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Prospective controlled study. Previous studies evaluated the effectiveness of sensory reeducation (SR) after peripheral nerve injury and repair. However, evidence for long-term clinical usefulness of SR is inconclusive. The purpose of this study is to compare the sensory results of patients with low-median nerve complete transection and microsurgical repair, with and without SR at long term. We prospectively studied 52 consecutive patients (mean age, 36 years; range, 20-47 years) with low-median nerve complete transection and microsurgical repair. When reinnervation was considered complete with perception of vibration with a 256-cycles per second tuning fork (mean, 3.5 months after nerve injury and repair), the patients were sequentially allocated (into 2 groups [group SR, 26 patients, SR; group R, 26 patients, reassured on recovery without SR). SR was conducted in a standardized fashion, in 2 stages, as an independent home-based program: the first stage was initiated when reinnervation was considered complete, and included instruction in home exercises to identify familiar objects and papers of different roughness, and localization of light touch (eyes open and closed); the second stage was initiated when the patients experienced normal static and moving 2-point discrimination (2PD) at the index fingertip of injured hand, and included instruction in home exercises for stereognosia, supplementary exercises for localization of light touch, and identification of small objects (eyes open and closed). Exercises were prescribed for 5-10 minutes, 4 times per day. At 1.5, 3, and 6 years after nerve injury and repair, we evaluated the static and moving 2PD, stereognosia with the Moberg's pick-up test, and locognosia with the modified Marsh test. Comparison between groups and time points was done with the nonparametric analysis of variance (Kruskal-Wallis analysis of variance). Static and moving 2PD and stereognosia were not significantly different between groups at any study period. Locognosia was significantly better at 1.5 and 3 years in group SR; locognosia was excellent in 17 patients of group SR vs 5 patients of group R at 1.5-year follow-up and in 14 patients of group SR vs 5 patients of group R at 3-year follow-up. Locognosia was not different between the study groups at 6-year follow-up. A 2-stage home program of SR improved locognosia at 1.5 and 3 years after low-median nerve complete transection and repair without significant differences in other modalities or the 6-year follow-up of a small subsample. [ABSTRACT FROM AUTHOR]

The aim of this study was to relate forearm anthropometric measures to ultrasound pronator teres depth to determine the necessary needle length to prevent median nerve (MN) injury during pronator teres dry needling. We conducted a study employing a diagnostic accuracy prediction model (NCT03308279) at a Spanish university center. The study recruited 65 participants to predict the depth of the MN (measured with ultrasound) in the pronator teres using a decision tree algorithm to reduce the risk of MN puncture using 2 needle lengths (13 mm or 25 mm). The decision tree was developed by automatically selecting a cutoff for body mass index, forearm length and circumference, and pronator teres thickness. For forearm circumferences ≤27.5 cm, the predictive value for the 13-mm needle was 92%. For forearm circumferences >27.5 cm and forearm lengths ≤26.75 cm, the predictive value for the 25-mm needle was 100%. Based upon the findings of this study, we suggest that needle length should be selected according to forearm anthropometric measures to prevent MN injury during pronator teres dry needling. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate if there is a place for ultrasonography (US) and ultrasonographic elastography (UE) in the diagnosis and follow up of carpal tunnel syndrome treatment.Materials and Methods: The study was performed on 25 patients (study group) and 17 healthy volunteers (control group). Measured US and UE criteria were median nerve area (MNA), proximal median nerve area (pMNA), difference between MNA and pMNA (dMNA) and strain values of carpal tunnel content (CTC) and median nerve (MN). Patients in the study group were also evaluated using the Boston questionnaire, Visual Analogue Scale (VAS) and nerve conduction studies. Thirty-three wrists in 23 patients received steroid injections on the same day. Patients were re-evaluated 6 weeks after steroid injection. To establish a cut off value for MNA, ROC Curve analysis was used.Results: Mean MNA and dMNA values in the control group were significantly lower than in the study group (7.33 ± 1.31 vs. 15.44 ± 5.10; p=<0.05 and 1.58 ± 0.75 vs. 8.91 ± 4.93; p = 0.00 respectively). Median nerve and CTC strain indices were significantly higher in the control group (p = 0.00 and p = 0.036). Decrease in MNA and dMNA values after treatment was meaningful (p = 0.00). While there was no significant change in MN elasticity, mean CTC strain index of the study group (4.680 ± 1.664) decreased significantly after treatment (3.621 ± 1.054 p = 0.002). This decrease in the CTC index was more pronounced in patients who benefited from treatment (p = 0.001).Conclusion: US and UE can be useful in the diagnosis of CTS and its response to treatment, if used together with clinical and electroneurophysiological tests. [ABSTRACT FROM AUTHOR]

Study Design: A retrospective cohort study. Introduction: Some patients after median or ulnar nerve injury report a diminished sensibility in the hngers that are supplied by the uninjured nerve. Purpose of the Study: The purpose of this study was to evaluate the function of the uninjured nerve in pabents after peripheral nerve injury to assess the presence and degree of its functional impairment Methods: There were 28 patients with median and 29 patients with ulnar nerve injury examined for sensory disturbances in the injured and uninjured nerves, using several tests assessing touch temperature, and vibration sensibility. Results. In 16 patients after ulnar and 13 patients after median nerve injury, some disturbances in the uninjured nerve were found, mostly in individual tests. Only 8 patients had 3 or more different tests abnormal Discussion: The injured nerve function in patients with functional disturbances in the uninjured nerve was worse than in patients with normal test results. Conclusion: Posttraumatic changes in central nervous system are the possible reasons. Level of Evidence: Level 111 study. [ABSTRACT FROM AUTHOR]

Peripheral nerve injuries result in reorganization within the contralateral hemisphere. Furthermore, recent animal and human studies have suggested that the plastic changes in response to peripheral nerve injury also include several areas of the ipsilateral hemisphere. The objective of this study was to map the inter-hemispheric plasticity in response to median nerve injury, to investigate normal differences in contra- and ipsilateral activation, and to study the impact of event-related or blocked functional magnetic resonance imaging (fMRI) design on ipsilateral activation. Four patients with median nerve injury at the wrist (injured and epineurally sutured >2 years earlier) and ten healthy volunteers were included. 3T fMRI was used to map the hemodynamic response to brain activity during tactile stimulation of the fingers, and a laterality index (LI) was calculated. Stimulation of Digits II–III of the injured hand resulted in a reduction in contralateral activation in the somatosensory area SI. Patients had a lower LI (0.21 ± 0.15) compared to healthy controls (0.60 ± 0.26) indicating greater ipsilateral activation of the primary somatosensory cortex. The spatial dispersion of the coordinates for areas SI and SII was larger in the ipsilateral than in the contralateral hemisphere in the healthy controls, and was increased in the contralateral hemisphere of the patients compared to the healthy controls. There was no difference in LI between the event-related and blocked paradigms. In conclusion, patients with median nerve injury have increased ipsilateral SI area activation, and spatially more dispersed contralateral SI activation during tactile stimulation of their injured hand. In normal subjects ipsilateral activation has larger spatial distribution than the contralateral. Previous findings in patients performed with the blocked fMRI paradigm were confirmed. The increase in ipsilateral SI activation may be due to an interhemispheric disinhibition associated with changes in the afferent signal inflow to the contralateral primary somatosensory cortex. [ABSTRACT FROM AUTHOR]

The c-Jun N-terminal kinase (JNK) in the central nervous system plays a critical role in the processing of neuropathic pain. Docosahexaenoic acid (DHA), a predominant omega-3 polyunsaturated fatty acid in the central nervous system, has a neuroprotective efficacy. In this study, we examined the relationships between JNK activation in the cuneate nucleus (CN) and behavioral hypersensitivity after chronic constriction injury (CCI) of the median nerve. We further investigated the effects of DHA administration on JNK activation and development of hypersensitivity. Using immunohistochemistry and immunoblotting, low levels of phosphorylated JNK (p-JNK) were detected in the CN of sham-operated rats. As early as 1 day after CCI, p-JNK levels in the ipsilateral CN were significantly increased and peaked at 7 days. Double-immunofluorescence labeling with cell-specific markers showed that p-JNK immunoreactive cells coexpressed OX-42, a microglia activation marker, suggesting the expression of p-JNK in the microglia. Microinjection of SP600125, a JNK inhibitor, into the CN 1 day after CCI attenuated injury-induced behavioral hypersensitivity in a dose-dependent manner. Furthermore, animals received intravenous injection of DHA at doses of 100, 250 or 500 nmol/kg 30 min after median nerve CCI. DHA treatment decreased p-JNK and OX-42 levels, diminished the release of proinflammatory cytokines and improved behavioral hypersensitivity following CCI. In conclusion, median nerve injury-induced microglial JNK activation in the CN modulated development of behavioral hypersensitivity. DHA has analgesic effects on neuropathic pain, at least in part, by means of suppressing a microglia-mediated inflammatory response through the inhibition of JNK signaling pathway. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to investigate the usefulness of muscle ultrasound for evaluating muscle changes caused by denervation in carpal tunnel syndrome (CTS), which is a focal neuropathy. Methods: The mean and standard deviation (SD) of echo intensity (EI) in the thenar and hypothenar muscles were calculated in 35 patients with CTS and 11 healthy subjects. Patients were assigned to three subgroups based on CTS severity as determined by electrodiagnostic tests. The ratio of thenar muscle pixel brightness to hypothenar muscle pixel brightness was used in statistical analyses. The ratio of mean pixel brightness was termed the EI ratio, and the ratio of the SD of pixel brightness was termed the inhomogeneity ratio. Results: Both the EI ratio and the inhomogeneity ratio were significantly higher in the patient group than in the control group. In a comparison of the three patient subgroups, the severe group showed significant differences in both the EI and inhomogeneity ratios compared to the other two groups. Subjects with denervation potential in the abductor pollicis brevis (APB) had higher EI and inhomogeneity ratios than subjects without denervation potential in the APB. Conclusion: The EI ratio and inhomogeneity ratio are useful variables with which to evaluate disease severity and the presence of denervation in patients with CTS. [ABSTRACT FROM AUTHOR]

Patients suffering from carpal tunnel syndrome (CTS) actively search for medical information on the Internet. The World Wide Web represents the main source of patient information. The aim of this study was to systematically assess the quality of patient information about CTS in the Internet. A qualitative and quantitative assessment of websites was performed with the modified Ensuring Quality Information for Patients (EQIP) tool that contains 36 standardized items. Five hundred websites with information on CTS treatment options were identified through Google, Bing, Yahoo, Ask.com and AOL. Duplicates and irrelevant websites were excluded. One hundred and ten websites were included. Only five websites addressed more than 20 items; quality scores were not significantly different between the various providing groups. A median of 15 EQIP items was found, with the top website addressing 26 out of 36 items. Major complications such as median nerve injury were reported in 27% of the websites and their treatment in only 3%. This analysis revealed several critical shortcomings in the quality of the information provided to patients suffering from CTS. There is a collective need to provide interactive, informative and educational websites for standard procedures in hand surgery. These websites should be compatible with international quality standards for hand surgery procedures. [ABSTRACT FROM AUTHOR]

Peripheral nerve injuries are devastating injuries and can result in physical impairments, poor functional outcomes and high levels of disability. Advances in our understanding of peripheral nerve regeneration and nerve topography have lead to the development of nerve transfers to restore function. Over the past two decades, nerve transfers have been performed and modified. With the advancements in surgical management and recognition of importance of cortical plasticity, motor-reeducation and perioperative rehabilitation, nerve transfers are producing improved functional outcomes in patients with nerve injuries. This manuscript explores the recent literature as it relates to current nerve transfer techniques and advances in post-operative rehabilitation protocols, with a focus on indications, techniques and outcomes. [ABSTRACT FROM AUTHOR]

Abstract: In the study described here, we examined the feasibility of a longitudinal design to measure sonographically swelling of the median nerve caused by controlled exposure to a work task and to evaluate the relationship of changes in morphology to diagnostic standards. Fifteen macaques, Macaca fascicularis, pinched a lever in various wrist positions at a self-regulated pace (8 h/d, 5 d/wk, 18–20 wk). Nerve conduction velocity (NCV) and cross-sectional area (CSA) were measured every 2 wk from baseline through working and a 6-wk recovery. Trending across all subjects revealed that NCV slowed and CSA at the carpal tunnel increased in the working arm, whereas no changes were observed in CSA either at the forearm or for any measure in the non-working arm. There was a small negative correlation between NCV and CSA in the working arm. This study provides validation that swelling can be observed using a longitudinal design. Longitudinal human studies are needed to describe the trajectory of nerve swelling for early identification of median nerve pathology. [Copyright &y& Elsevier]

Objective: To evaluate the relationship among obesity, incidence of idiopathic median nerve lesion at the wrist (MNLW), idiopathic severe MNLW and diabetes mellitus type 2 (DMT2)-associated severe MNLW. Methods: Clinical and electrodiagnostic data were prospectively collected from 676 patients (≥20years, 76% females) with carpal tunnel syndrome who were referred to our electrodiagnostic laboratories. In total, 229 patients had 314 cases of severe idiopathic MNLW, 447 had 777 cases of idiopathic non-severe MNLW, and 43 DMT2 patients had 62 cases of severe MNLW. We computed the standardized prevalence ratio (SPR) for obesity and compared the prevalence of obesity and body mass index (BMI) in patients with idiopathic MNLW and the 2009 OBesity EPIdemilogic (OBEPI) sample representing the prevalence of obesity in 24,455 French adults. We compared the prevalence of obesity in DMT2 patients and the Échantillon national témoin représentatif des personnes diabétiques (ENTRED) sample representing the prevalence of cardiovascular risk factors, including obesity, in 3894 French patients with DMT2. Results: The SPR for obesity was 1.60 (95% confidence interval 1.23–2.07) for idiopathic severe MNLW as compared with the OBEPI sample, and 1.72 (1.17–2.46) for DMT2-associated severe MNLW as compared with the ENTRED sample. The risk of severe MNLW increased with BMI: the adjusted odds ratio was 1.09 (1.05–1.13) for each 1-point increase in BMI. This risk was not significant for patients 60years and older. Discussion: The prevalence of obesity is increased for patients with severe MNLW and DMT2-associated severe MNLW as compared with their respective general populations. [ABSTRACT FROM AUTHOR]

Résumé: Nous rapportons la découverte d’une rupture subtotale du nerf médian par usure « sur chevalet » de celui-ci sur une séquelle de fracture du poignet datant de l’enfance. Cette observation inédite a été faite lors d’une chirurgie de reprise du canal carpien chez un patient de 80ans, pour qui l’indication de neurolyse avait été posée devant la récidive d’un syndrome sévère du canal carpien à 30ans d’une première intervention de neurolyse. Si les ruptures par usure des tendons fléchisseurs sont largement relatées dans la littérature, de même que la survenue de plaies nerveuses aiguës dans le cadre de traumatismes à haute énergie, la survenue d’une rupture secondaire d’un nerf par usure de celui-ci sur un relief osseux n’a, à notre connaissance, jamais été décrite. [ABSTRACT FROM AUTHOR]

Purpose: To present a technique for restoration of ulnar intrinsic function using a nerve transfer of the extensor carpi ulnaris (ECU) and extensor digiti minimi (EDM) nerve branches of the posterior interosseous nerve (PIN) to the deep branch of the ulnar nerve in the forearm when the anterior interosseous nerve is unavailable. Methods: We dissected 6 cadaveric upper extremities to identify the location of the EDM and ECU branches of the PIN and their distance to the ulnar nerve near the wrist. We present a case of a high combined median and ulnar nerve injury. We performed transfer of the EDM branch and 1 of the branches to the ECU of the PIN to the motor component of the ulnar nerve for intrinsic hand function. Results: Our anatomic data demonstrate the branching pattern of the PIN and the length of regeneration and nerve graft required. Our patient required a 10-cm nerve graft, and the length of regeneration to reach the wrist was 19 cm. The patient recovered useful but incomplete reinnervation of the intrinsic muscles and rated hand recovery at 70%. Conclusions: Transfer of the EDM and ECU branches of the PIN to the motor component of the ulnar nerve is feasible with the use of a nerve graft. Using some of the branches to the ECU as well increases the axonal load to maximize muscle reinnervation. Clinical relevance: Proximal ulnar nerve injuries with paralysis of the intrinsic hand muscles lead to severe disability. Distal nerve transfers eliminate key factors that result in poor outcomes by allowing for faster muscle reinnervation. This nerve transfer had no functional donor morbidity and could be useful in the setting of a combined high median and ulnar nerve injury. [ABSTRACT FROM AUTHOR]

The article discusses the recent advances in neuroscience and neuroimaging techniques that have led to a revision of Sensory Reeducation (SR) techniques and the timing when SR should be initiated. SR can be viewed in two phases: phase 1 and phase 2. It mentions that a literature search of the electronic bibliographic databases Medline, CINAHL, AMED and EMBASE was undertaken and provides assessment of methodological quality, results and interventions. It suggests the effect of SR programs need to be evaluated using validated impairment based measures of sensibility and patient rated outcome questionnaires of activities and participation.

Abstract: Aims: This study aimed to investigate temporal changes in glycine and its receptor expressions in cuneate neurons after median nerve transection (MNT), and the effects of glycine on neuropeptide Y (NPY) release and c-Fos expression in the cuneate nucleus (CN). Main methods: Immunohistochemistry methods were used to appraise changes of glycine- and GlyR-like immunoreactive (LI) neurons in the CN after MNT. The alterations in NPY and c-Fos expressions were used to assess the effects of saline, glycine or strychnine treatment. The CatWalk method was used to assess the efficiency of glycine treatment on the neuropathic signs of rats with MNT. Key findings: Approximately half of GlyR-LI neurons were fluorogold-labeled cuneothalamic projection neurons in the CN. Following MNT, the number of GlyR-LI neurons significantly decreased in the injured side of CN at 2 and 4weeks, but the number of glycine-LI neurons remained unchanged. Four weeks after MNT given with electrical stimulation, strychnine significantly decreased the NPY reduction level in the stimulated side CN compared to that of the saline group. However, numbers of c-Fos-LI neurons in the glycine and strychnine groups were both significantly less than that in the saline group. But the paw print width and area in CatWalk analysis showed only a moderate recovery. Significance: We conjecture that glycine increases glycine-mediated postsynaptic inhibition of cuneate neurons, and also blocks GABAergic neurons containing GlyRs which mediate presynaptic inhibition causing temperate NPY release. Consequently, the compromise results showed a weak reduction in c-Fos expression and a slight amelioration of neuropathic behaviors. [Copyright &y& Elsevier]

Purpose: Peripheral nerve injury of the upper extremity frequently causes changes in the thermoregulatory system of the hands and fingers and leads to reports of cold intolerance. In this study, we aimed to measure the influence of median or ulnar nerve injury on cold-induced vasodilatation (CIVD) during prolonged cooling at low temperatures. Methods: We tested 12 patients with a median (n = 6) or ulnar (n = 6) injury 4 to 76 months after nerve repair. The palmar sides of both hands were cooled continuously using a cold plate at 5°C. We measured the skin temperature of the fingers using videothermography and plotted graphs of the temperature changes of the nailbed. The presence of a CIVD reaction was defined as a minimum increase in temperature of 2.5°C starting at the distal phalanx. Furthermore, we measured self-reported symptoms of cold intolerance using the Cold Intolerance Severity Scale questionnaire. Results: A CIVD reaction was absent in the affected digits of 4 patients (follow-up, 6–37 mo), whereas the CIVD reaction in the uninjured hand was present. The CIVD was present in 6 patients after 50 months'' follow-up (range, 24–76 mo). Two patients had no CIVD reaction in the injured or uninjured fingers. All patients with a CIVD response had at least diminished protective sensation. Presence of the CIVD reaction did not exclude self-reported symptoms of cold intolerance. Conclusions: After peripheral nerve injury, it is possible to recover the CIVD reaction. This might be an indication of nerve recovery. However, a positive CIVD reaction does not exclude subjective symptoms of posttraumatic cold intolerance. Type of study/level of evidence: Diagnostic III. [Copyright &y& Elsevier]

We present a case of proliferative flexor tenosynovitis caused by Mycobacterium avium complex resulting in recurrent symptoms of median nerve compression. The patient was treated with radical tenosynovectomy and release of the carpal tunnel without antimicrobial therapy. She remains symptom-free and is apparently disease-free more than 2 years after surgery. [Copyright &y& Elsevier]

Purpose: To establish the rate of iatrogenic injury after endoscopic carpal tunnel release (ECTR) for a surgeon in the first 2 years of practice; to report the rate of conversion from ECTR to open carpal tunnel release (OCTR), the reason for conversion, and any increase in morbidity found in patients converted to OCTR; and to determine whether the conversion rate decreased with increasing surgeon experience. Methods: We conducted a retrospective review of patients undergoing ECTR by a single surgeon in the first 2 years of practice. Data collected or calculated included symptom relief, rate of conversion to OCTR, reason for conversion, and neurovascular complications. For patients converted to OCTR, we assessed satisfaction and function using the Disabilities of the Arm, Shoulder, and Hand questionnaire. We compared these results for 1 to 6 months, 7 to 12 months, and 12 to 24 months to determine whether a learning curve was present. Results: A total of 278 patients (358 procedures) underwent ECTR. Of these, 12 patients required conversion to OCTR during the index procedure over a 2-year period. In the first 6 months of practice, 8 of 71 ECTRs were converted to OCTR compared to 1 of 72 in the second 6 months. This was a statistically significant decrease (p = .017). In year 2, 3 of 215 patients were converted to OCTR. Average Disabilities of the Arm, Shoulder, and Hand score for patients converted from ECTR to OCTR was 9. No patients required repeat surgery for recurrence of carpal tunnel symptoms. We observed no major neurovascular complications. Conclusions: A learning curve for ECTR was present. Rates of conversion significantly diminished with increased surgeon and anesthesia experience. Patients requiring conversion showed no variation in Disabilities of the Arm, Shoulder, and Hand scores from established values after OCTR. Patients may be at a higher risk of conversion to OCTR during the learning curve time period; nevertheless, we found no increased morbidity. Type of study/level of evidence: Prognostic III. [Copyright &y& Elsevier]

Abstract: Background: Penile rehabilitation (PR) is widely applied after radical prostatectomy. Vacuum erectile device (VED) therapy is the one of three PR methods used in the clinical setting that improve erectile function (EF) and is the only PR method which may preserve penile length. However, its unknown mechanism hampered doctors’ recommendations and patients’ compliance. Objectives: To assess the effects of VED therapy on erectile dysfunction (ED) in a rat model of bilateral cavernous nerve crush (BCNC) and to investigate the molecular mechanism of VED in postprostatectomy ED. Design, setting, and participants: This was an experimental study using Sprague-Dawley rats in three groups: sham, BCNC, and BCNC plus VED. Intervention: Intervention included BCNC, electrical stimulation of the cavernous nerve (CNS), and VED therapy. Measurements: At the end of a 4-wk period, CNS was used to assess EF by maximum intracavernosal pressure (ICP)/mean arterial pressure (MAP) ratio and duration (area under the curve [AUC]). For the structural analyses, whole rat penis was harvested. Terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling assay was used for the assessment of apoptotic indices (AI). Immunohistochemistry was performed for endothelial nitric oxide synthase (eNOS), α-smooth muscle actin (ASMA), transforming growth factor beta 1 (TGF-β1), and hypoxia inducible factor-1α (HIF-1α). Staining for Masson''s trichrome was utilized to calculate the smooth muscle/collagen ratios. Results and limitations: EF was improved with VED therapy measured by ICP/MAP ratios and AUC. VED therapy reduced HIF-1α expression and AI significantly compared with control. Animals exposed to VED therapy had decreased TGF-β1 expression, increased smooth muscle/collagen ratios, and preserved ASMA and eNOS expression. Conclusions: To our knowledge, this is the first scientific study to suggest that VED therapy in the BCNC rat model preserves EF through antihypoxic, antiapoptotic, and antifibrotic mechanisms. [Copyright &y& Elsevier]

Background : Although there remain concerns of median nerve damage during endoscopic carpal tunnel release for carpal tunnel syndrome, carpal tunnel pressure variations during Chow's two-portal technique have not been well investigated. Methods : We performed a modified two-portal endoscopic carpal tunnel release on 30 patients by inserting a catheter pressure transducer into the carpal tunnel for continuous pressure measurement during the procedure. Grip and pinch strengths, Semmes–Weinstein monofilament test, and nerve conduction studies were examined preoperatively and at postoperative 1, 3, and 6months. Numbness and the Disabilities of the Arm, Shoulder and Hand score were also evaluated pre and postoperatively. Findings : Subjective symptoms and nerve conduction study findings improved uneventfully. The pressure was always observed to be maximum pressure immediately before the cannula was withdrawn from the exit portal, and carpal tunnel pressure >300mmHg was recorded in most of the patients. Interpretation : A transient increase in the carpal tunnel pressure occurred in all the patients; however, it did not correlate with their clinical outcome or with increased risk of peri-operative complications. Since time–pressure threshold of the median nerve during endoscopic carpal tunnel release is still unknown, our results did not guarantee its safety. [Copyright &y& Elsevier]

Background: Carpal tunnel syndrome is a commonly encountered entrapment disorder resulting from mechanical insult to the median nerve. Magnetic resonance imaging (MRI)-based investigations have documented typical locations of the median nerve within the carpal tunnel; however, it is unclear whether those locations are consistent within an individual on different days. Methods: To determine the day-to-day variability of nerve location, 3.0T MRI scans were acquired from six normal volunteers over multiple sessions on three different days. Half of the scans were acquired with the wrist in neutral flexion and the fingers extended, and the other half were acquired with the wrist in 35° of flexion and the fingers flexed. Prior to half of the scans (in both poses), subjects performed a preconditioning routine consisting of specified hand activities and several repetitions of wrist flexion/extension. The shape, orientation, location, and location radius of variability of the median nerve and three selected flexor tendons were determined for each subject and compared between days. Findings: Two of the six subjects had substantial variability in nerve location when the wrist was in neutral, and four of the subjects had high variability in nerve position when the wrist was flexed. Nerve variability was typically larger than tendon variability. The preconditioning routine did not decrease nerve or tendon location variability in either the neutral or the flexed wrist positions. Interpretation: The high mobility and potential for large variability in median nerve location within the carpal tunnel needs to be borne in mind when interpreting MR images of nerve location. [Copyright &y& Elsevier]

We have previously discussed compression neuropathies of the radial nerve in the forearm. In the second half of this 2-part review, we will now turn our attention to 2 compression neuropathies affecting the proximal median nerve, before its entry through the carpal tunnel: (1) pronator syndrome and (2) anterior interosseous nerve syndrome. [Copyright &y& Elsevier]

Abstract: The availability of effective experimental models for investigating nerve regeneration and designing new strategies for promoting this unique repair process is important. The aim of this study was to standardize a rat median nerve crush injury model using a non-serrated clamp exerting a compression force of 17.02MPa for a duration of 30s. Results showed that functional recovery, evaluated by grasping test, was already detectable at day-12 and progressively increased until day-28 after which animal performance plateaued until the end of testing (day-42), reaching a range of 75–80% of pre-operative values. Morphological analysis on the median nerve segments, distal to the crush lesion, which were withdrawn at the end of the experiment showed that regenerated nerve fibers are significantly more numerous and densely packed; they are also smaller and have a thinner myelin sheath compared to controls. Together, these results provide a baseline characterization of the crush median nerve injury experimental model for its employment in the investigation of nerve regeneration research, especially when a reproducible regeneration process is required, such as for the study of biological mechanisms of peripheral nerve fiber regeneration or development of new therapeutic agents for promoting posttraumatic nerve repair. [Copyright &y& Elsevier]

Abstract: Introduction: Wounds on the palmar side of the wrist affecting the median or ulnar nerves are responsible for motor and sensory sequelae, severe pain and cold intolerance. Materials and methods: Thirty-nine patients with 40nerve sections were retrospectively reviewed with a mean follow up of 23months. The median nerve alone was affected 20times, the ulnar nerve seven times and both nerves simultaneously 13times. In 75% of the cases, there was an associated vascular injury (radial artery and/or ulnar artery). The average number of tendons cut was 4.25. Results: After repair of the median nerve, 71% of patients recovered antepulsion and opposition that was normal or possible against resistance. The strength was approximately 70% of the opposite side. The sensitive recovery was good (S3 in≥50% of cases) but it was accompanied by cold intolerance one out of two patients. After repair of the ulnar nerve, 29% of the cases had an ulnar claw hand, 71% of patients recovered sensitivity greater or equal to S3 but with cold intolerance in 42% of the cases. The combined median and ulnar sections had a poorer sensory-motor prognosis. Revision surgery was necessary in 12 of these cases. Conclusion: Sensory recovery after an isolated ulnar nerve lesion at the wrist is better than after an isolated median nerve lesion but there is no difference in the motor recovery. Combined median and ulnar lesions have an especially bad prognosis and may require secondary palliative surgery. The existence of nerve contusion and a high number of tendon injuries were factors associated with a poorer prognosis. [Copyright &y& Elsevier]

Abstract: Objectives: Analyzing the literature and elaborating recommendations on the following topics: relevance of dorsal root entry zone (DREZ) lesions, surgical treatment for posttraumatic syringomyelia, other therapeutic approaches (peripheral nerve root pain, nerve trunk pain and Sign Posterior Cord [SCI] pain). Material and Methods: The methodology used, proposed by the French Society of Physical Medicine and Rehabilitation (SOFMER), includes a systematic review of the literature, the gathering of information regarding current clinical practices and a validation by a multidisciplinary panel of experts. Results: Ninety-two articles were selected, 10 with a level of evidence at 2, 82 with a level of evidence at 4. Some articles lacked information on the type of injury, the pain characteristics and the symptoms’ evolution over time. Drez: This type of procedure has been validated for its effectiveness on pain at the level of injury (transitional zone pain), but is inefficient for pain located below the level of injury. Posttraumatic syringomyelia (PTS): suspected when there is an increased neurological impairment, changes below the level of injury (mainly bladder dysfunctions) or a sudden onset of pain. The surgery associates arachnoid grafting, cyst drainage, expansile dural plasty (same treatment for posttraumatic tethered spinal cord and posttraumatic myelomalacia). Peripheral nerve root, nerve trunk or transitional zone pain: Surgical implants (screws or clips) can generate radicular pain caused by inflammation and they can even move around with time. The material-induced constraints can also trigger pain. Surgical removal of osteosynthesis material (with an eventual saddle block) remains a simple procedure yielding good results. Correcting surgeries can also be performed (malunion and nonunion). Finally, compressive neuropathies (carpal tunnel syndrome, ulnar nerve entrapment) already have a well-defined treatment. Conclusion: The literature review can define the relevance of surgical treatments on some types of SCI pain. However, the results of many articles are difficult to analyze, as they do not report clinical or follow-up data. [Copyright &y& Elsevier]

Abstract: Objectives: The aim of this study was to evaluate the function of Aδ fibers at the hand level in patients with clinical symptoms of Carpal Tunnel Syndrome (CTS) using CO2 laser evoked potentials (LEPs), in light of the intensity and distribution of sensory symptoms and pain. Methods: Thirty-four CTS outpatients (62 hands) were compared to 23 sex- and age-matched control subjects (46 hands). The periungueal skin of the first, second, third and fifth fingers, and the dorsum of the hands were stimulated in random order. The latency and amplitude of the N2, P2 and N1 components were evaluated with respect to the Nerve Conduction Study (NCS) data, clinical scales, pain intensity and glove-like symptoms distribution. Results: The amplitude of the N2–P2 complex was significantly reduced in CTS hands compared to normal hands after stimulation of the second and third fingers, even in patients with mild nerve conduction impairment. No significant fifth finger LEP abnormalities were found in patients with glove-like distribution symptoms. The N2–P2 amplitude at the second and third fingers was positively correlated with the severity of sensory symptoms. Conclusions: The involvement of median nerve Aδ fibers in CTS seems to be an early phenomenon, which concurs with the impairment of large motor and sensory afferents and is linked to the severity of the disease. Significance: The finding of reduced sensory symptoms in patients with severe thin afferents damage, may suggest a slight expression of central sensitisation phenomena in the advanced stage of CTS syndrome. [Copyright &y& Elsevier]

Purpose: Posttraumatic cold intolerance (CI) is a frequent and important sequel after peripheral nerve injury. In this study, it is hypothesized that altered rewarming patterns after peripheral nerve injury are related to the degree of posttraumatic CI. This hypothesis is tested by quantitatively comparing rewarming patterns of the digits in controls and in median or ulnar nerve injury patients and by investigating relationships between rewarming patterns, sensory recovery, and CI. Methods: Twelve median or ulnar nerve injury patients with a follow-up of 4 to 76 months after nerve repair and 13 control subjects had isolated cold stress testing of the hands. Video thermography was used to analyze and compare rewarming patterns of the injured and uninjured digits after cold stress testing. Temperature curves were analyzed by calculating the Q value as an indicator of heat transfer (temperature added during the first 10 minutes after start of active rewarming) and the maximum slope. Results: Test–retest reliability was 0.64 and 0.79, respectively, for the Q value and maximum slope. High Q values and maximum slopes were interpreted as the presence of active rewarming. Patients with return of active rewarming had better sensory recovery and lower Blond McIndoe Cold Intolerance Severity Scale (CISS) scores. Better sensory recovery was correlated with lower CISS scores. Conclusions: Test–retest reliability of cold stress testing was good, and we found a difference in rewarming patterns between nerve injury patients and controls. The presence of active rewarming in the nerve injury patients was related to sensory recovery and fewer complaints of posttraumatic CI. [Copyright &y& Elsevier]

Purpose: The objective of this study was to measure the relative motion of the middle finger flexor digitorum superficialis (FDS) tendon, its adjacent subsynovial connective tissue (SSCT), and the median nerve during single-digit motion within the carpal tunnel in human cadaver specimens and to estimate the relative motions of these structures in different wrist positions. Methods: Using fluoroscopy during simulated single-digit flexion, we measured the relative motion of the middle finger FDS tendon, SSCT, and median nerve within the carpal tunnel in 12 human cadavers. Measurements were obtained for 3 wrist positions: neutral, 60° flexion, and 60° extension. After testing with an intact carpal tunnel was completed, the flexor retinaculum was cut with a scalpel, and the same testing procedure was repeated for each wrist position. The relative motions of the tendon, SSCT, and median nerve were compared using a shear index, defined as the ratio of the difference in motion along the direction of tendon excursion between 2 tissues divided by tendon excursion, expressed as a percentage. Results: Both tendon–SSCT and tendon–nerve shear index were significantly higher in the 60° of wrist flexion and extension positions than in the neutral position. After division of the flexor retinaculum, the shear index in the 60° wrist extension position remained significantly different from that of the neutral position. Conclusions: We have found that the relative motion between a tendon and SSCT in the carpal tunnel is maximal at extremes of wrist motion. These positions may predispose the SSCT to shear injury. [Copyright &y& Elsevier]

Abstract: Standard electrophysiological techniques and analysis of the stimulus–response relationship (i.e., the input–output (I–O) curves) of the median nerve were performed in 16 patients with carpal tunnel syndrome (CTS) both prior to and 1 and 6 months after surgical decompression at the wrist. One month after carpal tunnel release (CTR), conduction in cutaneous and motor axons (i.e., sensory conduction velocity and distal motor latency) was found to be improved with respect to pre-surgical values, whereas motor action potentials and the motor I–O curve showed a decrease with respect to control values. This suggested reduced efficiency of axon recruitment following CTR. Six months after surgery, all parameters were significantly improved with respect to control values. The sensory and motor I–O curves suggested that the reduced motor fibre recruitment efficiency observed 1 month after CTR was due to changes in current density distributions under the surface stimulating electrode on the median nerve at the wrist. Slight transient compression (such as that due to post-surgical oedema) acting on median fibres located superficially within the nerve cannot be excluded, however. Since electrophysiological studies are an important, objective method of evaluating the outcome of surgical CTR, electrophysiologists must be aware of the possibility of reduced compound motor action potential (CMAP) in the first few months after surgery. [Copyright &y& Elsevier]

Summary: Background: Patients in a minimally conscious state (MCS) show restricted self or environment awareness but are unable to communicate consistently and reliably. Therefore, better understanding of cerebral noxious processing in these patients is of clinical, therapeutic, and ethical relevance. Methods: We studied brain activation induced by bilateral electrical stimulation of the median nerve in five patients in MCS (aged 18–74 years) compared with 15 controls (19–64 years) and 15 patients (19–75 years) in a persistent vegetative state (PVS) with 15O-radiolabelled water PET. By way of psychophysiological interaction analysis, we also investigated the functional connectivity of the primary somatosensory cortex (S1) in patients and controls. Patients in MCS were scanned 57 (SD 33) days after admission, and patients in PVS 36 (9) days after admission. Stimulation intensities were 8·6 (SD 6·7) mA in patients in MCS, 7·4 (5·9) mA in controls, and 14·2 (8·7) mA in patients in PVS. Significant results were thresholded at p values of less than 0·05 and corrected for multiple comparisons. Findings: In patients in MCS and in controls, noxious stimulation activated the thalamus, S1, and the secondary somatosensory or insular, frontoparietal, and anterior cingulate cortices (known as the pain matrix). No area was less activated in the patients in MCS than in the controls. All areas of the cortical pain matrix showed greater activation in patients in MCS than in those in PVS. Finally, in contrast with patients in PVS, those in MCS had preserved functional connectivity between S1 and a widespread cortical network that includes the frontoparietal associative cortices. Interpretation: Cerebral correlates of pain processing are found in a similar network in controls and patients in MCS but are much more widespread than in patients in PVS. These findings might be objective evidence of a potential pain perception capacity in patients in MCS, which supports the idea that these patients need analgesic treatment. Funding: FNRS; Reine Elisabeth Medical Foundation; University of Liège; European Commission; James S McDonnell Foundation; Mind Science Foundation; Concerted Research Action; Fondation Léon Frédéricq. [Copyright &y& Elsevier]

Purpose: This was an intraoperative anatomical study to identify the prevalence of variations in the motor branch of median nerve and to correlate these with the presence of a transverse carpal ligament (TCL) with superficial or interposed muscle. Methods: Over a period of 12 years in 1400 consecutive patients in whom the carpal tunnel was opened for any reason, observations were made in each hand to (1) determine the presence or absence of muscle fibers lying superficial to or within the TCL and (2) identify the anatomic branching patterns of the motor branch of median nerve. The primary objective was to ascertain whether the appearance of the TCL could be used to predict the anatomy of the motor branch. Results: A normal motor branch arising beneath a purely ligamentous TCL was found in 1011 hands (72%). The focus of this paper is on the remaining 386 hands (28%), in which muscle fibers were found lying superficial to or within the TCL; in this group, only 29 hands (8%) had a normal motor branch. An anomalous motor branch was found in 93% of hands with a TCL with superficial or interposed muscle fibers and in less than 1% of hands with a purely ligamentous TCL. Conclusions: In exposing the carpal tunnel, special care should be taken by the surgeon to identify and protect the motor branch when muscle fibers are encountered superficial to or within the TCL. [Copyright &y& Elsevier]

Purpose: A better understanding of the risk factors for acute carpal tunnel syndrome (CTS) associated with fracture of the distal radius might influence recommendations for prophylactic carpal tunnel release. Methods: Fifty patients who had release of an acute CTS in association with open reduction and internal fixation (ORIF) of a fracture of the distal radius were identified from orthopedic trauma databases at 2 institutions. Each patient was matched with a control patient (ORIF, but no acute CTS) of the same gender, similar age (±4 years), and similar injury mechanism. Results: The prevalence of acute CTS among patients with a surgically treated fracture of the distal radius was 5.4%. In univariate analysis, only fracture translation was a significant predictor of acute CTS, but ipsilateral upper extremity trauma and status as a multitrauma patient were nearly significant. The best multivariate model included fracture translation alone and accounted for 60% of the observed increase in risk. A subgroup analysis using receiver operating characteristics (ROC) identified a threshold of approximately 35% fracture translation associated with a significantly increased risk of acute CTS in women less than 48 years of age. No threshold was identified in the other 3 subgroups. Conclusions: Fracture translation is the most important risk factor for acute CTS in patients who subsequently had ORIF of a fracture of the distal radius. On the basis of these data, prophylactic carpal tunnel release might be appropriate in women less than 48 years of age with greater than 35% fracture translation, but further investigation is needed to confirm that a true threshold exists. Type of study/level of evidence: Prognostic III. [Copyright &y& Elsevier]

Abstract: Recurrence of carpal tunnel syndrome following surgery is not rare. The reported frequency of reoperation varies from 0.3 to 12%. We distinguish between persistent carpal tunnel syndrome, and recurrent carpal tunnel syndrome which we define as reappearance of the condition three months or more following surgery. More proximal nerve lesions or other erroneous diagnoses may cause either persistent or recurrent syndromes. In the cases of persistent syndromes, incomplete division of the flexor retinaculum is a frequent cause, but iatrogenic nerve lesions or active flexor tenosynovitis may also be to blame. In the cases of recurrent carpal tunnel syndrome, the problem is often due to perineural fibrosis. At the time of reoperation, except in those cases where an incomplete division of the flexor retinaculum is found, one must consider whether or not to combine the neurolysis with an additional procedure to prevent or diminish recurrent fibrosis. To achieve this goal, a number of measures have been proposed, including interposition of a biomaterial or raising a local flap to surround and protect the nerve. Others recommend early mobilization to diminish fibrous adhesions between the nerve and surrounding tissues. The results are at best modest, and may be counterproductive after several interventions. It is necessary to distinguish between improvement in symptoms that are due to local irritation, the priority for the patient, and improvement in neurologic function of the motor and sensory components of the nerve. According to the literature, from 43 to 90% of patients who undergo repeat operations continue to have symptoms, and one in five get no relief, while 80% of first operations for carpal tunnel syndrome give excellent results. These findings indicate that the first intervention must be performed with the most rigorous attention to technical detail. [Copyright &y& Elsevier]

Résumé: Contexte: Les critères cliniques et neurophysiologiques qui permettent de porter le diagnostic de syndrome du canal carpien (SCC) restent mal définis. Des manifestations compatibles avec un SCC existent souvent en l’absence de mononeuropathie du nerf médian. Une meilleure compréhension de la physiopathologie et de l’histoire naturelle du SCC permettrait d’établir des stratégies diagnostiques et thérapeutiques plus rationnelles. Objectif: Étudier les liens entre les manifestations cliniques de SCC et les résultats des mesures de la conduction nerveuse et de l’échographie, puis en déterminer les conséquences pour la pratique clinique. Méthodes: Nous avons inclus 232 malades (163 femmes et 69 hommes âgés de 20 à 91 ans) qui présentaient des manifestations compatibles avec un SCC, ainsi que 182 témoins bien portants. Le diagnostic de SCC a été porté selon les critères cliniques établis par l’American Academy of Neurology. Les malades et les témoins ont rempli des questionnaires. Quatre manœuvres cliniques pour le SCC ont été réalisées et sont les suivantes : test de Tinel, test de Phalen, test de Phalen inversé et compression du canal carpien. Des examens sanguins destinés à rechercher les causes de SCC secondaire ont été faits, ainsi qu’une étude de la conduction nerveuse et une échographie du canal carpien et du nerf médian. Résultats: Parmi les 232 malades, 177 (76.3 %) avaient des anomalies de la conduction nerveuse et 119 (51,3 %) des signes échographiques de ténosynovite en conjonction avec une symptomatologie à l’avant-bras. Les variables anthropométriques ne présentaient aucune différence significative entre les mains affectées et les mains des sujets témoins. Le test de Phalen et la compression du canal carpien étaient plus souvent positifs en cas de ténosynovite, indépendamment des résultats des mesures de la conduction nerveuse. Les tests de Tinel, Phalen, Phalen inversé et compression du canal carpien étaient plus sensibles pour le diagnostic de ténosynovite que pour celui de SCC (Tinel, 46 % versus 30 % ; Phalen, 92 % versus 47 % ; Phalen inverse : 75 % versus 42 % ; compression du canal carpien, 95 % versus 46 %). De même, la spécificité de ces quatre tests était meilleure pour la ténosynovite que pour le SCC. Conclusion: La sensibilité et la spécificité des tests de Tinel, Phalen, Phalen inversé et compression du canal carpien sont meilleures pour la ténosynovite des fléchisseurs de la main que pour le SCC. Ces tests peuvent orienter la prise en charge médicale. [Copyright &y& Elsevier]

Abstract: Objective: Sensory symptoms within the median nerve distribution are a primary clinical diagnostic criterion for the diagnosis of carpal tunnel syndrome (CTS). However, the distribution of the sensory symptoms in CTS varies from patient to patient. This study identifies the clinical and electrophysiological findings that correlate with the distribution of sensory symptoms in an Asian population with CTS. Methods: In a prospective study of 105 patients with electrophysiologically confirmed CTS, clinical and educational data were correlated with sensory symptom distribution. Results: Median nerve distribution was strongly associated with more severe nerve conduction abnormality, male gender, and relief by movement. Patients with a complete median sensory distribution had more electrophysiological abnormality than those with an incomplete median distribution. Extra-median distribution was associated with the least nerve conduction abnormality. Educational qualification, age, symptom duration and body mass index were not associated with the pattern of sensory symptoms. Conclusions: In carpal tunnel syndrome, sensory symptom distribution is strongly dependant on the degree of electrophysiological median nerve damage. Median nerve sensory distribution is associated with severe nerve damage. Significance: This study provides clinicians with a simple clinical rule for assigning the degree of median nerve damage in patients with CTS based on sensory distribution patterns. [Copyright &y& Elsevier]

Purpose: To reduce the rate of median nerve injury occurring during Chow’s original 2-portal technique, we developed a modified procedure. The surgical technique was introduced, and the results were evaluated with regard to the clinical findings, nerve conduction studies, and Disabilities of the Arm, Shoulder, and Hand (DASH) score. Methods: We analyzed 119 hands of 119 patients with idiopathic carpal tunnel syndrome who underwent our procedure, wherein a cannula assembly was inserted after a partial division of both distal and proximal parts of the transverse carpal ligament through the entry and exit portals. Postoperative examinations, including evaluation of numbness, grip strength, pinch strength, tenderness over and around the wounds, and nerve conduction studies, were performed at 1 month (n = 119), 3 months (n = 119), 6 months (n = 102), and 12 months (n = 39). The DASH score was also evaluated preoperatively and at 3, 6, or 12 months postoperatively. The rate of structural damage to the median nerve, the tendon, and the artery was calculated. Results: The patients resumed their daily activities or work by 13 days postoperatively. Tenderness around the wounds was detected in 66% of patients by 3 months postoperatively. Numbness disappeared or decreased in 99% of patients by 6 months postoperatively. The DASH score was available for 82 patients, and it improved from 28.2 to 18.3 points postoperatively. Nerve conduction studies indicated a significant decrease in motor distal latency postoperatively. Temporal worsening of median nerve function was observed in 2 patients; however, no structural damage to the nerve, tendon, or artery was observed. Conclusions: We found no injury to the tendon or artery and no laceration to the nerve in all 119 patients. However, temporal worsening of median nerve function was observed in 2 patients. Level of Evidence: Level IV, therapeutic case series. [Copyright &y& Elsevier]

Abstract: Objective: To study the skin temperature changes as a sign of altered blood flow regulation due to abnormal sympathetic nerve function in carpal tunnel syndrome (CTS) and the efficacy of carpal tunnel release (CTR) operation in the alleviation of those signs and other symptoms of CTS. Subjects and methods: Forty-one healthy hands (n =41) of 22 volunteers and 22 hands (n =22) with clinically diagnosed carpal tunnel syndrome of 16 patients were examined. A series of infrared photos of the hands of each subject were taken and stored by using digital infrared thermography (DIRT) before and 6 months after the CTR. The temperatures of the finger tips from digit 1 (D1) to digit 5 (D5), the center point of thenar (Th) and hypothenar (Ht) eminences were measured, the median nerve index (MI=(D1−D2)+(D1−D3)+(D2−D3)) and the temperature differences between the median and the ulnar nerve distribution area (MED·ULN=(D1−D5)+(D2−D5)+(D3−D5)+(Th−Ht)) were calculated. Absolute values were used when calculating the temperature differences between different points. Results: All the CTS patients were released from the CTS symptoms, i.e. numbness and pain after the operation, and the results of nerve conduction studies (NCS) were all back to normal. The MI and MED·ULN in CTS hands were significantly smaller before CTR compared to those of healthy control subjects (MI: p <0.001, MED·ULN: p <0.005), and those after CTR (p <0.005 for both parameters). The results also showed that all finger tips of the affected hand including those innervated by the ulnar nerve were cooler before but warmer after the operation. Before the operation, the non-CTS hands of the CTS patients, were also colder (although the difference was not significant) than the healthy control subjects but approached the same level after the CTR operation of the CTS hands. Conclusion: The results of DIRT measurements suggest that the blood flow regulation in CTS is abnormal possibly because of disturbed sympathetic vasomotor regulation and that the circulation gets normal together with the alleviation of the other symptoms of CTS as recorded 6 months after CTR operation. [Copyright &y& Elsevier]

Chronic compression of the median nerve at the elbow has been described as resulting from a number of structures including the lacertus fibrosus. Symptoms of chronic compressive peripheral neuropathy consist predominantly of an achy feeling, paresthesias, numbness, and a sense of weakness or fatigue, with the onset being insidious and frequently without a precipitating cause. In this series, 7 consecutive cases of acute median nerve compression in the antecubital fossa resulted from an extremely forceful injury to the elbow. In all 7 cases, a sudden, severe attempt at elbow flexion was performed against a substantial counterforce, resulting in immediate severe pain radiating from the elbow down into the forearm. Pain was persistent and unremitting in all 7 until the time of diagnosis and treatment. Surgical decompression was performed in all cases. At the time of surgery, we found evidence of partial rupture of the myotendinous junction of the biceps brachii creating increased tension across the median nerve by a tethered lacertus fibrosus. Surgical decompression resulted in complete relief of symptoms in all 7 cases. [Copyright &y& Elsevier]

Summary: We present a case of recurrent carpal tunnel syndrome in a child caused by fibrolipomatous hamartoma of the median nerve which was successfully treated by limited excision of the fibrolipomatous tissue and decompression. [Copyright &y& Elsevier]

Abstract: Objective: To determine whether patients with mild carpal tunnel syndrome (CTS) and conventional electrodiagnostic evidence of selective involvement of sensory conduction show changes in motor axon recruitment in the median nerve. Methods: Wrist-to-abductor pollicis brevis (APB) motor axon conduction was studied by analysing the relationship between the intensity of electrical stimulation and the size of motor response (input–output curve) in 30 CTS patients with conventional electrodiagnostic evidence of selective involvement of sensory conduction. Parameters (threshold, slope and plateau) of input–output curves were compared with those obtained in 30 controls. Results: The slope of the input–output curve of CTS patients was less steep than that of controls. For stimulus intensity above M-wave threshold (MTh), fewer motor axons were recruited in patients than controls. Conclusions: Motor fibres are affected in CTS when conventional electrodiagnostic tests show normal motor conduction. Altered recruitment of motor axons could mainly be due to impairment of energy-dependent processes which affect temporal dispersion of the compound volley or axonal conduction block. Significance: In mild CTS, motor fibres are more often affected than was originally thought. The sensitivity of wrist-to-APB motor conduction studies may be increased by using submaximal stimulus intensities. [Copyright &y& Elsevier]

Purpose: To clarify which part of the median nerve is the most compressed and to compare carpal canal pressure with the latency of the sensory nerve potential and the duration of symptoms. Methods: Fifteen patients with idiopathic carpal tunnel syndrome were studied using a pressure guidewire system to record canal pressure. The wire was introduced from the distal end of the carpal canal to 2 cm proximal to the distal wrist crease (DWC) and then retracted in 5-mm increments using an image intensifier to guide the progress. A nerve conduction study was performed, and all patients were asked how long the symptoms lasted. Results: Carpal canal pressure was significantly higher 5 to 15 mm distal to the DWC. The most compressed point was 10 mm distal to the DWC, with a pressure of 44.9 ± 26.4 mm Hg. The correlation coefficient between the highest canal pressure and the latency was 0.393 and between highest canal pressure and duration of symptoms was 0.402. Conclusions: Our study showed that the most compressed part of the median nerve in the carpal canal is 10 mm distal to the DWC. The carpal canal pressure was related to the latency and to the duration of symptoms. [Copyright &y& Elsevier]

Summary: Based upon bilateral carpal tunnel syndrome (CTS) we undertook a prospective randomised intra-individual comparison between open (OR) and 2-portal endoscopic release (2-PER) to establish if there is any demonstrable advantage in undertaking either technique in a 1 year follow-up. Ten patients with bilateral CTS were enrolled in this study and underwent a 2-PER on the one and an OR with two minimised incisions on the contralateral hand. Both hands were examined pre- and postoperatively after 2, 4, 6 and 12 weeks and after 6 and 12 months, respectively. Preoperatively both hands revealed statistically no significant differences in all the parameters recorded. Comparing both techniques no significant differences could be detected in the follow-up period. Nevertheless, both techniques showed significant improvements in the severity of symptoms and pain, in sensory nerve testing and in electro-diagnostic parameters, when comparing pre- with postoperative data after 1 year. The endoscopic approach revealed no distinct advantages over the open technique not only in the late but also in the early postoperative follow-up period when performing intra-individual comparison. Considering the higher complication rate and costs when performing 2-PER the OR with two minimised incisions seems to be a good alternative in order to keep the recovery period as short as possible. [Copyright &y& Elsevier]

Abstract: Objective: The aims of this study were to analyze normative data of nerve conduction studies (NCS) by optimal transformations, and compare the utility of electrodiagnostic tests in detecting mild carpal tunnel syndrome (CTS). Methods: In 131 hands of patients with mild CTS and 136 hands of controls, the segmental study of the median nerve between the digit–palm and palm–wrist segments, and the median-to-ulnar and median-to-radial comparative tests were performed. Normal limits were derived by calculating the mean±2 standard deviations of the optimally transformed data of the controls. The specificity, sensitivity, and misclassification rate were calculated to evaluate the utility of each test. Results: All tests had high specificities, ranging from 98.5 to 100%. The distoproximal latency ratio (DPLR) of the median nerve showed the highest sensitivity and the difference between the median and radial sensory latencies (D1M−D1R) the second highest, but there was no statistical difference between them. The difference between the median and ulnar mixed nerve latencies in the palm-to-wrist segment (PM−PU) showed the lowest sensitivity. Misclassification rates of the DPLR, D1M−D1R, and PM−PU were 6.9, 3.8, and 6.1%, respectively. Conclusions: Optimal transformation of NCS data is mandatory to diminish the effect of skewness and enhance the diagnostic accuracy. As compared to the comparative tests, the segmental study of the median nerve is more easily applied and yields higher sensitivity in detecting mild CTS. Significance: With a high diagnostic yield and easy application, the segmental study of the median nerve may routinely be used to evaluate patients with mild CTS. [Copyright &y& Elsevier]

Purpose: To identify the change score in the Symptom Severity Scale (SSS) of the Carpal Tunnel Syndrome (CTS) Questionnaire that is associated with an important change in clinical status. Methods: Twenty-eight patients with CTS treated with a carpal tunnel steroid injection completed the Brigham and Women’s Hospital CTS Questionnaire before steroid injections and at the 3-week follow-up visit. Satisfaction was determined by postcare review of the clinical management. To calculate the minimal clinically important difference, receiver operating characteristic curves were created. The area under the curve was calculated to determine and compare the responsiveness of the entire SSS and the pain and sensory questions in isolation. Results: The SSS of the CTS Questionnaire, including its pain and sensory domain, can show a meaningful clinical improvement after carpal tunnel injection. The SSS, its sensory domain, and its pain domain were statistically better than chance. All 3 measures showed predictive ability; however, the total SSS was the most sensitive in detecting a change. The minimal clinically important difference in the score of the SSS after carpal tunnel steroid injection was found to be 1.04. Conclusions: The SSS can be used to distinguish a clinically important change after carpal tunnel injection. A decrease of 1.04 or more in the SSS score may indicate a clinically important change in a patient’s state of health. Type of study/level of evidence: Prognostic, Level I. [Copyright &y& Elsevier]

Purpose: Traditional evaluation of suspected carpal tunnel syndrome (CTS) involves a thorough history, physical examination, and nerve conduction velocity studies (NCS). Ultrasound is used widely in Europe and has gained acceptance in the United States in the diagnosis of various musculoskeletal disorders. The purpose of this study was to document the ultrasonographic measurement difference in median nerve size between patients with CTS and controls and to correlate these findings with NCS findings, thereby allowing us to test the validity of ultrasound as a diagnostic modality for CTS. Methods: Forty-four wrists in 26 CTS patients and 86 wrists in 43 asymptomatic volunteers were imaged using a real-time ultrasound scanner with a 12/5 MHz linear-array transducer. The cross-sectional area of the median nerve was measured at the level of the distal wrist crease in both CTS patients and controls. All CTS patients had NCS. The ultrasonographic median nerve area was compared for the 2 groups and correlation analysis between ultrasonographic nerve sizes and NCS findings was performed. Results: The average cross-sectional area of the median nerve at the distal wrist crease was 9 mm2 in asymptomatic volunteers and 14 mm2 in CTS patients. For the CTS patients the Pearson correlation coefficient between ultrasound nerve measurement and NCS values was 0.37, suggesting that higher values of ultrasound measurements are associated with abnormal NCS findings. Conclusions: Our results indicate that high-resolution ultrasound is informative in the evaluation of CTS and shows enlargement of the median nerve at the distal wrist crease in symptomatic patients. Therefore it is a reliable modality for imaging the wrist in patients with CTS. In addition ultrasound is well tolerated and safe. Type of study/level of evidence: Diagnostic, Level I. [Copyright &y& Elsevier]

Abstract: Background: In carpal tunnel syndrome (CTS), certain changes were expected in sympathetic skin response (SSR) because median nerve carries postganglionic unmyelinated fibres. Purpose: To investigate the median and ulnar SSR in idiopathic and diabetic CTS without autonomic dysfunction in hands and to find possible relations with electrophysiological features of these diseases. Patients and methods: SSRs were elicited by electrical stimulation on the supraorbital nerve and recorded from the median and ulnar territories in the hand from 20 diabetic patients with only CTS (29 hands), 24 idiopathic CTS patients (42 hands) and 13 normal subjects (26 hands). Hands with ulnar neuropathy at the wrist without symptoms and normal hands of unilateral CTS were excluded. In addition to classical parameters and comparative methods, SSR waveform changes and percentile method was used in finding abnormality. Results: Median SSRs had significant delayed latency compared to ulnar latency in both CTS patients but this was not important clinically (1.38/1.37s for idiopatic CTS; 1.43/1.36s for diabetic CTS). Median and ulnar SSR amplitude, area, median/ulnar latency difference, amplitude and area ratio were compared and only median/ulnar latency difference and median/ulnar latency ratio were found different between the three groups. Four idiopathic CTS hands were outside of the limits or absent (9.5%). SSR waveforms were significantly different from normal subjects in CTS patients. P type SSR replaced M type in idiopathic CTS and N type in diabetic CTS. Conclusions: Findings regarding SSR parameters suggest that unmyelinated C fibers were affected in CTS. These values were not useful because they were too small. Data on SSR were not normally distributed and the percentile method seems to be more convenient for finding any abnormality in clinical practice. Also, SSR waveform analysis could give us valuable data and should add to the SSR examination parameters. [Copyright &y& Elsevier]

Abstract: Objective: To determine normative cutoffs and sensitivities for median distal latency (MDL), median–thenar to ulnar–thenar latency difference (TTLD), and median–thenar to ulnar–hypothenar latency difference (THLD) at various amplifier gains for carpal tunnel syndrome (CTS) electrodiagnosis. A prior study utilized only an amplifier gain of 0.2mV/division. Methods: Abnormal cutoffs for MDL, TTLD and THLD were determined based on 34 control hands at gains of 0.2, 0.5, 1, 2, and 5mV. Diagnostic sensitivities were determined for 50 patients (80 hands) with clinically and electrodiagnostically defined CTS. Results: At a gain of 0.2 and 0.5mV/division, abnormal cutoffs for MDL, THLD, and TTLD were: 3.7, 1.2, and 0.8ms. At gains of 1, 2, and 5mV the abnormal cutoffs were 4, 1.2, and 1ms. The sensitivities at gains of 0.2, 0.5, 1, 2, and 5mV for MDL, THLD, and TTLD were: 65, 66, 53, 57, 61/86, 83, 88, 86, 86/91, 91, 76, 73, 59. Conclusions: MDL and THLD sensitivities are gain-independent. THLD is substantially more sensitive than MDL at all gains. TTLD sensitivity is maximized with 0.2 and 0.5mV gains. Significance: TTLD and THLD increase diagnostic sensitivity with minimal additional effort. TTLD sensitivity is maximized with 0.2 or 0.5mV gains. The electromyographer''s preferred gain may be used. [Copyright &y& Elsevier]

Abstract: The affect of muscle length and voluntary contraction upon compound muscle action potentials (CMAPs) in subjects with carpal tunnel syndrome (CTS) has been evaluated. Twenty-five hands in a CTS patient group and 29 hands in a normal subject control group were studied. The CMAPs from the abductor pollicis brevis induced by median nerve stimulation at the wrist were obtained for five thumb positions: neutral, abduction for shortening with and without contraction, and adduction for lengthening with and without contraction. Upon muscle shortening with relaxation, CMAP duration decreased in both groups, whereas waveform amplitude increased in the control group and showed no significant change in the CTS group. Muscle shortening with contraction afforded decreased CMAP duration and increased CMAP amplitude in both groups. Upon muscle lengthening with relaxation, both groups showed a reduction in CMAP amplitude and an increase in CMAP duration. Upon lengthening with contraction, CMAP duration decreased in the control group; in contrast, the CTS group showed further amplitude reduction and the waveform duration returned to the neutral value. These results demonstrate that, in patients with CTS, physiologic CMAP summations by muscle shortening or contraction may be less effective, whereas decreases in amplitude and increases in duration may be accentuated by lengthening and contraction. [Copyright &y& Elsevier]

Purpose: To determine the outcomes of carpal tunnel decompression in elderly patients and whether outcomes can be predicted by the severity of presurgical nerve conduction study results. Methods: We performed a retrospective study of all patients over 70 years of age who had elective carpal tunnel release at Dunedin Hospital between April 1999 and April 2002 with a minimum of 1-year follow-up evaluation. A grading system for presurgical nerve conduction studies was formulated that scored patients from 1 to 6 according to severity. Patients were evaluated by a mailed questionnaire (Symptom Severity Score) with follow-up telephone calls to nonresponders. Results: Eighty-three carpal tunnel release procedures performed in 70 patients were included in the study. Eighty percent had marked to severe neurophysiologic changes (grades 4–6). The median postsurgical Symptom Severity Score was 1.3 (inter-quartile range, 1.1–1.7). Patients expressed satisfaction with the outcome of the surgery in 78 of 83 cases (94%). There was a significant relationship between presurgical nerve conduction grade and postsurgical Symptom Severity Score. Conclusions: This study shows that elderly patients have low postsurgical symptom scores and express high levels of satisfaction after surgery for carpal tunnel syndrome. There was a significant relationship between severity of neurophysiologic abnormalities and a higher Symptom Severity Score after surgery. Severe abnormality, however, should not exclude elderly patients from surgery. [Copyright &y& Elsevier]

Abstract: In ultrasound evaluation, median nerve can be measured quantitatively with a high reproducibility. In this study we looked for the diagnostic role of ultrasound in the carpal tunnel syndrome and its correlation with some clinical tests as Phalen and Tinnel sign. Methods. – Twenty-four patients with signs and positive EMG results of CTS along with 14 age and sex matched healthy subjects were evaluated with ultrasound. The flattening ratios, cross-sectional areas of the nerve were calculated. The ultrasonographic results of the patient and control groups were compared with t-test. The correlations between clinical tests were investigated. Results.– Mean cross-sectional area of the median nerve in the carpal tunnel was 10.29 ± 3.39 mm2 proximally, 15.28 ± 6.16 mm2 in the middle, 13.78 ± 4.76 mm2 distally. Mean flattening ratio in the carpal tunnel was 2.20 ± 0.36 proximally, 2.61 ± 0.54 in the middle, 3.07–0.69 distally. In the control group the cross-sectional areas were as follows: 6.46 ± 0.72 mm2 proximally, 6.94 ± 0.72 mm2 in the middle, 6.65 ± 0.64 were mm2 distally; mean flattenning ratios were 1.76 ± 0.18 proximally, 2.00 ± 0.21 in the middle, 2.36 ± 0.23 distally. At all of the levels the cross-sectional areas were significantly different between the two groups (p < 0.001). The sonographic signs were found correlated with both Phalen test (r = 0.80, p < 0.001), and Tinnel sign (r = 0.70, p < 0.001). The sensitivity and specificity of ultrasound was 89% and 100%, respectively. Conclusion.– The combination of typical clinical symptoms and at least one pathologically increased sonographic measurement of median nerve is highly predictable for diagnosis of carpal tunnel syndrome. [Copyright &y& Elsevier]