibers of nylon suture. Nerves were transected, repaired with these various suture configurations using an AxoGuard conduit, and loaded to failure. Results: The 2-way analysis of variance (ANOVA) showed that repairs performed with 8-0 suture have significantly higher maximum failure load compared with 9-0 suture repairs (P < .01). Increasing the number of sutures in the repair significantly increased the maximum failure load in all groups regardless of suture caliber used (P < .01). Repairs with 9-0 suture at the coaptation site did not jeopardize repair strength when compared with 8-0 suture. Conclusions: Conduit-assisted primary digital nerve repairs with 8-0 suture increases the maximum load to failure compared with repairs with 9-0 suture, as does increasing the overall number of sutures. Using 9-0 suture at the coaptation site with 8-0 suture at the nerve-conduit junction does not jeopardize tensile strength when compared with similar repairs using all 8-0 suture and may decrease inflammation at the repair site while still achieving sufficient tensile strength.

Functional, motor, and sensory assessment instruments upon nerve repair in adult hands: systematic review of psychometric properties.

BACKGROUND: Outcome after nerve repair of the hand needs standardized psychometrically robust measures. We aimed to systematically review the psychometric properties of available functional, motor, and sensory assessment instruments after nerve repair. METHODS: This systematic review of health measurement instruments searched databases from 1966 to 2017. Pairs of raters conducted data extraction and quality assessment using a structured tool for clinical measurement studies. Kappa correlation was used to define the agreement prior to consensus for individual items, and intraclass correlation coefficient (ICC) was used to assess reliability between raters. A narrative synthesis described quality and content of the evidence. RESULTS: Sixteen studies were included for final critical appraisal scores. Kappa ranged from 0.31 to 0.82 and ICC was 0.81. Motor domain had manual muscle testing with Kappa from 0.72 to 0.93 and a dynamometer ICC reliability between 0.92 and 0.98. Sensory domain had touch threshold Semmes-Weinstein monofilaments (SWM) as the most responsive measure while two-point discrimination (2PD) was the least responsive (effect size 1.2 and 0.1). A stereognosis test, Shape and Texture Identification (STI), had Kappa test-retest reliability of 0.79 and inter-rater reliability of 0.61, with excellent sensibility and specificity. Manual tactile test had moderate to mild correlation with 2PD and SWM. Function domain presented Rosén-Lundborg score with Spearman correlations of 0.83 for total score. Patient-reported outcomes measurements had ICC of 0.85 and internal consistency from 0.88 to 0.96 with Patient-Rated Wrist and Hand Evaluation with higher score for reliability and Spearman correlation between 0.38 and 0.89 for validity. CONCLUSIONS: Few studies included nerve repair in their sample for the psychometric analysis of outcome measures, so moderate evidence could be confirmed. Manual muscle test and Rotterdam Intrinsic Hand Myometer dynamometer had excellent reliability but insufficient data on validity or responsiveness. Touch threshold testing was more responsive than 2PD test. The locognosia test and STI had limited but positive supporting data related to validity. Rosén-Lundborg score had emerging evidence of reliability and validity as a comprehensive outcome following nerve repair. Few questionnaires were considered reliable and valid to assess cold intolerance. There is no patient-reported outcome measurement following nerve repair that provides comprehensive assessment of symptoms and function by patient perspective.

Comparison of 2 methods of neuropathic pain assessment in carpal tunnel syndrome and hand functions.

OBJECTIVE: To compare the effectiveness of the Leeds Assessment of Neuropathic Symptoms and Signs Scale (LANSS) to the painDETECT questionnaire (PD-Q) in Carpal Tunnel Syndrome (CTS), and determine if there are any differences between hand related functions in the 2 questionnaires. METHODS: This prospective clinical trial was conducted from April to July 2014. Ninety patients with a positive Tinel or Phalen sign were recruited. Hands were evaluated by electromyography and grouped according to mild, moderate or severe involvement. Neuropathic pain was analysed by the LANSS and the PD-Q; hand functions were evaluated by the Duruoz Hand Index (DHI), Semmes Weinstein monofilaments and grip strength. RESULTS: Electromyographic findings revealed 32.9% of hands had mild, 61.8% had moderate and 5.3% had severe CTS. There was a correlation between the LANSS scores and the Visual Analogue Scale (VAS) pain, while the PD-Q scores were correlated with the VAS pain, DHI and Semmes Weinstein Monofilaments (SWM). Comparison of the hand related parameters of the questionnaires showed there was a statistically significant difference between the 2 groups with respect to the DHI and SWM tests in the PD-Q. However, there was no difference in the LANSS. CONCLUSION: Although there was a significant correlation between the LANSS and PD-Q scores, the PD-Q scores revealed better correlation coefficients in VAS pain, DHI scores and SWM tests. In conclusion, the PD-Q seems to be better than the LANSS both in neuropathic pain and in detecting functions related to hand abilities.

Assessment of the Ipsilesional Hand Function in Stroke Survivors: The Effect of Lesion Side.

BACKGROUND: The aim of this study was to examine the effect of the side of brain lesion on the ipsilesional hand function of stroke survivors. METHODS: Twenty-four chronic stroke survivors, equally allocated in 2 groups according to the side of brain lesion (right or left), and 12 sex- and age-matched healthy controls performed the Jebsen-Taylor Hand Function Test (JTHFT), the Nine-Hole Peg Test (9HPT), the maximum power grip strength (PwGSmax) test, and the maximum pinch grip strength (PnGSmax) test. Only the ipsilesional hand of the stroke survivors and both hands (left and right) of the controls were assessed. RESULTS: PwGS max and PnGS max were similar among all tested groups. Performances in JTHFT and 9HPT were affected by the brain injury. Individuals with left brain damage showed better performance in 9HPT than individuals with right brain damage, but performance in JTHFT was similar. CONCLUSIONS: Individuals after a brain injury have the capacity to produce maximum strength preserved when using their ipsilesional hand. However, the dexterity of their hands and digits is affected, in particular for stroke individuals with right brain lesion.

A novel BCI-controlled pneumatic glove system for home-based neurorehabilitation.

Commercially available devices for Brain-Computer Interface (BCI)-controlled robotic stroke rehabilitation are prohibitively expensive for many researchers who are interested in the topic and physicians who would utilize such a device. Additionally, they are cumbersome and require a technician to operate, increasing the inaccessibility of such devices for home-based robotic stroke rehabilitation therapy. Presented here is the design, implementation and test of an inexpensive, portable and adaptable BCI-controlled hand therapy device. The system utilizes a soft, flexible, pneumatic glove which can be used to deflect the subject's wrist and fingers. Operation is provided by a custom-designed pneumatic circuit. Air flow is controlled by an embedded system, which receives serial port instruction from a PC running real-time BCI software. System tests demonstrate that glove control can be successfully driven by a real-time BCI. A system such as the one described here may be used to explore closed loop neurofeedback rehabilitation in stroke relatively inexpensively and potentially in home environments.

Assessment of transverse ultrasonographic parameters to optimize carpal tunnel syndrome diagnosis in a case-control study.

INTRODUCTION: Transverse ultrasound measurements of the median nerve (MN) for diagnosis of carpal tunnel syndrome (CTS) suffer from inconsistent findings within and between patients and healthy subjects. The objective of this study was to improve ultrasound assessment of CTS. METHODS: In a case-control study (51 patients, 25 controls) we evaluated the performance gained by: (1) correcting for ultrasound probe angulation; (2) including active parameters such as forceful gripping of the hand; and (3) including hand flexor tendon parameters. RESULTS: Correcting ultrasound probe angulation increased the correct classification rate by 4.5%; including forceful gripping resulted in increasing it by 2.8%; and including the hand flexor tendon resulted in an increase of 1.3%. CONCLUSIONS: The best predictive model combines correcting probe angulation with forceful gripping parameters and hand flexor tendon parameters. However, the clinically most practical model might use only probe angulation correction.

Assessment of the haptic robot as a new tool for the study of the neural control of reaching.

Current experimental methods for the study of reaching in the MRI environment do not exactly mimic actual reaching, due to constrains in movement which are imposed by the MRI machine itself. We tested a haptic robot (HR) as such a tool. Positive results would also be promising for combined use of fMRI and EEG to study reaching. Twenty right-handed subjects performed reaching tasks with their right hand with and without the HR. Reaction time, movement time (MT), accuracy, event-related potentials (ERPs) and event-related desynchronisation/synchronisation (ERD/ERS) were studied. Reaction times and accuracies did not differ significantly between the two tasks, while the MT was significantly longer in HR reaching (959 vs. 447 ms). We identified two positive and two negative ERP peaks across all leads in both tasks. The latencies of the P1 and N2 peaks were significantly longer in HR reaching, while there were no significant differences in the P3 and N4 latencies. ERD/ERS topographies were similar between tasks and similar to other reaching studies. Main difference was in ERS rebound which was observed only in actual reaching. Probable reason was significantly larger MT. We found that reaching with the HR engages similar neural structures as in actual reaching. Although there are some constrains, its use may be superior to other techniques used for reaching studies in the MRI environment, where freedom of movement is limited.

Robot-assisted assessment of vibration perception and localization on the hand.

Sensory perception is crucial for motor learning and the control of fine manipulations. However, therapy after stroke still strongly focuses on the training of motor skills. Sensory assessments are often left out or provide only very subjective data from poorly controlled stimuli. This paper presents a vibration detection/localization test with the Robotic Sensory Trainer, a device that focuses entirely on the assessment and training of sensory function of the hand, with the aim of gaining insights into the prevalence and severity of sensory deficits after stroke, and to provide semiobjective data on absolute and difference perception thresholds in patients. An initial feasibility study investigated localization performance and reaction time during the discrimination of vibration stimuli presented in four locations on the dominant and nondominant hands of 13 healthy volunteers. High correct detection rates were observed (mean ± SD of 99.6% ± 0.6%), touch screen PC Robotic Sensory Trainer which were found to be significantly different between stimulus locations on the dominant hand. Average correct detection rates were not statistically different between dominant and nondominant hand. These data will serve as baseline for future measurements on elderly and stroke subjects, and suggest that data from the nonimpaired hand could be used to identify and assess sensory deficits in the affected hand of stroke patients.

Novel assessment of cortical response to somatosensory stimuli in children with hemiparetic cerebral palsy.

The brain's response to somatosensory stimuli is essential to experience-driven learning in children. It was hypothesized that advances in event-related potential technology could quantify the response to touch in somatosensory cortices and characterize the responses of hemiparetic children. In this prospective study of 8 children (5-8 years old) with hemiparetic cerebral palsy, both event-related potential responses to sham or air puff trials and standard functional assessments were used. Event-related potential technology consistently measured signals reflecting activity in the primary and secondary somatosensory cortices as well as complex cognitive processing of touch. Participants showed typical early responses but less efficient perceptual processes. Significant differences between affected and unaffected extremities correlated with sensorimotor testing, stereognosis, and 2-point discrimination (r > 0.800 and P = .001 for all). For the first time, a novel event-related potential paradigm shows that hemiparetic children have slower and less efficient tactile cortical perception in their affected extremities.

Early intensive hand rehabilitation after spinal cord injury ("Hands On"): a protocol for a randomised controlled trial.

BACKGROUND: Loss of hand function is one of the most devastating consequences of spinal cord injury. Intensive hand training provided on an instrumented exercise workstation in conjunction with functional electrical stimulation may enhance neural recovery and hand function. The aim of this trial is to compare usual care with an 8-week program of intensive hand training and functional electrical stimulation. METHODS/DESIGN: A multicentre randomised controlled trial will be undertaken. Seventy-eight participants with recent tetraplegia (C2 to T1 motor complete or incomplete) undergoing inpatient rehabilitation will be recruited from seven spinal cord injury units in Australia and New Zealand and will be randomised to a control or experimental group. Control participants will receive usual care. Experimental participants will receive usual care and an 8-week program of intensive unilateral hand training using an instrumented exercise workstation and functional electrical stimulation. Participants will drive the functional electrical stimulation of their target hands via a behind-the-ear bluetooth device, which is sensitive to tooth clicks. The bluetooth device will enable the use of various manipulanda to practice functional activities embedded within computer-based games and activities. Training will be provided for one hour, 5 days per week, during the 8-week intervention period. The primary outcome is the Action Research Arm Test. Secondary outcomes include measurements of strength, sensation, function, quality of life and cost effectiveness. All outcomes will be taken at baseline, 8 weeks, 6 months and 12 months by assessors blinded to group allocation. Recruitment commenced in December 2009. DISCUSSION: The results of this trial will determine the effectiveness of an 8-week program of intensive hand training with functional electrical stimulation. TRIAL REGISTRATION: NCT01086930 (12th March 2010)ACTRN12609000695202 (12th August 2009).

Topographical assessment of symptom resolution following open carpal tunnel release.

PURPOSE: Patients with carpal tunnel syndrome commonly present with paresthesias and pain extending into the small finger and proximal to the hand. This study was conducted to assess the ability of carpal tunnel release to relieve symptoms outside of the median nerve distribution. METHODS: We enrolled 34 consecutive surgical patients (40 wrists) diagnosed exclusively with carpal tunnel syndrome based on the history, physical examination, and electrodiagnostic studies. Preoperative symptoms were categorized as pain, numbness, tingling, or "burning and electrical shocks." The presence or absence of each symptom type was recorded in 5 topographical areas (zone I, palmar thumb/index/long; zone II, small finger; zone III, volar forearm; zone IV, volar arm; and zone V, dorsal hand/forearm/arm). Patients were contacted at 4 to 6 weeks postoperatively to assess resolution of each symptom type by topographic zone. RESULTS: Preoperatively, the cohort reported symptoms in all zones: zone I, 120 reports; zone II, 47 reports; zone III, 33 reports; zone IV, 7 reports; and zone V, 23 reports. Numbness (n = 40) and tingling (n = 38) were the most common symptoms, followed by pain (n = 29) and "burning/shocks" (n = 16). Postoperatively, the total number of reports within the 5 zones decreased from 230 to 20. The probability that surgery would eliminate patient symptoms was 88% (104 of 120) in zone I, 96% (45 of 47) in zone II, 97% (32 of 33) in zone III, 86% (6 of 7) in zone 4, and 100% (23 of 23) in zone V. Across zones, the overall probability of symptom resolution was as follows: pain > 80%, numbness/tingling > 85%, and "burning/shocks" > 90%. CONCLUSIONS: Symptoms experienced outside of the median nerve distribution had a high likelihood of resolution after carpal tunnel release. Over 85% of symptoms in each of the anatomic zones studied resolved. Feelings of burning or shock-like sensations were most reliably relieved at early follow-up. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

An assessment of vibration threshold using a biothesiometer compared to a C128-Hz tuning fork.

A standardised method of assessment of vibration threshold (VT), with a C128-Hz tuning fork (TF), was compared to VT measured with a biothesiometer in normal patients free of neurological disease at four separate bony points. The biothesiometer is more accurate compared to a timed tuning fork. The accuracy of both declined with patient age, however, especially for patients older than 50years. The longer the nerve tested, the greater the age-related decline. The C128-Hz tuning fork, provided consistently applied, may be meaningfully employed at the thumb or hallux proximal nail fold to assess VT-TF at the bedside, but remains less able to discriminate VT at all ages.