Técnicas de Dissecção

8/21/2019 Técnicas de Dissecção

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Aq Nupsiquiat 2008;66(2-A):282-287

282

Dissection technique for the stuDy of

the cerebral sulci, gyri anD ventricles

João Paulo Mattos1 , Marcos Juliano dos Santos 2, João Flavio Daniel Zullo 2 ,

Andrei Fernandes Joaquim 2

, Feres Chaddad-Neto1

, Evandro de Oliveira3

Abstract – Nuanatm in aitin t nuphsig, a th basic aas f th pp fmatin fm

hath stunts t spciaiz pfssinas in nuscinc. A stp b stp gui f pactica stuis f

nuanatm is qui f this kin f kng t bcm m accptab amng mica stunts,

nusugns, nugists, nupiaticians an pschiatic phsicians. Bas n th knn cuss

f suci, gi an ntics ff b Bnficência Ptugusa Hspita in Sã Pau, Bazi, t tims a

a, sinc 1994, ttaizing m than 20 cmpt cuss, an ansing th qust f man nuscinc

stunts an pfssinas hs ask f a pactica gui t th nuanatm stu, th auths suggst

a ptc f th stu f supficia an p bain stuctus shing h t appach th m stuctus

as pssib ith minimum amag t th anatmic pic an ith th sma numb f bains.

Key wordS: nuanatm, bain, issctin tchniqu.

técnica de dissecação para o esudo dos sulcos, giros e venriculos cerebrais

Resumo– Nuanatmia a nufisigia sã as áas básicas paa a aquaa fmaçã s stuants

na áa a saú a pfissinais spciaizas m nuciências. Um guia pátic, pass a pass, paa stu

nuanatmia é ncssái paa tna ss cnhcimnt mais acssí nt stuants micina,

nugistas, nufisigistas, nuciugiõs, nupiatas psiquiatas. Basas m cuss cnhcis

nacina intnacinamnt a spit s sucs, gis ntícus cbais abas aizas p

Institut Ciências Nuógicas (ICNe) n Hspita Bnficência Ptugusa Sã Pau, Basi, uas zs

a an, ttaizan mais 20 cuss já aizas, s auts apsntam um ptc isscaçã paa

stu as stutuas supficiais pfunas ncéfa, mstan cm xp máxim stutuas

cm um mínim manipuaçã an à pça anatômica utiizan mn núm ncéfas pssíis.

PAlAvrAS-CHAve: nuanatmia, céb, técnicas isscaçã.

labatói Micciugia, Hspita Bncência Ptugusa Sã Pau, Sã Pau SP, Basi; Institut Ciências Nuógicas, Sã Pau SP,

Basi (ICNe) an discipina Nuciugia, Facua Ciências Méicas a Unisia Campinas, Campinas SP, Bazi (UNICAMP): 1MéicAssistnt; 2Méic rsint; 3Pfss dut.

rci 14 dcmb 2007, ci in na fm 17 Mach 2008. Accpt 3 Api 2008.

Dr. Feres Chaddad Neto – Praça Amadeu Amaral 47 / 7º andar - 01327-010 São Paulo SP - Brasil.

Th stuy f nuanatmy is n f th mst cha-

nging issus f th pp fmatin f mica stu-

nts, sints f nugy, nusugy, nupiat-

ics an f ths intst in mica scincs. Th-

f, accing t Baziian Ministy f eucatin an Cu-

tu, th a tms f a mica schs that mak

th stuy f nuanatmy an bigatin f th accp-

tanc f that institutin as n gist an a tff nuscinc sincy pgams1. Th us f x

bains f this pups is i accpt but sm tais

f nuanatmy a usuay miss if a n pt-

c f issctin is nt f. Th amag t th f-

miz bain is anth matt that can happn if th

is n guianc in that stuy, spciay ith th ifcut

accss t ths gans in mst pacs.

Th sciptin f th aay namy stuctus, su-

ci, gyi an ntics mnts an its atins a nt

th bjcti f this pap as it is aay scib an

i accssib t a nuscinc stunts2-5.

w suggst a stp by stp ptc f bain issc-

tin f th stuy an inticatin f th supatntiastuctus sinc th acquisitin f th bain fm th ca-

a t th stuy f th p anatmic stuctus.

MethoD

Th bains us in th cuss mntin bf in th txt,



Aq Nupsiquiat 2008;66(2-A)

283

Cba suci, gyi an ntics: issctin tchniqu

Matts t a.

as as ths issct an shn in th pictus cms fm

th Serviço de Vericação de Óbitos (Svo) fm S.Pau, Bazi,

hich is a pubic gan f ath instigatin. A fsh bain is

th bst ay t achi an aquat nuanatmica stuy.

It must b m fm th caa as sn as pssib. Th

intna catis an th basia aty shu b cathtiz

ith a numb 10 sica catht an ash ith sain su-tin at f sa tims, unti th b is ash aay

fm th tissu an, aft that, th bain shu b immiaty

imms in 4% fm sutin. It must b kpt imms f a

mnth, at ast. Aft that, th xat bain is ash ith abun-

ant at f bginning th stps f pactica stuy.

results

S 1

Th aachni an th ctica an suca sss must

b takn ut fm th bain t xps th suci an gyi.

An aquat tchniqu must b f t ai am-

ag t th ctx as shn in Figu 1A. Aft that, thbain is ay t bgin th inticatin f supcia an

basa stuctus.

Th bain has th sufacs: mia, supata

an basa sufacs. Thy a imit by th bs f th

bain: supmia, infata, mia ccipita an

mia bita. Th inticatin f th suci an gyi b-

gins fm th cnxity (Tab), in th supata su-

fac, hich is imit by th supata an infat-

a bs. Th syian ssu, ata sucus, an its

iisins must b inti st. Th anti hiznta

amus an anti ascning amus f th ata sucusmust b k f, spciay in th ft si, h thy

a th imits f th Bca’s aa. Th psti amus f

th ata sucus shu b inti as . Th insu-

a, in th f th syian ssu, an its atins ith

ach iisin f this ssu is y imptant, an shu

b k f2,3.

Th supi (SFS) an infi fnta suci (IFS) as th

supi (SFG), mi (MFG) an infi (IFG) fnta gyi

must b inti. At th ft si, th 3 iisins f in-

fi fnta gyus btn th anti ascning an

anti hiznta amus f th ata sucus a fun

( pars orbitalis, triangularis and opercularis) an its c-

spnnc ith th insua imits must b sach f2-4,6-8.

Th atins f th supcia stuctus ith th p

ns, as th pac f famn f Mn accing t th

supcia anmaks must aays b k f2-4,6-8. P-

cnta (PCS), cnta (CS) an pst-cnta suci (PsCS)

a as inti. Th p-cnta an ps-cnta gyi

a intifi ith th CS btn thn, fming th

“cnta b”. Th inta-paita sucus (IPS) cming fm

pst-cnta supi tmpa sucus (STS) a in-

ti. It iis th paita b in supi an infi

paita bus. Th pint h th IPS ns th PsCS

Table. Checklist for the study of the supercial brain structures.

SupeRolAteRAl SuRfAce

lara ss (Syvia ssr)

Stm ang sphni ig

Anti hiznta amus

Anti ascing amus

Psti amusInsua in th

cra ss

fra b

Pcnta gyus an sucus

Supi fnta gyus an sucus

Mi fnta gyus

Infi fnta gyus an sucus

Pas bitais,tianguais,pcuais

paria b

Cnta sucus (anti imit)

Pstcnta sucus

Pstcnta gyus

Intapaita sucus

Supi paita bu

Infi paita bu

Supamagina gyus

Angua gyus

Acus tmpa-cciptas

tmra b

Supi tmpa sucus

Supi tmpa gyus

Infi tmpa sucus

Infi tmpa gyuslata n f tan. tmpa gyi

oia b

Pccipta ntch

Supi n f paitccipta sucus

Tans ccipta sucus

lata ccipta sucus

Supi ccipta gyi

Infi ccipta gyi

Isa

Cicua sucus

Cnta sucus f insua

lng an sht gyi f insua

MedIAl SuRfAce

rstum f cpus casum

Gnu f cpus casum

By f cpus casum

Spnium f cpus casum

Sptum puciumPaatmina gyus

Pstfacty sucus

Anti paafacty sucus

Subcasa aa

Cinguat sucus

Mia fnta gyus

Paacnta bu

Cinguat gyus

Isthmus f th cinguat gyus

Paahipccampa gyus

Paitccipta sucus

Cacain sucus

Cunus

Pcunus

InfeRIoR SuRfAce

Arir ar (rbia)

ofacty sucus

Gyus ctus

Anti bita gyus

Psti bita gyus

Mia bita gyus

lata bita gyus

P pCata an ccipttmpa suci

rhina sucus

lingua

Paahipccampa gyus

Mia ccipttmpa gyus

lata ccipttmpa gyus

is ca inta-paita pint an taks yu t th atium

f ntics9,10. Th ccipita b has an incnstant gyi

an suci but n ata ccipita suci at ast must b

inti as cntinuity fm th IPS. Th imits f th c-

cipta b, gin by anatmic anmaks shu b cg-

niz in supata sufac2,11, a imaginay in btn

pccipta ntch an th supcia n f th paitc-

cipta sucus is th anti imit f this b.




284


Matts t a.

Fig 1. (A) After the xed brain is achieved, the arachnoid membrane and its vessels must be taken off using appropriatetechnique. One of the easiest way is to hold the major sulcal arteries near the superior convexity border and pull it allthe way down following the same direction of the sulci. It will avoid that strong and hard vessels cut the brain surfacewhen pulled off. (B) As exposed earlier, the long knife is located in the frontoparietal operculum with the base of the

pars triangularis and a point 2 cm superior to the posterior end of the sylvian ssure as landmarks. This cut must beaimed to the superior limit of the corpus callosum, in the midline, to preserve the lateral ventricle roof to be opened

later, what can be difcult in some hemispheres. If that is the case, this step should be done with more than one move-ment, with deeper cuts until it gets in the corpus callosum by the midline. (C) The pre-central gyrus is separated fromthe remained frontal and parietal lobes and put in its original position for the study of the relations between the pri-mary motor cortex with the deeper structures as the corpus callosum and foramen of Monro. In the picture, the pos-central gyrus is also placed in anatomic position, dening the “central lobe” and the paracentral lobule in the medial

surface. This step can be done before and after the removing of the lateral ventricular roof, as shown in the picture.(D) Opening the lateral ventricular roof. With a number 10 blade, the roof of the lateral ventricle is removed, begin-ning from the frontal horn, in an anterior-posterior way. Care should be taken here, to avoid lesion of the ventricularoor. If the rst cut in the hemisphere, made by the long-knife, was succesfull, the ventricular roof should be thin as 1-

2 mm, what makes easier the identication of the ventricular cavity to be opened. The ventricular cavity must be en-tirely exposed, from the frontal horn to the atrium in this step.

Th basa sufac is imit by th infata anmia ccipita an mia bita bs f th bain.

Th basa suci an gyi fm tmpa an fnta bs

a as stui (Tab)6. Th atin f anti pfat-

substanc ith th nighbh stuctus, cistns

an ith th p catins in th basa gangia is a

stp that shu nt b fgttn. As, th basa cistn

gins an its atin must b stui2,3,6,12 .

In th mia sufac, btn th mia bita an

ccipta bs an th supata b f th bain,

th ptins f th cpus casum, paatmina gyus,

pstfaty sucus, paafaty gyus, cinguat sucus,

mia fnta gyus, paacnta bu, cinguat gyus

cntinuing thugh isthmus t paahippcampa gyus,

paitccipta sucus, cacain sucus, cunus an pcu-

nus as spci in Tab2-4,6-8 .

S 2

Aft th inticatin f supcia stuctus, th

bain must b cut t pi a p bain stuctus stuy.

A ng knif is us t pfm this stp. A its ngth

must b us t this stp at nc as mnstat by

Figu 1B. Th anti pint t put th knif in pac is

th bas f th pars triangularis f th IFG an th ps-




285


Matts t a.

ti pint is cat 2 cm ab th psti n f

th syian ssu. Th ictin f th knif must b f-

in ictin t th immiaty supi pat f th

cpus casum t kp its intgity an mak th at-

a ntic f as thin as pssib.

Th PC gyus must b isat fm th main

ctx an put it in its igina pac t sh th atin

f this mt aa ith th cpus casum an ntic-

ua caity aft its pning (Fig 1C).

Aft this st cut ith th ng knif, th mia su-

fac f th bain is n ca an n btt f inti-

catin an stuy f th mia sufac again.

S 3

Th nticua caity must b pn. F this pu-

ps, a numb 10 ba is us ith cafu cu m-

mnts t xps th nti ntic ithut amag t

th insua b n th miin stuctus. It is scib

in Figu 1d. Th stuy f nticua as, its imits, th

atin ith th assciat stuctus, th chi s-

Fig 2. (A) The remaining fronto-partietal operculum must be taken out from the hemisphere to show the insula andthe temporal operculum. With one hand, the frontoparietal operculum must be elevated while excised with a number10 blade along the superior circular sulcus, from the remaining frontal and parietal lobes. The circular sulcus from in-

sula must be shown in all its length after that, as all the short and long insular gyri as well. (B) At the left side of this specimen, no cuts were made in the insular lobe after the frontoparietal operculum was removed. In the right side, af-ter this step, axial cuts from the superior to the inferior aspect of the insular lobe, the central core of the brain, weremade to show the deepest structures in the insular lobe and their relations with the ventricular cavity, frontoparietal

and temporal operculum. It’s the option A, described in the text. These cuts must be done with the long knife in a lat-eral to medial way, sparing the thalamus to show the ventricular oor, with the help of a number 10 blade as it getscloser to the ventricles. (C) The foramen of Monro is shown with the dissector and the genu of the internal capsule

points it, as a usefull tip seen in MRI images. From lateral to medial, the insular cortex, the extreme capsule, the claus-trum, the external capsule, the putamen, the globus pallidus, the internal capsule, the caudate nucleus, the thalamus,the choroid ssure, and the fornix should be exposed after these axial cuts in the central core, as shown in the picture.(D) To expose the temporal horn of the lateral ventricles, a cut with the long knife must be done in the superior tem-

poral sulcus, from lateral to medial, toward the insular cortex, removing the superior temporal gyrus or the temporaloperculum. After that, progressively deeper cuts are made from lateral to medial in the temporal lobe pointing theinferior circular sulcus of the insula until the tapetum of the corpus callosum, as the most lateral roof of the temporalhorn, is thinned. If it hasn’t been opened yet, it can be gently done with the number 10 blade following the same tech-nique used when the anterior ventricular horn, body of the ventricle and atrium was opened. The choroid ssure, the

Amon’s horn, the collateral eminence, the pes hipoccampus, the thalamus, the mbriae, the anterior choroidal point

and the amigdala in the anterior wall of the temporal horn should be identied after this step, as shown.




286


Matts t a.

su, famn f Mn, chi pxus, nticua s-

ss, fnix, an sptum pucium is n4. Th stuy f

um intpsitum must b n. Th sugica uts t

accss th thi ntic a anth taining pgam t

this stp13. Th tansnticua accss t th quaigm-

ina cistn is as stui.

S 4

Th fntpaita pcuum n t b takn ut

t xps th insua ctx an th pcua si fm

th tmpa b. It is shn in Figu 2A. Th cicu-

a sucus fm th insua, insua gyi, cnta sucus f

th insua an its imits must b inti. Th atin

fm th insua gin t th nticua, basa gangia

an iffnt ptins f th intna capsu is n f

th mst imptant mnts t unstan th thi i-

mnsin i f th supcia an p supatntia

stuctus2,4,7 (Fig 2B).

Option A – A pgssi p cut in axia pan in th

insua b can b pfm t isuaiz th atin f

th intna capsu, nticua nucus, thaamus, cauat

nucus an th famn f Mn insi th ntics

an th insua ctx. It is scib in Figus 2B an 2C.

Fig 3. (A) The aspect of the specimen dissected should be as shown in the picture, with the roof of the temporal horn opened by the cuts to-ward the inferior circular sulcus of the insula. The Ammon’s horn, the collateral eminence, the choroid ssure, choroids plexus and the ventric-ular and atrial walls are exposed, by the dissection. With a number 10 blade, the posterior extension of the temporal horn and atrium shouldbe opened. (B) The option B described in the text is shown in this picture. A sagittal cut was made in the insular lobe. The relations of the ven-tricular structures with the insular lobe are clear in this dissection. The cuts should be made progressively from lateral to medial, with the longknife, and every cut should be studied before the more medial next one is done. That’s because the relations between the structures in the cen-tral core are changed in different sagittal planes. The amigdala, located at the anterior wall of the temporal horn, is evident in this picture,and its relations with the globus pallidum, internal capsule and ventricular structures should be done. In these cuts, the different portions ofthe internal capsule are also evident. (C) Basal surface of the brain .The uncal notch at the uncal apex is used as an initial landmark for the in-cision in the basal surface of the temporal lobe. This curved incision, shown by the red dotted line in the picture, doesn’t have to be made inonly one movement. Instead, progressively medial to lateral curve cuts should be made toward the collateral sulcus. The objective is to removethe inferior or basal part of the uncus. There is an arachnoid plane and vessels coming from the crural and ambient cistern in the uncal notch

which helps the identication of the correct plane of dissection. Posteriorly, the incision removes the subiculum, making more evident the cho-roid ssure from below. If the correct plane of the dissection was carried on, the dentate gyrus and mbriae should be exposed without dam-age in the posterior part of the temporal lobe. (D) The uncal notch of the right temporal lobe is shown in an inferior and medial angle. The un-cal notch at the uncal apex, just anterior to the dissector in the picture, is the point where the incision should begin, and is the correct depth ofthe incision as well. (E and F) After the removal of the inferior part of the uncus and the subiculum, the dentate gyrus and the mbria just me-dial to it should be exposed. The identication of the dentate gyrus is made by the unique aspect of this structure, with transversal stripes, andthe arachnoid membrane and vessels between it and the uncus and subiculum, evident in the picture. The mbria is found in the dissection as awhite structure medial and superior to the dentate gyrus from above. The fasciolar gyrus is shown at the 3E gure. The lateral geniculate bodyand the choroid ssure turns clearly exposed after the removing of the subiculum, showing the relations of the temporal horn and the mesialtemporal lobe with the thalamus. The optic tract, as the roof of the crural cistern, is evident. The uncinate gyrus, band of Giacomini and intra-limbic gyrus are evident in this specimen, after the dissection described.




287


Matts t a.

S 5

expsing th tmpa hn f th ata ntic

an th atium. Th ng knif is us t pfm th cut

taking th supi tmpa sucus as a anmak. Th

pcu is scib in Figu 2d. Th pning f th

infi cicua sucus fm insua an nting th tm-

pa hn f th ata ntic i a th inti-catin f Ammn’s hn, th cata minnc, th ch-

i ssu, an th nticua an atia as. Th stuy

f th chi ssu at this must b cai ut t

xps th ambint cistn an its cntnt as its atin

t th nticua stuctus4,5,14 (Figs 3A an 3B).

Option B – At this , an ptin B is aaiab if th

ptin A as nt cai ut at th th si f th

bain, ppsit t th axia sic cnta c. A sagitta

cut can b n if th intntin is t stuy th amigaa

an its atins t th gbus paium, uncus, nticua

f an anti nticua as an as th inti-

catin f th t an subnticua pats f th intna

capsu. Th inticatin an th stuy f th chi

ssu is as faciitat fm this pint f i (Fig 3B).

S 6

Msia tmpa b issctin. Initiay, a cu in-

cisin is ma in th mia aspct f th paahipcam-

pa gyus using th apx f th uncus, fm by th am-

bint gyus f th uncus, an unca ntch (Figs 3C an 3d)

antiy an th ata msncphaic sucus psti-

y as anmaks. Pgssiy p an atay int- cuts a n ta th hina sucus, ith th bjc-

ti f ming th paahipcampa gyus an subicuum

(Figs 3e an 3F). Th issctin pan is assu by th s-

ss nting th unca ntch fm cati an cua

cistn. Aft that, th issctin shu xps th m-

bia, th ntat gyus, th mbi-ntat sucus, ch-

i ssu, th ata an mia gnicuat bis an

puina f th thaamus an th th itt gyi f th

psti sgmnt f th uncus (uncinat gyus, ban f

Giacmini an intaimbic gyus). Th anatmic atins

btn ths stuctus, as th atins btn thman th thaamus an gnicuat bis, ptic tact an

msncphan, spciay th ata msncphaic su-

cus shu b bs2,4,5,14.

Discussion

Sinc th atin btn nuanatmy an th

cinica pictus puc by y stuctu an thi

sins is int, th stuy f nuanatmy, spciay

f th bain, is ssntia f many pfssinas. Mst f

th atics an bks in th subjct scibs th stuc-

tus an th atins btn thn, an nt scib

th issctin xcis. w bi that this xcis is a

piity an sinc n spcimns a ay aaiab in

mst f th abatis, th issctin an ppaatin

f ths spcimns a y imptant, an shu bgui ith th pups f shing th agst numb f

stuctus as pssib, ith minima amag f th pic.

F that, a stanaiz utin squnc f cuts is th

bst chic. Th “stp-by-stp” issctin scib, a-

th stunt t intify a th imptant stuctus in

ach fas f th stuy, ithut th isk f amaging th

pats f th bain in th attmpt t sh n in paticu-

a. In th n f th stuy, th stunt must chck th

stuctus stui, as a chckist, t b su that nn f

thn as ft bhin.

In cncusin, th issctin is a ssntia pat in thstuy f nuanatmy, spciay f nusugns, b-

caus f th numus stuctus in th bain an th

ca atin btn thn an cinica pictus. F that,

a squnc f n issctin stps assus th

inticatin f a th imptant stuctus f th bain,

ithut asting th spcimn.

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Técnicas de Dissecção