대한임상신경생리학회지 10(1):43~47,08 ISSN 1229-6414 급성상완신경총염의임상소견과전기생리학적소견 부산대학교의과대학신경과학교실 조희영 김대성 Clinical Features and Electrophysiological Findings of Acute Brachial Plexitis Hee Young Jo, M.D., Dae-Seong Kim, M.D. Department of Neurology, Pusan National University Hospital, Busan, Korea Received 17 April 08; received in revised form 12 June 08; accepted 13 June 08. Background: Acute brachial plexitis is an acute idiopathic inflammatory disease affecting brachial plexus, which is characterized by initial severe pain in shoulder followed by profound weakness of affected. This is a retrospective study to evaluate the clinical and electrophysiological profile of acute brachial plexitis. Methods: Sixteen patients with acute brachial plexitis were sampled. The electrodiagnostic studies included motor and sensory nerve conduction studies (NCSs) of the and ulnar, sensory NCSs of medial and lateral antebrachial cutaneous nerves, and needle electromyography (EMG) of selected muscles of upper extremities and cervical paraspinal muscles. The studies were performed on both sides irrespective of the clinical involvement. Results: In most of our patient, upper trunk was predominantly affected (14 patients, 87.50%). Only two patients showed either predominant lower trunk affection or diffuse affection of brachial plexus. All had an acute pain followed by the development of muscle weakness of shoulder girdle after a variable interval (7±8.95 days). Ten patients (62.50%) had severe disability. In NCSs, the most frequent abnormality was abnormal lateral antebrachial cutaneous sensory nerve action potentials (SNAPs). On needle EMG, all the patients showed abnormal EMG findings in affected muscles. Conclusions: In this study, pain was the presenting feature in all patients, and the territory innervated by upper trunk of the brachial plexus was most frequently involved. The most common NCS abnormality was abnormal SNAP in lateral antebrachial cutaneous nerve. Our findings support that the electrodiagnostic test is useful in localizing the trunk involvement in acute brachial plexitis. Key Words: Brachial plexus neuritis, Electrodiagnosis, Lateral antebrachial cutaneous nerve, Sensory nerve action potential 서 론 Address for correspondence; Dae-Seong Kim, M.D. Department of Neurology, Pusan National University School of Medicine, 10, 1-ga, Ami-dong, Seo-gu, Busan, 602-739, Korea Tel: +82-51-240-7672 Fax: +82-51-245-2783 E-mail: dskim@pusaac.kr 급성상완신경총염 (acute brachial plexitis) 은상완신경총을침범하는염증질환으로서, 신경통근육위축증, 잠재상완신경총신경병증, 양성신경총신경병증, 파르소니지- 터너증후군등으로불리기도한다. 1-3 이질환은급성으로 Copyright 08 by The Korean Society for Clinical Neurophysiology 43
조희영 김대성 시작되고심한통증을수반하는데, 수일이지나면서근력약화가시작되고근위축이흔히발생한다. 하지만경한경우에는근위축없이통증과근위약만나타나기도한다. 4 급성상완신경총염의진단에서는이러한특징적인임상소견이가장중요하지만정확한병변부위와침범된신경및근육을파악할수있는전기생리학적검사가유용한진단보조도구로사용되고있다. 이연구는급성상완신경총염으로진단받은환자 16명의후향적연구를통해그임상적, 전기생리학적특성을규명하는데그목적이있다. 대상과방법 1998년 5월부터 08년 3월까지부산대학교병원에내원한환자중다음의선별기준에부합되는환자를대상으로하였다. 포함기준으로는 1) 급성견갑부통증이발생한후상지근육의마비및위축이발생한병력, 2) 임상소견및신경학적검사에서상완신경총병증에부합되는소견을보인경우, 3) 전기생리학적검사를한환자이며, 제외기준으로는 1) 외상성상완신경총병증이나암종의전이에의한경우등명확한선행요인에의해발생한상완신경총병증, 2) 명백한경부신경근병증이나다발성신경병증이동반된경우, 3) 유전성압궤편향성말초신경병등다른질환에의한경우등이다. 이상의선별기준에부합된환자는총 16 명이었으며, 이들을본연구의대상으로하였다. 신경전도검사와근전도검사는 Cantata (Dantec, Denmark) 또는 Keypoint (Dantec, Denmark) 근전도기기를사용하였으며, 모든환자에서양측상지의정중신경, 척골신경의운동신경전도검사, 정중신경, 척골신경, 외측전완피신경 (lateral antebrachial cutaneous nerve), 내측전완피신경 (medial antebrachial cutaneous nerve) 의감각신경전도검사를하였다. 또한세명의환자에서는양측쇄골위오목 (supraclivicular fossa, Erb s point) 에서액와신경을자극하여어깨세모근육에서복합근육활동전위를기록하였다. 근전도검사는추정되는병소에상응하는근육들과경추부척추옆근육을포함하였다. 운동신경전도검사의복합근육활동전위의진폭, 운동신경전달속도, 말단잠시, F파및감각신경전도검사의감각신경활동전위의진폭과감각신경전달속도에대한판정기준은본원신경과전기진단검사실의정상치를사용하였다. 결과 1. 임상적특성총 16명의환자중남자는 13명, 여자는 3명이었으며진단시의연령은 16세에서 79세의분포 ( 평균 49.9 세 ) 였다. 모든환자에서특별한선행사건이없었으며, 대상자모두가갑작스런상지와견갑부의통증을첫증상으로호소하였는데, 첫증상이후상지운동장애가발생하기까지걸린시간은평균 7±8.96 일이었다. 운동장애는 14명은상지의근위부마비, 1명은수부및수지의마비, 나머지 1명은상지전체의마비를보였다. 16명모두편측으로만증상이발생했으며, 좌측상지마비가 9명, 우측상지마비가 7명이었다. 근력약화의정도는가장현저하게손상받은관절의움직임을기준으로하였을때, 10명 (62.50%) 이 Medical research council grade (MRC) 3 이하의심각한운동장애를호소하였으며, 그중 3명에서는근력약화가가장현저한부위에근육위축이관찰되었다. 이중한명은내원시임상증상이이미호전된상태로서근력저하를관찰할수없었다. 감각장애는상신경간 (upper trunk) 손상의임상양상을보이는 4명의환자에서좌측전완피신경분포영역에서관찰되었다. 추적조사가가능하였던 14명중 3 개월이후근력약화가호전된환자는 10명이었으며, 증상변화가없는환자는 4명이었다. 임상양상으로상완신경총염의병변을분류하였을때상신경간손상이 14명, 하신경간 (lower trunk) 손상이 1명이었으며, 전체신경간손상이 1명이었다. 전체 16명중 5명이 MRI 척수강조영술검사에동의하였고이들중 2명에게서만경미한추간판탈출이동반되어있었을뿐, 상완신경총의비후, T2 강조영상에서의신호증가등이상소견을보인환자는없었다 (Table 1). 2. 전기생리학적소견신경전도검사에서 5명은정상이었고, 11명은임상적으로국지화된신경에서이상소견을보였으며, 근전도검사에서는모든환자에서임상적으로의심되는병소에상응하는근육판분포 (myotomal distribution) 를따라이상소견이나타났다. 신경전도검사와근전도검사의시기는상지의통증발생으로부터평균 89.8 일째 (3~1 일 ) 였다. 신경전도검사에서양측을비교하였을때병측의감각신경활동전위의감소나소실을보이는소견들이운동신경전달속도의저하, 복합운동활동전위의감소, 말단잠복기지연및 F파의지연보다흔하였다. 감각신경전도검사상외측전완피신경의이상이가장많았으며 (8명, 50%), 그외척골 44 Korean J Clin Neurophysiol / Volume 10 / June, 08
급성상완신경총염의임상소견과전기생리학적소견 Table 1. Clinical profiles of 16 patients with acute brachial plexitis Patient sex age associated disease onset pain side interval to motor weakness (day) motor weakness sensory change muscle atrophy MRI findings (cervical and/or brachial) localization of major plexopathy on clinical basis 1 M 70 - rapid shoulder right 10 MRC4 - - not done upper 2 F 44 - rapid shoulder left 0 MRC5 - - not done upper 3 M 45 - rapid left 3 MRC2 lateral - not done upper 4 M 55 - rapid shoulder left 30 MRC3 - - not done lower 5 M 44 - rapid shoulder left 0 MRC4 - - not done upper 6 M 45 - rapid shoulder, right 1 MRC5 - - not done upper scapular 7 F 37 - rapid shoulder left 1 MRC3 - - not done upper 8 M 41 - rapid shoulder right 1 MRC4 - - mild disc bulging upper 9 M 60 carpal tunnel syndrome rapid shoulder, 10 F 30 - rapid shoulder, neck 11 M 41 - rapid shoulder, neck 12 M 62 - rapid shoulder, 13 M 79 carpal tunnel syndrome right 7 MRC2 lateral deltoid not done diffuse right 7 MRC4 - - not done upper right 3 MRC3 - deltoid normal upper right 1 MRC2 lateral - not done upper rapid shoulder left 4 MRC2 - - normal upper 14 M 75 - rapid shoulder left 3 MRC3 lateral - mild disc bulging upper 15 M 54 - rapid left MRC2 - - not done upper 16 M 16 - rapid shoulder left 21 MRC3 - deltoid normal upper MRC; Medical research council grade 신경 (3명, 18.75%), 내측전완피신경 (2명, 12.5%) 의순이었다. 증상을호소하지는않았지만 2명에서손목굴증후군이동반되어있었다. 근전도검사에서경추부척추옆근육에서비정상적자발전위가보이는환자는 2명이었고, 이들을포함하여본연구의대상모두손상된병소의근육판분포에상응하는근육에서비정상적자발전위 (16 명, 100%) 혹은동원감소현상 (13 명, 81.25%) 이나타났다 (Table 2). 고찰급성상완신경총염은갑작스런견갑대의심한통증에이은어깨주변근육의근력약화와위축이특징적이며, 감각저하는피판분포 (dermatomal distribution) 에대응하는 피부감각의변화를보인다. 4 이질환의원인은아직명확하지않다. 그러나이전보고들에의하면약 50% 는선행하는사건이있는데, 백신주사, 약물남용, 바이러스감염, 결체조직질환, 임신, 수술, 외상등이이에속한다. 또한, 남녀비율은 2:1에서 4:1로남성에서빈번하며좌측보다는우측에서발병빈도가높고양측이동시에발병하는경우도 12.8~34% 에이르며, 재발률은약 5% 정도로보고되고있다. 1,5,6 또한기능은대부분이만족스러울회복하지만회복의속도는느려서 1~2 년정도의기간이지나야하며, 약 10% 는회복이안되어기능장애가남는다. 1,5 본연구에서도모든대상자가견갑대의심한통증출현이후수일 (7± 8.96 일 ) 이내에운동장애가발생하였고, 남성의발병률 (13 명, 81.25%) 이우세하였다. 그러나기존의보고와는달리 Korean J Clin Neurophysiol / Volume 10 / June, 08 45
조희영 김대성 Table 2. Results of nerve conduction study and electromyogram in patients with acute brachial plexitis patient sex age Abnormal parameters in electrophysiologic study CMAP or SNAP amplitude* conduction velocity distal latency F-wave latency EMG abnormal muscles interval to EMG, NCV (day) 1 M 70 - - - - deltoid, biceps, infraspinatus, triceps, 60 rhomboideus 2 F 44 - - - - biceps, infraspinatus, deltoid 6 3 M 45 axillary CMAP - - - biceps, pronator teres, deltoid, infraspinatus, triceps, rhomboideus 4 M 55 medial antebrachial SNAP, medial antebrachial ulnar n ulnar first dorsal interosseous, extensor digitorum communis, abductor pollicis brevis, flexor digitorum profundus, triceps, supraspinatus, infraspinatus, rhomboiedus 5 M 44 - - - - supraspinatus, infraspinatus, rhomboiedus 6 M 45 - - - - triceps, extensor digitorum communis, first dorsal interosseous 7 F 37, axillary CMAP - - - supraspinatus, infraspinatus, rhomboiedus, biceps, triceps, extensor digitorum communis 8 M 41 - - - - pronator teres, biceps, triceps, deltoid, infraspinatus, serratus anterior 9 M 60 CMAP, lateral and medial antebrachial SNAP 10 F 30 axillary CMAP, biceps, pronator teres, deltoid, infraspinatus, triceps - - - infraspinatus, deltoid, biceps, brachioradialis 11 M 41 - - - deltoid, supraspinatus, triceps, cervical 5 12 M 62 ulnar CNAP, 13 M 79 ulnar CNAP, CMAP ulnar ulnar - biceps, pronator teres, deltoid, infraspinatus, supraspinatus, triceps, first dorsal interosseous, abductor digiti minimi biceps, pronator teres, deltoid, infraspinatus, supraspinatus, triceps, rhomboideus 14 M 75 - - - rhomboideus, flexor pollicis longus, biceps, extensor indicis proprius, cervial 6 15 M 54 ulnar CNAP, - - - pronator teres, biceps, deltoid, infraspinatus 16 M 16 ulnar ulnar biceps, trapezius,supraspinatus, infraspinatus, pronator teres, deltoid CMAP; compound motor action potential, CNAP; compound nerve action potential, SNAP; sensory nerve action potential, EMG; electromyogram, NCV; nerve conduction velocity *including difference between sides 1 60 30 14 14 7 3 1 좌측 (9명, 56.25%) 이더많았고, 추적조사상 3개월이내에기능회복을보이지않은경우가 14명중 4명 (24.5%) 이었으며, 전체환자중선행사건이있었던환자는없었다. 이는본연구가후향적연구이므로다양한선행사건을조사하지못하였으며, 3개월이상장기적인추적조사를하 지못한한계가있기때문인것으로판단하였다. 현재까지급성상완신경총염에서는상신경간이가장흔히침범되는것으로알려져있는데, 본연구에서도상신경간손상이 14 명, 하신경간손상이 1명, 신경간전체손상이 1명으로서상신경간손상이가장흔하였다. 7,8 46 Korean J Clin Neurophysiol / Volume 10 / June, 08
급성상완신경총염의임상소견과전기생리학적소견 급성상완신경총염에서는탈수초보다는축삭손상으로인해왈러변성이생기게되어주로병소의원위부인말단분지의신경전도검사에서이상이나타나게된다. 1,6,8-10 따라서말단잠복기와신경전도속도의연장이나감소보다는진폭의감소나소실이자주관찰되며, 또한진폭이정상범위내에속하는경우에도좌우측을비교하였을때병변측에서현저히감소된소견을보인다. 1,6,9,10,12,13 한편, 감각신경전도검사의진폭감소는병변이뿌리신경절 (dorsal root ganglion) 의원위부임을확인하는데중요하며, 이는목신경근병증과의감별에도움을준다. 본연구의증례들에서는외측및내측전완피신경전도검사를추가한결과, 16명중 10명에서이들신경의감각신경활동전위의진폭이감소하거나양측비교시현저히감소하여이전의보고내용들에부합하였다. 이처럼목신경근 5, 6번이지배하거나목신경근 8번및가슴신경근 1번이지배하는근육판의근육이침범되었을경우외측삭 (lateral cord) 에서직접분지되는근피신경 (musculocutaneous nerve) 의감각분지인외측전완피신경과내측삭 (medial cord) 에서직접분지되는내측전완피신경의감각신경활동전위의이상소견은목신경근병증보다는상완신경총병변을시사한다. 13 본연구의증례중 2명은척추옆근육에서비정상적자발활동을보였지만이들에게서도외측및내측전완피신경의감각신경활동전위진폭이감소됨으로써이들을목신경근병증과감별하는전기생리학적증거로생각하였다. 침근전도검사는신경전도검사보다이상소견을찾아낼확률이높을뿐아니라, 병변의위치를정확히국소화하고, 목신경근병증과도감별할수있다. 급성상완신경총염의가장초기에는근전도검사에서운동단위의동원감소가나타나며, 이후탈신경이진행되면비정상적자발활동이나타나기시작한다. 그러나급성상완신경총염에서도척수신경또는그근위부까지침범하는경우가있어척추옆근육에서도비정상적자발전위가나타나기도한다. 6,11 본연구에서도모든환자의손상된신경총에해당하는근육판분포에따르는근육에서이상소견이나타났다. 저자들은급성상완신경총염환자들을대상으로임상소견과전기생리학적소견을분석하여다음의결론을얻었다. 견갑대부위의급성통증에이은근력약화와감각이상을보이는환자는급성상완신경총염을의심해야하며, 전기진단검사가진단의확인과정확한병소부위의국소화 에도움이된다. 특히상완신경총염과유사한임상소견을보이는목신경근병증과감별하기위해서는복합신경활동전위의변화, 특히외측및내측전완피신경의감각신경활동전위진폭감소의전기생리학적증거를포착하는것이중요하다고생각한다. REFERENCES 1. Tsairis P, Dyck PJ, Mulder DW. Natural history of brachial plexus neuropathy. Report on 99 patients. Arch Neurol 1972; 27:109-117. 2. Parsonage MJ, Tuner JW. Neurologic amyotrophy: The shoulder-girdle syndrome. Lancet 1948;1:973-978. 3. Turner JW, Parsongage MJ. Neuralgic amyotrophy (paralytic brachial neuritis); with special reference to prognosis. Lancet 1957;273:9-212. 4. Schott GD. A choronic and painless form of idiopathic brachial plexus neuropathy. J Neurol Neurosurg Psychiatry 1983;46:555-557. 5. Amato AA, Jackson CE, Kim JY, Worley KL. Chronic relapsing brachial plexus neuropathy with persistent conduction block. Muscle Nerve 1997;:1303-1307. 6. James JL. Miles DW. Neuralgic amyotrophy: a clinical and electromyographic study. Br Med J 1966;29;2:1042-1043. 7. Puri V, Chaudhry N, Jain KK, Chowdhury D, Nehru R. Brachial plexopathy: a clinical and eletrophysiological study. Eletromyogr Clin Neurophysiol 04;44:229-235. 8. Suarez GA, Giannini C, Bosch EP, Barohn RJ, Wodak J, Ebeling P, et al. Immune brachial plexus neuropathy: suggestive evidence for an inflammatory-immune pathogenesis. Neurology 1996;46:559-561. 9. Flaggman PD, Kelly JJ Jr. Brachial plexus neuropathy. An electrophysiologic evaluation, Arch Neurol 1980;37:160-164. 10. Moqherkar AR, Karli N, Chaudhry V. Brachial plexopathies: etiology, frequency, and electrodiagnositic localizatio J Clin Neuromusculo Dis 07;9:243-247. 11. Kim KK. Acute brachial neuropathy-electrophysiological study and clinical profile. J Korean Med Sci 1996;11:158-164. 12. Aminoff MJ, Olney RK, Parry GJ. Raskin NH. Relative utility of different electrophysiologic techniques in the evaluation of brachial plexopathies. Neurology 1988;38:546-550. 13. Seror P. Medial antebrachial cutaneous nerve conduction study, a new tool to demonstrate mild lower brachial plexus lesions. A report of 16 cases. Clin Neurophysiol 04;115: 2316-2322. Korean J Clin Neurophysiol / Volume 10 / June, 08 47