Bệnh thần kinh ngoại vi

G S. TS. HO HUTU LlfCfNG G IANG V IEN C A O CAP BENH THAN KINH NGOAI VI GS.TS. HO HOU LtfONG GIANG VIEN CAO CAP BENH THAN KINH NGOAIVI ■ n h A x u a t ba n y h o c h A NOI - 2005 Chitting I DAI CITONG VE BENH THAN KINH NGOAI VI I. DAC DIEM CHUNG Than kinh ngoai vi bao gom cac day, re, dam roi, day than kinh tuy song va cac day than kinh so nao. Benh than kinh ngoai vi rat pho bien. Theo Ho Hiiu Ludng va cong stf (1991), benh than kinh ngoai vi chiem ty le tifdng doi cao (38,36%) trong cac benh than kinh noi chung, trong do dai dien cho he than kinh ngoai vi chi diidi la hoi chiing that liing - hong (chiem t6i 60,32%) va dai dien cho he than kinh chi tren la hoi chvfng co - vai - canh tay. Hoi chiing nay thifdng gap trong hii xiidng sun cot song co (cervical osteochondrosis), chiem 2,53% tong so' benh nhan n&m dieu tri tai Khoa than kinh Benh vien 103 trong 10 nam - tti 1980 den 1989). Thiidng ton cua he than kinh ngoai vi thifdng dan den nhflng roi loan nang ne cac chilc nang van dong, cam giac va thiic vat dinh diidng. Hon nuia neu la mot thiidng ton trUOng dien thi benh con co the dan den thoai hoa cac day than kinh ngoai vi gay nen thUdng ton than kinh lau dai. II. DAC DIEM GIAI PHAu THAN KINH NGOAI VI Day than kinh song co hai re, re trudc hay re van dong, re sau hay re cam giac. Re cam giac co hach gai. Hai re chap lai thanh day than kinh song. Moi day than kinh song chia ra thanh hai nhanh: nhanh sau phan bo" 3 cho cac cd cham, cd phia sau co va liing. Nhutng nhanh trUdc to hdn phan bo"cho cac cd va da phan trUdc than va chi. Hinh 1.1: So do r l day TK ngoai vi 1 - Re trufdc 2 - Re sau 3 - Hach gai 4 - Nhanh sau cua day TK song 5 - Nhanh tri/dc cua day TK song 6 - Dam roi TK 7 - Day TK song 8 - Nhanh thong trang 9 - Nhanh thong xam 10 - Hach giao cam canh song Nhiing nhanh trUdc cua khoanh tuy liing hinh thanh cac day than kinh gian siidn. Nhiing nhanh trUdc cua cac khoanh tuy co, tuy that liing va tuy cung ket hop vdi nhau mot cach nhat dinh hdp thanh nhiJng bo (fasciculi) cua cac dam roi co - canh tay va that lung - cung. Tu dam 4 roi cho ra nhiing than (trunci) hay day than kinh ngoai vi. Khi cac day than kinh bi thtfdng ton, cC khong nhan diidc kich thi'ch va se bi liet. i 'V I Slvn Is)VIII <fTC&lX Hinh 1.2: Tuy song, cac re va dam roi than kinh, lien quan gii/a tuy song vdi cac re than kinh va cot song. 5 4 ► ■* -> -4 - —► Hinh 1.3: Sieu cau true cua day than kinh ngoai vi (Theo J.D Waggener va Coll 1965) 6 Da so cac day thin kinh ngoai vi la cac day hon hop bao gom nhflng sdi van dong cua re trvfdc (axon cua te bao suing trade), nhiing sdi cam giac (duoi gai cua cac te bao hach gai) va cac sdi giao cam, doi giao cam (van mach, bai tiet, dinh difdng) tii sifng ben cua chat xam tuy song va chuoi hach giao cam canh song. Do do khi day than kinh ngoai vi bi thUdng ton thi gay ra cac roi loan van dong, cam giac, van mach va bai tiet, dinh dUdng. Axon Te bao Schwann Hinh 1.4: Qua trinh phat trien cua te bao Schwann va sdi true 7 Myelin Axon Myelin Hinh 1.5: So do sieu cau true tren mot that vong Ranvier (Thiet do difng doc theo J. Poirier, 1968) Dua vao chutc nang va sU co hay khong co bao myelin ngUdi ta phan loai sdi than dinh: sdi A la sdi co bao myelin thuoc he than kinh nao - tuy. Sdi B la sdi co bao myelin thuoc he TK thtfc vat, sdi C khong co bao myelin thuoc he than kinh thUc vat. Nhutng sdi A dufdc phan chia thanh Aa, A[3, A,y Noi chung cac sdi co dUdng kinh cang 16n thi to"c do d in truyen cang cao, cac sdi co difdng kinh cang be thi toe do dan truyen cang cham. Cac sdi 16n lien quan den 8 chOfc nang van dong va cam giac ban the, cac sdi be tham gia vao chiic nang thUc vat va cam giac dau. Cac sdi co ki'ch thtfdc khac nhau thi tinh nhay cam doi BANG 1.1: CAC LOA1 SOI TK 0 DONG VAT CO VU Loai sdi Bi/dng kinh (micro - met) Toe do dan truyen (m/sec) Chute nang A. alpha (Aa ) 12 - 22 70 - 120 Van dong cd xtfdng cam giac ban the A. beta B. (AP) 8 - 12 40 - 70 Xuc giac, ap luC A.Gamma (A y) 4 - 8 15 - 40 Xuc giac, ap lUc van dong thoi cd A delta (A 6) 1 - 4 5 - 15 Cam giac nhiet, ap lut, dau. B 1 - 3 3 - 12 Cac sdi tru6c hach TK thut vat C 0 ,5- 1 0,5 - 2 Cac sdi sau hach TK thi/c vat dau, ap life, nhiet. vdi su: thieu Oxy (hypoxie) va cac thuoc vo cam (anesthesie) cung khac nhau. NhiJng sdi truyen cam dau la nhuing sdi co dadng kinh nho, co myelin (sdi A delta) hoac khong myelin (sdi C). Thuoc vo cam tai cho co the lam mat stf dan truyen cua cac sdi C. 9 hi. su’THOAi hoA v A tAi sinh cAc sdi thA n kinh Binh thUdng sdi true dUdc bao quanh bdi cac te bao Schwann xep canh nhau doc theo chieu dai cua no. Cac te bao Schwann chi cach nhau mot khe nho goi la that vong Ranvier. NhvJng sdi khong co myelin, moi te bao Schwann chi cuon quanh mot sdi true va tu phan doan. Mot trong nhiing chiic nang cua bao myelin la lam tang nhanh toe do dan truyen luong than kinh. Nhii vay sdi co myelin truyen nhanh hdn nhiing sdi khong co myelin. 1. Thoai hoa Waller (do Waller mo ta lan dau tien (1856): khi c&t dtit day than kinh, cac sdi true se bi thoai hoa, dac biet tram trong la d phan ngoai vi, lam cho neuron mat han chiic nang sinh ly, sau mot thdi gian dai m6i hoi phuc dUdc: O than neuron 48 gid sau khi cat, cac the Nissl (nhilng hat mau xam, chiia nhieu phan til ARN (acidribonucleic) co tac dung tong hdp protein) bien mat het, lUdi td TK (nhiing sdi co dtfdng kinh khoang 90A°, dan thanh mot mang lu6i trong than neuron) bi tan vd, than neuron nd ra va nhan bi day lech sang mot ben; neu thUdng ton qua nang thi nhan cung bi tieu tan va neuron hoan toan bi pha huy. Thong thUdng tvf ngay thii hai mUdi, d cho cat nhiing tua bao tufdng se raoc ra va b it diu thdi ky hoi phuc. - Phan ngoai vi sdi true bi ckt (hinh 1.6): 24 gid sau khi bi cat, bao myelin bi vd thanh tting mang, sdi true bi tan bien chi con lai mot ong bao Schwann rong. cac tg' bao Schwann nd to ra lap ca ong. 10 [...]... mo ke (viem ke day than kinh) d cac sdi than kinh (viem nhu mo day than kinh) Trong hai trUdng hdp dau, thay co dich ri viem v6i nhting bach cau, tang sinh cac nhan Schwann va dtit quang bao myelin Trong viem nhu mo day th in kinh, sdi true ton tai d trong bao mat myelin nen co benh canh giong nhu thoai hoa Waller sau khi c it mot day than kinh ngoai vi VI CG CHE THl/CfNG TON THAN KINH NGOAI VI ThufOng... nam 2 Viem day than kinh quanh true tifng doan (nevrite sementaire periaxile) La hau qua cua thUdng ton nguyen phat cua te bao Schwann (hinh 1.6) bieu hien bdi sii mat bao myelin d mot hay nhieu doan IV PHAN LCAI BENH THAN KINH NGOAI VI 1 Phan loai theo vi tri thiidng ton Phan loai theo vi tri thifdng ton neuron than kinh ngoai vi (re, dam roi, day than kinh) Day chi la nhiing quy u6c tUdng doi vi viem... kich thich he than kinh van dong ngoai vi, cac cd va he than kinh cam giac d vi tri nong diidi da de xem xet phan ilng dien trong chan doan benh thin kinh - cd Nam 1948, Hordes, Larabe da nghien cilu dan truyen than kinh van dong Nam 1962 Gillatt va Thomas dung phiidng phap do d in truyen th in kinh de nghien cilu cac benh ly cua day thin kinh ngoai vi va thay rang khi day than kinh bi thiidng ton... cac re than kinh d cac doan noi tao dieu kien tot cho cac qua trinh viem Tuy theo vi tri giai phau ma phan biet ra: Viem re than kinh co - canh tay Viem r l than kinh lifng Viem re than kinh that lifng - cung 15 2 Viem dam roi than kinh Thudng d mot ben, bat dau bang giai doan dau day than kinh tu phat, tang len khi cii dong va khi de ep vao dam roi, sau do co the la giai doan liet kem theo giam phan... kinh gitia, day than kinh gian sUdn b Viem day than kinh - Benh can: Chan thUdng trUc tiep, dung dap, cang keo, tiem thuoc Nhiem doc: thudng lam thudng ton nhieu day than kinh Do lanh: chu yeu trong liet mat Do nhiem khuan TrUdng hdp viem mot day than kinh thudng do cd che de ep hoac thieu mau cuc bo hoac ca hai yeu to' do gay ra Giai phau benh hoc: ThUdng ton co the gidi han (viem quanh day than kinh) ... day thiidng lan sang re than kinh 2 Phan loai theo nguyen nhan thvfOng ton Benh than kinh ngoai vi co the la nguyen phat hoac thii phat Nguyen phat: ThUdng ton b it nguon tif than kinh ngoai vi (vi khuan trUc tiep lam thUdng ton day than kinh hoac chan thUdng trUc tiep gay nen diit, giap day than kinh) - Thii phat: sau mot thUdng ton cua cot song, nhiem doc chi, asen, thieu vitamin B l (benh Beriberi)... khong bi dtit day th in kinh thi sii hoi phuc chtic nang se rat tot Neu bi dtit day th in kinh ma khong khau noi hai d iu bi cat thi svf tai sinh se khong co ket qua Do roi loan chuyen hoa va benh ly vi mach (xem benh th in kinh ngoai vi do dai thao difdng) VII TRIEU CHLTNG LAM SAN G BENH THAN KINH N G O A I VI 1 Roi loan van dong Liet mem hay liet cd chi phoi bcii day than kinh bi thifdng ton 18 2... lao, viem mang nao mu - Chan thUdng - Thoat vi dla dem chen ep vao re than kinh Thii phat sau benh Pott, u ngoai tuy, di can ung thu hay viem nao - Zona b Giai phau benh hoc Cac re than kinh khi rdi khoi tuy tao thanh bo sdi than kinh difdc bao boc bdi mang nhen noi tiep vdi mang mem Cac nhom te bao bieu mo phu, cac re than kinh d cac doan noi tao dieu kien tot cho cac qua trinh viem Tuy theo vi tri... than cac cau true than kinh cam giac (trung tfdng, ngoai vi) Dac diem chinh cua dau than kinh la khu tru tai vung phan bo" cua cac day than kinh hoac lan theo dai phan bo" cam giac cua re than kinh, dau ca d vung giam hay mat cam giac, tang ve dem va dap ting rat kem vdi cac thuoc giam dau truyen thong Cac loai dau than kinh thudng gap: Dau than kinh do dai thao dtfdng Dau th in kinh sau herpes (dau... day than kinh va viem day than kinh a Dau day than kinh Dac diem cua dau day than kinh la dau doc day than kinh, nhieu khi khong co nguyen nhan thuc the ro rang, 16 khong kem roi loan chtic nang thUc sU d cac cd quan hoac cac cd tUdng ting Cac cdn dau thudng d mot ben, phat sinh do bi kfch thi'ch mot vung nhat dinh Ngoai cdn khong co roi loan khach quan Trong thuc te thudng hay gap dau day than kinh hong . THAN KINH NGOAI VI 1. Phan loai theo vi tri thiidng ton Phan loai theo vi tri thifdng ton neuron than kinh ngoai vi (re, dam roi, day than kinh) . Day chi la nhiing quy u6c tUdng doi vi viem. biet ra: Viem re than kinh co - canh tay Viem r l than kinh lifng Viem re than kinh that lifng - cung 15 2. Viem dam roi than kinh Thudng d mot ben, bat dau bang giai doan dau day than kinh tu. co the gidi han (viem quanh day than kinh) hay d mo ke (viem ke day than kinh) d cac sdi than kinh (viem nhu mo day than kinh) . Trong hai trUdng hdp dau, thay co dich ri viem v6i nhting bach