1、Noctural hand discomfort, paresthesia in the thumb and second, third, and radial side of the fourth fingers, and weakness and atrophy of the thenar musculature.

夜間手部不適，拇指、第二、三指及第四指橈側感覺異常，大魚際肌的萎縮、無力。

2. Tingling in the digits supplied by the median nerve.Flex both wrists for 60 seconds—numbness in the median nerve distribution should occur within 60 seconds in the presence of carpal tunnel syndrome.

Tinel征陽性指正中神經支配的手指出現(xiàn)麻木刺痛感。

Phalen實驗指腕關節(jié)彎曲，60秒內出現(xiàn)正中神經支配區(qū)麻木提示腕管綜合征。

3. Compression, diffuse flattening, or an abrupt change in the morphology of the median nerve,edema of the nerve, or enhancement with gadolinium administration.

正中神經受壓、扁平，或形態(tài)出現(xiàn)突然變化，神經水腫或增強掃描出現(xiàn)強化。

4. Abrupt change in morphology.

正中神經形態(tài)出現(xiàn)突然變化是最為特征性的變化。

References

Andreisek G, Crook DW, Burg D, et al: Peripheral neuropathies of the median, radial, and ulnar nerves: MR imaging features. Radiographics26:1267–1287, 2006.

Yu JS: Magnetic resonance imaging of the wrist.Orthopedics17:1041–1048, 1994.

Cross-Reference

Musculoskeletal Imaging: THE REQUISITES, 3rd ed, p 157.

Comment

Carpal tunnelsyndrome is a common neuropathy of the upper extremity caused by compression ofthe median nerve in the carpal tunnel. It typically involves middle age womenand presents as a bilateral condition in nearly one half of those affected.Several common causes of carpal tunnel syndrome include tenosynovitis, masses (ganglion or neuroma), synovial proliferation, anddiminished girth of the carpal channel from post-traumatic osseous changes andfibrosis. Chronic hypoxia has also been suggested as a potential precipitatingevent. Most cases of carpal tunnel syndrome, however, are idiopathic and arelikely the result of a normal aging process.

Magnetic resonanceimaging is useful for confirming the diagnosis of carpal tunnel syndrome inpatients exhibiting symptoms. Characteristic findings are depicted on truetransaxial images of the wrist. Observations diagnostic of this conditioninclude compression and flattening of the median nerve, increased signalintensity in the median nerve on T2W images (as seen in this patient), bowingof the flexor retinaculum, loss of the normal fat between the carpal bones andthe tendons, and/or an abrupt change of the diameter of the median nerve.

腕管綜合征是指正中神經在腕管內受壓引起的上肢神經卡壓性疾病，好發(fā)于中年女性，近一半患者表現(xiàn)為雙側發(fā)病。腕管綜合征的常見原因包括腱鞘炎、腫塊（神經節(jié)或神經瘤）、滑膜增生、及外傷后骨化纖維化導致的腕管縮小。慢性缺氧也可能是發(fā)作的誘因之一，但腕管綜合征大部分仍為自發(fā)性，表現(xiàn)為與年齡增大相關。當出現(xiàn)類似癥狀時，MRI對腕管綜合征的確診有一定意義，橫軸位圖像最為典型，可以觀察到正中神經的受壓扁平，T2WI信號增高（本例圖中可顯示），屈肌支持帶彎曲，腕骨和肌腱之間的脂肪間隙消失，和/或正中神經的直徑突然改變。