Fig. 1. Diagram of cross sectional anatomy of peripheral nerve. Axons are covered by Schwann cell, surrounded by endoneurium which are bundled into fascicles by perineurium. Fascicles are surrounded by interfascicular epineurium grouped into a nerve by epineurium. Fig. 2. Normal MR imaging of the peripheral nerve. Axial FSE T2-weighted image demonstrates the sciatic nerve. Clustered iso-signal intensity fascicles are well demonstrated within sur- high signal fat (white arrow). rounding 75
Fig. 3. Diagram of pronator syndrome. The median nerve (short arrow) normally passes between two heads of pronator teres (long arrows), subsequently passing under the edge of the flexor digitorum sublimes (open arrow). Median nerve could be compressed in these regions. 76
Fig. 4. Anterior interosseous nerve entrapment. Axial FSE T2- weighted and contrast enhanced T1-weighted images show high signal intensity and enhancement of pronator quadratus (white arrows) respectively, indicating selective denervation myopathy. A B Fig. 5. A. Diagram of carpal tunnel and the Guyon s canal at the level of the pisiform. B. Diagram of carpal tunnel at the level of the hamate. (open arrow; ulnar nerve, thick arrow; median nerve, UA; ulnar artery, FCR; flexor carpi radialis tendon, P; pisiform, T; triquetrum, L; lunate, S; scaphoid, H; hamate, C; capitate, Td; trapezoid, Tz: trapezium). 77
김성준 외: 말초신경 포획 및 압박 증후군의 자기공명영상 주관 증후군은 수근관 증후군에 이어서 두 번째로 많은 말 초신경 포획 및 압박 증후군이다. 주관(cubital tunnel)은 내 측상과(medial epicondyle)와 척측 수근굴근(flexor carpi ulnaris)의 두 갈래 사이의 fibro-osseous canal이며 천정 (roof)은 주관지대(cubital tunnel retinaculum), 삼각건막(triangular aponeurosis)이고 바닥(floor)은 관절포(joint capsule)와 내측 측부인대의 후부와 횡부로 이루어져 있다. 주관 지대는 epicondylo-olecranon ligament 혹은 Osborne s ligament라고도 하며 삼각건막(triangular aponeurosis)은 척측 수근굴근의 두 갈래 사이를 연결하는 궁상인대(arcuate lig- ament) 라고도 한다(Fig. 7). 상기된 인대들은 여러 보고에 서 서로 혼동되어 사용되기도 하지만 척골신경은 이 인대들 에 의하여 주관 내에서 압박을 받게 된다(22-24). 원인은 다양하여 급성 외상, 외상을 받은 후에 오랜 시간이 지나 주관절에 외반(valgus) 변형이 점차적으로 일어나면서 생기는 지연성 척골 신경마비(tardy ulnar nerve palsy), 그 리고 기타 관절염과 낭종 등의 종괴, accessory epitrochleoanconeus muscle, 신경의 아탈구, 탈구 등이 원인이 될 수 있으며, 볼을 던지는 운동선수나 음악가에게 잘 생긴다. 임상 증상은 감각 이상과 척측 수근굴근, 4, 5번째 손가락의 심 수 Fig. 6. Carpal tunnel syndrome. A. Normal median nerve in the carpal tunnel. Axial T1 weighted image (upper row) and FSE T2 weighted image (lower row) at pisiform (p) and hamate (h) level shows normal median nerve (white arrows). Median nerve shows a fascicular pattern with iso-signal intensity with muscle, surrounded by slightly high signal intensity fat. B. Morphologic change of the median nerve in carpal tunnel syndrome. Axial T1 weighted image (upper row) and FSE T2 weighted image (lower row) shows enlarged median nerve (white arrows) with slightly low signal intensity comparing with muscle and increased signal intensity respectively. Fascicular pattern is obliterated. A B 78
Fig. 7. Diagram of cubital tunnel. In the view from the medial aspect of the elbow. Ulnar nerve (UN) passes between medial epicondyle of humerus and olecranon at the condylar groove deep to the cubital tunnel retinaculum (A) and aponeurosis (B) formed between two head of flexor carpi ulnaris (C). Cubital tunnel retinaculum and aponeurosis of flexor carpi ulnaris blend with each other at margin. Ulnar nerve might be entrapped in this region. 79 Fig. 8. Ulnar neuropathy at cubital tunnel. Axial T1 weighted image (top) shows ulnar nerve at cubital tunnel of condylar groove with loss of normal clustered dot like fascicular pattern (white arrow). Axial FSE T2 weighted image (bottom) also shows loss of normal fascicular pattern and slightly increased signal intensity of ulnar nerve (white arrow).
김성준 외: 말초신경 포획 및 압박 증후군의 자기공명영상 Saturday night palsy Posterior interosseous nerve syndrome(supinator entrapment 요골신경이 액와부나 상완골의 나선구(spiral groove, 삼두 근의 외측과 내측 갈래 사이)에서 압박 받아 나타나며 삼두 근(triceps), 상완요골근(brachioradialis)의 약화와 손의 내신 전근과 수근 신전근의 약화가 생긴다(30, 31). syndrome) 요골신경의 깊은 분지인 후골간신경이 arcade of Frohse라 는 회외근(supinator)의 근위 변연(edge) 아래에서 압박을 받 아서 생기는 것으로(Fig. 10) 주관절의 탈골, 골절, 류마티스 관절염, 종양, 섬유대 등이 원인이 되고 손가락을 중수지절관 절(metacarpophalangeal joint)에서 신전시키지 못하여 마치 신전건의 파열 혹은 상완 외과염(lateral epicondylitis)과 유 사하게 보인다(Fig. 11). Radial tunnel syndrome 후골간신경 증후군과 함께 요골신경 압박의 가장 흔한 형 태이다(32). 요골신경은 주관절에서는 상완근과 상완요골근 Fig. 9. Ulnar neuropathy at Guyon s canal. Axial FSE T2 weighted image at pisiform (top) and hamate (bottom) level shows markedly enlarged ulnar nerve at Guyon s canal. The nerve also shows markedly increased signal intensity (white arrow). Fig. 10. Diagram of posterior interosseous nerve course. Radial nerve passes beneath brachioradialis muscle (BR) branching into superficial branch and deep branch (posterior interosseous nerve). Posterior interosseous nerve (thick black arrow) which is purely motor branch of radial nerve passes into the supinator muscle (S). These spaces are narrow enough to entrap the radial nerve. (PIA; posterior interosseous artery) Fig. 11. Compression neuropathy of posterior interosseous nerve. Fat saturated axial T2 weighted image at the proximal forearm shows a juxtacortical lipoma with a low signal intensity, almost encircling proximal radius (white arrow) and compressing the passage for the posterior interosseous nerve (Right). Denervation myopathy of the extensor muscle groups (black arrow) was evident at the distal level showing increased signal intensity with atrophy. 80
Fig. 12. Diagram of suprascapular nerve passage viewing from the back. (SSN; suprascapular nerve, SSM; supraspinatus muscle, ISM; infraspinatus muscle) Fig. 13. Compression neuropathy of suprascapular nerve. A ganglion (white arrow) is visible at spinoglenoid notch, on axial T1 weighted image (top) and T2 weighted image (bottom). Subtle signal alteration is limited in the infraspinatus muscle (black arrow). Suprascapular nerve in the spinoglenoid notch already branch off the nerve to the supraspinatus muscle, so that the supraspinatus muscle does not show signal alteration, (not shown in this cross-section). 81
김성준 외: 말초신경 포획 및 압박 증후군의 자기공명영상 nerve), 장흉신경(long thoracic nerve) 등이 압박 받을 수 있는 신경들이다. 상완신경총(Brachial Plexus) 상완신경총은 흉곽 출구부(thoracic outlet region)에서 쇄 골하동맥, 쇄골하정맥과 함께 주행하는데 이 부위에서 주로 압박을 잘 받을 수 있는 부위가 3군데로 나누어 설명된다. 먼 저 전사각근 증후군(anterior scalene syndrome)은 상완신경 총이 전사각근과 중사각근(anterior and middle scalene muscle)과 첫 번째 늑골로 이루어지는 사각근간 삼각(interscalene triangle)을 지날 때 압박 받는 경우이다. 둘째로 늑 골쇄골공간 증후군(costoclavicular syndrome)은 상완신경총 이 지나가는 쇄골과 첫 번째 늑골 사이의 공간에서 압박을 받 는 경우를 말한다. 마지막으로 과외전 증후군(hyper abduction syndrome)은 팔을 180도 외전 할 때 신경이 소흉근이 오훼돌기(coracoid process)에 붙는 부위의 아래에서 압박 받 아 나타난다. 하 지 하지에서는 요추천추신경총(lumbosacral plexus)에서 대퇴 신경과 좌골신경을 형성하여 하지에 신경분포를 이룬다. 대퇴 신경은 2, 3, 4번 요추신경으로부터 형성되고 좌골신경은 4, 5번 요추신경과 1, 2, 3번 천추신경으로부터 형성된다. 대퇴 신경은 요추천추신경총에서 시작되어 장골근(iliacus muscle) 을 따라서 앞으로 주행하여 서혜부 인대 깊은 곳으로 주행하 여 대퇴부 내로 들어가게 된다. 좌골신경은 역시 요추천추신 Fig. 14. Diagram of posterior tibial nerve passage at tarsal tunnel. Posterior tibial nerve branches within the tarsal tunnel into medial plantar, lateral plantar, medial calcaneal nerve in most cases with minor exception. (PTN; posterior tibial nerve, MPN; medial plantar nerve, LPN; lateral plantar nerve, FR; flexor retinaculum, AH; abductor hallucis) Fig. 15. Tarsal tunnel syndrome caused by ganglion cyst. Axial T2 weighted image shows a ganglion cyst at tarsal tunnel (arrow heads) compressing posterior tibial nerve and its branches (A) and posterior tibial vascular bundles (B). 82
Fig. 16. Diagram of peroneal nerve at the fibular neck level. Common peroneal nerve winds around the fibular neck beneath the peroneus longus tendon branching into superficial and deep branches afterwards. (SN; sciatic nerve, TN; tibial nerve, CPN; common peroneal nerve, PL; peroneus longus tendon) 83
Fig. 17. Entrapment of common fibular nerve at fibular neck. Common peroneal nerve passage is well demonstrated in sequential axial T2 weighted image winding around the fibular neck (thick short arrow) (from figure of left top to right bottom downward in anatomical location). No definite nerve compressing pathology is seen, but atrophy of anterior compartment muscle group with increased signal intensity is suggestive of denervated common peroneal nerve (thin long arrow). 84
19. Gardner RC. Confirmed case and diagnosis of pseudocarpal-tunnel (sublimis) syndrome. N Engl J Med 1970;282:858 20. Monagle K, Dai G, Chu A, Burnham RS, Snyder RE. Quantitative MR imaging of carpal tunnel syndrome. AJR Am J Reontgenol 1999; 172:1581-1586 21. Lee D, van Holsbeeck MT, Janevski PK, Ganos DL, Ditmars DM, Darian VB. Diagnosis of carpal tunnel syndrome. Ultrasound versus electromyography. Radiol Clin North Am 1999;37:859-872 22. Campbell WW, Pridgeon RM, Riaz G, Astruc J, Sahni KS. Variations in anatomy of the ulnar nerve at the cubital tunnel: pitfalls in the diagnosis of ulnar neuropathy at the elbow. Muscle Nerve 1991;14:733-738 1. Spratt JD, Stanley AJ, Grainger AJ, Hide IG, Campbell RS. The role of diagnostic radiology in compressive and entrapment neuropathies. Eur Radiol 2002;12:2352-2364 2. Maravilla KR, Bowen BC. Imaging of the peripheral nervous system: evaluation of peripheral neuropathy and plexopathy. AJNR Am J Neuroradiol 1998;19:1011-1023 3. Kuntz C 4th, Blake L, Britz G, Filler A, Hayes CE, Goodkin R, et al. Magnetic resonance neurography of peripheral nerve lesions in the lower extremity. Neurosurgery 1996;39:750-756;discussion 756-757 4. Filler AG, Kliot M, Howe FA, Hayes CE, Saunders DE, Goodkin R, et al. Application of magnetic resonance neurography in the evaluation of patients with peripheral nerve pathology. J Neurosurg 1996;85:299-309 5. Grant GA, Goodkin R, Kliot M. Evaluation and surgical management of peripheral nerve problems. Neurosurgery 1999;44:825-839; discussion 839-840 6. Grant GA, Britz GW, Goodkin R, Jarvik JG, Maravilla K, Kliot M. The utility of magnetic resonance imaging in evaluating peripheral nerve disorders. Muscle Nerve 2002;25:314-331 7. Aagaard BD, Maravilla KR, Kliot M. MR neurography. MR imaging of peripheral nerves. Magn Reson Imaging Clin N Am 1998;6: 179-194 8. Gebarski SS, Telian SA, Niparko JK. Enhancement along the normal facial nerve in the facial canal: MR imaging and anatomic correlation. Radiology 1992;183:391-394 9. Sugimoto H, Miyaji N, Ohsawa T. Carpal tunnel syndrome: evaluation of median nerve circulation with dynamic contrast-enhanced MR imaging. Radiology 1994;190:459-466 10. Wertsch JJ, Melvin J. Median nerve anatomy and entrapment syndromes: a review. Arch Phys Med Rehabil 1982;63:623-627 11. Morgan RF, Terranova W, Nichter LS, Edgerton MT. Entrapment neuropathies of the upper extremity. Am Fam Physician 1985;31: 123-134 12. Stern MB. The anterior interosseous nerve syndrome (the Kiloh- Nevin syndrome). Report and follow-up study of three cases. Clin Orthop 1984:223-227 13. Spinner M. The anterior interosseous-nerve syndrome, with special attention to its variations. J Bone Joint Surg Am 1970;52:84-94 14. Shuman S, Osterman L, Bora FW. Compression neuropathies. Semin Neurol 1987;7:76-87 15. Yoshioka S, Okuda Y, Tamai K, Hirasawa Y, Koda Y. Changes in carpal tunnel shape during wrist joint motion. MRI evaluation of normal volunteers. J Hand Surg [Br] 1993;18:620-623 16. Zeiss J, Skie M, Ebraheim N, Jackson WT. Anatomic relations between the median nerve and flexor tendons in the carpal tunnel: MR evaluation in normal volunteers. AJR Am J Reontgenol 1989; 153:533-536 17. Skie M, Zeiss J, Ebraheim NA, Jackson WT. Carpal tunnel changes and median nerve compression during wrist flexion and extension seen by magnetic resonance imaging. J Hand Surg [Am] 1990;15: 934-939 18. Mesgarzadeh M, Schneck CD, Bonakdarpour A, Mitra A, Conaway D. Carpal tunnel: MR imaging. Part II. Carpal tunnel syndrome. Radiology 1989;171:749-754 85 23. O Driscoll SW, Horii E, Carmichael SW, Morrey BF. The cubital tunnel and ulnar neuropathy. J Bone Joint Surg Br 1991;73:613-617 24. Barrios C, Ganoza C, de Pablos J, Canadell J. Posttraumatic ulnar neuropathy versus non-traumatic cubital tunnel syndrome: clinical features and response to surgery. Acta Neurochir (Wien) 1991;110: 44-48 25. Britz GW, Haynor DR, Kuntz C, Goodkin R, Gitter A, Maravilla K, et al. Ulnar nerve entrapment at the elbow: correlation of magnetic resonance imaging, clinical, electrodiagnostic, and intraoperative findings. Neurosurgery 1996;38:458-465 26. Grundberg AB. Ulnar tunnel syndrome. J Hand Surg [Br] 1984;9: 72-74 27. Moneim MS. Ulnar nerve compression at the wrist. Ulnar tunnel syndrome. Hand Clin 1992;8:337-344 28. Mackinnon SE. Double and multiple crush syndromes. Double and multiple entrapment neuropathies. Hand Clin 1992; 8:369-390 29. Eaton CJ, Lister GD. Radial nerve compression. Hand Clin 1992;8: 345-357 30. Fernandez E, Pallini R, Talamonti G. Sleep palsy (Saturday-night palsy) of the deep radial nerve. Case report. J Neurosurg 1987;66: 460-461 31. Reddy MP. Peripheral nerve entrapment syndromes. Am Fam Physician 1983;28:133-143 32. Eversmann W. Operative hand surgery. Edinburgh: Churchill Livingstone, 1988 33. Ehrlich W, Dellon AL, Mackinnon SE. Classical article: Cheiralgia paresthetica (entrapment of the radial nerve). A translation in condensed form of Robert Wartenberg s original article published in 1932. J Hand Surg [Am] 1986;11:196-199 34. Cormier PJ, Matalon TA, Wolin PM. Quadrilateral space syndrome: a rare cause of shoulder pain. Radiology 1988;167:797-798 35. Nagaoka M. [An anatomical study of tarsal tunnel]. Nippon Seikeigeka Gakkai Zasshi 1990;64:208-216 36. Ryan W, Mahony N, Delaney M, O Brien M, Murray P. Relationship of the common peroneal nerve and its branches to the head and neck of the fibula. Clin Anat 2003;16:501-505 37. Rawal A, Ratnam KR, Yin Q, Sinopidis C, Frostick SP. Compression neuropathy of common peroneal nerve caused by an extraneural ganglion: a report of two cases. Microsurgery 2004;24: 63-66 38. Dezawa A, Kusano S, Miki H. Arthroscopic release of the piriformis muscle under local anesthesia for piriformis syndrome. Arthroscopy 2003;19:554-557 39. Diop M, Parratte B, Tatu L, Vuillier F, Faure A, Monnier G. Anatomical bases of superior gluteal nerve entrapment syndrome in the suprapiriformis foramen. Surg Radiol Anat 2002;24:155-159 40. Rodrigue T, Hardy RW. Diagnosis and treatment of piriformis syndrome. Neurosurg Clin N Am 2001;12:311-319