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Prof. Ion V. Moldovanu
Catedra de Neurologie
Universitatea de Medicin i Farmacie N.Testemitanu
Neuropsihologia clinic
Neuropsihologie: ntrebri majore
1. Afazia. Definiie. Deosebirea de disartrie
2. Agnozia. Tipurile de agnozie. Prosopagnozia
3. Definiia apraxiei i formele ei clinice
4. Sindromul lobului frontal
5. Sensory Neglect Syndrome. Definiie
6. Alte manifestri clinice n leziunea lobului parietal
7. Leziunea lobului temporal - manifetri clinice
8. Lobul occipital - semnele de leziune
9. Demena. Definiie.
10. Maladia Alzheimer i demena vascular
Predecesorii Neuropsihologiei:
Frenologia
Disciplin care se ocup de funciile mentale superioare n cadrul raportului lor cu structurile cerebrale* (Hecaen H. 1973 )
nelegerea relaiilor dintre creier i
comportament
funcionarea creierului ce produce o varietete de
aciuni proprii fiinei umane
Neuropsihologia
Paul Pierre Broca (1824 - 1880)
Zona Broca
In 1861 Broca descrie cazul unui pacient, care
a pierdut capacitatea de vorbire (putea doar s emit zgomote i sunete neinteligibile)
La necropsie s-a constatat o leziune n zona cortexului frontal al emisferei stngi.
Actualmente, aceast deteriorare este referit zonei Broca ce determin afazia Broca: vorbile lent, nceat cu o structur gramatical foarte simpl
Celebru prin lucrarea sa despre afazia
sensorial (1874) i poliomielita hemoragic superioar, ambele i poart numele
Carte despre leziunea capsulei interne
Manual de neurologie.
DR. CARL WERNICKE
(1848-1904)
Asimetria funcional a emisferilor cerebrale
Asimetria funcional a emisferilor
cerebrale Dou structuri simetrice = aceleai funcii? (ochi, urechi,rinichi, plmni)
Broca 1861,Wernicke 1874 i conceptul emisferei dominante
Curentul localizator (creierul un mozaic de centre funcionale)
Curentul globalist (creierul o mas omogen cu excepia ariilor motorii i
senzoriale primare)
A localiza leziunea care duce la pierderea vorbirii i a localiza vorbirea sunt dou lucruri diferite
(Jackson,1864)
Asimetria funcional a emisferilor
cerebrale (II)
Comisurotomia, creier
secionat (split-brain)
Conceptul de asimetrie
funcional
Asimetria funcional a emisferilor
cerebrale (II)
Comisurotomia, creier secionat (split-brain)
Conceptul de asimetrie funcional
Conflictul interemisferic
(intermanual)
analiza modificrilor capacitilor intelectuale de percepie limbaj memorie personalitate
aprute n urma unei leziuni cerebrale
Neuropsihologia clinic
Paul Pierre Broca (1824 - 1880)
Zona Broca
In 1861 Broca descrie cazul unui pacient, care
a pierdut capacitatea de vorbire (putea doar s emit zgomote i sunete neinteligibile)
La necropsie s-a constatat o leziune n zona cortexului frontal al emisferei stngi.
Actualmente, aceast deteriorare este referit zonei Broca ce determin afazia Broca: vorbire lent, nceat cu o structur gramatical foarte simpl
Celebru prin lucrarea sa despre afazia
sensorial (1874) i poliomielita hemoragic superioar, ambele i poart numele
Carte despre leziunea capsulei interne
Manual de neurologie.
DR. CARL WERNICKE
(1848-1904)
AFAZIA Afazia este o alterare achiziionat a
limbajului n rezultatul unei leziuni cerebrale
Nu se consider afazie: Deficienele de nsuire ale limbajului leziuni precoce
insuf. dezvoltrii creierului autizm
surditate
Tulburri psihice
Atingere sensorial
Paralizia organelor efectorii
disfonie
dizartrie
Afazia motorie (Broca)
Afazia Broca este o varietate a afaziilor non fluente, care se caracterizeaz prin reducerea discursului. (N =90 c/min)
Vorbirea e:
rar, constnd esenial din nume, verbe tranzitive i adjective eseniale;
cuvintele scurte sunt omise, dnd limbajului un stil telegrafic, agramat.
eforturile bolnavului pentru a vorbi i mimica sa denot prezena contiinei erorilor cu reacii de enervare sau angoas frecvente.
Discursul e:
aspontan
ncetinit monoton
silabisit
laconic
emis cu efort ( disprozodie )
Afazia motorie (Broca)
Comprehensiunea oral ( nelegerea limbajului adresat pacientului ) este relativ pstrat
Denumirea la ordin a obiectelor i imaginilor e corect i n absena apraxiei pacienii execut comenzile simple
Cauza:
consecina unei leziuni ischemice, interesnd emisfera stng i se asociaz cu o hemiplegie dreapt cu sau fr hemianestezie, apraxie bucco-facial, eventual cu apraxie ideo-motorie.
Fluena verbal
Fluen categorial* : denumiri de animale 2 min
Fluena fonematic: Cuvinte comune ce ncep cu litera m
Scorul < 20 pentru denumiri de animale (16)
< 15 pentru cuvinte comune (10)
Variaz n funcie de nivelul socio-cultural
Afazia senzorial (Wernicke)
Afazia Wernicke- afazie fluent
(producie verbal abundent i incoerent).
Limbajul este :
normal articulat
spontan
logoreic (incontinuu)
parafazii, neologisme asemantice
test.cuvintelor decupate:
/iepurii/ / vneaz/ /vntorul/
Afazia senzorial (Wernicke) Coninutul discursului este, ca regul, lipsit de sens
neneles pentru persoanele nconjurtoare
Anosognozia
Comprehensiunea pacientului e perturbat
Afazia Wernicke se manifest n absena hemiplegiei. O hemianopsie lateral omonim pe dreapta se asociaz frecvent
Leziunile responsabile intereseaz cortexul auditiv asociativ
(partea posterioar a primei circumvoluii temporale) i lobul parietal inferior ( gyrus supramarginal i angular ).
AGNOZIA
Agnozia deficit de recunoatere
a stimulilor externi i interni
Absena tulburrilor
de percepie
de limbaj
psihice
AGNOZIA
AGNOZIA
AGNOZIA Agnozii vizuale
Agnozia vizual pentru obiecte i imagini este
incapacitatea de a identifica vizual un obiect sau reprezentarea sa grafic
(n absena tulburrilor funciilor vizuale elementare sau a capacitilor intelectuale. Obiectul nu este recunoscut vizual, dar e identificat palpator)
Agnozia culorilor - imposibilitatea de a numi culorile atunci, cnd ele sunt corect aplicate obiectelor.
Agnozia facial (prozopagnozia)- imposibilitatea recunoaterii feelor persoanelor chiar apropiate.
(Identificarea poate deveni posibil la auzirea vocii).
Afectarea lobului occipital e cauza manifestrii diferitor forme de agnozii vizuale.
Prozopagnozia Agnozii vizuale
Agnozia facial (prozopagnozia)- imposibilitatea recunoaterii feelor persoanelor chiar apropiate.
Identificarea poate deveni posibil la auzirea vocii.
AGNOZIA
Agnozii auditive
Surditatea cortical sau agnozia auditiv (rar). Pacientul e
incapabil de a identifica sunetele, fie c e vorba de zgomote familiare, muzic sau mesaj verbal
Leziunile responsabile sunt bilaterale cu afectarea zonei Heschl sau a relaiilor ei cu corpul geniculat intern
Surditatea verbal constituie un deficit selectiv de identificare a coninutului mesajului verbal. Ea e, ca regul, asociat cu afazia Wernicke
Amuzia desemneaz incapacitatea de a identifica melodiile, determinat de afectarea lobului temporal drept
AGNOZIA Stereognozia: cunoaterea tactil
a obiectelor
Astereognozia este incapacitatea de a
identifica un obiect pe cale tactil n absena oricrei informaii vizuale sau auditive.
Astereognozia e frecvent n leziunile cortexului parietal, fiind, ca regul, asociat cu tulburri importante ale sensibilitii de localizare, de poziie i discriminare ale stimulilor tactili.
AGNOZIA Cunoaterea spaiului extra- i
intracorporal
Sensory Neglect (Neglijarea spaial unilateral -NSU) deficit lateralizat a cunoaterii spaiale,condiionat
de leziunea lobului parietal, care se caracterizeaz prin imposibilitatea de a descrie verbal, de a rspunde i de a se orienta n raport cu stimulrile de partea controlateral leziunii
Cunoaterea spaiului extra- i intracorporal
Bolnavii ignor de obicei hemispaiul
stng: un dirijor ignor muzicanii din
orchestr plasai la stnga sa, pacienii i rad doar hemifaa dreapt,
etc.
tulburri de citire, cci nu cerceteaz jumtatea stng a paginii.
Pentru a cerceta NSU se utilizeaz copierea unui desen. Pacientul cu NSU va uita jumtatea stng a figurii.
Sensory Neglect
(Neglijarea spaial unilateral -NSU)
lldfkdlkdlkdflkdsgk
,mv.,mv.mv.,mv.m
D,..,fv,.vn dfn
dd.Mds Sensory Neglect
(Neglijarea spaial unilateral -NSU)
.msdmsd,.m
lsdsldmflsdmfsdm
Sdms.dmd,mds.m
sdmsdm.sm.dm
Sd,fmas,.mf.d
fkslfk
AGNOZIA Anozognoziile hemiplegiei (sindromul Anton- Babinski)
dispariia mai mult sau mai puin total a hemicorpului stng din cmpul contiinei. E o form major de hemiasomatognozie. Pacientul refuz existena deficitului su motor. Aparine preponderent leziunilor vasculare ale lobului parietal n perioada lor iniial
Autotopagnozia - pierderea capacitii de a indica la comand
oral prile propriului corp Sindromul Gerstmann (tetrad simptomatic): agnozie digital, agrafie pur, dezorientare dreapta-stnga acalculie.
APRAXIA Apraxia perturbare ale micrilor
voluntare achiziionate
Nu sunt atribuite:
- tulburrilor motorii primare
- deficitului de nelegere
leziunii frontale sau parietale
ACTIVITI GESTUALE: APRAXIILE
Principalele aspecte ale apraxiei
Apraxia dinamic
incapacitatea de a supune aciunea unui plan, evideniat prin testele de apraxie: incapacitatea de a reproduce un grafism regulat alternant
Ansamblul acestor tulburri indic o perturbare a controlului exercitat de lobul frontal asupra
gestului. Apraxia dinamic e sever n cadrul leziunilor frontale bilaterale.
ACTIVITI GESTUALE: APRAXIILE
Apraxia ideo-motrice (gestual i de mimare)*
Pacientul e incapabil de a executa la ordin salutul militar sau de a mima gestul utilizrii unui ciocan.
Executarea e perfect atunci, cnd pacientului i se propune s utilizeze real un obiect (de exemplu, ciocanul) n loc s-i mimeze ntrebuinarea
Ca regul, apraxia ideo-motrice e bilateral i rezult din leziunea lobului parietal stng.
Apraxia ideatorie
se manifest n cadrul utilizrii obiectelor n aciuni simple: utilizarea unui creion, a aprinde un chibrite sau n aciuni mai complexe: a face un plic, a aprinde o lumnare
Apraxia ideatorie e bilateral, ca regul asociat cu o important apraxie ideo-motrice ca consecin a unei leziuni vaste a lobului parietal stng.
Apraxia constructiv
Perturbri de utilizare a relaiilor spaiale. Apraxia constructiv rezult dintr-o leziune parietal stng sau dreapt sau a
corpului calos. Ea e facilitat prin asocierea unei leziuni frontale.
Examenul apraxiilor
Apraxia reflexiv (imitaie) :
Inel dublu
Aripi defluture
Mnile ncruciate
Mnile ncruciate (invers)
Ideomotorie(reproducerea gesturilor cunoscute)
Salut militar
Adio
A trimite un srut
A curi o banan
Constructivitatea grafic
Copierea desenelor
Stephen
Haking
Semiologia clinic neuropsihologic n cadrul leziunilor diverselor structui
cerebrale
Lobul frontal
Lobul frontal Zona prefrontal (funciile cognitive superioare ) planificare
organizare
soluionarea problemelor
atenie selectiv
personalitatea
o varietate de " funcii cognitive superioare " incluznd comportamentul i emoiile
.
Zona premotorie
modificarea micrilor
Sindromul lobului frontal
(fenomene neuropsihologice)
Apraxia mersului (aria premotorie)
Lips se iniiativ Mersul n foarfece Reacii de magnet (magnet apraxia Denny Brown) Reflexul de prehensiune i de tatonare
Personalitate frontal (cortexul prefrontal) Apatie i inerie motorie Moria -comportament dezinhibat,pueril
-schimbari de dispaziie -tendin spre calambururi -megalomanie
-hipersexualitate, bulimie
Perseveraii motorii
Comportament de utilizare i imitare
Tulburri de atenie
Afazia Broca
Sindromul Diogene
Sindromul lobului parietal
(fenomene neuropsihologice)
Epilepsie somato - senzitiv parial
Hemianestezie parietal
Amiotrofie parietal
Extincia (neatenie senzitiv)
Asteriognozie
Apraxie
Hemiasomatognozie
sindromul Alice n ara minunilor hemi-depersonalizare (parc n-ar exista jumtate de corp)
Sindrom Anton- Babibnski ( anozognozia hemiplegiei)
Sindromul Gerstman agnozie digital agrafie pur dezorientare dreapta stnga acalculie
Negligen (agnozie) spaial unilateral
Sindromul lobului temporal
(fenomene neuropsihologice)
Tulburri de audiie
Sunete nedifereniate (zgomote simple)
Halucinaii auditive bine organizate (cuvinte ,cntece,clopot)
Tulburri olfactive (gyrusul hipocampic)
Halucinaii olfactive (benzin, fum, usturoi)
Tulburri gustative
Halucinaii gustative (n cadrul crizelor uncinate)
Epilepsie temporal somatosenzorial
(crize gustative,olfactive,auditive,vertiginoase, vegetative)
Tulburri de comportament (sndr. Kluver - Bcy )
(tendine orle, placiditate, comp.sexual anormal, tend. de a fi distrat )
Leziuni bilaterale
Amnezie global (afectarea hipocampului bilateral)
Agnozie auditiv
Agnozie vizual
sndr. Kluver Bcy
Sindromul lobului occipital
(fenomene neuropsihologice)
Iluzii i halucinaii vizuale
scotom
iIuzii
halucinaii
Cecitate cortical (cecitate psihic) [leziune bilateral+abs. tulb vederii periferice]
refl. foto-pupilar N
motilitate ocular pstrat
reflex de ameninare absent
Amnezie i dezorientare n spaiu (amnezie occipital)
pierderea memoriei topogrqafice (analogie cu prozopagnozia)
Prozopagnozia
(nu poate fi explicat printr-o deteriorare intelectual i mnezic global i nici printr-o tulburare perceptual )
Sndr Balint
paralizia psihic a privirii
ataxia optic
tulburare atenional (simultagnozia)
MEMORIA
Memoria este capacitatea organismelor vii de
a obine, de a reine i de a utiliza un ansamblu de
cunotine sau de informaii
Procesul mnezic (Memoria)
CODIFICAREA
STOCAREA (procesul de memorizare)
RECUPERAREA
Alzheimer
mbtrnire Depresie
Depresie
mbtrnire
SEMIOLOGIA AMNEZIILOR
Amnezia anterograd imposibilitatea sau diminuarea capacitii de a reine informaii actuale, noi, aprute dup instalarea tulburrilor mnezice
Amnezia retrograd- corespunde imposibilitii evocrii amintirilor dobndite nainte de instalarea acut sau progresiv a tulburrilor de memorie
Amnezia lacunar - desemneaz o perioad de via a subiectului, care n-a lsat nici o urm n memoria sa.
Confabulaiile - rspunsuri verbale eronate referitoare la rememorarea amintirilor recente sau din trecut
SEMIOLOGIA AMNEZIILOR
Sindromul Korsakoff i amneziile axiale - tulburare sever a memoriei cu confabulaii i recunoateri false asociate cu polineuropatie consecutiv unei carene de tiamin la alcoolici denutrii. Asemenea tulburri mnezice se mai constat la subieci cu afeciuni bilaterale ale structurilor limbice sau ale regiunii diencefalice.
(exemplu clinic)
Amneziile lacunare- ca regul, sunt consecina unei pierderi a contiinei sau a unei perioade de confuzie mental: pe parcursul acestei perioade nici o tras mnezic n-a fost nregistrat. Exist o ntrerupere n biografia bolnavului
Ictusul amnezic- se instaleaz brusc la subiecii de 50-70 de ani fr cauz declanatoare precis, dureaz 6-8 ore i nu las alte sechele dect o amnezie lacunar
Amneziile globale se nregistreaz n cadrul diferitelor forme de demen, atunci cnd tulburrile mnezice nu sunt dect un aspect al unei deteriorri mai vaste a funciilor intelectuale.
Sindromul demenial : DSM IV
Apariia diverselor deficite cognitive multiple
Altrerea memoriei pe termen scurt
Una sau mai multe tulburri cognitive ce urmeaz:
Afazie, apraxie, agnozie, tulb. funciilor executive
Alterri importante a funcionrii sociale
Declin n comparaie cu nivelul de funcionare anterior
Consecine patologice organice
Necondiionate de o stare confuziunal
Maladia Alzheimer :
definiie
Asocieri :
un sindrom demenial
Absena altor cauze
diagnosticul de prezumie, de eliminare
Maladia Alzheimer probabil sau posibil
Sunt oare leziuni cerebrale
caracteristice: DNF(degenerescen neuro-fibrilar), plci neuritice
Caz clinic
MMS Orientation :
Noter 1 point par rponse exact ; 0 si la rponse est inexacte ou en labsence de rponse.
1) En quelle anne sommes-nous ? _____
2) En quelle saison ? _____
3) En quel mois ? _____
4) Quelle est la date ? _____
5) Quel jour de la semaine sommes-nous ? _____
6) Dans quel ville nous trouvons-nous ? _____
7) Quel est le nom du dpartement ? _____
8) Dans quelle rgion sommes nous ? _____
9) Quel est le nom de lhpital (ou adresse du mdecin) ? _____
10) A quel tage sommes-nous ? _____
Mmoire immdiate (apprentissage) :
Nommez trois objets, attendez une seconde entre chaque. Demandez au patient de les rpter tous les trois. Compter 1 point
par mot correctement rpt.
11) Cigare Citron _____
12) Fleur Clef _____
13) Porte Ballon _____
Rpter jusqu ce que les 3 mots soient appris, noter le nombre dessai.
Attention et calcul mental :
Le patient doit soustraire 7 de 100, arrter aprs 5 soustractions. Compter 1 point par soustraction correcte. En cas
derreur, demander tes-vous sr ? et compter 1 point si la rponse est bonne ;
14) 100-7 _____
15) 93-7 _____
16) 86-7 _____
17) 79-7 _____
18) 72-7 _____
Pouvez-vous peler le mot monde lenvers (preuve obligatoire mais non cote).
MMS Mmoire court terme :
Vous souvenez-vous des trois mots que vous avez rpts tout lheure ? Compter 1 point par mot rpt.
19) Cigare Citron _____
20) Fleur Clef _____
21) Porte Ballon _____
Langage :
22) Dnommer un crayon en prsentant lobjet (rponse juste = 1 point) _____
23) Dnommer une montre en prsentant lobjet (rponse juste = 1 point) _____
24) Rptez : Il ny a pas de mais, de si, ni de et. _____
Faire excuter un ordre triple :
25) Prenez ce papier dans la main droite _____
26) Pliez-le en 2 _____
27) Jetez-le par terre. _____
Notez 1 point par item soulign correct.
28) Faites ce qui est marqu fermez les yeux (1 point si lordre est effectu). _____
29) Copiez ce dessin sur une feuille _____
30) Ecrivez-moi une phrase, ce que vous voulez, mais une phrase entire. _____
(compter 1 point pour une phrase comprenant au moins un verbe, un sujet, un complment, smantiquement correcte,
grammaire et orthographe indiffrentes).
Score total sur 30 :
Toutes les cases doivent tre remplies
MMS
Prob cognitiv global Examen de depistare i supraveghere Facil i rapid la utilizare De luat n calcul nivelul socio- cultural
30 - 28 normal sau MCI sau MA n debut 26/24>MMS>20 demen leger 19>MMS>10 demen moderat
Neuropsihologie: ntrebri majore
1. Afazia. Definiie. Deosebirea de disartrie
2. Agnozia. Tipurile de agnozie. Prosopagnozia
3. Definiia apraxiei i formele ei clinice
4. Sindromul lobului frontal
5. Sensory Neglect Syndrome. Definiie
6. Alte manifestri clinice n leziunea lobului parietal
7. Leziunea lobului temporal - manifetri clinice
8. Lobul occipital - semnele de leziune
9. Demena. Definiie.
10. Maladia Alzheimer i demena vascular
MEMORIA.
Memoria (M) este capacitatea organismelor vii de a obine, de a reine i de a utiliza un ansamblu de cunotine sau de informaii.
Memoria pe termen scurt (memoria imediat sau primar) se refer la un sistem, ce menine informaii temporar (de ordinul unui minut), nainte ca aceasta s fie transformat sub o form mai durabil n memoria pe termen lung (memoria secundar). Memoria imediat are o capacitate limitat la 7 cifre sau fenomene prezentate auditiv sau vizual. Fiind efemer, memoria imediat nu poate fi suportul memoriei de lucru (a reine temporar numrul unui telefon), dect ccu preul unui efort de atenie.
Memoria de lung termen se refer la achiziii durabile, accesibile la o reamintire contient (memoria declarativ sau explicit)sau ce in de nsuirea procedurilor tehnice i cognitive (memoria procedural sau implicit). Memoria explicit poate fi explorat prin intermediul ntrebrilor relativ la cunotine didactice i evenimente ale trecutului. Printre aceste achiziii unele se refer la o circumstan definit a vieii subiectului i evocarea lor se produce n context specific (memoria epizodic). Altele aparin fondului cultural i condiiile nsuirii lor au fost uitate (memoria semantic).
DR. CARL WERNICKE
(1848-1904)
Wernicke was born in Tarnovitz, Poland but his family moved to Germany where he received all his education.
Interested in psychiatry, traditionally he studied anatomy initially and neuropathology later. He published a small volume on aphasia which vaulted him into international
fame. In it was precise pathoanatomic analysis paralleling the clinical picture. He is best known for his work on
sensory aphasia and poliomyelitis hemorrhagia superior. Both of these descriptions bear his name. Further, his books on the disorders of the internal capsule and his
textbooks on diseases of the nervous system perpetuate him.
Wernicke's drawing of Motor and Sensory Speech areas
Frontal Lobe Damage
Cognitive Impairments Following Frontal Lobe Damage.
Milner & Petrides (1984) reviewed the effects of frontal lobe damage in humans and concluded that the following behaviours were impaired:
Temporal sequencing: i.e the ability to say which of 2 pictures had been presented most recently.
Shifting of attention: there is an increased tendency to persevere with an action when it is obviously incorrect (perseveration).
Conditional associations: the ability to associate a correct response with a particular stimulus.
Working memory: the ability to maintain a response in memory and then act upon it appropriately.
Previous slide Next slide Back to first slide View graphic version
Understanding words
When you listen to (or read) words, you are using a part of your brain known as Wernicke's area. It was named after the German doctor Carl Wernicke, who first realised that speaking and understanding words were controlled by different parts of the brain. He described patients who couldn't understand speech. Although they could speak words clearly, they made no sense. They had damage to the left temporal cortex of their brains.
Wernicke's area (arrowed) is needed to understand language.
Keith Johnson, Harvard University
DR. CARL WERNICKE (1848-1904)
Wernicke was born in Tarnovitz, Poland but his family moved to Germany where he received all his education. Interested in psychiatry, traditionally he studied anatomy initially and neuropathology later. He published a small volume on aphasia which vaulted him into international fame. In it was precise pathoanatomic analysis paralleling the clinical picture. He is best known for his work on sensory aphasia and poliomyelitis hemorrhagia superior. Both of these descriptions bear his name. Further, his books on the disorders of the internal capsule and his textbooks on diseases of the nervous system perpetuate him. Wernicke's drawing of Motor and Sensory Speech areas
Petite Biographie : Fils d'un chirurgien des armes impriales, il est n Sainte-Foy-la-Grande le 28 juin 1824. C'est Paris qu'il fera ses tudes de mdecine. Titulaire du Doctorat en avril 1849, il mnera alors de front deux carrires accomplies au prix d'un travail forcen : Chirurgien, chercheur, il participe ce grand mouvement scientifique du XIXme Sicle. Reconnu par ses pairs, il cumulera alors les charges, les honneurs. Membre de l'Acadmie de Mdecine en 1866, il est le fondateur de l'Anthropologie moderne, vaste science volutive. Il crera en 1868, le Muse et le laboratoire d'Anthropologie de l'cole des Hautes-tudes Paris. Mettant ses pas dans ceux de Pierre Gratiolet, son an (1815-1865) et concitoyen, il prononcera son loge funbre trs touchant (cf. Archives Municipales de Sainte-Foy) et comme lui ses travaux sur les localisations crbrales, illustrent le savant (voir croquis).
Rpublicain ardent, il est lu snateur en 1880. Courte vie politique hlas, car il dcde le 8 juillet 1880 de faon foudroyante. La science perd alors un Grand Homme.
______________________
Dfinition : Zone et Aphasie de Broca, Il existe une zone dans le lobe frontal de l'hmisphre gauche, appele la zone de Broca.
Elle est situe ct de la rgion qui contrle le mouvement de certains muscles faciaux: ceux de la langue, des mchoires et de la gorge. Si cette zone est dtruite, des difficults mettre des sons spcifiques en rsulteront. On est alors dans l'incapacit d'effectuer de faon adquate, les mouvements de la langue ou des muscles faciaux pour produire des mots. La personne est encore capable de lire et de comprendre les mots mais prouve de la difficult crire (la formation de lettres ou de mots ne se fait pas sur les lignes). Ce problme est appel aphasie de Broca.
Sainte-Foy-la-Grande : La Place Broca et sa statue avant qu'elle ne soit dboulonne par les allemands durant la guerre.
La ville bastide de Sainte-Foy-
la-Grande, porte du Prigord, est btie en bordure de la Dordogne, aux confins de trois
dpartements: la Gironde, la Dordogne et le Lot-et-Garonne.
Elle occupe une plaine
verdoyante entoure de coteaux, premiers versants o dj s'tirent les ceps de vigne...
Paul Pierre Broca (1824 - 1880)
Petite Biographie : Fils d'un chirurgien des armes impriales, il est n Sainte-Foy-la-Grande le 28 juin 1824. C'est Paris qu'il fera ses tudes de mdecine. Titulaire du Doctorat en avril 1849, il mnera alors de front deux carrires accomplies au prix d'un travail forcen : Chirurgien, chercheur, il participe ce grand mouvement scientifique du XIXme Sicle. Reconnu par ses pairs, il cumulera alors les charges, les honneurs. Membre de l'Acadmie de Mdecine en 1866, il est le fondateur de l'Anthropologie moderne, vaste science volutive. Il crera en 1868, le Muse et le laboratoire d'Anthropologie de l'cole des Hautes-tudes Paris. Mettant ses pas dans ceux de Pierre Gratiolet, son an (1815-1865) et concitoyen, il prononcera son loge funbre trs touchant (cf. Archives Municipales de Sainte-Foy) et comme lui ses travaux sur les localisations crbrales, illustrent le savant (voir croquis).
Rpublicain ardent, il est lu snateur en 1880. Courte vie politique hlas, car il dcde le 8 juillet 1880 de faon foudroyante. La science perd alors un Grand Homme.
Hemispheric Specialization
The two hemispheres of the cerebral cortex are linked by the corpus callosum, through which they communicate and
coordinate. Nevertheless, they appear to have some separate
functions. The right hemisphere of the cortex excels at
nonverbal and spatial tasks, whereas the left hemisphere is
usually more dominant in verbal tasks such as speaking and
writing. The right hemisphere controls the left side of the
body, and the left hemisphere controls the right side.
When split-brain patients stare at the "X" in the center of the
screen, visual information projected on the right side of the
screen goes to the patient's left hemisphere, which controls
language. When asked what they see, patients can reply
correctly.
When split-brain patients stare at the "X" in the center of the screen, visual
information projected on the left side of the screen goes to the patient's right
hemisphere, which does not control language. When asked what they see,
patients cannot name the object but can pick it out by touch with the left
hand.
The left frontal lobe (colored regions at left) supports our ability to retrieve the meaning of words and objects. (Courtesy of Prof. Anthony Wagner.)
Highlights of this Course
This course features selected lecture notes associated with lecture content and readings. The assignments give students the opportunitiy to delve into the course's subject matter by writing research proposals and delivering class presentations.
Course Description
Surveys the literature on the cognitive and neural organization of human memory and learning. Includes consideration of working memory and executive control, episodic and semantic memory, and implicit forms of memory. Emphasizes integration of cognitive theory with recent insights from functional neuroimaging (e.g., fMRI and PET). Staff
Instructor: Prof. Anthony Wagner Course Meeting Times
The Forebrain.
The forebrain consists of the two cerebral hemispheres.
Each hemisphere receives sensory information from the opposite (contralateral) side of the body, and controls the muscles on the contralateral side of the body.
The outer cellular layer of the hemispheres is called 'cortex' and consists of gray matter, axons descend from the cortex to form 'white matter'.
Hubel & Wiesel (1979): the cortex contains around 50-100 billion neurons, unfolded it would occupy an area of 2000cm
Neurons in one hemisphere communicate with corresponding areas of the other hemisphere via two fibre pathways: the corpus callosum, and the anterior commissure.
Key Features of the Forebrain.
White matter
Grey matter
Corpus callosum
Lateral ventricle
Anterior commissure
Central sulcus
Longitudinal fissure
Key Features of the Forebrain.
White matter
Grey matter
Corpus callosum
Lateral ventricle
Anterior commissure
Central sulcus
Longitudinal fissure
Examples of Laminar Differences.
Layer IV contains small cells that receive sensory information and this layer is prominent in cortical regions which process sensory information.
Layer IV is absent in brain regions that control movement.
It is thicker in the visual cortex of people with photographic memories, and in the auditory cortex of musicians (Scheibel, 1984).
Layer V contains large pyramidal cells which are responsible for motor control.
Such cells predominate in areas of motor cortex.
Mapping the Cortex
Maps have been developed of cortical subregions based upon differences in cell density, cell shape, size, and connectivity.
Divisions based upon structural criteria define functional zones such as specialised areas for touch, perception and even distinct cognitive processes.
Columnar Organisation.
Cells that perform similar functions are organised into collumns each around 3mm deep, arranged perpendicular to the laminae.
E.g. if a single cell within a column responds to touch on the palm of the left hand, then other cells within the same column will also respond to that stimulus.
Mountcastle (1979) referred to these columns as 'macrocolumns' and estimated that around a million of them existed in human cerebral cortex.
These can be further subdivided into 'minicolumns' and there are an estimated half a billion of them.
1. Frontal Lobes.
These extend from the central sulcus to cover the anterior portion of the brain.
They contain:
Primary motor cortex (area 4).
Premotor cortex (area 6).
Broca's area (area 44).
Prefrontal cortex.
Each receives input from the thalamic nuclei, limbic system, hypothalamus, and the other lobes, making it a 'control centre'.
Damage to the frontal part of the brain is thus likely to affect behaviour
Motor Cortex
Damage to the motor areas (4 and 6) produce a range of impairments to the motor system including:
Loss of fine motor control.
Reduction in strength.
Interruption of open-loop motor programmes (sequences of fast muscle actions (e.g typing, piano playing, speech).
This area also controls fine movements of the facial muscles, patients with frontal lobe damage show relatively little spontaneous facial expression (Kolb & Whishaw, 1990).
Broca's Area.
In 1861 Broca reported the case of a man who
had lost the power of speech (though he could
could still make speech noises and understand
speech).
At autopsy the damage was found to be localised
to a specific region on the left hemisphere of
frontal cortex.
This impairment is now referred to as Broca's
aphasia and is characterised by slow, deliberate
speech with a very simple grammatical structure.
Role of Prefrontal Cortex.
A key role of prefrontal cortex concerns working memory - the ability to retain pieces of information for short periods of time (Goldman-Rakic, 1984).
Brain imaging studies, case studies of brain-damaged humans, single-cell recordings confirm that this region is extremely active during delayed response tasks.
Prefrontal cortex is also involved in higher-order cognitive behaviours:
Planning.
Organisation.
Monitoring events, their outcomes, and the emotional value of such actions (Tucker et al., 1995).
Cognitive Impairments Following Frontal Lobe Damage.
Milner & Petrides (1984) reviewed the effects of frontal lobe damage in humans and concluded that the following behaviours were impaired:
Temporal sequencing: i.e the ability to say which of 2 pictures had been presented most recently.
Shifting of attention: there is an increased tendency to persevere with an action when it is obviously incorrect (perseveration).
Conditional associations: the ability to associate a correct response with a particular stimulus.
Working memory: the ability to maintain a response in memory and then act upon it appropriately.
Parietal Lobes
Damage to the Parietal Lobes.
Damage here produces deficits in tactile function, disorders of body image, right-left confusion, and disorders of spatial ability (Kolb & Whishaw, 1990).
A common feature is sensory neglect, the tendency to ignore one side of the body or features of the outside world.
target
Patients response
The Binding Problem.
We perceive an integrated world despite the fact that neural processing is conducted by distinct (but interconnected) modules.
How are separate functions integrated?
As yet this remains a mystery but Robertson et al., (1997) proposed that regions of parietal cortex may serve to combine different aspects of information to form a coherent whole.
This theory is based upon individuals with brain damage to parietal cortex who can no longer bind together different aspects of perception.
Frontal Lobe - Front part of the brain; involved in planning, organizing, problem solving, selective attention, personality and a variety of "higher cognitive functions" including behavior and emotions.
The anterior (front) portion of the frontal lobe is called the prefrontal cortex. It is very important for the "higher cognitive functions" and the determination of the personality.
The posterior (back) of the frontal lobe consists of the premotor and motor areas. Nerve cells that produce movement are located in the motor areas. The premotor areas serve to modify movements.
The frontal lobe is divided from the parietal lobe by the central culcus
Parietal Lobes
Damage to the Parietal Lobes.
Damage here produces deficits in tactile function, disorders of body image, right-left confusion, and disorders of spatial ability (Kolb & Whishaw, 1990).
A common feature is sensory neglect, the tendency to ignore one side of the body or features of the outside world.
target
Patients response
The Binding Problem.
We perceive an integrated world despite the fact that neural processing is conducted by distinct (but interconnected) modules.
How are separate functions integrated?
As yet this remains a mystery but Robertson et al., (1997) proposed that regions of parietal cortex may serve to combine different aspects of information to form a coherent whole.
This theory is based upon individuals with brain damage to parietal cortex who can no longer bind together different aspects of perception.
Neuropsihologia clinic
Prof. Ion V. Moldovanu
Catedra de Neurologie
Universitatea de Medicin i Farmacie N.Testemitanu