TAP CHi Y HOC VIET HAM TAP 452 - THANG 3 - SO 2 - 2017
DAC DIEM DIEN THE KICH THICH THI GIAC a BENH NHAN VIEM THI THAN KINH HAU NHAN CAU
T O M T A T
Viem 1h\ than kinh hau nhSn c^u la benh 1'^ do nhieu nguyen nhan gay nen tinh trang viem khu tru d bo hoang diem gay mat myelin phan day than kinh thi giac tif sau vj tn dgng mach trung tam vong mac chui vao day than Idnh thj. Ghi dien the kich thich thj giac (VEP) CO the phat hien du'dc stf thay doi chu'e nang trong giai doan sdm ciia benh. be gop phan tim hieu gia^tn va hah che cua phifdng phap ghi VEP trong chan doan liinh ly viem thi tiian kinh nau nhan cSu, chung toi tJii/c hien nghien cu\j nay vdi muc tieu:/*^ ta dSc diem cac sdng dlin the kich tfjfch thj giac tren benh nhan viim Wi thin kinh hau nhan au. Ket qua nghien ciTu tren 46 benh nhan viem thi than kinh hau nh|n (3u, tu6i ti^ 18 den 60, trung biiih 37,3 ±-12,2 tijoi cho thay: Tan suat xuat hien cac song N75 Pioo, N145 d chuyen dao cung ben va doi ben kich thi'ch la 100%. l a n suat wat hien ciia song P175 d chuyen dao ding ben ia'di thfch la 42%, doi ben la 43,5%; I^lat bj viem thj than kinh hau nhan cau co thdi gian tierri tang cua cac song N75, Pva, NMS; Thdi gian lien dinh N75 - Pioo keo dai; Dien itie lien dinh BL - N75, N ^ - Pioo( Piop - NH5 thap r5 ret so vdi mat lanh va mat dJa ngudi binh thudng. Ket qua nghien cuU^ cho thay dp nhay cua ky thuat ghi Pr-VEP trong chan doan viem thj tiian lanh hau nhan cau tuong difdng vdi ky thuat chup MRI.
Tif khda: Dien the kkh thich thi giac, viim tiii than idnh hau nfiin au.
SUMMARY
CHAIU^CTERISnCS OF VISUAL EVOKED POTENTIALS I N RETROBULBAR N E U R I T I S
PATIENTS
R^TObulbar neuritis is a form of optic neuritis in which the optic nerve at the back of the eye becomes inflamed. Tlie inflamed area Is between the back of tiie eye and the brain. Retrobulbar neuritis can be caused by a variety of conditions. Whereas,Visual evoked potentials obtained on pattern stimulation (PVEP) represent an averaged response of the visual cortex induced by repeated visual stimulations and as such refledjng optic nerve function such as its electrophysiologic conductivity of its axons. To identify the values and limitations of this method in early diagnose retrobulbar neuritis, we processed this study with objective desoibing the characteristic PVEP findings In Retrobulbar neuritis. The results indicate
^B$nh viin Nhl$tddi TW
^Tn/dng Dai hge YHa Noi Chiu trach nhiem chi'nh: L i Dinh Tung Email: [email protected] Ngay nhan bai: 22.12.2016 Ngay phan bien khoa hoc: 17.2.2017 Ngay duyet bai: 28.2.2017
Nguyen Dire Quynh^ Le Dinh Tiing^
that, in retrobulbar neuritis eye, the occun-ent ratio of N75, PIOO, N145 nearly 100 percent N75, NlOO, P145, inteipeak latency of N75-P100 were significantiy delayed. The amplihjde of N75, N75-P100, PIOO - N145 drasti'cily decreased in comparison with normal eye and normal people. And, the sensitivity of tiiis method was similar with MRI findings.
Keywords: Retrobulbar neuritis, Pr-VEP.
I. OAT V A N OE
Viem thj than kinh hau nhan c3u la mpt the cua benh ly viem day than kinh thi giacTai Hoa Ky, ty le mac benh vao khoang 5 - 6,4/100000 [1] nhuhg chu'a co so lieu thong ke cu the d Viet Nam. Benh do nhieu nguyen nhan khac nhau gayra tinh trang viem khu tru d bo hoang diem phan day tiian kinh thj giac t i f sau v| t n dpng mach trung tam vong mac chui vao day than kinh thi,gay mat myelin anh hu'dng tdi sif dan truyen xung dpng than kinh, lam giam thi lu'c nhieu va nhanh chong. Chan doan benh hien nay chu yeu dda vao trieu chifng lam sang, sol day mat va chup epng hu'dng tCf sp nao.
Vdi benh viem thi than kinh hau nhan cau (VriKHNC), ghi VEP ed the phat Iiien du'de su*
thay doi chifc nang trong giai doan s d ^ ciia benh [ 2 ] , [ 3 ] . 6 Viet Nam, da co mot so cong trinh nghien cdM dng dung VEP de chan doan, tiieo doi, danh gia mpt so benh lien quan den thi than kinh. Tuy nhien, chu'a co nghien cifu nao duttc thifc hien ben benh nhan VTTXHNC, \n vay chung toi tiiut hien nghien culj nay vdi muc tieur Motadac dmn cac sdng der? tfiikkh tiikdi thi giac tiin benh ntSnvmn thj dSn kinh hau nhan cau. .?
II. 0 6 l T i r p N G VA PHI/ONG PHAP NGHIEN CUU - Phu'dng phap nghiin cut/; mo ta eat ngang, chpn mau thuan tien, tren 46 doi tu'dng tCf 18 den 60 tuoi. Cd mau du'dc tinh theo cong thu'c:
n ^ , trong d o : n la cd mau toi tiiieu can nghien cu'u, • " ; He so gidi han tin cay, chpn a = 0,05, d : mu'c sai lech mong muon cho phep, chpn d=0,09; p = 6,9 ( t / ie benh nhan VTTKHNC co VEP bat thu'dng theo nghien cifu tru'dc [ 2 ] .
J Dor tu'dng nghien ah/: cac benh nhan du'dc chan doan xac djnh viem thj than kinh hau nhan cau tai Vien Mat Trung u'dng.
VIETNAM MEDICAL JOURNAL N°2 • MARCH • 2017 Tieu chuan chan doin: Giam thj lu'c
nhanh, dot ngot; dau nhiJc hoc mat,^(fau tang khi van d6ng hoac efn vao nhan c3u;^ton thuHng dong hJ hu'dng tam tu'dng doi, c6 the c6 roi ioan sac giac; ttii lu'c giam slit fl nhieu mu'c d9;ton thi/dng thi trtfclng dang am diem trung tam, canh trung tam hay lan toa (do bang thj tnfdng k^ Humphrey); day matva nhan ap binh thu'dng;
thj than kinh tang kfch thu'dc {> 5mm), tang tfn hieu tren MRI.
• -Tieu chuan loai triif: khong phan biet du'dc sang toi, mac cac benh ly khac gay giam thj lu'c nhl/ ton thu'dng ban phan tn/dc, due thCiy Hnh the,phLi gai thj, loi mat, mu mau bam sinh, benh vong mac do dai thao du'dng, viem vong mac sac to, bong vong mac cu, tang nhan ap, dai thao du'dng, tang huy^ ap, migraine, dung cac thuoc anh hirdng tdi sac giac ^ (chlqroquin, carbamazepin,...), khong hdp tac de ghi VEP,
-PhiAfng phap thu thap so lieu: Boi tudng nghien ciiU duHc ghi VEP trang phong toi, cuSng do anh sang nin < 9 cd/m^ nhiet do phong 25 - 27»C. Dien cue ghi du'dc dat theo sd ^ dudi day.
Tru'dc khi ghi, doi tudng giai thich ro ve muc dich, quy trinh ghi Pr - VEP.Oien ciTc ghi du'dc dat tren da dau theo tieu chuan Queen Square.
Vj tri |w|0 each u cham ngoai 5cm ve phia trUdc
theo du'dng giiia. LO doi xftig vdi RO va each
• MO 5em ve ben trai. fiien cifc tham chieu duBcdat tai diem Fj (MF) each goc mjil 12 cm tren du'dng noi giUa goc mui va ii cham ngoaN Kich thich th] giac bang bang mau gom cac 6 vuong den, trang, xen ke, deu nhau, kich thu'dc 16' tren man hinh co do tu'dng phan 50 - 80%.
Tan so doi mau eua cac 6: IHz; ghi 200 kfch thfeh CO dap iJng, moi mat ghi hai lan, tru'dng : hdp chu^a xac djnh dUdc ehinh xac dfnh song:
tang kich thu'dc 6 vuong (check size) len 8', 4' hoac tang tan so kfch thfch.
- Phin tich vi xit If so lieu: Si dung kiem dinh Studen T-test de so sanh gia trj trung binh cfia 2 nhom. ANOVA - one way so sanh nhieu gia trj frung binh.Klem djnh x^ de so sanh cac ly le.C8 mau nho siJ dung kiem dinh Mann-Whitney U test. Vdi p < 0,05 dUdc cho la khac biet co y nghTa thong ke.
- Oao du'c nghien cu'u: Ghi VEP la ky thuat khong xam lan, khong gay dau, an toan, khong bien chutig. Boi tUdng du'de glal thidi ky t-u'dc khi thu'c hien ky ttiuati so lieu chi siJ dung cho muc dfch nghien cuXi vdlsu' dong •/ cua doi tu'dng.
111. KFT QUA NGHIEN CCTU
3.1. Sac diem doi tu'dng nghien ci^u: 46 doi tu'dng (20 namchiem 43,5% va 26 nif, 56,5%) tCf IB den 60 tuoi, du'dc chan doan VTTKHNC tai Khoa Bay mat - Vien Mat Trung u'dng. Tuoi trung binh cua benh nhan la 37,3 ± 12,2. Trong so 46 benh nhan, eo 21 benh nhan dUdc chan doan VTTKHNC hai mat, 25 benh nhan dUdc chan doan VTTKHNC mot mat (bieu d5 3.1).
Bieu do 3.1. Phan bo benh nhan theo nhom tuoi (trai) va gidi tinh (phai) 3.2. Ket qua ghi VEP tren benh nhan VTTKHNC
3.2.1. Tin suit xuat Men cic sdng.^n suat xuat hien cac sdng VEP dUdc tfnh bang so lan xuat hien song chia cho tong so lan ghi.
Bang 3.2. T^n suat xuat hign cac sdng tren cac dudng ghi VEP CB va PB Sdng
N75 ( L I ) Pino (L2)
Cling ben n
193 193
T a n suat 100%
100%
B O I b e n n
192 193
T a n suat 9 9 , 5 %
100%
1 TAP CHl Y HOC VIET NAM TAP 452 - THANG 3 • SO 2 - 2017
1
• N,45 (L3)
• Pi« (L4)
• Tonq so lan qhi
193 81
100%
42%
193
193 84
100%
43,5%
193
Ltan suat xuat hien cac song 1^75, Pjoo, N^s d chuyen dao ciing ben va doi ben kich thich la 100%
l^sdng N75 xuat hien vdi tan suat 99,5% d ehuyen dao doi ben. Tan suat xuat hien cua song P ^ cf chuyen dao ciing ben kfch thfch la 42%, doi ben la 43,5%.
3.2.2. Thdi gian tiem tang, tiidi gian lien dinh, bien do lien dinh cua cac song VEP cung bgn va doi ben khi kich thich mat du'dc chan doan VTTKHNC va mat lanh
So sanh thdi gian tiem tang, thdi gian lien dinh, dien the lien dinh ciia eac song VEP d duSng ghi VEP ciing ben va doi ben vdi mat viem thj than kinh difdc trinh bay d bang 3.3.
Bang 3.3. Ket qua ghi VEP cung ben va doj ben khi kich thich mat bi yTTKHNC Chl so
TGTT(ms) TGLB (ms) OTLB (pV)
P,nn N„
N,„
N,s - P.no Pim-N,45
BL-N7, Nys - Pinn P
CBfn = 67)XiSD 97,2 ± 24,5 131,3 ± 28,5 166,7 ± 31,5 34,0 ± 14,9 35,5 ± 12,5 1,22 ± 1,15 3,23 ± 2,83 3,36 ± 3,10
BB(n = 67)J^ iSD 97,4 ± 25,2 130,9 ± 29,9 167,0 ± 32,8 33,7 ± 14,5 36,1 ± 13,9 1,24 ± 1,23 3,15 ± 2,26 3,40 ± 2,74
>0,05
Ket qua VEP thu du'de khi kfeh thfeh mat bi VTTKHNC du'dc trinh bay d bang 3.3 cho thay: khong CO sd khac biet ve TGTT cua cac sdng (N^, Pioo/ i^iis)/ TGLO (N75 - Pioo, Pioo - N145), OTLD (BL - N75, N75 - Pioo, Pioo - N145) gili du'dc d du'dng ghi ciing ben va doi ben (p > 0,05)
3.2.3. Thdi gian tiem tang, thdi gian lien dinh, bien do liSn dinh ciia cac song VEP du'dc ghi d chuy€n dao cdng ben va d6ii ben vdi mat lanii d benh nhan du'dc chan doan VTTKHNC
Mat lanh la mat du'de ket luan la binh thu'dng khi tham kham tren lam sang va ket qua chup MEU.
So sanh TGTT, TGLD, OTLD ciia cac song VEP tren du'dng ghi cung ben va doi ben vd\ mat lanh cf benh nhan VTTKHNC du'dc trinh bay d bang 3.4.
Bang 3.4. Ket qua VEP cdng ben va dm ben khi kich thich mat lanh Chi so
TGTT (ms) TGLB (ms) BUB (pV)
P
N75 N„5
Nys-P,™
Pion - N,4s BL-N7S N7., - Pino Pinn - NMS
CB(n = 25)^ ±SD 74,7 ± 14,1 103,3 ± 19,5 136 ± 24,8 28,6 ± 8,1 33,5 ± 12,7 1,20 ± 1,13 5,72 ± 4,56 6,37 ± 6,30
> 0 ,
BBCn = 2S)'^ ±SD 73,7 ± 13 102,1 ± 20,7 135,2 ± 23,5 28,4 ± 9,7 34,1 ± 14,1 1,3 ± 1,06 5,60 ± 4,58 5,69 ± 5,03 05
Ket qua VEP thu du'dc khi kfeh thfch mat lanh (n = 25) trinh bay 6 bang 3.4 cho thay: khong CO stf khac biet ve TGTT cua cac sdng (N75, Pmo,
Ni«), TGLB (I*l7s - P ™ , PIOO - NMS), B T L B (BL -
N75, N75 - Pjoo, Pioo - N145) ghi du'dc d du'dng ghi cung bgn va doi ben (p > 0,05).
3.2.4. Thdi gian tiem tang, thdi gian lien dinh, bien do iiSn dinh cua cac sdng VEP l<hl kich thich mat VTTKHNC va mat lanh
Khi kich thich mat VTTKHNC va mat lanh, ket qua ghi VEP d chuyen dao cung ben va doi ben
vdi mat dUde kich thfch khong cd sU khac biet (p> 0,05), do do Chung toi lay trung binh giife chuyen dao cung iDen va doi ben lam gia tri Chung cho mat dUdc kfch thfeh. So sanh thdi gian tiem tang, thdi gian lien dinh cua eac song VEP glu^ mat VTTKHNC va mat lanh d benh nhan VTTKHNC, ket qua trinh bay d bang 3.5 cho thay; khong co s\i khae biet ve TGLB Pioo - Ni,s va BTLB BL - N75 (p > 0,05); khac biet ro ret ve TGTT (N75, Pmo, N^s), TGLB (N75 - P,oo), BTLB (N,5 - Pioo, Pion - Ni45) CP < 0,05).
Bang 3.5. Ket qua ghi VEP l<hi l<ich thich mat benh va mat ianh Chlso
TGTT (ms) N,.,
Pino
MB(n = 67}x ±SD 97,2 ± 23,4 132,1 ± 27,1
ML(n=2S)X ±SD 74,6 ± 14,6 103,9 ± 19,5
P
< 0,001
< 0,001
VtETNAM MEDICAL JOURNAL N''2 • MARCH • 2017
TGLB ( m s ) B U B ((IV)
Nl,5 N 7 , - P i n o Pino - Ni45
B L - N 7 , N „ - P,on Pinn ~ N145
167,6 ± 30,0 34,7 ± 14,2 35,8 ± 12,1 1,20 ± 1,19 3,14 ± 2,68 3,23 ± 2,99
134,9 ± 25,7 29,2 ± 7,6 31,7 ± 10,0 1,28 ± 1,20 5,50 ± 3,80 5,81 ± 4.68
< 0,001
< 0 , 0 5
>0,05
>0,05
< 0 , 0 1
< 0 , 0 5 Nhtf vay, khi kich thfch mat VTTKHNC eac
song VEP CO thdi gian tiem tang keo dai ro ret so vdi kich thfch mat lanh (p < 0,05). Bien the lien dinh eija eac song VEP khi kfeh thfch mat VTTKHNC CD xu hu'dng thap hdn so vdi khi kfeh thfch mat lanh.
iV. BAN WAN
4.1. Dac diem doi tu'dng nghien c6ti va ky thuat ghi Pr-VEP; Boi tu'dng nghien euU la nhiing lienh nhan dUdc chan doan xac djnh viem thj than kinh hau nhan cau tren lam sang (dap utig day du tieu chi du'de de cap den trong phan doi tUtfng nghien cifti). 46 benh nhan du'de chan doan VTTKHNC vdi 67 mat bj benh. Benh nhan nhd tuoi nhat la 18, Idn nhat la 60 tuSi, trung binh la 37,3 ± 12,2 tuoi. Theo Hiep hoi Bien sinh ly Nhan khoa Quoc te (ISCEV); ngu'di binh thu'dng tir 6 den 60 tuoi dien the kfch thfch thj gfac da tUdng doi on djnh va ft thay doi [4]. VS ky thuat ghi Pr-VEP, trong nghien ciIu nay chiing toi thu'c hien ghi VEP theo cac tieu ehuan du'de thong nhat tai Hoi nghi Dien sinh \y Nhan khoa quoc te d Hoa Ky nam 1984 va 1992 [5] va hien dang dUdc thUc hien d hau het cae labo Bl§n sinh ly trong va ngoai nu'dc.
4.2. Ket qua ghi VEP dmat ianh va mat du'dc Chan doan VTTKHNC
Nghien cCfu ve VEP tren ngudi binh thu'dng, Leslie Huszar va cs nhan thay d nhifng ngu'di dydi 60 tuoi thi gidi han tren cua TGTT song Pioo la 115 ms, gia tri nay tang ro nhat d nhuhg ngu'di tren 60 tuoi (tren 120 ms doi vdi nit, 125 ms doi vdi nam) [6], Trong nghien cu'u nay, Chung toi ap dung tieu chuan chan doan VEP b§ft thudng cua Hiep hoi Sinh ly than kinh Lam sang Hoa Ky 2008 [7], ISCEV nam 2009, so lieu tham ehieu VEP tren ngudi binh thu'dng liis tiioi 20 - 50 eua labo Bien sinh ly TrUdng Bai hpc Y Ha Noi. Ket qua thu dUdc tir nghien ciJii eua chung toi cho thay VEP bat thu'dng gap d 40/46 benh nhan du'dc chan doan VTTKHNC ehiem 87%!BO nhay ciia ky thuat ghi VEP la 86,6% tu'dng duting vdi do nhay ciJa phu'dng phap chup MFa SO nao theo nghien ciJu ciia tac gia ii Minh Thong (83,9%) [2]. Ket qua tren cho thay VEP la mpt ky thuat eo hieu qua eao trong chan doan benh 1'^ VTTKHNC.
4.3. Khong co siT khac biet ve thdi gia tiiem tang, thdi gian ll§n dinh, dien th^ li£
dinh cua cac song VEP d chuyen dao cun ben va dofi ben khi kich thich mat VTTKHN va khi kich thich mat lanh
Nghien cihj cija chung toi eho thay thdi gia tiem li^ng, thdi gian lien dinh va dien the lie dinh eua cac song VEP glDs chuyen dao cijn ben va doi ben d mat VTTKHNC eung nhi/ d m;
lanh khong co si/ khac biet (p > 0,05) (bang 3.;
3.4, 3.5). Leslie Huszar va Di - Rusoeho ran VEP CO nguSn goc tir du'dng dan truyen thj gia nen khi k/ch thfch mpt ben mat, tfn hfeu se dtfp truyen theo day than kinh thj dl qua clieo th| d?
vo nao vung cham d ca 2 ben ban cau nen'diei the do kfch thfeh thj glae xuat hl|n d ca chuyii dao cung b§n va doi ben [6], 6 mat VTTKHNC ehung toi cho rang than kinh thj bj viem khu tn tu' sau nhan cau cho tdi tru'dc giao thoa thj giac tSn thu'dng viem chii yeu la mat myelin lidn li ton thu'dng sdl true. Vi v|y, neu cd ton thu'dni tru'dc giao thoa thj giac, sau khi qua cheo thj si anh hu'dng tdi du'dng dan truyen thj giac ciJa ci hai ben, do do VEP bat thu'dngnhu' nhau ca c ehuyin dao ciing ben va doi ben.
V. KET LUiSiN
1. Tan suat xueft hien eac sdng N75, Pm, NM d ehuyen dao ciing bgn va doi ben kfeh thich li 100%. Tan suat xuat hlSn cua song P175 ( chuyen dao ciinjben kfch thfeh la 42%, doi ber la 43,5%.
2. Mat bj VTTKHNC Co thdi gian tiem tang ciii cae s6ngN75, P,oo, NMS; Thdi gian lien dinh N75 - Pion keo dai; BiSn the lien dinh BL - N7S, N7S • Pioo, Pioo - N145 thap ro ret so vdi mat lanh vi mat eua ngu'di binh thu'dng.
TAI LIEU THAiVi KHAO
1. Brigell M., Kaufmann D.L., Bobak P., et il (1994). The pattern visual evoked potential S multicenter study using standardized teS
Ophthalmology. 65-79. -^
(20iq).£6/7A gia dan doan wkit qua dki th i # tfw than kinh hau nhan i^u, Truing Oai hoc Y'DIA Tiianh pho HS Chi Minh, Thanh pho HB i3ii min ' 3. Sreng Huong (2013).M,/,« cutj tic dung c
twyen Solumedrol tmng dieu tn Kem ihl th.
kinh, Trudng Bai hpc Y Ha Npi, HaNoJ '