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.     

Ultrasound Elastographic Evaluation in the Diagnosis of Carpal Tunnel Syndrome: Initial Findings

The purpose of this study was to investigate ultrasound (US)- and US elastography-detected changes in the median nerve of patients with carpal tunnel syndrome (CTS). Seventy-four wrists of 41 female patients with CTS (mean age, 47.73 ± 11.45 y) and 45 wrists of 24 asymptomatic female controls (mean age, 42.83 ± 10.66 y) were examined with US and US elastography. Electromyography results confirmed the diagnosis of CTS in the patients. The mean median nerve perimeter (MN-P = 15.26 ± 2.18 mm) and median nerve cross-sectional area (MN-CSA = 11.81 ± 4.05 mm²) of patients with CTS were higher than those of controls (12.08 ± 1.54 mm and 7.76 ± 1.40 mm², respectively) (p < 0.05). Mean tissue strain was lower in the patients with CTS (0.094 ± 0.045 than in the controls (0.145 ± 0.068) (p < 0.05). The most sensitive cut-off value for tissue strain was 0.0635, and the most specific was 0.19. US and US elastography, in addition to electromyography, proved to be beneficial in the diagnosis of CTS. US elastography is a new technique that may well find a place in the diagnosis of nerve entrapment syndromes.     

Restless legs syndrome - the under-recognised non-motor burden: a questionnaire-based cohort study

Objectives: Non-motor symptoms (NMS) range from neuropsychiatric to pain and are an important but underexplored feature of restless legs syndrome (RLS). There are currently no tools available which enable the holistic assessment of NMS in RLS in clinical practice. The primary aim of this study was to systematically assess NMS prevalence and burden in patients with RLS using the NMS Questionnaire (NMSQuest) validated for Parkinson’s disease.

Methods: Patients with idiopathic RLS according to the criteria of the international RLS study group (IRLSSG) were included. Patients underwent a physical examination and clinical interview as well as completed the NMS Questionnaire and the international restless legs syndrome study group (IRLSSG) rating scale.

Results: Seventy-four patients with primary RLS were included (mean age 64.6 ± 14.4 years, 62.2% female, mean disease duration 23.5 ± 17.8 years, mean Levodopa equivalent daily dose 63.3 ± 67.4 mg). On average patients reported an IRLSSG rating scale score of 24.8 ± 8.2 (maximum 40) and NMSQuest score of 9.9 ± 5.0 (maximum 30). Patients reported a minimum of two NMS with the majority (39.2%) reporting a moderate NMS burden, followed by severe (28.4%) and very severe (17.6%) burden. The most frequent NMS were insomnia (89.2%) followed by nocturia (70.3%), feeling sad (59.5%), forgetfulness (54.1%), urgency (47.3%), feeling anxious (43.2%), unexplained pain (41.9%), difficulty concentrating (40.5%) and dizziness (40.5%). There were no significant differences in NMSQuest total scores according to disease duration and gender (p = 0.739, p = 0.849).

Conclusion: In conclusion, this study is one of the first to address NMS in RLS systematically and the data underlines the need to holistically assess NMS in RLS in order to deliver true value-based healthcare for these patients.     

Comparative diagnostic sensitivities of orthodromic or antidromic sensory inching test in mild carpal tunnel syndrome

OBJECTIVES: To compare the reliability, sensitivity, and specificity of the "inching test" (IT) or "centimetric test," performed orthodromically (OIT) and antidromically (AIT). METHODS: Incremental palmar study of the sensory fibers of the median nerve was evaluated over 10cm across the wrist in 20 patients with mild carpal tunnel syndrome (CTS) and in 20 controls. Mild CTS was defined as clinical features of CTS with normal electrophysiologic findings by standard methods. The CTS patients were preselected with abnormal orthodromic median-ulnar latency difference of the fourth digit (mean .66+/-.21ms; nl < .40ms). RESULTS: In controls, the mean conduction delay per centimeter (CD/cm) was .192ms for OIT and .191ms for AIT; the mean maximum conduction delay per centimeter (MCD/cm) was .250+/-.032ms for OIT and .344+/-.10ms for AIT. MCD/cm was located inside the carpal tunnel in 85% of patients (OIT) versus 80% for AIT. No MCD/cm was greater than .32ms (OIT) or .60ms (AIT). With corresponding pathologic thresholds of .36ms (mean + 3.4 standard deviation [SD]) for OIT and .64ms (mean + 2.6 SD) for AIT, IT was abnormal in 20 patients (100%) with OIT compared with only 4 patients (20%) with AIT. CONCLUSIONS: The orthodromic method was superior to the antidromic method in controls and in patients (chi2 = 23; p = 1.8 x 10(-6)). These findings suggest that orthodromic IT should be used when standard electrodiagnostic tests fail to reveal median nerve sensory abnormality in persons with mild CTS.     

Idiopathic Carpal Tunnel Syndrome: Evaluation of the Depth of the Carpal Tunnel by Ultrasonography

The objective of the work described here was to evaluate the depth of the carpal tunnel (DCT) in patients with idiopathic carpal tunnel syndrome (CTS) and healthy volunteers by ultrasonography (US), through measurement of the distance from the flexor retinaculum to the surface of the capitate bone at the carpal tunnel outlet, and compare it with other ultrasonographic and electrophysiologic parameters in CTS. The study was conducted in 60 non-diabetic patients with idiopathic carpal tunnel syndrome (unilateral n = 37, bilateral n = 23) evidenced by electrophysiologic diagnosis according to the criteria of the American Association of Electrodiagnostic Medicine (AAEM). Furthermore, 40 hands from 20 healthy volunteers were examined. Median nerve cross-sectional area (CSA); flattening ratio (FR), the ratio of the length to the width of the median nerve; and DCT at the canal outlet were measured for all participants. The mean age was 35.6 ± 9.48 y. The female-to-male ratio was 47:13 in the CTS patients. The sensitivity and specificity were 82% and 95% for CSA, 75% and 60% for FR and 75% and 87.5% for DCT, respectively. Differences between patients and healthy controls were significant for all three parameters, greatest for DCT, followed by CSA and then FR. We conclude that DCT increased in CTS and this new parameter is comparable in sensitivity and specificity to CSA and FR. DCT increased independently of the cause of the CTS (decrease in size of canal or increase in contents).     

Multiple blood donations associated with iron deficiency in patients with restless legs syndrome

OBJECTIVE: To describe a series of patients with restless legs syndrome (RLS) and iron deficiency with and without anemia related to repeated blood donations. PATIENTS AND METHODS: Study patients were identified by asking consecutive patients with RLS seen at the Mayo Clinic in Rochester, Minn, from February 1 to December 31, 2001, whether they donated blood. All patients who fulfilled the International Restless Legs Syndrome Study Group criteria for RLS, had donated blood a minimum of 3 times a year the preceding 3 years, and had iron deficiency (serum ferritin concentration <20 microg/L) were included in the study. RESULTS: Eight patients met the study criteria. The mean +/- SD serum ferritin concentration was 8.1 +/- 3.5 microg/L, and 4 patients had anemia. In 6 of the 8 patients, RLS began at about the same time of or after blood donation. Patients had donated blood for 4.2 +/- 13 times a year (range, 3-6 times a year) for 15.2 +/- 83 years (range, 5-25 years). Hemoglobin concentrations were 12.8 +/- 1.8 g/dL (range, 10.6-15.5 g/dL). In 2 patients, RLS essentially resolved with correction of iron stores alone, and medications for RLS were successfully discontinued in 2 other patients. CONCLUSIONS: Repeated blood donation is associated with induction or perpetuation of RLS due to iron deficiency with or without coexisting anemia. Potential blood donors should be questioned about RLS, and donation should not be allowed until the serum ferritin concentration has been measured and iron stores replenished if necessary.     

铁蛋白和血红蛋白与原发性不宁腿综合征的关系

目的 探讨血红蛋白和铁蛋白水平与原发性不宁腿综合征(RLS)发病之间的关系.方法 对35例原发性不宁腿综合征患者(RLS组)及对照组20例失眠患者的血红蛋白及铁蛋白水平进行检测并行统计学比较.结果 RLS组患者血清铁蛋白水平为(89.77±48.52)μg/L,对照组为(123.36±35.06)μg/L,RLS组较对照组血清铁蛋白水平低,差异有统计学意义(t=-2.713,P<0.01),而血红蛋白水平RLS组为(142.77±11.79)g/L,对照组为(139.05±12.33)g/L,2组相比差异无统计学意义(t=1.108,P>0.05).结论 血清铁蛋白的降低可能是原发性不宁腿综合征的危险因素之一,而血红蛋白水平可能与原发性不宁腿综合征无关.     

Ultrasound-based measures in carpal tunnel syndrome: What to measure?

Carpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy and is caused by compression of the median nerve (MN) at the level of transverse carpal ligament of the volar wrist. Radiomics is an advanced semi-automated image analysis method that is utilized to identify characteristics in the MN that can detect CTS with considerable reproducibility.     

The ultrasonographic and electrodiagnostic findings of ulnar neuropathy at the elbow

OBJECTIVE: To evaluate and compare the morphologic changes of the ulnar nerve at the elbow, using ultrasonography, between patients with cubital tunnel syndrome and retrocondylar compression syndrome determined with electrodiagnosis. DESIGN: Prospective study using electrodiagnosis and ultrasonography. SETTING: An outpatient rehabilitation clinic in a tertiary university hospital in South Korea. PARTICIPANTS: Thirteen patients (8 men, 5 women; mean age, 48.2y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: In the electrodiagnostic study, we used the inching technique to localize the ulnar nerve lesion at the elbow. In the ultrasonography study, we measured the length of the swollen ulnar nerve and the ratio of the nerve diameter between the proximal end of the medial epicondyle to the elbow joint level and the tip of medial epicondyle to the elbow joint level. RESULTS: The mean length of the swollen ulnar nerve segment in retrocondylar compression syndrome (2.58+/-0.58cm) was significantly longer than that of cubital tunnel syndrome (1.64+/-0.31cm). The mean ratio of the nerve diameter between the proximal end of medial epicondyle and the elbow joint level was significantly larger in retrocondylar compression syndrome (1.52+/-0.25) than that of cubital tunnel syndrome (1.06+/-0.06). CONCLUSIONS: Ultrasonography detected the morphologic changes and the extent of the ulnar nerve lesion at the elbow, and it can become a screening and follow-up imaging modality in patients with ulnar neuropathy at the elbow.     

Somatosensory cortical plasticity in carpal tunnel syndrome--a cross-sectional fMRI evaluation

Carpal tunnel syndrome (CTS) is a common entrapment neuropathy of the median nerve characterized by paresthesias and pain in the first, second, and third digits. We hypothesize that aberrant afferent input in CTS will lead to cortical plasticity. Functional MRI (fMRI) and neurophysiological testing were performed on CTS patients and healthy adults. Median nerve innervated digit 2 (D2), and digit 3 (D3) and ulnar nerve innervated digit 5 (D5) were stimulated during fMRI. Surface-based and ROI-based analyses consistently demonstrated more extensive and stronger contralateral sensorimotor cortical representations of D2 and D3 for CTS patients as compared to healthy adults (P < 0.05). Differences were less profound for D5. Moreover, D3 fMRI activation in both the contralateral SI and motor cortex correlated positively with the D3 sensory conduction latency. Analysis of somatotopy suggested that contralateral SI representations for D2 and D3 were less separated for CTS patients (3.8 +/- 1.0 mm) than for healthy adults (7.5 +/- 1.2 mm). Furthermore, the D3/D2 separation distance correlated negatively with D2 sensory conduction latency-the greater the latency, the closer the D2/D3 cortical representations (r = -0.79, P < 0.05). Coupled with a greater extent of SI representation for these CTS affected digits, the closer cortical representations can be interpreted as a blurred somatotopic arrangement for CTS affected digits. These findings provide further evidence that CTS is not manifest in the periphery alone. Our results are consistent with Hebbian plasticity mechanisms, as our cohort of CTS patients had predominant paresthesias, which produce more temporally coherent afferent signaling from affected digits.     

Association between low serum ferritin and restless legs syndrome in patients with attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a neurobehavioral disorder characterized by pervasive inattention and/or hyperactivity-impulsivity. It has been suggested that ADHD symptoms are associated with restless legs syndrome (RLS), which is a neurological condition that is defined by an irresistible urge to move the legs. Increasing evidence suggests iron deficiency may underlie common pathophysiological mechanisms in subjects with ADHD and with RLS. To further define the relationship between iron deficiency and RLS in children and adolescents with ADHD, we evaluated 87 ADHD subjects: 79 boys and 8 girls with age 9.3 +/- 2.5 years (6-16 years). Various psychopathologies and the severity of the ADHD symptoms and serum ferritin levels were assessed. Diagnosis of RLS was made according to the International RLS Group criteria. The patients were evaluated for the iron deficiency (ferritin < 12 ng/ml). RLS was found in 29 (33.3%) of the 87 ADHD subjects. Parent- and teacher-rated behavioral and emotional problems and the severity of ADHD symptoms were not significantly different between ADHD subjects with RLS and those without RLS (n = 58). The rate of iron deficiency was significantly higher in ADHD subjects with RLS (n = 6, 20.7%) when compared with ADHD subjects without RLS (n = 1, 1.7%, p = 0.005). Our results showed that depleted iron stores might increase the risk of having RLS in ADHD subjects. Iron deficiency, which is associated with both ADHD and RLS, seems to be an important modifying factor in the relationship between these two conditions.     

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。     

Nerve Density: A New Parameter to Evaluate Peripheral Nerve Pathology on Ultrasound. Preliminary Study

The possibility to realize a quantitative evaluation of nerve density on ultrasound is clinically important to enhance the evaluation of peripheral nerve disorders. We developed software that quantifies the ratio between the hypoechoic and hyperechoic areas of peripheral nerves on ultrasound. Nerve density was defined as (hypoechoic pixels)/(total pixels) and the purpose of our study was to asses if nerve density can be used to differentiate pathologic conditions affecting peripheral nerves. Ultrasound images of peripheral nerves were obtained with a high-frequency probe (17–5 MHz, 288 elements). Sixty-five different patients and (n = 65) controls (age range, 35–81 years; mean 55 years) were prospectively evaluated. Thirty-five patients had carpal tunnel syndrome and 30 patients had neurofibromas. Three radiologists performed a semiautomated evaluation with intra and interobserver agreement. A complete automatic evaluation was performed with no need of intra and interobserver evaluation. With the semiautomated evaluation, mean intraobserver agreement was good (K = 0.85). Interobserver agreements was good as well (reader 1 vs reader 2: k = 0.72; reader 2 vs reader 3: k = 0.80; reader 3 vs reader 1: k = 0.72). Differences among value of nerve density in normal nerves, CTS and neurofibromas were statistically significant (p < 0.0001). There were no statistically significant differences between the results obtained using the automatic or the semiautomatic method. Nerve density is capable of discriminating between normal and pathologic nerves of patients affected by carpal tunnel syndrome or neurofibromas. Moreover, nerve density measure is useful to discriminate between patients with mild and severe CTS. (E-mail: atagliafico@sirm.org)     

透析相关淀粉样变致腕管综合征外科治疗20例疗效分析

目的 总结透析相关的β2微球蛋白淀粉样变,导致腕管综合征（Carpal tunnel syndrome,CTS）的临床特点,评估腕管松解术疗效.方法 回顾性调查中日友好医院从2010年3月～2014年3月完成的透析相关腕管综合征患者20例,所有患者均行腕管松解术.患者男11例、女9例,年龄58.45±8.95 （46～75）岁,血液透析时间18.05±2.60 （14～23）年.其中表现为单侧症状为主的4例（左腕2例,右腕2例）,双侧症状16例;肌电图示平均神经传导速度为18.1±3.2m/s,平均潜伏期为5.1±1.2m/s.麻醉方式：局麻、臂丛麻醉18例,全麻2例.结果 术后随访20例术后症状改善或消失,未见症状复发,手指功能逐渐恢复.肌电图提示神经传导速度及动作电位波幅逐渐恢复.所有患者BCTQ评分较术前降低.其中症状评分术前为3.67±0.19、术后为2.42±0.14（t=19.112,P＜0.01）;功能评分术前为3.5±0.26、术后为2.48±0.18（t=12.329,P＜0.01）.结论 随着长透析龄患者增多,透析相关CTS也逐渐高发.外科腕管松解术是晚期CTS的有效治疗措施,可以明显改善患者手腕症状,促进手功能恢复.     

多发性硬化合并不宁腿综合征12例临床分析

目的探讨多发性硬化（MS）患者合并不宁腿综合征（RLS）的临床特点,且进一步研究MS患者合并RLS的相关因素。方法选取确诊的70例MS患者,根据是否合并RLS分为伴RLS组和单纯MS组,比较两组患者的MS发病年龄、病程及神经功能损害严重程度（EDSS评分）等临床资料;分析RLS症状严重程度与EDSS的关系。结果70例MS患者中12例合并RLS,发生率为17．1％（12／70）。伴RLS组患者发病年龄为（47．6±10．0）岁,单纯MS组为（40．1±10．4）岁,两组比较差异有统计学意义（t=2．29,P=0．030）;病程分别为（12．6±6．8）、（8．2±6．6）年,两组比较差异有统计学意义（t=2．10,P=0．039）;EDSS评分分别为（4．5±2．5）、（2．5±2．0）分,两组比较差异有统计学意义（t=3．02,P=0．004）。RLS严重程度评分与EDSS评分无相关性（r=0．45,P=0．15）。结论RLS在MS患者中发病率较高,MS发病年龄越大,病程越长,神经功能损害越严重,发生RLS的可能性越大。     

Prevalence of restless legs syndrome among native South Americans residing in coastal and mountainous areas

OBJECTIVE: To determine the prevalence of restless legs syndrome (RLS) in native South Americans and identify the impact of geographic location. PARTICIPANTS AND METHODS: An epidemiological telephone survey of RLS symptoms involving natives from coastal and mountainous areas was performed during July 2, 2004, through September 28, 2004. The process consisted of 2 phases: the creation of the epidemiological instrument and the telephone survey. RESULTS: Five hundred adults, 250 from the mountainous regions and 250 from the coastal region (190 men and 310 women; age range, 25-85 years) were interviewed and subsequently divided on the basis of International Restless Legs Syndrome Study Group criteria into those who had RLS (RLS+ group) and those who did not (RLS- group). Ten (2.0%) had RLS. The overall rate of RLS in adults living in the mountainous region at 2816 m above sea level (3.2% [8/250]) was significantly higher than that for adults living in the coastal region at 4 m above sea level (0.80% [2/250]; P = .002). The mean age of the RLS+ group was 49.5 years (SD, 15.20 years; range, 25-85 years). CONCLUSION: Native South American adults have a prevalence of RLS well below that reported in populations with European ancestry but similar to that in Asian and Turkish populations. Furthermore, in Ecuador, geographic differences were identified in areas of similar population density.     

剑桥-霍普金斯不宁腿量表诊断中国人群不宁腿综合征的临床研究

目的：在中国人群中对自填型剑桥-霍普金斯不宁腿量表（Cambridge-Hopkins questionnaire for restless legs syndrome, CH-RLSq）诊断不宁腿综合征（restless legs syndrome/Willis-Ekbom disease, RLS/WED）的灵敏度和特异度进行验证。方法：共26例RLS/WED患者和21例对照（18例其他疾病患者和3名正常人）入组,其中其他疾病指类似RLS/WED表现的疾病（包括4例神经根病变,3例糖尿病周围神经病变,4例痛性痉挛,1例静脉曲张,另6例患者的诊断暂不确定）,所有对象均进行CH-RLSq量表检测,进行临床诊断与问卷诊断的一致性研究,并同时记录RLS/WED患者的临床资料。结果：RLS/WED的临床诊断和CH-RLSq量表的诊断具有较好的一致性（Kappa=0.745, McNemar test: P=0.216）。CH-RLSq量表诊断RLS/WED的灵敏度为80.8%,特异度为95.2%。RLS/WED患者中女性患者较多见,且患者的家族史阳性率较高、合并症较多。结论：CH-RLSq量表在我国人群的RLS/WED诊断中具有较高的灵敏度和特异度,可用来作为筛查RLS/WED的问卷。     

Outcome of surgical release among diabetics with carpal tunnel syndrome

OBJECTIVE: To compare the results of surgical decompression of carpal tunnel syndrome (CTS) in patients with diabetes with those of patients with idiopathic CTS. DESIGN: Prospective case series. SETTING: Ambulatory care in Italy. PARTICIPANTS: Twenty-four consecutive patients with diabetes type 1 or 2 and CTS (mean age, 66.7 y) were matched for age and sex with 72 patients (mean age, 66.2 y) with idiopathic CTS. INTERVENTIONS: All patients underwent surgical release of CTS by the mini-incision of palm technique. MAIN OUTCOME MEASURES: Clinical and electrophysiologic evaluation and patient self-administered Boston Questionnaire (BQ) for the assessment of severity of CTS symptoms and hand functional status before and 1 and 6 months after surgery. RESULTS: After surgical release, almost all patients of both groups reported an absence of pain, disappearance or reduction of paresthesia, and improvement in hand function. One month after surgery, there was a significant improvement in clinical status, BQ scores, and distal conduction velocities of the median nerve. A further improvement was evident at 6-month follow-up. There were no differences between the 2 groups in the number of surgical complications, in clinical and electrophysiologic status, or in BQ scores before and after surgery. The improvement in distal conduction velocities of the median nerve, BQ scores, and clinical and electrophysiologic status were similar in the 2 groups after surgery. CONCLUSION: Diabetes is not a risk factor for poor outcome of surgical decompression of CTS. Patients with diabetes have the same probability of positive surgical outcome as patients with idiopathic CTS.     

Differential involvement of A-delta and A-beta fibres in neuropathic pain related to carpal tunnel syndrome

Carpal tunnel syndrome (CTS), a common entrapment neuropathy involving the median nerve at the wrist, frequently manifests with neuropathic pain. We sought information on pain mechanisms in CTS.We studied 70 patients with a diagnosis of CTS (117 CTS hands). We used the DN4 questionnaire to select patients with neuropathic pain, and the Neuropathic Pain Symptom Inventory (NPSI) to assess the intensity of the various qualities of neuropathic pain. All patients underwent a standard nerve conduction study (NCS) to assess the function of non-nociceptive Aβ-fibres, and the cutaneous silent period (CSP) after stimulation of the IIIrd and Vth digits, to assess the function of nociceptive Aδ-fibres. In 40 patients (75 CTS hands) we also recorded laser-evoked potentials (LEPs) in response to stimuli delivered to the median nerve territory and mediated by nociceptive Aδ-fibres. We sought possible correlations between neurophysiological data and the various qualities of neuropathic pain as assessed by the NPSI.We found that the median nerve sensory conduction velocity correlated with paroxysmal pain and abnormal sensations, whereas LEP amplitude correlated with spontaneous constant pain.Our findings suggest that whereas paroxysmal pain and abnormal sensations reflect demyelination of non-nociceptive Aβ-fibres, spontaneous constant pain arises from damage to nociceptive Aδ-fibres.     

Development of a clinical prediction rule for the diagnosis of carpal tunnel syndrome

OBJECTIVES: To develop a clinical prediction rule (CPR) and to assess the reliability and diagnostic accuracy of individual clinical examination items for the diagnosis of carpal tunnel syndrome (CTS). DESIGN: Prospective diagnostic test study with blind comparison to a reference criterion of a compatible clinical presentation and abnormal electrophysiologic findings. SETTING: Multicenter medical center and community hospital with patient referrals from ambulatory primary care and specialty practice settings. PARTICIPANTS: Eight-two consecutively referred patients (50% men; mean age, 45+/-12 y) with suspected cervical radiculopathy or CTS referred for electrophysiologic examination. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Sensitivity, specificity, and likelihood ratios. RESULTS: The CPR identified in this study consisted of 1 question (shaking hands for symptom relief), wrist-ratio index greater than .67, Symptom Severity Scale score greater than 1.9, reduced median sensory field of digit 1, and age greater than 45 years. The likelihood ratio for the CPR was 18.3 when all 5 tests were positive. Interrater reliability was acceptable for all but 2 clinical examination items. CONCLUSIONS: The CPR identified was more useful for the diagnosis of CTS than any single test item and resulted in posttest probability changes of up to 56%. Further investigation is required both to validate the test-item cluster and to improve point-estimate precision.