Bilateral deficits in fine motor control and pinch grip force in patients with unilateral carpal tunnel syndrome

Subjects with carpal tunnel syndrome (CTS) typically describe self-perceived pinch grip deficits, clumsiness sensations and difficulty with grasping small objects, which suggest the existence of a fine motor control deficit. No previous studies have investigated fine motor control and pinch grip force bilaterally in patients diagnosed with moderate CTS. Our aim was to investigate differences in fine motor control ability and pinch grip force between patients with unilateral CTS and healthy controls. Subtests of the Purdue Pegboard Test (one-hand, bilateral and assembly) and pinch grip force were evaluated bilaterally in 20 women with unilateral CTS (aged 22–66 years), and 20 age and hand dominance-matched healthy women. Differences between sides (affected/unaffected or dominant/non-dominant) and groups (patients or controls) were analysed with an analysis of variance (ANOVA). The ANOVA found significant differences between both groups (F = 65.7; P < 0.001) and between sides (F = 5.4; P = 0.02) for the one-hand pin placement subtest: CTS patients showed bilateral worse scores on one-hand pin placement than controls (P < 0.001). Patients also showed significantly lower scores in bilateral pin placement and assembly subtests when compared to healthy controls (P < 0.001). The ANOVA also revealed significant differences between groups (F = 141.2; P < 0.001), and fingers (F = 142.2; P < 0.001), but not between sides (F = 0.9; P = 0.4) for pinch grip strength: CTS patients showed bilateral lower pinch grip force levels in all fingers when compared to controls (P < 0.001). Fine motor control and pinch grip were negatively related to the hand pain intensity and duration of symptoms history (all, P < 0.01). Our findings revealed bilateral deficits in fine motor control ability and pinch grip force in patients with unilateral moderate CTS when compared to controls.     

Sympathetic pathology evidenced by hand thermal anomalies in carpal tunnel syndrome.

OBJECTIVE: To clarify sympathetic pathology in carpal tunnel syndrome and the usefulness of digital infrared thermography as a diagnostic aid. MATERIAL AND METHODS: 38 clinically diagnosed carpal tunnel syndrome hands from 30 patients (confirmed by the standard nerve conduction studies) and 41 hands from 22 healthy volunteers (the hands having current finger inflammation were excluded) were studied. A series of hand infrared photos of each subject were taken and stored by using the technique of digital infrared thermography. We studied the infrared pictures and measured the temperatures of finger tips from digit 1 (D1) to digit 5 (D5), the center point of thenar (Th) and hypothenar eminences (Ht), then we calculated the temperature differences (absolute values) between each two of the 7 points, and median index (MI): (D1-D2)+(D2-D3)+(D1-D3). The means of D2 and Th (MD2+Th), D5 and Ht (MD5+Ht) were also calculated. RESULTS: The results showed that the temperatures of median nerve distribution area in the hands were highly significantly different (Th-Ht, p < 0.001, MI, p < 0.001) between carpal tunnel syndrome (CTS) and the control group. The differences between the median and ulnar nerve distribution area were also highly significantly different in CTS hands (MD2+Th compared to MD5+Ht, p < 0.01). The sensitivity and specificity of digital infrared thermography were 84 and 91%, respectively. CONCLUSION: Digital infrared thermography suggests sympathetic neural pathology in carpal tunnel syndrome. It may also be useful as an additional non-invasive tool in the diagnosis of CTS especially in the early stage.     

MR imaging and electrophysiological evaluation in carpal tunnel syndrome

The objective of this study was to compare the MRI findings of wrists in patients diagnosed with CTS with those of the healthy controls, and to evaluate the correlation between the MRI differences and the electrophysiological findings in the patient group. This study involved 55 wrists, 30 of which were clinically and electrophysiologically diagnosed with CTS and 25 healthy controls. These 55 wrists were evaluated electrophysiologically, and in terms of median nerve diameter, ratio of median nerve diameter at psiform bone level to distal radio-ulnar joint level, the flexor retinaculum bulging ratio and the median nerve intensity by MRI. When the patient group, which were clinically and electrophysiologically diagnosed with CTS, and the healthy control group were compared, a significant difference (p < 0.001) was observed between the two in terms of median nerve diameters (at psiform bone level: 8.47 +/- 1.41mm and 2.91 +/- 1.01 mm, distal radio-ulnar joint level: 4.04 +/- 1.06 mm and 2.42 +/- 0.95 mm), ratio of median nerve diameter at psiform bone level to distal radio-ulnar joint level (2.17 +/- 0.54 and 1.25 +/- 0.12), their flexor retinaculum bulging ratios (26.21 +/- 5.98% and 7.27 +/- 4.53%) and their median nerve intensities. In the patient group, no significant correlation between MRI and the electrophysiological findings was found (p > 0.05). According to the data obtained from the study, we believe that the MRI examination of structural changes that occur in the carpal tunnel, neighboring structures and the median nerve would be useful in the diagnosis of CTS, especially in cases with suspected clinical and electrophysiological diagnosis.     

Clinical, electrophysiological and magnetic resonance imaging findings in carpal tunnel syndrome

OBJECTIVE: To assess magnetic resonance imaging (MRI) findings in carpal tunnel syndrome (CTS) and to compare them with electrophysiological findings. METHODS: Routine motor and sensory nerve conduction examinations and needle EMG were performed in 42 hands of 22 patients, who were clinically diagnosed as having CTS in at least one wrist. RESULTS: Of 29 wrists with clinically and electrophysiologically confirmed CTS, MRI could detect abnormality in 18 wrists (62%). Median nerve was found to be abnormal in MRI in 1 of 2 wrists with suspected clinical symptoms and proven CTS by electrophysiological examination. MRI was abnormal in 1 of 4 wrists with normal clinical and electrophysiological examination. MRI was abnormal in 46, 7% of wrists with mild CTS, in 61.6% of moderate CTS and in 100% of severe CTS. Volar bulging of the flexor retinaculum was detected in a single wrist with severe CTS. Enlargement of median nerve was observed in 3 of 5 severe CTS. CONCLUSION: MRI could be useful in the diagnosis of unproven cases in CTS. It also provides anatomical information that correlate well with electrophysiological findings in regard of the severity of median nerve compression.     

腕管综合征患者的临床与神经电生理研究

目的：观察神经电生理检测对腕管综合征(CTS)的诊断价值。方法：对腕管综合征的临床特征及病因进行了分析，并作神经传导速度(NCV)和肌电图检测和分析。结果：40条患病神经中8条正中神经诱发波形消失，32条正中神经感觉潜伏期延长、波幅降低或(和)感觉神经传导速度减慢。25例患者伴有30条正中神经运动末梢潜伏期延长或(和)动作电位波幅降低。22块正中神经支配肌有去神经电位。结论：神经电生理检查在腕管综合征的诊断与鉴别诊断中有重要意义。     

腕管内压力测定在内镜下微创治疗腕管综合征中的应用

目的探讨腕管内压力测定在内镜下微创治疗腕管综合征中的应用。方法38例47腕应用内镜下微创松解腕横韧带治疗腕管综合征,其中16例21腕手术前后分别在休息位、屈腕位、伸腕位及Okutsu试验下作腕管内压力测定。结果在同一体位下,腕横韧带松解术后腕管内的压力与术前相比有明显降低(P<0.01)。结论根据手术前后腕管内压力的变化判断松解程度,避免因腕横韧带松解不完全而影响手术疗效,具有良好的临床实用价值。     

腕管综合征的神经电生理检测与容积传导问题

目的：探讨腕管综合征（CTS）患者神经电生理检测中的容积传导误差。方法：对17例患者进行顺向法与逆向法拇、环指感觉潜伏期测定，并对其结果进行比较分析。结果：8例患者顺向与逆向法检测结果不一致。顺向法检测出现二种形式的容积传导干扰。结论：在CTS的神经电生理诊断中，拇、环指潜伏期测定时，逆向法与顺向法并用可排除容积传导的干扰。     

CNS activation by noxious heat to the hand or foot: site-dependent delay in sensory but not emotion circuitry

Recently, functional magnetic resonance imaging has been used as a novel method of evaluating the CNS response to noxious stimuli. In a previous study, a prolonged noxious thermal stimulus applied to the dorsum of the hand produced more than one hemodynamic response that was temporally segregated. The two major responses displayed activation in primary sensory regions (classic pain circuitry) and regions involved in emotion (reward/aversion circuitry), respectively. In the current study, we applied the same thermal stimulus separately to the dorsum of the left foot and the dorsum of the left hand in the same subjects and compared the hemodynamic responses to evaluate the effects of conduction distance on CNS activation within these two segregated systems. After stimulus delivery to the foot, the hemodynamic response in primary sensory networks occurs after a delay of 3.6 +/- 1.3 s as compared with the response after hand stimulation. The relative delay of the hemodynamic response in reward/aversion regions is not significantly different between hand and foot stimulation (0.6 +/- 2.1 s). These results within the primary sensory system are consistent with the greater conduction distance of the peripheral nerves from the hand versus the foot. The observation that the response within the reward/aversion pathways occurs with the same rapid temporal characteristics after either hand or foot stimulation supports the notion that the circuitry involved in the evaluation of aversive stimuli is rapid in onset and probably represents a major protective mechanism for survival.     

Tapentadol,but not morphine,selectively inhibits disease-related thermal hyperalgesia in a mouse model of diabetic neuropathic pain

Neuropathic pain in diabetic patients is a common distressing symptom and remains a challenge for analgesic treatment. Selective inhibition of pathological pain sensation without modification of normal sensory function is a primary aim of analgesic treatment in chronic neuropathic pain. Tapentadol is a novel analgesic with two modes of action, μ-opioid receptor (MOR) agonism and noradrenaline (NA) reuptake inhibition. Mice were rendered diabetic by means of streptozotocin, and neuropathic hyperalgesia was assessed in a 50 °C hot plate test. Normal nociception was determined in control mice. Tapentadol (0.1–1 mg/kg i.v.) and morphine (0.1–3.16 mg/kg i.v.) dose-dependently attenuated heat-induced nociception in diabetic animals with full efficacy, reaching >80% at the highest doses tested. Tapentadol was more potent than morphine against heat hyperalgesia, with ED₅₀ (minimal effective dose) values of 0.32 (0.316) and 0.65 (1) mg/kg, respectively. Non-diabetic controls did not show significant anti-nociception with tapentadol up to the highest dose tested (1 mg/kg). In contrast, 3.16 mg/kg morphine, the dose that resulted in full anti-hyperalgesic efficacy under diabetic conditions, produced significant anti-nociception in non-diabetic controls. Selective inhibition of disease-related hyperalgesia by tapentadol suggests a possible advantage in the treatment of chronic neuropathic pain when compared with classical opioids, such as morphine. It is hypothesized that this superior efficacy profile of tapentadol is due to simultaneous activation of MOR and inhibition of NA reuptake.     

Gliding characteristics of flexor tendon and tenosynovium in carpal tunnel syndrome: a pilot study

The characteristic pathological finding in carpal tunnel syndrome (CTS) is noninflammatory fibrosis of the synovium. How this fibrosis might affect tendon function, if at all, is unknown. The subsynovial connective tissue (SSCT) lies between the flexor tendons and the visceral synovium (VS) of the ulnar tenosynovial bursa. Fibrosis of the SSCT may well affect its gliding characteristics. To investigate this possibility, the relative motion of the flexor tendon and VS was observed during finger flexion in patients undergoing carpal tunnel surgery, and for comparison in hands without CTS, in an in vitro cadaver model. We used a camera to document the gliding motion of the middle finger flexor digitorum superficialis (FDS III) tendon and SSCT in three patients with CTS during carpal tunnel release and compared this with simulated active flexion in three cadavers with no antemortem history of CTS. The data were digitized with the use of Analyze Software (Biomedical Imaging Resource, Mayo Clinic, Rochester, MN). In the CTS patients, the SSCT moved en bloc with the tendon, whereas, in the controls the SSCT moved smoothly and separately from the tendon. The ratio of VS to tendon motion was higher for the patients than in the cadaver controls. These findings suggest that in patients with CTS the synovial fibrosis has altered the gliding characteristics of the SSCT. The alterations in the gliding characteristics of the SSCT may affect the ability of the tendons in the carpal tunnel to glide independently from each other, or from the nearby median nerve. These abnormal tendon mechanics may play a role in the etiology of CTS.     

腕管综合征类固醇腕管局部注射的临床和电生理评估

目的：运用临床评分和神经传导检测（NCS）评估类固醇腕管局部注射对腕管综合征（CTS）的疗效。方法：2009年4月至2010年1月间就诊的CTS患者共66例,符合纳入标准者41例（64只腕）。进行症状严重程度评分（SSS）、功能状态评分（FSS）以及常规NCS,记录腕-拇短展肌末端运动潜伏期（DML）、拇短展肌复合肌肉动作电位（CMAP）波幅,腕-食指／环指感觉传导速度（SCV）、正中／尺神经感觉潜伏期差（△DSL）和感觉神经动作电位（SNAP）波幅。嘱患者改变生活方式且行夜间腕部夹板,2周后症状无好转者行类固醇腕管局部注射。紧挨掌长肌腱尺侧、腕皱褶近侧,用25号针头以30。角朝向腕管进针,注射利多卡因1ml（20mg）和甲基强的松龙1ml（40mg）。注射前、注射（3．23±0．56）个月后分别进行临床评分和NCS。结果：①18例（28只腕）进行了注射,12例（19只腕）完成随访。与注射前比较,注射后SSS和FSS减少、DML缩短、△DSL减小、腕-环指SCV增快、SNAPCMAP波幅增高。注射前、注射后SSS分别为（2．31±0．45）、（1．89±0．46）（t=5．82,P=0．000：FSS为（2．29±0．64）、（1．79±0．59）（t=5．21,P=0．000）;DML（ms）为（5．08±1．58）、（4．66±1．76）（t=2．81,P=0．012）;△DSL（ms）为（1．25±40．67）、（0．93±0．67）（t=3．90,P=0．002）;SCV（m／s）为（40．55±11．48）、（44．70±13．66）（t=-2．55,P=0．029）;SNAP波幅（uV）为（12．72±10．83）、（15．07±11．00）（t=-2．17,P=0．048）;CMAP波幅（mV）为（5．31±3．37）、（6．13±3．04）（t=-2．42,P=0．026）;3例（4只腕、21％）注射后临床评分无改善。②SSS、FSS与NCS各参数之间均无相关性（P均〉0．05）。结论：CTS患者类固醇腕管局部注射治疗至少在短期内有效;临床评分与NCS无相关性,两者共同评估疗效更有意义。     

Descending facilitatory influences from the rostral medial medulla mediate secondary, but not primary hyperalgesia in the rat

Prolonged nociceptive input following peripheral injury results in hyperalgesia (enhanced response to a noxious stimulus), which is thought to occur as a consequence of sensitization of primary afferent nociceptors and enhanced excitability of spinal dorsal horn nociceptive neurons (central sensitization). Since there is often an expansion of hyperalgesia to tissue adjacent, and even distant from the site of injury (secondary hyperalgesia), it is thought that this phenomenon primarily involves mechanisms of central modulation/plasticity. In contrast, hyperalgesia observed at the site of tissue injury (primary hyperalgesia) involves peripheral mechanisms. In the current study, we examined the relative contribution of descending nociceptive facilitatory systems from the rostral medial medulla to enhanced behavioral nociceptive responses in models of primary and secondary hyperalgesia in awake rats. The effect of bilateral rostral medial medulla lesions produced by the soma-selective neurotoxin ibotenic acid was determined in three different models of cutaneous thermal hyperalgesia following peripheral inflammation: (i) intraplantar injection of carrageenan into the hindpaw (model of primary hyperalgesia); (ii) intra-articular injection of carrageenan/kaolin into the knee of the hind leg (model of secondary hyperalgesia); and (iii) topical application of mustard oil to the hind leg (model of secondary hyperalgesia). Compared with sham lesion animals, a bilateral lesion of the rostral medial medulla completely blocked thermal hyperalgesia in the two models of secondary hyperalgesia (intra-articular carrageenan/kaolin injection into the knee and topical mustard oil application to the hind leg), but was ineffective in blocking facilitation of the thermal paw withdrawal response in the model of primary hyperalgesia (intraplantar carrageenan injection into the hindpaw). These results suggest that primary and secondary hyperalgesia are differentially modulated in the CNS, and support the notion that descending nociceptive facilitatory influences from the rostral medial medulla significantly contribute to secondary, but not primary, hyperalgesia.     

Comparison of short- and long-axis nerve hydrodissection for carpal tunnel syndrome: A prospective randomized,single-blind trial

Background: This study is to compare the efficacy of short-axis hydrodissection with long-axis hydrodissection for patients with mild-to-moderate carpal tunnel syndrome (CTS).Methods: Forty-seven patients with mild-to-moderate CTS were enrolled in a prospective, randomized, single-blinded, controlled trial (6 months follow-up). With ultrasound guidance, patients in both groups (short-axis or long-axis groups) were injected with normal saline (5 mL per session). Assessments were performed before and 2 weeks after the injection, as well as at 1, 3, and 6 months post-intervention. The primary outcome measure was the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) score and secondary outcomes included the cross-sectional area of the median nerve and electrophysiological studies.Results: Forty-four patients (21 wrists in the short-axis group and 23 wrists in the long-axis group) completed the study. Compared with the baseline, both groups showed improved BCTQ and cross-sectional area at all follow-up assessments (p<0.05). The short-axis group was not more effective except significant improvements in BCTQ-severity and BCTQ-function 1 month post-injection compared to the long-axis group (p = 0.031 and p = 0.023, respectively).Conclusions: Both short- and long-axis hydrodissection were effective for patients with mild-to-moderate CTS and the short-axis approach was not more effective than long-axis injection. Further studies with larger sample sizes, multiple injections, and larger injection volume are encouraged in the future.     

The effects of low level laser in clinical outcome and neurophysiological results of carpal tunnel syndrome

OBJECTIVES: Carpal tunnel syndrome (CTS) is the most common neuropathy that can be diagnosed with confidence by the nerve conduction study (NCS). One of the recent treatments of CTS is the application of low power laser (LPL) therapy. The present study evaluates the effects of LPL irradiation through NCS and clinical signs and symptoms. METHODS: A total of 80 patients were included in this study. Diagnosis of CTS was based on both clinical examination and electromyographic (EMG) findings. Patients were randomly assigned into two groups. Test group (group A) underwent laser therapy (9-11 joules/cm2) over the carpal tunnel area. Control group (group B) received sham laser therapy. Pain, hand grip strength, median proximal sensory and motor latencies, transcarpal median sensory nerve conduction (SNCV) were recorded. After fifteen sessions of irradiation (five times per week), parameters were recorded again and clinical symptoms were measured in both groups. Pain was evaluated by Visual Analog Scale (VAS; day-night). Hand grip was measured by Jamar dynometer. Paired t-test and independent sample t-test were used for statistical analysis. RESULTS: There was a significant improvement in clinical symptoms and hand grip in group A (p < 0.001). Proximal median sensory latency, distal median motor latency and median sensory latencies were significantly decreased (p < 0.001). Transcarpal median SNCV increased significantly after laser irradiation (p < 0.001). There were no significant changes in group B except changes in clinical symptoms (p < 0.001). CONCLUSIONS: Laser therapy as a new conservative treatment is effective in treating CTS paresthesia and numbness and improves the subjects' power of hand grip and electrophysiological parameters.     

47例腕管综合征患者的临床及神经电生理改变特征

目的：分析腕管综合征（CTS）患者临床及神经电生理改变特征,以提高临床诊断准确性。方法：对47例临床症状、体征均符合CTS患者的正中神经和尺神经各55条分别进行运动神经传导速度（MCV）和感觉神经传导速度（SCV）测定,其结果与正常参考值作比较;对拇短展肌和某些病例的掌长肌作针极肌电图（EMG）,观察失神经电位以作鉴别诊断。结果：本组正中神经肘-腕MCV有6条未引出动作电位,41条正常,8条减慢,平均MCV较正常参考值减慢,差异有显著意义（P％0．05）;正中神经远端潜伏期（DML）异常率为96％,平均DML较正常参考值延长,经比较差异有显著意义（P〈0．05）;尺神经肘-腕MCV均在正常范围,其DML异常率为2％,与正常参考值比较差异无统计学意义;正中神经SCV异常率为98％;尺神经SCV异常率为2％;47例共55块拇短展肌EMG有49％见失神经电位。结论：结合临床及神经电生理改变特点,可对CTS作出明确诊断,为治疗提供依据。     

Diathermy treatment increases heat shock protein expression in female,but not male skeletal muscle

Heat shock treatments have been used to appreciably increase heat shock protein 70 (Hsp70) content and the phosphorylation of heat shock protein 27 (Hsp27p). The purpose of this investigation was to determine whether diathermy can increase Hsp70 and Hsp27p content in skeletal muscle. Fourteen subjects (7 males and 7 females, 18–35 years) received a muscle biopsy from the v. lateralis and then underwent 20 min of diathermy followed by 20 min of hot pack heating on the contralateral leg. Twenty-four hours following treatment, a second muscle biopsy was performed on the treated leg. All samples were analyzed for Hsp70 and Hsp27p content using western immunoblotting. Images of the blots were obtained and analyzed via densitometry. A paired t-test was used to examine differences in heat shock protein content between the treated and untreated legs. Twenty-four hours following the heat treatment, female subjects significantly (P < 0.05) increased Hsp70 (+58%) and Hsp27p (+100%) content compared to the untreated leg. Male subjects had non-significant increases in Hsp70 (+35%) and Hsp27p (+32%) skeletal muscle content. These results implicate that diathermy can be an effective means to induce Hsp70 and Hsp27p in human skeletal muscle.     

Role of fasciae around the median nerve in pathogenesis of carpal tunnel syndrome: microscopic and ultrasound study

This study investigated the connections between the median nerve paraneural sheath and myofascial structures near it, from both macroscopic and microscopic points of view. Four samples of median nerve and surrounding tissues were excised from nine non-embalmed upper limbs for microscopic analysis. Ultrasound images were analysed in 21 healthy subjects and 16 carpal tunnel syndrome patients to evaluate median nerve transversal displacement during finger motion at carpal tunnel and forearm levels. An anatomical continuity between epimysium and paraneural sheath and a reduction of paraneural fat tissue from proximal to distal was found in all samples. Median nerve displacements at both levels were significantly reduced in carpal tunnel syndrome subjects (P < 0.001). It was observed that the median nerve is not an isolated structure but is entirely connected to myofascial structures. Therefore, unbalanced tension of epimysial fasciae can affect the paraneural sheath, limiting nerve displacement, and consequently this must be included in carpal tunnel syndrome pathogenesis.