Wrist flexion as an adjunct to the diagnosis of carpal tunnel syndrome

The effects of five minutes of wrist flexion on median motor and sensory evoked potential latencies in 87 individuals were studied. Nineteen subjects had carpal tunnel syndrome (CTS) as diagnosed by increased median nerve latencies across the wrist, and 68 had values in the normal range and were assigned to the control group. A slight prolongation of up to 0.5m sec of evoked potential latencies was observed in both groups after flexion, but the differences between the two groups were not significant to establish the value of adding wrist flexion to conventional screening methods.     

Carpal tunnel syndrome: the new 'industrial epidemic'

1. Symptoms of carpal tunnel syndrome (CTS) include numbness, tingling, and decreased sensation in the fingers. 2. The main occupational causes of CTS include repetitive wrist flexion and extension, strong gripping with ulnar deviation, impact forces on the palm, and vibratory forces. 3. Conservative treatment includes a metal-reinforced splint that prevents flexion and extension of the wrist. Surgical treatment may be needed for severe symptoms. 4. Prevention of CTS requires early diagnosis, job reassignment, and tool redesign.     

Carpal tunnel syndrome in patients on long-term hemodialysis

Sixteen cases with carpal tunnel syndrome (CTS) were reported out of 412 patients on long-term hemodialysis due to chronic renal failure. Clinical symptoms included numbness in the area innervated by the median nerve in 100% of symptomatic hands and pain in the wrist and hand in 81%. This pain usually became severer at night and during hemodialysis. Muscle atrophy was noted in 41% of the hands. Nerve conduction studies revealed prolonged distal sensory latency, slowed sensory nerve conduction velocity across the wrist and normal distal motor latency in 18%, prolonged distal motor latency in 51% and no response in motor or sensory stimulation in 31%. Evidence of denervation on electromyography was seen in 36% of the hands. Patients were conservatively treated avoiding daily activities precipitating the condition with volar wrist splint only at night in 18% and in 90% with steroid hormone injection in the carpal tunnel. Median nerve release was performed in 18% of the hands. Amyloid deposit was demonstrated in 3 of 4 operated hands. Although the relation between long-term hemodialysis and the occurrence of the amyloid deposition in the carpal tunnel has not been established, the present data along with other recent reports strongly indicate that amyloid deposit in the carpal tunnel on hemodialysis patients could be one of the most possible cause of CTS.     

High-resolution ultrasonography of the carpal tunnel

Twenty-eight wrists of 25 patients with carpal tunnel syndrome (CTS) and 28 wrists of 14 normal control subjects were studied with high-frequency real-time ultrasonography. Three general findings could be observed in CTS, regardless of its cause: swelling of the median nerve at the entrance of the carpal tunnel; flattening of the median nerve in the distal carpal tunnel; and increased palmar flexion of the transverse carpal ligament. Quantitative analysis proved these findings to be significant. We conclude that high-resolution sonography is able to diagnose median nerve compression in the carpal tunnel syndrome and to detect some of its potential causes.     

80例腕管综合征患者的神经电生理测定

目的：观察神经电生理检测对腕管综合征(CTS)的诊断敏感性。方法：80例临床提示为CTS或不能除外CTS的患者进行神经电生理测定并进行回顾性分析。结果：80例116侧正中神经复合肌肉动作电位末端运动潜伏期和波幅、肘至腕的运动传导速度、指至腕部的感觉传导速度及感觉神经动作电位波幅等5项指标检测异常率分别为75．0％、19．8％、9．5％、88．8％及37．9％；45例65侧拇指正中／桡浅神经潜伏期差(MRLD)及环指正中／尺神经潜伏期差(MULD)检测异常率95．4％。结论：正中神经拇指至腕段的感觉传导速度测定是诊断CTS的敏感指标，采用MRLD及MULD测定，诊断敏感性更高。     

Carpal tunnel syndrome caused by gouty tophus of the flexor tendons of the fingers: sonographic features

We report the case of a 23-year-old male presenting with carpal tunnel syndrome and a swelling over the flexor surface of the wrist. MRI findings were initially suggestive of a median nerve schwannoma but sonography (US) showed a heterogenous mass infiltrating the flexor tendons of the fingers and displacing the median nerve in the carpal tunnel. US findings were confirmed by surgical exploration, which revealed a gouty tophus of the flexor tendons of the fingers at the wrist with secondary median nerve displacement and compression.     

Electrodiagnosis of mild carpal tunnel syndrome

Electrophysiologic tests have been reported to detect mild carpal tunnel syndrome (CTS). Such tests include (i) absolute palmar latency of median wrist segment; (ii) comparison of median and radial distal sensory latencies in digit I; (iii) comparison of median and ulnar distal sensory latencies in digit IV; (iv) comparison of median and ulnar palmar latencies; (v) comparison of median and ulnar sensory potential amplitudes in digits II and V. To clarify the clinical utility of these tests, the parameters of all five tests were determined across four carefully established patient subgroups: group A, controls; group B, CTS referrals with normal nerve conduction studies (NCS) and normal needle electromyography (EMG); group C, CTS referrals with abnormal NCS and normal EMG; group D, CTS referrals with abnormal NCS and abnormal EMG. Special attention was focused on patients in group B who represent the diagnostic dilemma. In group B, tests ii and iii each yielded abnormal results in 44% of hands, while the combination of tests ii and iii yielded abnormal results in 51% of hands.     

The carpal tunnel syndrome.

Chronic carpal tunnel syndrome was initially described by James Jackson Putnam in 1880. A number of medical luminaries have also contributed to our understanding of the syndrome, including Paget, Marie, Ramsay Hunt, Phalen. and Osler. Carpal tunnel syndrome is the most common peripheral compression neuropathy. Most cases are idiopathic, with nonspecific tenosynovitis leading to median nerve compression. A number of diseases and other conditions are also associated with chronic carpal tunnel. Patients characteristically complain of nocturnal paresthesias or burning pain. Motor complaints relate to thenar muscular weakness and atrophy. Bedside diagnostic tests include Tinel's and Phalen's signs, and application of pressure over the median nerve by inflating a sphygmomanometer over the wrist. Tinel's sign is the induction of paresthesias by tapping over the site of the median nerve at the wrist. In Phalen's sign, symptoms are reproduced by maximum flexion of the wrist for 60 s. The classically described patients are middle-aged women. In addition, another distinct population is receiving increased attention, the relatively young male and female workers who experience symptoms performing repetitive manual labor.     

Randomized controlled trial of nocturnal splinting for active workers with symptoms of carpal tunnel syndrome

OBJECTIVES: To determine whether nocturnal splinting of workers identified through active surveillance with symptoms consistent with carpal tunnel syndrome (CTS) would improve symptoms and median nerve function as well as impact medical care. DESIGN: Randomized controlled trial. SETTING: A Midwestern auto assembly plant. PARTICIPANTS: Active workers with symptoms suggestive of CTS based on a hand diagram. INTERVENTION: The treatment group received customized wrist splints, which were worn at night for 6 weeks; the control group received ergonomic education alone. MAIN OUTCOME MEASURES: Change in wrist, hand, and/or finger discomfort, carpal tunnel symptom severity index, median sensory nerve function, and the percentage of subjects who had carpal tunnel release surgery. RESULTS: The splinted group, unlike the controls, had a significant reduction in wrist, hand, and/or finger discomfort and a similar trend in the Levine carpal tunnel symptom severity index, which was maintained at 12 months. A secondary analysis showed that more median nerve impairment at baseline was associated with less clinical improvement among controls but not among the splinted group. CONCLUSIONS: Workers identified with CTS symptoms in an active symptom surveillance tended to benefit from a 6-week nocturnal splinting trial, and the benefits were still evident at the 1-year follow-up. The splinted group improved in terms of hand discomfort regardless of the degree of median nerve impairment, whereas the controls showed improvement only among subjects with normal median nerve function. Results suggest that a short course of nocturnal splinting may reduce wrist, hand, and/or finger discomfort among active workers with symptoms consistent with CTS.     

高频超声在腕管综合征病因学评价中的应用

目的探讨高频超声在评价腕管综合征病因中的作用。 方法选取2015年3月至2019年12月在解放军总医院经电生理检查诊断或手术证实腕管综合征的患者,首先对腕管进行灰阶超声检查,观察腕管内正中神经的位置、走向,神经受压情况、神经束结构、神经外膜回声以及神经周围结构的异常,横切面扫查腕管及正中神经时观察正中神经横截面情况、测量豌豆骨平面正中神经的横截面积以及观察神经周围结构的异常;应用能量多普勒超声以观察正中神经及腕管内其他结构的血流情况。采用独立样本t检验比较患侧腕和无症状侧腕豌豆骨平面正中神经横截面面积的差异。利用受试者操作特征（ROC）曲线分析豌豆骨平面正中神经的横截面面积的诊断价值并找出最佳的诊断界值。 结果腕管综合征患者63例,共95侧腕。腕管综合征患者高频超声表现为腕管内正中神经的卡压近端肿胀、增粗,神经束结构模糊,神经外膜增厚。能量多普勒超声显示正中神经内血流信号增加。患侧腕与无症状侧腕的豌豆骨平面正中神经横截面面积比较［（15.91±5.95）mm² vs（8.71±1.62）mm²］,差异具有统计学意义（t=-2.51,P＜0.001）,ROC曲线下面积为0.946,截断值为10.5 mm2时,敏感度为89.5%,特异度为83.9%。高频超声诊断为特发性腕管综合征者73侧腕（76.8%,73/95）,可明确诊断病因的共22侧腕（23.2%,22/95）,其中13侧腕（13.7%,13/95）为腕管内屈肌腱腱鞘炎,1侧腕（1.1%,1/95）为腕管内屈肌腱腱鞘积液,2侧腕（2.1%,2/95）为腕管内腱鞘囊肿,1侧腕（1.1%,1/95）为腕管内实性肿块,2侧腕（2.1%,2/95）为腕管内指浅屈肌肌腹过低,2侧腕（2.1%,2/95）为正中神经高位分叉伴永存正中动脉,1侧腕（1.1%,1/95）为桡骨远端术后瘢痕压迫正中神经。 结论高频超声可作为评估腕管综合征病因的一种手段。     

Day-to-day variability of median nerve location within the carpal tunnel

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, 3.0 T 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.     

正中神经压迫试验对腕管综合征神经传导速度的影响

目的比较正中神经压迫试验对腕管综合征（carpal tunnel syndrome,CTS）患者正中神经传导速度的影响。方法设置CTS组和对照组两个组别,共29例受试者纳入研究。CTS组为14例CTS患者,对照组为15例健康受试者。神经传导速度测定包括正中神经和尺神经的感觉传导末端潜伏期（distal sensory latency,DSL）、感觉神经动作电位（sensory nerve action potential,SNAP）、跨腕关节感觉传导速度（sensory conduction velocity,SCV）、运动传导末端潜伏期（distal motor latency,DML）及复合肌肉动作电位（compound muscle action potential,CMAP）。先测感觉传导,再测运动传导。正中神经压迫试验5min后再次测量上述指标。结果正中神经压迫试验前后电生理检查考虑诊断CTS分别为22侧和24侧。压迫正中神经后,CTS组正中神经DSL较压迫前显著延长（P〈0.05）。CTS组尺神经和对照组正中神经及尺神经的各参数在压迫前后均无显著改变（P〉0.05）。与对照组相比,在压迫试验前后CTS组的正中神经DSL和DML均明显延长（P〈0.05）,尺神经DSL和DML均无显著改变（P〉0.05）。结论正中神经压迫试验5min能使CTS患者正中神经的感觉传导末端潜伏时明显延长,有助于提高神经传导测定对早期CTS的诊断率。     

Lack of predictive power of the "tethered" median stress test in suspected carpal tunnel syndrome

OBJECTIVE: To investigate the value of the "tethered" median nerve stress test (TMST) in predicting electrodiagnostically confirmed carpal tunnel syndrome (CTS) in patients with symptoms suggestive of CTS. STUDY DESIGN: Blinded comparison of a clinical diagnostic test with neurophysiologic testing. SETTING: Portland (OR) Veterans Administration Medical Center Electrodiagnostic Laboratory. PATIENTS: One hundred two consecutive patients referred for symptoms suggestive of CTS. Study inclusion criteria were referral for evaluation of symptoms of paresthesia (with or without pain) inclusive of the median nerve distribution distal to the wrist. RESULTS: Fifty-seven percent of referred patients had electrodiagnostically confirmed CTS. The sensitivity of the TMST was 50%. The specificity was 59.1%. The positive predictive value was 61.7%. The negative predictive value was 47.3%. CONCLUSION: The TMST does not have utility in predicting electrodiagnostic consult results in veteran patients with symptoms suggestive of CTS.     

Automated Segmentation of the Median Nerve in the Carpal Tunnel using U-Net

Nerve area and motion in carpal tunnel syndrome (CTS) are currently under investigation in terms of prognostic potential. Therefore, there is increasing interest in non-invasive measurement of the nerve using ultrasound. Manual segmentation is time consuming and subject to inter-rater variation, providing an opportunity for automation. Dynamic ultrasound images (n = 5560) of carpal tunnels from 99 clinically diagnosed CTS patients were used to train a U-Net-shaped neural network. The best results from the U-Net were achieved with a location primer as initial region of interest for the segmentations during finger flexion (Dice coefficient = 0.88). This is comparable to the manual Dice measure of 0.92 and higher than the resulting automated Dice measure of wrist flexion (0.81). Although there is a dependency on image quality, a trained U-Net can reliably be used in the assessment of ultrasound-acquired median nerve size and mobility, considerably decreasing manual effort.     

Trigger finger at the wrist caused by an intramuscular lipoma within the carpal tunnel: A case report

BACKGROUNDTrigger finger at the wrist, which occurs with finger movement, is an uncommon presentation. Few reports describing cases of trigger finger at the wrist have been published. Thus, we present a case of an intramuscular lipoma arising from an anomalous flexor digitorum muscle belly in a 48-year-old female patient causing painful finger triggering at the wrist and carpal tunnel syndrome (CTS).CASE SUMMARYA 48-year-old woman with complaints of a catching sensation during wrist motion and a progressive tingling sensation on the palmar aspect of the right hand for approximately 2 years was referred to our hospital. Triggering of the index to middle finger was evident with a palpable and audible clunk over the carpal tunnel during passive motion. Tinel’s sign was positive over the carpal tunnel of the right wrist with a positive Phalen’s test. Nerve conduction studies of the median nerve demonstrated a right CTS. Ultrasound examination revealed a 2.5 cm × 2.0 cm subcutaneous hyperechoic mass with no obvious blood flow at the wrist of the right arm. Surgical excision of the tumor and muscle mass led to a resolution of the patient’s symptoms, and any triggering or discomfort disappeared. The patient has had no evidence of recurrence at more than 1 year of follow-up.CONCLUSIONTriggering of the fingers at the wrist is rare. It must be noted that there are many possible causes and types of triggering or clicking around the wrist. Accurate diagnosis is mandatory to avoid inaccurate treatment of patients with trigger wrist. During the diagnosis and treatment of CTS, attention should be paid to the variation of tendon tissue in the carpal tunnel, to avoid only focusing on the release of transverse carpal ligament and ignoring the removal of anomalous muscle belly.     

Transverse Ultrasound Assessment of Median Nerve Deformation and Displacement in the Human Carpal Tunnel during Wrist Movements

The symptoms of carpal tunnel syndrome, a compression neuropathy of the median nerve at the wrist, are aggravated by wrist motion, but the effect of these motions on median nerve motion are unknown. To better understand the biomechanics of the abnormal nerve, it is first necessary to understand normal nerve movement. The purpose of this study was to evaluate the deformation and displacement of the normal median nerve at the proximal carpal tunnel level on transverse ultrasound images during different wrist movements, to have a baseline for comparison with abnormal movements. Dynamic ultrasound images of both wrists of 10 asymptomatic volunteers were obtained during wrist maximal flexion, extension and ulnar deviation. To simplify the analysis, the initial and final shape and position of the median nerve were measured and analyzed. The circularity of the median nerve was significantly increased and the aspect ratio and perimeter were significantly decreased in the final image compared with the first image during wrist flexion with finger extension, wrist flexion with finger flexion and wrist ulnar deviation with finger extension (p < 0.01). There were significant differences in median nerve displacement vector between finger flexion, wrist flexion with finger extension and wrist ulnar deviation with finger extension (all p's < 0.001). The mean amplitudes of median nerve motion in wrist flexion with finger extension (2.36 ± 0.79 normalized units [NU]), wrist flexion with finger flexion (2.46 ± 0.84 NU) and wrist ulnar deviation with finger extension (2.86 ± 0.51 NU) were higher than those in finger flexion (0.82 ± 0.33 NU), wrist extension with finger extension (0.77 ± 0.46 NU) and wrist extension with finger flexion (0.81 ± 0.58 NU) (p < 0.0001). In the normal carpal tunnel, wrist flexion and ulnar deviation could induce significant transverse displacement and deformation of the median nerve.     

高频超声对ECTR术后神经解剖学参数的动态评估价值

目的 探讨高频超声对关节镜下腕管松解术后神经解剖学参数的动态评估价值。方法 随访31例（44腕）腕管综合症患者术前3天,术后2周、4周、3月、6月、1年正中神经卡压近端水肿范围、腕管入口正中神经直径及横截面积,并根据横截面积绘制高频超声诊断腕管综合征ROC曲线。结果 术后各神经解剖学参数逐步改善,术后1个月至3个月各解剖学参数改善最明显。高频超声对CTS具有较高的诊断效能。结论 高频超声能够对关节镜下腕管松解术后神经解剖学参数进行有效地的动态评估。     

Morphological and positional changes of the carpal arch and median nerve associated with wrist deviations

BackgroundCarpal tunnel and median nerve dynamically change with wrist motion. The purpose of this study was to investigate the morphological changes and positional migration of the carpal arch and median nerve, as well as nerve-arch positional relationship associated with wrist deviation in healthy volunteers.MethodsTwenty asymptomatic male volunteers performed wrist motion from neutral to deviated positions combining flexion-extension and radioulnar deviation. Ultrasound images of the carpal arch and median nerve at the distal carpal tunnel were collected during wrist motion. Morphological and positional parameters of the carpal arch and median nerve were derived from the ultrasound images.FindingsCarpal arch height, area, and palmar bowing of the transverse carpal ligament (TCL) increased with flexion related wrist motion and decreased with extension related motion (P < 0.05). Arch width increased with radial flexion and decreased with extension and ulnar extension (P < 0.05). Median nerve circularity increased with flexion and radial flexion but decreased with extension, ulnar extension, and ulnar deviation (P < 0.05). Nerve centroid displaced ulnarly with radial deviation, radial flexion, and radial extension and displaced radially with ulnar deviation, ulnar flexion, and ulnar extension (P < 0.05). Nerve centroid displaced in the dorsal direction with flexion and radial flexion, but in the palmar direction with extension (P < 0.05). Nerve-TCL distance increased with flexion related motion and decreased with extension relation motion (P < 0.05).InterpretationThe current study advances our understanding the effect of wrist motion on the carpal tunnel and its contents, which has implications for pathomorphological and pathokinematic changes associated with wrist disorders.     

Restless hand symptoms in carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is a nerve entrapment disorder, involving the median nerve when it passes the carpal tunnel at the wrist. Using a case-control methodology, 312 electrophysiologically confirmed CTS patients with mean age of 51.3+/-9.4 (27-74) years (81.7% women) and 100 controls with mean age of 50.4+/-9.2 (21-88) years (75% women) were examined utilising a questionnaire similar to the clinical diagnostic criteria of restless legs syndrome (RLS). Forty-four (14.1%) of the CTS patients have symptoms compatible with restless hand syndrome compared with none (0%) in the control group (p < 0.0001). The severity of CTS was not significantly associated with the motor restlessness. Our observations suggest that entrapment syndromes such as CTS can be associated with a form of restlessness in the hands, analogous to RLS.     

Reduced longitudinal excursion of the median nerve in carpal tunnel syndrome

OBJECTIVE: To determine if longitudinal excursion of the median nerve is reduced in patients with carpal tunnel syndrome (CTS). DESIGN: Case-control study. SETTING: University human movement laboratory. PARTICIPANTS: Nineteen patients with CTS (8 men, 11 women; mean age, 57+/-15 y), and 37 healthy controls (8 men, 29 women; mean age, 48+/-10 y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Longitudinal excursion of the median nerve, and the ratio of nerve to flexor digitorum superficialis tendon excursion at the carpal tunnel evoked by finger extension. Measurements were taken using a validated Doppler ultrasound technique, and tests were conducted with the elbow positioned in extension and flexion. RESULTS: Mean longitudinal excursion of the median nerve was significantly greater in controls (11.2+/-2.8 mm) than patients (8.3+/-2.6 mm) with the elbow extended (P=.013), but not with the elbow flexed (controls, 12.5+/-2.5 mm; patients, 10.2+/-3.1 mm; P=.089). Mean nerve/tendon excursion ratios were significantly greater in controls (.32+/-.07) than patients (.23+/-.06), with the elbow extended (P<.001), and flexed (controls, .36+/-.06; patients, .28+/-.10; P=.019). Discriminant analysis identified that 11 (58%) of the 19 patients and 3 (8%) of the 37 controls showed a nerve/tendon excursion ratio of .25 or less when tested with the elbow in extension. CONCLUSIONS: Reduced longitudinal excursion of the median nerve at the carpal tunnel was identified in a substantial proportion of patients with CTS. Further studies are merited to determine if reduced median nerve excursion at the carpal tunnel is clinically relevant in CTS, and can be influenced by movement-based interventions.