Value of High-Frequency Ultrasound in the Diagnosis of Pronator Teres Syndrome / 中国医学科学院学报

Objective To investigate the clinical value of high-frequency ultrasound in the diagnosis of pronator teres syndrome (PTS). Methods The high-frequency ultrasound was employed to examine and measure the median nerve of the pronator teres muscle in 30 patients with PTS and 30 healthy volunteers (control group).The long-axis diameter (LA),short-axis diameter (SA) and cross-sectional area (CSA) of the median nerve were measured.The receiver operating characteristic curve of the median nerve ultrasonic measurement results was established,and the area under the curve (AUC) was calculated.The diagnostic efficiency of each index for PTS was compared with the surgical results as a reference. Results The PTS group showed larger LA[(5.02±0.50) mm vs.(3.89±0.41) mm;t=4.38,P=0.013],SA[(2.55±0.46) mm vs.(1.70±0.41) mm;t=5.19,P=0.009],and CSA[(11.13±3.72) mm2 vs.(6.88±2.68) mm2;t=8.42,P=0.008] of the median nerve than the control group.The AUC of CSA,SA,and LA was 94.3% (95%CI=0.912-0.972,Z=3.586,P=0.001),77.7% (95%CI=0.734-0.815,Z=2.855, P=0.006),and 78.8% (95%CI=0.752-0.821,Z=3.091,P=0.004),respectively.With 8.63 mm2 as the cutoff value,the sensitivity and specificity of CSA in diagnosing PTS were 93.3% and 90.0%,respectively. Conclusion High-frequency ultrasound is a practical method for diagnosing PTS,and the CSA of median nerve has a high diagnostic value.

Sensibilidad y especificidad de tres métodos complementarios para el diagnóstico de síndrome de túnel carpiano / Sensitivity and specificity of three complementary methods in the diagnosis of carpal tunnel syndrome

Resumen: Introducción: Actualmente, no existe un estándar de referencia aceptado universalmente para el diagnóstico del síndrome de túnel carpiano, por lo que se le considera una patología de «clase latente¼, es decir, que carece de alguna prueba diagnóstica que dé certeza absoluta de la presencia de la enfermedad. Métodos: Estudio prospectivo, observacional y analítico en el cual se evaluaron los tres métodos diagnósticos utilizados para el síndrome de túnel carpiano (examen clínico, ecografía y electromiografía). En él, se establecieron valores de normalidad para cada método diagnóstico. Resultados: Se evaluó un total de 50 personas (14 hombres y 36 mujeres). El examen clínico presentó correlación positiva y significativa con el diámetro del nervio mediano afectado (ecografía) (R = 0.694 y p = 0.032). Los valores del área bajo la curva (AUC, por sus siglas en inglés) para la velocidad de conducción del nervio mediano (VCNM), velocidad de conducción de nervio cubital (VCNC) y latencia distal motora (LDM) por electromiografía fueron de 0.60, 0.519 y < 0.50, respectivamente, lo cual determinó que el valor diagnóstico de las características por electromiografía es malo. Conclusión: Nuestro trabajo establece al examen clínico como una herramienta de buena calidad, siendo el método más sensible para el diagnóstico de síndrome de túnel carpiano. Si existiera la necesidad de realizar una confirmación diagnóstica, la ecografía mostró ser un estudio altamente satisfactorio, el cual genera menos estrés, dolor e invasión al paciente, disminuyendo, a su vez, el gasto de salud y agilizando el proceso.

Abstract: Introduction: Currently there is no universally accepted standard of reference for the diagnosis of carpal tunnel syndrome so it is considered a «latent class¼ pathology, that is, it lacks any diagnostic tests that absolutely certain the presence of disease. Methods: Prospective, observational and analytical study evaluating the three diagnostic methods used for carpal tunnel syndrome (clinical examination, ultrasound and electromyography). Normality values were set for each diagnostic method. Results: 50 people (14 men and 36 women) were evaluated. The clinical examination showed a positive and significant correlation with the diameter of the affected median nerve (ecography) (R = 0.694, p = 0.032). The values of the under the curve area (UCA) for median nerve conduction speed (MNCS), cubital nerve conduction speed (CNCS), and distal latency (DL) by electromyography were 0.60, 0.519 and less than 0.50 respectively. This states that the diagnostic value of electromyography characteristics is bad. Conclusion: Our work establishes clinical examination as a good quality tool being the most sensitive method for diagnosing carpal tunnel syndrome. If there was a need for diagnostic confirmation, the ultrasound proved to be a highly satisfactory study generating less stress, pain and invasion to the patient, decreasing health expenditure and speeding up the process.

Variantes anatómicas del canal carpiano y distancias de estructuras vasculares en ecografía / Anatomical variants the carpal tunnel and distances of vascular structures in ultrasound

El síndrome de canal carpiano es una patología frecuente. Si bien el diagnóstico es clínico, la ecografía cumple un rol en caso de duda diagnóstica y como apoyo a proce-dimientos intervencionales.Existen variables anatómicas y distancias de estructuras vasculares útiles de conocer antes de planear un gesto quirúrgico o de infiltración para disminuir el riesgo de lesiones secundarias, en donde la ecografía podría tener un rol.Estudiamos una muestra de 267 ecografías de muñeca con especial hincapié en va-riantes neurogénicas, vasculares o tendinosas que podrían resultar lesionadas en relación a algún procedimiento.

Carpal tunnel syndrome is a frequent pathology. Although the diagnosis is clinical, ultrasound plays a role in case of diagnostic doubt and as support and guide for inter-ventional procedures.There are anatomical variants and distances of vascular structures that may be useful to know before planning a surgical or infiltration procedure to reduce the risk of iat-rogenic injuries, where ultrasound could play a role.We studied a sample of 267 wrists ultrasounds with special emphasis on neurogenic, vascular or tendinous variants that could be injured in relation to procedures.

Sonographic Findings of the Bifid Median Nerve and Persistent Median Artery in Carpal Tunnel: A Preliminary Study in Chinese Individuals

OBJECTIVE: The aim of this study was to investigate the prevalence of anatomic variations of the bifid median nerve, persistent median artery and persistent median vein in Chinese individuals and their relationship with carpal tunnel syndrome. METHODS: One hundred and sixty median nerves were examined using ultrasonography and colour Doppler ultrasonography. The location, shape, and size of the bifid median nerve, persistent median artery and persistent median vein were recorded. The cross-sectional area of the bifid median nerve (two trunks) was measured at the level of the pisiform. RESULTS: Among the 160 wrists examined, a bifid median nerve was observed in 15 (9.4%) wrists, and a persistent median artery was observed in 12 (7.5%) wrists. These two variations either coexisted or were observed independently, and the probability of coexistence (6.3%) was higher than the probability of existing independently (bifid median nerve only 3.1%, persistent median artery only 1.3%). The cross-sectional area of the radial trunk was greater than (13 in 15, 86.7%) the cross-sectional area of the ulnaris trunk. Persistent median vein was observed in 9 wrists (5.6%). CONCLUSIONS: The persistent median artery and bifid median nerve tend to coexist, and the persistent median vein sometimes runs parallel to the persistent median artery. Their positional relationship in carpal tunnel is uncertain, and thus, preoperative ultrasound is necessary. These three variations do not present any additional risk for the development of carpal tunnel syndrome.

RE: Value of Power Doppler and Gray-Scale US in the Diagnosis of Carpal Tunnel Syndrome: Contribution of Cross-Sectional Area just before the Tunnel Inlet as Compared with the Cross-Sectional Area at the Tunnel

No abstract available.

Value of Power Doppler and Gray-Scale US in the Diagnosis of Carpal Tunnel Syndrome: Contribution of Cross-Sectional Area just before the Tunnel Inlet as Compared with the Cross-Sectional Area at the Tunnel

OBJECTIVE: To determine the value of gray-scale and power Doppler ultrasonography in the evaluation of carpal tunnel syndrome (CTS). MATERIALS AND METHODS: Median nerves at the carpal tunnel were evaluated by using gray-scale and power Doppler ultrasonography and by using accepted and new criteria in 42 patients with CTS (62 wrists) confirmed by electromyogram and 33 control subjects. We evaluated the cross-sectional area of the nerve just proximal to the tunnel inlet (CSAa), and at mid level (CSAb). We then calculated the percentage area increase of CSAb, and area difference (CSAb-CSAa). We measured two dimensions of the nerve at the distal level to calculate the flattening ratio. The power Doppler ultrasonography was used to assess the number of vessels, which proceeded to give a score according to the vessel number, and lastly evaluated the statistical significance by comparing the means of patients with control subjects by the Student t test for independent samples. Sensitivities and specificities were determined for sonographic characteristics mentioned above. We obtained the receiver operating characteristic (ROC) curve to assess the optimal cut-off values for the diagnosis of CTS. RESULTS: A statistically significant difference was found between patients and the control group for mean CSAb, area difference, percentage area increase, and flattening ratio (p < 0.001, p < 0.001, p < 0.001, p < 0.05, respectively). From the ROC curve we obtained optimal cut-off values of 11 mm2 for CSAb, 3.65 for area difference, 50% for the percentage of area increase, and 2.6 for the flattening ratio. The mean number of vessels obtained by power Doppler ultrasonography from the median nerve was 1.2. We could not detect vessels from healthy volunteers. Mean CSAbs related to vascularity intensity scores were as follows: score 0: 12.3 +/- 2.8 mm2, score 1: 12.3 +/- 3.1 mm2, score 2: 14.95 +/- 3.5 mm2, score 3: 19.3 +/- 3.8 mm2. The mean PI value in vessels of the median nerve was 4.1 +/- 1. CONCLUSION: Gray-scale and power Doppler ultrasonography are useful in the evaluation of CTS.