kham than kinh so y5 2015-2016

Khm thn kinh s Y5 2015

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KHM THN KINH S (i tng: Y5 Thi gian: 02 tit)

BS. H Hu Tht BM. Thn kinh Trng H Y Khoa Phm Ngc Thch

Mc tiu bi ging 1. Thc hin c thao tc khm cc dy thn kinh s.

2. Gii thch c cc triu chng bt thng ca mt s dy thn kinh s nh: dy II, III-IV-VI, VII.

3. Vn dng c cc triu chng tn thng thn kinh s trong chn on cc bnh l h thn kinh.

Hnh 1: Thn no nhn t mt di v cc dy thn kinh s1

1. Dy I (khu gic)

1.1. Gii phu

Cc dy thn kinh khu gic thc s l cc si phng chiu ngn t nim mc mi n

hnh khu nm bn trong hp s. Mi bn no c khong 9 n 15 dy thn kinh khu gic.

Hnh khu nm ngay trn xng sng v bn di thy trn. Si trc ca hnh khu tp trung

li thnh cung khu gic, tip hp trong nhn khu gic trc, v tn cng v no khu gic

nguyn pht.


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Hnh 2: Mt bn ca hnh khu, di khu, mng nhy, v cc dy thn kinh khu gic

1.2. Khm

Dy thn kinh khu gic t khi c khm trong thc hnh lm sng. Vic nhn bit hu

ht cc mi i hi dy thn kinh khu gic phi cn nguyn vn. Tuy vy, mt vi tc nhn

(nh ammoniac) c th c nim mc mi nhn bit m khng cn dy thn kinh khu gic

phi cn nguyn vn.

Nn khm dy khu gic trong nhng trng hp c chn thng u, nghi ng bnh l

ti nn s (cc u mng no mt di ca thy trn, cc loi glioma thy trn c th chn p vo

dy thn kinh khu gic nm ngay bn di).

Dng cc l nh c cha cc cht quen thuc (nh x phng, c ph, du gi, nc

hoa), trnh cc cht c tnh kch thch (nh ammoniac) v c th gy kch thch dy thn

kinh V. BN c yu cu nhm mt, v che kn mt l mi. Ngi khm a l nh cha cht

chn vo l mi cn li, v yu cu bnh nhn xc nh l mi g.

n gin hn, c th s dng cc vt dng ca BN (mt mu bnh m, tri cy, nc

ngt) v hi xem liu BN c cn ngi c mi ca cc vt dng ny khng.

1.3. nh gi

BN c th xc nh c chnh xc cc mi: bnh thng.

BN khng th nhn bit c cc mi: mt mi (anosmia).

Tnh trng mt mi c ngha khi BN khng c cc bnh l ti mi (nght mi). Tn

thng dy I c th do khi u (meningioma, hoc him hn l glioma) chn p vo.


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2. Dy II (th gic)

2.1. Gii phu

Dy thn kinh th gic (optic nerve) dn truyn cc si hng tm cho hai chc nng:

gic quan (th gic) v co ng t (pupilloconstriction).

Hnh 3: ng th gic

Dy thn kinh th gic cha cc si trc myelin ha, xut pht t cc t bo hch ti vng

mc. Sau khi ri khi nhn cu, n c bc trong bao mng no. Sau khi qua khi giao thoa th

gic, n c i tn thnh di th (optic tract). Cc si trc tip tc phng chiu n c no sinh

t trn, v n th gi ngoi thuc i th. Sau s truyn thng tin v v no th gic thuc

thy chm thng qua tia th (optic radiation) (Hnh 3).


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2.2. Khm th lc

Nguyn tc: khm tng mt ring bit, cho BN mang mt knh iu chnh cc tt khc

x nu c.

Khm sng lc th lc bng cch yu cu BN c ch trn nhng vt dng xung quanh

(nh sch, bo, tp ch).

Nu BN c than phin gim th lc, tip tc khm bng cch yu cu BN m ngn tay

ngi khm cc khong cch khc nhau (v d bt u m khong cch 30 cm, nu cha

m c khong cch 30 cm th tip tc vi cc khong cch 20 cm, 10 cm). Nu BN

khng m c ngn tay, cho BN quan st bng bn tay di chuyn qua li trc mt BN. Nu

BN vn khng thy c bng bn tay, khm tip tc cm nhn sng/ti bng cch chiu n pin

vo mt. Nu BN vn khng thy c nh sng chiu vo mt th ghi nhn l m hon ton.

Phn khm thn kinh thng quy khng bao gm khm th lc bng bng ch Snellen

hoc khm cm nhn mu sc. Nu cn thit, c th cho BN khm thm nhn khoa.

Kt qu

Gim th lc c th iu chnh c bng mt knh: tt khc x.

Gim th lc khng th iu chnh c bng mt knh: c th c cc v tr tn

thng trn ng i ca h thng th gic nh so gic mc, c thy tinh th,

xut huyt vng mc, bnh dy thn kinh th gic (do vim, thiu mu, chn

p), hoc tn thng v no thy chm hai bn (m v no)

2.3. Khm th trng

Nguyn tc: khm tng mt ring bit, v khm bng phng php th trng i chiu.

Hnh 4: khm th trng i chiu


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Khm th trng i chiu bng cch ngi i din vi BN khong cch khong 50 cm

nh hnh v. Yu cu BN dng bn tay (T) che mt bn (T) li, nhn thng vo mt ngi

khm, khng c lic nhn ra xung quanh.

Gi ngn tr bn tay (T) ca ngi khm ngay bn ngoi th trng ca ngi khm

mt phn t di th trng pha thi dng. Di chuyn chm ngn tay ca ngi khm dn dn

v pha trung tm. Yu cu BN ni thy ngay khi thy c ngn tay ngi khm, v so snh

vi th trng ca ngi khm. Khm tng mt phn t ca mi mt ring bit.

Kt qu

Kt qu khm th trng, v cc v tr tn thng tng ng c minh ha trong

Hnh 5.

Hnh 5: Cc v tr tn thng in hnh ca ng th gic: (A) m mt mt; (B) bn

manh hai thi dng; (C) bn manh ng danh bn (P); (D) gc manh ng danh 1/4

trn bn (P); (E) bn manh ng danh bn (P).


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2.4. Soi y mt (c gii thiu trong mt bi ring)

3. Dy III (vn nhn chung), IV (rng rc), v VI (vn nhn ngoi)

3.1. Gii phu

Dy III, IV xut pht t nhn vn nhn chung v nhn rng rc ti trung no, sau khi ri

khi hp s, dy III v IV vo mt qua khe mt trn. Dy III chi phi cho cc c: thng

trong, thng trn, thng di, cho di, v c nng mi trn. Dy IV chi phi cho c cho trn.

Ngoi ra, phn i giao cm ca dy III cn chi phi cho hch mi, v c co ng t.

Dy VI xut pht t nhn vn nhn ngoi ti cu no, cng vo mt qua khe mt trn,

v chi phi cho c thng ngoi (Hnh 6).

Hnh 6: Cc dy thn kinh s III, IV, VI, v cc c vn nhn

Hnh 7: S cc c vn nhn


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Hnh 8: khm cc hng vn nhn theo s hnh ch H2

3.2. Khm vn nhn

Trong lc hi bnh s, ngi khm cng nh gi s b cc hng vn nhn ca BN.

Bt u khm vn nhn bng cch t nh tay ln nh u ca BN v yu cu BN ch di

chuyn mt, khng xoay u. Yu cu BN nhn c nh vo mt ngn tay ca ngi khm t

cch BN khong 50 cm (khi khm cc hng vn nhn theo chiu ngang v khm hi t, t

ngn tay ngi khm theo chiu dc. Ngc li, khi khm cc hng vn nhn dc, t ngn tay

ngi khm theo chiu ngang).

Bt u khm v tr s 1 nh Hnh 8, sau di chuyn ngn tay n v tr s 2 v dng

li quan st tm vn nhn ca c hai mt, nystagmus (nu c)

Tip tc di chuyn ngn tay n v tr s 3 v s 4, mi v tr u dng ngn tay ngi

khm li v quan st tm vn nhn ging nh v tr s 2.

Di chuyn ngn tay v li mt phng ngang, v tip tc n cc v tr 5,6, v 7.

Di chuyn ngn tay v li v tr 1 v yu cu BN nhn thng vo ngn tay ngi khm,

sau ngi khm di chuyn ngn tay dn v pha mi BN khm hi t ca hai mt.

Cui cng, di chuyn ngn tay ngi khm n v tr s 8 v s 9 v quan st tm vn

nhn ging nh v tr s 2.

mi hng nhn, hi BN xem nhn thy mt hay hai ngn tay, kho st BN c b

song th hng nhn no hay khng.


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Hnh 9: Lit dy III (T) bnh nhn i tho ng. Mt (T) nhn v trong b gii hn, sp

mi, v chc nng ng t cn bnh thng.

3.3. Khm ng t

Bt u khm ng t vi nh sng phng bnh thng, yu cu BN nhn vo mt im

bt k trn tng, trn nh trnh co ng t do phn x iu tit.

ng t bnh thng trn u, hai bn bng nhau, ng knh khong 2-3 mm.

Quan st kch thc, hnh dng ng t, v so snh hai bn.

Khm phn x ca ng t vi nh sng trc tip v ng cm: hng dn BN nhn vo

mt im bt k trong phng, chiu n pin vo mi mt ring bit t pha bn ngoi vo. Quan

st xem ng t hai bn c co li ging nhau khng. ng t ca mt c chiu sng co trc

tip c gi l phn x nh sng trc tip (direct light reflex). Co ng t ca mt cn li c

gi l phn x nh sng ng cm (consensual light reflex). Bnh thng phn x trc tip v

ng cm ging nhau.

Trnh chiu nh sng t ngt v trc tip t pha trc mt ca BN v c th lm BN

nhn vo n pin to ra phn x iu tit gy co ng t, v c th gy kh chu cho BN.


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Hnh 10: ng i ca phn x ng t vi nh sng

4. Dy V (sinh ba)

4.1. Gii phu

Dy V l mt dy hn hp cha cc si cm gic chi phi cho hu nh ton b da v

nim mc vng u mt, v phn vn ng nh hn chi phi cho hu nh tt c cc c nhai v c

tensor tympani tai trong. Nhn vn ng ca dy V nm ti cu no; nhn cm gic ko di t

trung no n hnh no trong nhn cm gic chnh nm ti cu no.


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Hnh 10: S phn b cm gic ca dy V

4.2. Khm

Khm cm gic s nng:

Yu cu BN nhm mt li, dng mu bng gn nh chm vo mt BN theo tng vng

phn b ca ba phn nhnh ca dy V. Yu cu BN ni c mi khi cm nhn c mu bng

gn chm vo mt. Chm vo cc vng mt, v thay i khong thi gian gia cc ln chm mt

cch ngu nhin trnh tnh trng BN d on nhng ln chm mt cch u n.

Hnh 11: v tr chm bng gn khi khm phn x gic mc

Khm phn x gic mc:

Phn x gic mc l phn x nhm mt li khi c kch thch chm vo gic mc. Phn x

ny nh gi s nguyn vn ca hai dy thn kinh s: dy V (hng tm) v dy VII (ly tm).

Dng mt mu nh bng gn v cun li thnh mt im nh (trnh dng bng gn trong

que tm bng). Gii thch cho BN trc khi khm. Yu cu BN nhn v pha i bn vi mt

c khm. Chm nh mu bng gn t pha bn ngoi vo pha bn ca gic mc nh im


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nh cho trn hnh. Trnh chm vo lng mi, v trnh BN nhn thy mu bng gn v c th

gy chp mt do th gic ch khng phi do phn x gic mc.

Cng ging nh vi phn x nn, c th b qua phn khm phn x gic mc nu BN

khng c nhng triu chng bt thng.

Khm cm gic nhit:

Yu cu BN nhm mt li v tr li liu c nhit nng hay lnh chm vo mt (ch

khm kh nng ca BN phn bit c nng hay lnh, khng khm kh nng chu c nhit

nng hay lnh n mc no).

Dng vt dng kim loi nh rung m thoa, ba phn x v ngn tay ca ngi khm

thay nhau t ln m BN cng v tr v yu cu BN tr li khi no l nng l khi no l lnh.

Khm mt cch ngu nhin, khng theo trnh t, trnh BN c th d on c khi

no l ngn tay v khi no l vt kim loi.

V cc th th au v nhit vng mt c s trng lp nhau, v u c dn truyn

chung bi b sinh ba-i th (trigeminothalamic tract), nn thng thng ch cn khm cm gic

nhit v hn ch khm cm gic au (c bit l khm cm gic au bng cch dng u kim nh

chm vo vng mt).

5. Dy VII (mt)

5.1. Gii phu

Dy thn kinh s VII cng l mt dy hn hp. Phn vn ng bao gm nhn lng (chi

phi cc c trn, c da mt trn, na trn c vng mi), nhn bng chi phi cho cc c na di

ca mt. Phn cm gic v giao cm (cn c gi l dy VII, hay thn kinh Wrisberg) chi phi

cm gic v gic cho 2/3 trc li, ng tai ngoi, mng nhv chc nng phn tit ca tuyn

l v cc tuyn nc bt.

5.2. Khm

Mc d l khi khm thn kinh thng quy, chng ta thng khng khm v gic; nhng

chng ta bit dy VII phn b v gic 2/3 trc ca li, cng vi vm ming mm v vm

ming cng. C th khm v gic bng dung dch mn, ng, chua, hoc ngt.


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Hnh 12: chi phi vn ng trung ng v ngoi bin cho c vng mt. Vng trn mi bn

nhn si trc chi phi ca neuron vn ng trn (Upper Motor Neuron: UMN) t hai bn

cu, trong khi vng mt thp hn ch nhn si trc chi phi ca UMN t bn cu i bn3

Bt u quan st cc c ng vng mt BN trong sut qu trnh hi bnh. Ch cc c

ng ca co mt khi BN ni chuyn hoc biu l cm xc. Mt s bnh l v d nh hi chng

Parkinson hoc trm cm c th lm gim c ng ton b c mt hai bn (cn gi l masked

face: mt c eo mt n).

Quan st xem c nhng biu hin ri lon vn ng khc trn mt nh co tht m mt

(blepharospasm), co tht c na mt (hemifacial spasm), tics

Tip theo, quan st tnh i xng ca: np mi m hai bn (bng cch yu cu BN nhn

hm rng), c vng mi hai bn (yu cu BN nhm cht mt li), v np nhn trn hai bn (yu

cu BN nhn trn ngc nhn ln trn). Trong nhng trng hp c lit mt nng, thng s d

nhn ra. Tuy vy, trong nhng trng hp c lit mt nh, cn quan st k tnh bt i xng ca

mt bn mt. Cng c th gp mt s trng hp bt i xng bm sinh (v d np mi m mt

bn m nh hn so vi bn cn li), khi cn hi li bnh s bit xem s bt i xng ny

mi xut hin hay c t trc.


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Hnh 13: BN bn (P) c lit mt bn (P) kiu trung ng (mt bn (P) ca BN ch c mt np

mi m, vn cn nhm mt c). BN bn (T) c lit mt bn (T) kiu ngoi bin (mt bn

(T) ca BN mt np mi m, v mt nhm khng kn)

6. Dy VIII

6.1. Gii phu

Dy thn kinh VIII xut pht t hch tin nh v hch c tai trong m o ca tai trong.

N vo trong thn no tip hp ti nhn tin nh, v nhn c tai thuc im ni gia cu v

hnh no (Hnh 14).

Hnh 14: Dy thn kinh tin nh - c tai.

6.2. Khm


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Hi BN xem c bt thng v thnh lc khng. BN c th nghe c in thoi, ni

chuyn vi ngi xung quanh, nghe c nhng ting ni thm bnh thng khng. BN c b

tai (tinnitus) khng.

To m thanh bn mt tai ca BN bng cch xoa nh cc u ngn tay ca ngi khm

li vi nhau, v hi xem BN c nghe c bnh thng khng. Yu cu BN so snh hai bn.

Khm nghim php dn truyn xng-kh (Rinne test):

Khi BN c than phin gim thnh lc mt bn, chng ta s khm tip nghim php Rinne

xem gim thnh lc ny do nguyn nhn dn truyn (conduction hearing loss: ch nhm

nguyn nhn do bnh l ca tai ngoi hoc tai gia lm gim dn truyn m thanh t mi trng

bn ngoi vo n cc t bo tip nhn thnh gic ca c quan Corti tai trong), hay do nguyn

nhn thn kinh (neurosensory hearing loss: do tn thng c quan Corti hoc dy thn kinh c

tai).

t m thoa ang rung ln trn mm chm ngay pha sau vnh tai ca tai gim thnh lc

(dn truyn qua xng), hi xem BN c nghe c ting rung t m thoa pht ra hay khng.

Ngay khi BN va ni ht nghe c m thanh ca m thoa rung, t m thoa k bn tai ca BN

v hi xem BN cn nghe c m thanh na khng (dn truyn qua kh).

tai bnh thng, dn truyn kh (khi m thoa t k bn tai) tt hn so vi dn truyn

xng (khi m thoa t trn mm chm). Do vy, khi BN ht nghe c dn truyn xng, ta

a m thoa n k bn tai ca BN, BN vn nghe thm c mt lc na. i vi tai c gim

thnh lc do nguyn nhn dn truyn, sau khi BN ht nghe m thanh t dn truyn xng, khi

a m thoa n k bn tai ca BN th BN cng khng nghe c thm (dn truyn xng > dn

truyn kh). i vi tai c gim thnh lc do nguyn nhn thn kinh th dn truyn kh > dn

truyn xng.

Khm nghim php Weber (Weber test):

t m thoa ang rung ln trn nh u ca BN. Bnh thng, BN s nghe m thanh u

c hai bn tai. Nu mt tai BN c gim thnh lc do nguyn nhn dn truyn, tai bn bnh s

nghe m thanh r hn tai bn bnh thng (v tai bn bnh c ri lon dn truyn, nn cn tr cc

tp m t mi trng bn ngoi, nn s nghe m thanh t nh u r hn). Ngc li, nu mt

tai BN c gim thnh lc do nguyn nhn thn kinh, tai bn bnh thng s nghe m thanh r hn

tai bn bnh.


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Ch : kt qu ca nghim php Weber ch c ngha thc s khi cho cng kt qu sau

vi ln thc hin nghim php.

Hnh 15: khm nghim php Rinne v Weber

7. Dy IX (thit hu) v X (lang thang)

7.1. Gii phu

Nhn ca dy IX, v X hu ht nm hnh no. Hai dy ny c nhng nhn chung (nhn

nc bt di, nhn m h, nhn ca b n c), v ng i trong thn no, trong hp s,

v v tr thot ra khi hp s cng tng i ging nhau, nn thng c khm chung.

7.2. Khm

Trong sut qu trnh hi bnh, ngi khm nh gi c phn no ging ni ca BN.

Xc nh xem BN c ni (dysarthria) hay khng. Nu BN c ni , khm tip xem liu ni

ny do nhm dy thn kinh s IX, X chi phi (bng cch yu cu BN pht m cc m vng

hu hng nh kh, kh, kh), do dy XII chi phi (yu cu BN ni cc m li nh la, la,

la), hoc do dy VII chi phi (cc m mi nh mi, mi, mi).

Khm nut kh bng cch quan st BN ung khong 150 ml nc sui hoc nc un si

ngui xem liu BN c nut sc khng. Lu ch khm nghim php ung nc khi BN c

than phin kh nut nh hoc trung bnh. i vi BN c kh nut mc nng, hoc n qua

sonde d dy th khng khm nghim php ung nc na v c th gy vim phi do ht sc.


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Khm vm hu: yu cu BN h to ming v ni Ah, Ah, quan st cung vm hu xem

c nng u hai bn, hay c bn no nng ln km hn bn cn li hay khng.

Khm phn x nn quan st r hn ng tc nng vm hu. Dng que li chm

nh vo vng hnh nhn ca tng bn hng, v quan st nng vm hu hai bn. Phn x nn c

ng hng tm l dy IX, v ng ly tm l dy X. Lu : thng ch khm phn x nn vo

cui phn khm thn kinh v phn khm ny gy kh chu nhiu cho BN. Nu BN khng c biu

hin ni , kh nut, v khng c triu chng g km theo nghi ng c lit dy IX v dy X,

th b qua phn khm phn x nn. Ngoi ra, c nhiu BN ln tui khe mnh bnh thng, vn

c phn x nn m tnh.

Hnh 16: BN A c vm hu nng u hai bn (bnh thng). BN B c vm hu bn (P) nng

ln km hn bn (T) (lit dy IX, X bn (P))

8. Dy XI (thn kinh ph)

8.1. Gii phu

Dy XI bao gm 2 thnh phn. Phn s (hay cn gi l phn ph: accessory) xut pht t

nhn m h (hnh no), v chi phi cho cc c ca thanh qun; phn ny i chung vi dy XI

trong hp s, nhng khi ra khi hp s, th i chung vi dy X. Phn ty gai (spinal) xut pht t

mt bn ca sng trc ty sng c on t C1 n C5 hoc C6 (Hnh 17).

Phn ty gai chi phi cho c c n chm v mt phn ba bn c thang (hai phn ba di

ca c ny do m ri c chi phi). Khm dy XI ch khm phn ty gai.


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Hnh 17: S ca dy thn kinh ph, nhn t bn di

8.2. Khm

Quan st kch thc v tnh i xng ca c c n chm v phn trn ca c thang hai

bn.

Khm sc c c n chm bn (P) bng cch yu cu BN xoay u qua (T) chng li

sc cn ca bn tay ngi khm, v ngc li. Khm sc c thang bng cch yu cu BN nng

hai vai ln trn chng li sc cn bn tay ngi khm. So snh sc c hai bn.

9. Dy XII

9.1. Gii phu

Dy XII xut pht t nhn h thit nm ti hnh no, v chi phi tt c cc c ca li.


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Hnh 18: chi phi hot ng ca c li. Hnh nh bn (P) cho thy khi ch c li bn (P)

co, n s ko phn nn ca li bn (P) ra trc, lm li th ra ngoi v u li lch v

bn (T)

9.2. Khm

Quan st c li lc li ang trng thi ngh ngi l triu chng quan trng nht i

vi tn thng dy XII. Quan st xem c teo c li hoc rung git c li bn no hay khng.

Mt s bnh l gy tn thng neuron vn ng di hai bn (v d nh trong bnh x cng ct

bn teo c: ALS (Amyotrophic Lateral Sclerosis)) gy ra teo c li v rung git c li hai bn.

Khm sc c li bng cch yu cu BN th li thng ra trc. Bnh thng u li

nm ngay ng gia. Nu c li bn no b yu (do tn thng dy XII) th u li s lch

v bn .


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Hnh 19: Lit dy XII bn (P). BN c yu cu th li thng ra trc. Li bn (P) teo v

u li lch v bn (P)

Ti liu tham kho

1. Clinical Neuroanatomy te, McGraw-Hill LANGE, 2010.

2. DeMyers The Neurologic examination (2011) se, McGraw-Hill, New York. 3. Aminoff MJ GD, Simon RP. Stroke. In: Aminoff MJ, Greenberg DA, Simon RP. Clinical Neurology,

eighth edition, McGraw-Hill, New York, 2012.

kham than kinh so y5 2015-2016

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