Vietnam Journal of Physiology 19(1), 3/2015 ISSN: 1859-2376 MOT S 6 DAC DigM DIEN THE KiCH THiCH THI GlAC (VEP)
TREN TR^ EM BINH T H U a N G LCTA T U 6 | TLT 6 D^N 14
Nguyen The T u n g \ Le Dinh TungS Le Ngoc H u n g ' , Nguydn Thj Thu Hlen^
T 6 M T A T : Ky thuat ghi diin thi kieh thich thj giie (VEP- Visual Evoked Potential) cho phep danh gii ehux: nang din truydn thi giac. Bdi viy, VEP da va dang duqc s d dqng rong rai di nghien cuv trong mqt sd binh ly thin kinh thi. Trong nghien cuu nay chUng tdi tidn hanh ghi VEP vol kich thich bSng man hinh dio (PR-VEP) tren 50 ddi tuqng tre em khoe manh /da tudi 6-14 tudi nhim tim hiiu mdt sd dac didm dien the kieh thich thi giac. lim ca sd tham chiiu trong nghiin eUu eie benh ly than kinh thj a tre em lua tudi niy. Kit qui nghien cuv cho thiy: Thai gian tiem tang (TGTT) cua cic sdng N75, Pm, Nusdnam vi nir cua nhom nghien cuv tuang Ong li: 70,92 ± 4,47 ms va 69,71 ± 4,26 ms; 102,53 ± 6,32 ms va 100,74 ± 5,96 ms; 139,12 ± 7,01 ms va 138,79 ± 6,79 ms. Biin do (BD) cua cac sdng N75, P100, N-,45 a nam va nu" cua nhdm nghien cuv tuang ung la:
1,95 ± 0,36 pV va 1,49 ± 0,41 pV; 7,23 + 1.32 pV vi 6.67 ± 1,54 pV; 7,49 ± 2,53 pV vi 6,59 ± 2,82 pV. Thdi gian lien dinh (TGLD) N75 - Pm: P100 - Wi45.' W75 - Nus a nam vi nO"
cua nhdm nghien cuv tuang ung la- 31,61 ± 4,06 ms va 31,02 ± 3,94 ms; 36,59 ± 4,54 ms va 38.06 ± 4,23 ms; 68,15 ± 5,00 ms vi 69,30 ± 4,88 ms. Khdng cd su khic nhau cua TGTT, BD va TGLD cac sdng VEP giu-a mSt phai (MP) vi mit trii (MT) cua ddi tuang nghien cuv
Tii' khoa: Dien the kich thich thj giac, he thdng thj giie.
i.oATvANoe
Tren thd gidi ky thugt ghi dien thd kich thich (EP) da va dang dugc ung dung r6ng rai de danh gia chuc nang din truydn ciia hg Uiln kinh. Cac ky Uiugt ghi dien the kich thich nay bao gdm ky thuat ghi dien thd kich thich cam giac than the (SSEP). ky thuat ghi dien the kich Uiich cam giac (SEP) cho phep danh gia chuc nang d i n truyen cam giac, ghi dien Uie kich thich van dgng (MEP) cho phep danh gia chuc nang dan truydn van dgng va ky thugt ghi 6i^n thd kich Uiich Uij giac (VEP) cho phep danh gia chuc nang dSn fruyen thi giac. VEP da va dang dugc sd dung rgng rai dd nghien cdu dan truyen Uii giac d ngudi binh thudng va d mgt sd
Tnrang dgi hgc Y-Duac Thai Nguygn
^ Dgi hpc Y Ha Npi
^ Benh vi|n M i l Trung ucng ' Tac gia chju trach nhiem chinti:
Nguyin Th4 Tung Email' drtunqk32(S>qmai[ com Ngay nhgn bai: 31/10/2014 Ngay nhgn bar phan bi§n: 12/2/2015 Ngay chap nhgn dang: 8/3/2015
bgnh ly nhu vi^m thi than kinh, u day than kinh thj giac...
0 nudc ta, trong nhung nam gan day da CO nhieu ca sd lam sang da b i t d i u then khai dng dung ghi dign the kich thich trong chan doan cung nhu trong dieu tri cac banh ly vd d i n tmydn than kinh. Tuy nhien. khi dng dung cac ky thugt nay.
ehijng ta can phai xay dung sd lieu tham chieu cae ehi sd EP tren ngudi Vigt Nam binh thudng [7].
Hi6n nay, d Viet Nam ehua c6 du sd ligu ve cac ehi sd EP cua ngudi Vigt Nam binh thudng, dae bigt la cac chi sd vd VEP. cae chi sd vd VEP d tra em blnh thudng h l u nhu chua eo e6ng trinh nghi&n cuu nao dd cap den. Bdi vgy, vi§c xay dyng sd lieu cac chi sd VEP d Xri em Vigt Nam binh thudng de lam cae chi sd tham ehieu trong chan doan va dieu trj cac benh ly cua he t h i n kinh thi d tre em nhu viem thj t h i n kinh, u day t h i n kinh th|
giac... la v6 cung quan trgng va can thidt.
Xuat phat t d van dd tren. ehiing to! tidn hanh de tai nay nhim muc tieu' "Xic djnh
Vietnam Joumal of Physiology 19(1). 3/2015 ISSN: 1 8 5 9 - 2 3 7 6 thdH gian tiim tang, bien do, thai gian liin
dinh eic sdng N75, Pwo. WMS cua VEP tren tri em binh thuang lua tudi tU 6 den 14 2. D 6 | TU-g^NG VA PHUONG P H A P NGHIEN cCru
2.1. Doi tipqng nghien cuu Nghien edu dugc tien hanh tren 50 tre em Vigt Nam binh thudng, khoe mgnh Ida tudi t u 6 ddn 14 tudi.
2.1.1. Tieu chuan lua chgn:
- Tre em binh thudng, khoe mgnh t d 6 den 14 tudi.
- Thi lye > 8/10, thi trudng binh thudng.
- Khfing bj tat khuc xg va eac banh ly vd m i l .
- Bd mg hogc ngudi bao hfl ddng y cho tre tham gia nghign edu.
2.12, Tieu chuin loai tru:
- Benh ly loan than nang va cap tinh.
- Tre va gia dinh khong hgp tac hoac hgp tac kem.
2.2. Phwong phip nghien cwu
* Thiit ke nghien cuv: phuang phap mo ta cat ngang,
* Chisd nghien cUv:
- Dgc diem ciia ddi tugng nghien cuu, chi sd thi lye, thi trudng.
- Cac chi sd nghien cuu khi ghi VEP: thdi gian tiem tang (TGTT), bian do va thdi gian \\in dinh (TGLD) cac song VEP giua hai dudng ghi ciing ban (CB) va ddi ben (DB) d m i l phai (MP) va m i t trai (MT) ciia ddi tugng nghiSn edu
* Phuang phap thu thap sd liiu:
- Ghi VEP theo phuang phap PR-VEP tren may Neuropax 11 (Nihon Kohden).
- Ddi tugng nghien cuu ngdi each man hinh 29 inch khoang each la 2,5m, vdi t u thd thoai mai, ngdi lya lung vao ghe.
khong gong ca, nhin tap trung vao diem c^inh giua man hinh. Kich thudc 6 vuong tring/den tren man hinh dgt d muc 16 phiit goc dam bao goc nhin trong gidi han 10° - 20° Tuang phan man hinh 50 - 80%, cudng do chidu sang nen 9 cd/m^, cudng do chidu sang tai man hinh 50 cd/m^. Kich thich d tan sd 2 Hz. Dai Ige nhidu 5 - 300 Hz.
- Dat dign cyc theo tieu chuan Queen Square, kiem tra dign trd dign cyc hogt dgng dudi 5kQ.
- Ghi VEP tdng mit.
- Kdt qua thu dugc la gia tri trung binh cua 200 kich thich co dap ung dugc luu va in ra giay.
2.3. X ( > / y s d / f e u
Cac sd lieu nghien cuu dugc quan ly va xu ly theo phuang phap thdng ke y hgc tren phin mem EPI INPO 6.04 va SPSS 16.0. S u dung Student t-test khi so sanh hai gia tri trung binh. su dung test ) ^ khi so sanh hai ty le .
2.4. Van de dao difc nghien cu'u Cha hoac mg hoac ngudi giam hg ciia tre tham gia nghien cdu ddu dugc giai thich vd muc dich, yeu c l u , y nghTa ciia nghien cuu.
Chi Uen hanh nghi§n cdu vdi cac doi tuang tu nguyen, san sang tham gia vao nghien cuu,
Cac thong (in ciia doi tugng dugc dam bao bi mat va chi phuc vu cho muc dich khoa hpc,
3. K E T QUA NGHliN Ct>U
3.1.Dac diem cua ddi twang nghien cwu
Bang 3.1 Dac diem Tuoi Thi iLFcm^ttrai (1) Thi ii,FC mat phai (2) Thi lye hai mat
P
Tuoi va thi iuc cua doi tyong nghien ci>u theo Nam (n = 25)
9,58 ±2,71 9,53 ± 2,04 9,02 ± 2,53 10,08 + 2,65
P,.2 > 0,05
Uu (n = 25) 9,31 ± 2,59 9,24 ±2,15 9,71 ±2,42 10,14 + 2,83 P,-2 > 0,05
gioi.
P
>0,05
>0,05
>0,05
>0,05
27
Vietnam Journal of Physiology 19(1). 3/2015 ISSN: 1859-2376 Ket qua bang 3.1 cho thiy: Tudi taing
binh hai gidi la tuong duong Kh6ng co s u Wiac biat ed y nghTa Uidng ke (p > 0,05) ve cac chi sd thi luc giua nam va nu va giua m i t phai va mat Uai cua ciing mgt gidi.
Bang 3.2. TGTT cua cac song VEP giua hai dudng ghi CB va DB d MP va MT cOa ddi tugng nghien cdu
3.2. TGTT, bien dd va TGLD cua cac sdng VEP giwa hai dwang ghi CB va DB & MT va MP cua tre em lu'a tudi tip 6 den 14 tuoL
TGTT Njs (ms)
Pioo (ms)
N„5 (ms)
Giai MP MT MP MT MP MT
CB BB CB OB CB BB CB BB CB BB CB BB P
Nam (n = 25) 70,76 ± 4,95 71,75 ±3,81 71,08 ±4,08 72,00 ± 4,29 102,63 ±6,90 103,52 ±5,53 102,43 ±6,12 101,97 ±6,58 138,73 ±8,53 140,47 ±9,17 139,52 ±8,80 140,36 ±7,08
PMp.MTdeu>0 P
>0,05
>0,05
>0,05
>0,05
>0,05
>0,05 05 nim-nodeu
Ni> (n = 25) 69.14 ±4.29 69,84 ± 3,73 70.28 ± 4,40 70,92 ± 3.72 100.15 ±4.56 103.83 ±6,11 101,30 ±5,70 102,70 ±5,66 138,31 ±8,16 141, 68 ±7,82 139,27 ±7,79 141,00 ±8,42
P
>0,05
>0,05
>0,05
>0,05
>0.05
>0.05 PMP-MT deu > 0,05
>0,05
Nhan xet: TGTT cCia c^c song N75. deu > 0,05) kh\ so sanh cac chi so nay a Pioo, N145 giOa hai du-ong ghi CB va DB 6 cung mpt gioi cung nhu- khi so sanh cac MP va MT cua tre em 6 - 14 tuoi khong co chi so nay giu'a nam va nu".
sv Ithac biet CO y nghTa thong l<e {v&i p
Bang 3.3. Bien do cua cac sdng VEP giOa hai du'dng ghi CB va BB 6 MP va MT cCia doi tifcng nghien CLPU
~"""----~^_Gidi Dien the ~~~——-^
N75 (pV)
Pioo (UV)
N,4, (pV)
MP MT MP MT MP MT
CB BB CB BB CB BB CB BB CB DB CB BB P
Nam (n = 25) 1,86 ±0.37 1.62 ±1,05 2,04 ±1,10 1,57 ±1,35 7,97 ±2,19 7,82 ± 3,76 6,49 ± 3,77 6,86 ±3,57 7,41 ± 2,52 6,60 ± 2,07 7,58 ± 3,02 6,76 ± 3,33
PMp-MTdeu>0 P
>0,05
>0,05
>0,05
>0,05
>0,05
>0,05 05
P n a m - nO'
Nu (n = 25) 1,28 ±0.34 1.28 ±0,53 1,69 ±1,24 2,39 ±1,36 6,77 ±4,05 7,71 ± 4,42 6,56 ± 3,00 6,83 ± 3,90 6,67 ± 4,54 7,05 ±5,18 6,51 ± 3,46 7,66 ± 4,08
P
>0,05
>0,05
>0,05
>0,05
>0,05
>0,05 PMP.MT deu > 0,05 deu > 0,05
Vietnam Joumal of Physiology 19(1). 3/2015 ISSN: 1 8 5 9 - 2 3 7 6 Nhan xet: DiSn thd eiia cac s6ng N75. deu > 0,05) khi so sanh eac ehi sd nay d P1001 N145 giOa hai dudng ghi CB va DB d ciing mgt gidi cung nhu khi so sanh cac MP va MT eua tre em 6 - 14 tudi khong eo chi sd nay giua nam va nu.
sy khae bigt c6 y nghla thdng ke (vdi p
Bang 3.4. TGLD cua eac song VEP giua hai dudng ghi CB va DB d MP va MT eiia ddi tugng nghien cdu
TGLD N75-P,00
(ms)
f 100 - N145 (ms)
N,5-N,45 (ms)
Gioi MP MT MP MT MP MT
CB BB CB DB CB DB CB BB CB BB CB BB P
Nam (n = 25) 31,87 ±4,35 31,77 ±4,08 31,35 ±4,34 29,97 ± 3.22 36,10±4,13 36,95 ± 3,30 37,09 ±4,52 38,39 ± 3,96 67.79 ± 5,02 68,83 ±4,87 68,52 ± 4,79 68,11 ±5,11 PMp.MTdeu>
p
>0,05
>0,05
>0,05
>0,05
>0,05
>0,05 0,05
NO' (n = 25) 31,01 ±4.06 33.99 ± 3.88 31,02 ±4,01 31,78 ±4,31 38,16 ±4,58 37,85 ± 3,89 37,97 ±4,15 38,30 ± 4,61 69,83 ± 4,92 70.11 ±4.59 68,78 ± 5,05 70,10 ±4,76 PMp-Mjdeu >
P
>0,05
>0,05
>0,05
>0,05
>0,05
>0.05 0,05 Pnam-nCF deu > 0,05 Nhgn xet: TGLD ciia cac song N75,
Pioo. Ni45 giua hai dudng ghi CB va DB d MP va MT cua tre em 6 - 14 tudi khong cd sy khac bigt co y nghTa thdng ke (vdi p deu > 0,05) khi so sanh cac chi sd nay d eiing mpt gidi cung nhu khi so sanh cac ehi sd nay giua nam va nu.
3.3. TGTT, di$n the va TGLD trung binh cOa cac sdng VEP d> tre em tudi tip 6 din 14 tuoL
Ket qua bang 3.2, 3.3 va 3.4 cho thay TGTT, bien dp va TGLD cua c^c song VEP giua hai dudng ghi CB va DB d MP va MT cua cac doi tugng d cung mgt gidi khong co sy khac bigt. Chinh vl vay chung toi co the Idy gia tri trung binh cac chi sd tren ciia MP va MT tren dudng ghi CB d mdi gidi de lam sd tham chieu cho nam va nu Ida tudi tu 6 den 14 tudi.
Bang 3.5. TGTT trung binh eiia cac sdng VEP giua nam va nu
" " ^ ^ - - . . t S i * ! TGTT ^ ^ " ^ - - . ^
N75 (ms) Pioo(ms) N,4s (ms)
Nam (n = 25) 70,92 ± 4,47 102,53 ±6,32 139.12 ±7,01
(n = 25) 69,71 ±4,26 100,74 ±5,96 138,79 ±6,79
P
>0,05
>0,05
>0,05 Kdt qua bang 3.5 cho thay TGTT trung
binh giua cac song N75; Piool N145 khong
CO sy khac bigt co y nghTa thong ke giua hai nhom nam va nu (p deu > 0,05).
Vietnam Journal of Physiology 19(1), 3/2015 ISSN: 1 8 5 9 - 2 3 7 6 Bang 3.6. Bien dp eua cac song VEP giua giua nam va nu
~"~-~-~...^Gidi Dien t h e ^ ^ ^ " ^ ^ ^ ^
N75(MV) PIOO(MV) NI45(MV)
Nam (n = 25) 1,95 ±0,36 7,23 ±1,32 7,49 ± 2,53
Ni>
(n = 25) 1.49 ±0,41 6,67 ±1,54 6,59 ± 2,82
P
>0,05
>0,05
>0,05 Ket qua bang 3.6 cho thdy: Bien do
trung binh giua eac sdng N75; Pioo; N,45
Bang 3.7. TGLD ciia cac song VEP giua nam va nu
khong co sy khac biet co y nghTa thdng kS giua hai nhdm nam va n u (p ddu > 0,05).
" ~ ~ ^ - ^ ^ ^ G i 6 ' i T G L B ^ ^ ^ - - . ^
N7s-Pioo(ms) Pioo-N,45(ms) N75-N,4s(ms)
Nam (n = 25) 31,61 ±4,06 36,59 ± 4,54 68,15 ±5,00
NO' (n = 25) 31,02 ±3,94 38,06 ± 4,23 69.30 ± 4,88
P
>0,05
>0,05
>0.05 Ket qua bang 3.7 cho thiy: TGLD
tmng binh giua eac song N75- P,oo; Pioo - N145; N75- N145 khong co sy khac bigt c6 •y 4. B A N L U A N
4.1. TGTTcua cic sdng VEP TGTT tmng binh cua cac song VEP trSn hai dudng ghi CB va DB khi kich thich d MP cung nhu MT cua cac ddi tugng nghien cdu la gdn nhu nhau (khong khac bi#t vdi p deu > 0,05). Ket qua nghien cdu cua chung toi phu hgp vdi ket qua nghien cuu cua Valeria Bekhtereva, Takashi Yoriftjji [1],[2]. Sd dT TGTT tran hai dudng ghi CB va DB khong c6 sy khac bigt la ed sy bdt cheo tren dudng di cua day than kinh thi giac nen dign the hoat dSng nay ddng thdi dugc d i n truyen vd vo nao thuy chdm d ca hai ban eau. Vi vgy TGTT cua cac song d dudng ghi CB va DB vdi mdt kich thich co gia tn gan nhu nhau.
TGTT cua cac song tren hai dudng ghi CB va DB khong co sy khac biet cho phep chiing toi eo the ehi can chgn dgc kdt qua d dudng ghi CB, eon ket qua cua dudng ghi DB dugc diing de so sanh vdi dudng ghi CB. Dieu d6 co y nghTa khi danh gia
nghTa thdng ke giua hai nhom nam va nu (p ddu > 0,05).
ket qua chung ta ehi edn nhan djnh cac s6ng tren dudng ghi cung ben. Nhidu tac gia nudc ngoai khi nghien edu vd VEP nhu Ratal M. Skiba, Simon P. Kelly deu lam nhu vay [3]. [5]. TGTT ciia mgt sdng EP dugc tinh t u luc kich thich cho ddn dinh cua song, khi co nhidu dudng ghi thi dudng ghi nao eo TGTT cac song ciia VEP n g l n nhat thi ta se lay gia tn TGTT eua song do.
Tren mdt ddi tugng nghien cdu TGTT ciia cac song ghi duge d m i l phai khong eg s y khac biet so vdi cac song ghi dugc d m i l trai. Dieu nay co y nghTa r l l quan trgng trong danh gia chdc nang th| giac.
Khi bj rdi logn dan Uuyen d mgt ben m i l thi cac gia tri thu dugc d ben m i l khong bj tdn thuang se la sd ddi chieu chinh xae va tin egy.
Ket qua nghien cdu cua ehung toi cho thay TGTT trung binh cua cae song N75va P100 d nam dai han so vdi d nu, tuy nhien sy khac bigt nay chua thyc su ro rgt. Kdt qua nay ehua cd s y khac bigt ro r#t co le
Vietnam Journal of Physiology 19(1), 3/2015 ISSN: 1 8 5 9 - 2 3 7 6 la do so lugng ddi tugng nghien cuu cua
chimg 161 con IL Dd Um hidu rd han, cdn cd nhung nghien edu tidp theo vdi sd lugng ddi tugng nhidu han. Theo chung toi, TGTT eua cac song d nu ngan hon nam e6 le la do khoang each t u vong mgc den ngudn sinh ra cac s6ng d nu n g l n han so vdi d nam, dd iam ro van dd nSy eung cdn eo nghiSn edu them 4.2. Bien do cac sdng VEP cua cac ddi twqng nghiin cwu
Bien dp eac song cua VEP sinh ra do sy khu eye ddng bg ciia cac sgi true d dudng dan truyen cam giac thj giac tu vong mac d i n vo nao thiiy eham. Bien do cua ehiing phg thugc vao sd lugng cac sgi tham gia khu cyc va sy khu cyc co ddng bg hay khong ddng bg. Ket qua d bang 3.3 cho thay bien dp ciia cac s6ng VEP giua hai dudng ghi CB va DB m i l dugc kich thich d MP cQng nhu MT ciia cac ddi tugng nghien cdu deu cho ket qua tuang t y nhu nhau. Didu nay cijng phii hgp vdi nhgn xet ciia nhieu tac gia khi nghian cdu vd VEP nhu Dhan Krishna Sen, Thomas Meigen [6],[7]. Cae tac gia cho rdng sy gidng nhau nay la do dign thd hogt dgng ciia cac dudng d i n truyen thi giac tgo ra cac song VEP d MP va MT ddu c6 chung mOt ngudn. Han nua, khoang cdch giua nai phat sinh va noi ghi lgi sPng cua hai mdt cung gan nhu nhau.
4.3. TGLD cOa cac song VEP cua cac ddi twang nghiin c^u
Bang 3.4 cho t h i y TGLD cac song ghi dugc d mdt phi\ tuang t y nhu ghi duac d mat trai. TGLD cac song ghi dugc d nam va d nu khong khac bigt co y nghTa thdng ke vdi p ddu > 0,05. Didu nay cung phil hgp vdi nhgn xat va kdt qua nghien edu eiia eiia Justin M. Ales, Jacob L khi cac tac gia nghien cdu tren cac ddi tugng d Ida tudi idn ban [6]. Trong nghien cuu cua chung toi nhung th6ng sd nay tuang ddi dn djnh the h\in if d6 lech chuin nho.
T d kdt qua vd TGLD cua cac song VEP d tre em binh thudng khong co sy khae biet giua mat phai va mat trai cho phep ehung ta co the l l y gia trj trung blnh TGLD cua eac song VEP eiia hai mat (phai va trai) lam con sd dai dien cho gia tri tham chidu ve TGLD ciia cac song VEP d mdi ddi tuang.
5. K^T LUAN
T u kdt qua nghien cuu chung toi co ket luan sau:
Tren 50 tre em binh thudng Ida tuoi I d 6 ddn 14 c6 m6t sd chi sd ve di#n thd kich thich thj giac (VEP) la:
- TGTT ciia cac song N75, P,oo, Ni45d nam va nu tuang ung la 70,92 ± 4,47 ms va 69,71 ± 4,26 ms; 102,53 ± 6,32 ms va 100,74 ± 5,96 ms; 139,12 ± 7,01 ms va 138,79 ± 6,79 ms.
- Bien dg ciia cac song N75, Pioo, N145 d nam va nu tuang ung la 1,95 ± 0,36 pV va 1,49 ± 0.41 pV; 7,23 ± 1,32 pV va 6,67 ± 1,54 pV; 7,49 ± 2,53 pV va 6,59 ± 2.82 pV.
- TGLD eiia cac song N75-rioo, Hmo- N145, N75-Ni45d nam va nu tuang ung la 31,61 ±4,06 msva 31.02 ± 3,94ms; 36,59
± 4,54ms va 38,06 ± 4,23 ms; 68,15 ± 5,00 ms va 69,30 ± 4,88ms.
T A I L i e u THAM K H A O 1. Valeria Bekhtereva, Christian Sander (2014). Effects of EEG-vigilance regulation paUerns on early perceptual processes in human visual cortex. Clinial Neurophysiology 125 p. 98 - 107.
2. Takashi Yorifuji, Katsuyuki Murata (2013). Visual evoked potentials in children prenatally exposed to methylmercury Neuro Toxicology 37 p. 15 - 1 8 .
3. Rafal M. Skiba, Chad S. Ducan, Michael A. Crognale (2014). The effects of luminance contnbution from large fields to chromatic visual evoked potentials Vision Research 95 p. 68 - 74
31
Vietnam Journal of Physiology 19(1), 3/2015 ISSN: 1 8 5 9 - 2 3 7 6 4. Justin M. Ales, Jacob L. Yates,
Anthony M. Norcia (2013) On determining the intracranial sources of visual evoked potentials from scalp topography. Neurolmage p. 703 - 7 1 1 .
5. Simon P. Kelly, Charles E.
Schroeder, Edmund C. Lalor (2013).
What does polarity inversion of extrastriate activity tell us about striate contributions to the early VEP? Acomment on Ales et al (2013) Neurolmage p. 442 - 445.
o. Dhan Krishna Sen (1982) Results of treatment of anisohypermetropic amblyopia w/ithout strabismus. British Joumal of Ophthalmology p. 680 - 684.
7. Thomas Meigen, Mathias Kramer (2007). OpUmizing electrode positions and analysis strategies for multifocal VEP recording by ROC analysis. Vision Research p. 1445 - 1454.
SUMMARY
SOME CHARACTERISTICS OF VEP RESPONSES IN NORMAL CHILDREN AGED FROM 6 TO 14
Nguyen The T u n g \ Le Dinh T u n g ^ Le Nggc Hu-ng^, Nguyen Thi Thu Hien' 'r/ia/ Nguyen Medical Pharmaceutical University;
'Ha Noi Medical University; ^Cenral Eye Hospital Visual evoked potentials (VEPs) can provide imporiant diagnostic infomation regarding the functional integrity of the visual system. VEP had used to studying disease visual system. A study of 50 normal children aged from 6 to 14 with pattern-reversal VEPs elicited by checkerboard stimuli with medium eheacks. Results of VEP showed that The latency of N75. Pwo, WMS ' " mate and female children groups respectively were 70,92
±4,47 msvi 69,71 ± 4,26 ms; 102,53 ± 6,32 ms vi 100,74 ± 5,96 ms; 139,12 ± 7,01 ms vi 138,79 ± 6,79 ms. Amplitude of W75, Pwo, H^s were 1,95 ± 0,36 pV va 1.49 ± 0,41 pV;
7.23 ± 1,32 pV vi 6.67 ± 1,54 pV; 7.49 ± 2,53 pV va 6,59 ± 2,82 pV. Interval of N75 - PIOO, PIOO - N145, N75 - N145 were 31.61 ± 4.06 ms and 31,02 ± 3,94 ms; 36,59 ± 4,54 ms and 38,06 ± 4,23 ms; 68,15 ± 5,00 ms and 69,30 ± 4,88 ms. No statistically significant difference in latency, amplitude and interval of VEP waveforms was noted between right eye and left eyes.
Keywords: Visual evoked potentials. The visual system.
