Brain Structure Notes PDF

S t r u c t u re o f t h e b r ai n : 1 B r a in s t e m M e d u lla P o n s...

S t r u c t u re o f t h e b r ai n : 1 B r a in s t e m M e d u lla P o n s M id b r i n ↓ b ↓ C e n te r o f : C o n t r o l : P a r t i c ip a t e in : C a r d io v a s c u la r f e c ia l e x p r e s s io n v is io n S e n s a t io n s H e a r in g R e s p ir a tor y B o d y e r a ilib r u m m o t o r c on t r ol c o u g h in g / s w a l l o w i n g / P o s t u r e S le e p - w a k e c y c l e v o m i t in g c o n s c io u s n e s s 2 C e r e b e llu m R e s p o n s ib le for : C o o r d in a t in g - E x c u t in g m o v e m e n t s - P la n n in g - B a la n c e , P o s t u r e - le a r n m o t or s k ills 3 3 r d or d e r n e u r on ↳ m e la t o n i n p r o d u c t io n I n c e re b r a l c o rt e x B r o c a 's a r e a G e n e r a t io n o f s p o k e n w or d W e r n i c k 's a r e a c o m p r e h e n s io n I n n e r s t a n d in g o f S p e e c h  ↳ A l l b lo o d v e s s e ls , c r a n ia l n e r v e s. ( v o lu n t a r y ) P y r am id a l ( m o tor ) t r ac t C o r t ic o s p i n a l t r a c t C o r t i c o b u lb a r P ath w ay S t a r t s from t h e P a r a c e n t r a l ( u p p e r C e n t r a l n e u r o n s) C o n d u c t im p u l s e f r o m b r a in t o C N D e c u s a t e in t h e in t e r n a l c a p s u l e ( a n t e r i o r 2 1 3 o r P o s t e r io r lim b ) - C o n t r o l f a c i a l, n e c k m u s c le s T w o t y p es b a s e d o n d e c u s s a t io n - o n ly n e r v e s c o n t r o ll in g m u s c le s s o f L a t e r a l c o r t ic o s p i n a l t r a c t A n t e r io r c o r t i c o s p i n a l t r a c t lo w e r f ac e d e c u s s a t e R e s o n s ib le f o r R e s p o n s i b le fo r - U n ila t e r a l d a m a g e o n ly in lo w e r in e - m o tor m ov e m e n t G r os s, Pos t u r a l m o v em e n t o f fa c e 8 5 % d e c o u s a t e in t r u n k - P s e u d o b u lb a r P a ls y it is in a b i lit y m e d u lla r y P y r a m id s 1 5 % d o n o t d e c u s s a t e t o c o n t r o l f a c i a l m u s c le s t h e y d e c u s s a t e a t s p i n a l le v e l C N V , V , X I , X b t h e y in n e r v a t e c h e w in g N e c k m is t o n g u e T h row a n te r ior h or n s A n t e r io r r o o t s C N V I ( lo w e r h a lf o r t h e f a c e d , C N X I N M J T h e s e U P M N r e c e iv e in f o r m a t io n f r o m t h e c o n t r a la t e r a l C e r e b r a l c o r t e x  4 L e s s io n s o r t h e m o t o r t r a c t 1 - M o n o p le g ia → le s s i o n a t t h e Par a c e n tr a l g y r u s 2 - C o n t r a la t e r a l h e m ip l e g ia → le s s i o n a t i n t e r n a l c a p s u le 3 - I p s ila t e r a l P le g i a → le s s i o n a t c o r t ic o s p in a l 4 - P e r ip h e r a l P a r a l y s i s → le s s i o n a t a n t e r i o r h o r n s R e f le x e s B ic e p B r a c h io r a d ia ls T r ic e p s k n e e A c h il le s r e f le x C b , C b C F , C S C S , C 8 1 2 - 4 S t, 5 2 S p in a l le s io n f r om C 1 - C A t e t r a p l a s ia , U P P e r a n d lo w e r l i m b s , U M N e f f ec t E x t r a P r a m e d ia l t r a c t s : C o n t r o l r e f l e x e s , lo c o m o t in , c o m p le x m o v e m e n t , P os t u r e 4 T r a c t s R u b r o s p in a l L a t e r a l v e s t i b u le s p i n a l t r a c t R e t ic u lo s p i n a l T e c to s p in a l t r a c t t r a c t t e r m in a t e s i n C e r v ic a l s p in a l c o r d T P s ila t e r a l m o t o r lo c o m o t io n , P o s t u r e c o n t r o ls n e c k m u s c le s A c t e v a t e s f le x o r m u s c le s n e u r o n s in s p in a l c o r d M o d u la t e s P a in I n h i b it s e x t e n s o r m u s c le s - A c t iv a t e s e x t e n s o r D a m a g a t / j u s t b e lo w R e s o n s e t o f c o r t ic o s p i n a l t r a c t is d a m a g e d n h ib it s f le x o r s le v e l o f r e d n u c le u s c a u se v is u a l a n d + I t a k e t h e le a d - R e c ie v e in p u t f r o m D e c e r b a t io n u n o p p os e d a u d i t o r y r e f le x D a m a g e = s lo w n e s s o r m o v e m e n t c e r e b e l lu m e x t e n s i o n o r h e a d , lim b s P o n t i n e ( m e d ia l) A n t i g r a v it y e x t e n sor m u s c le s M e d u l la r y ( l a t e r a l) I n h ib it s e x c it a t o r y a x ia l e x t e n so r s  D a m a g e b e f o r e d e c u s s a t io n C o n t r a la t e r a l D a m a g e a f t e r d e c u ssa tio n I p s ila t e r a l C e r e b e llu m d y s f u n c t io n D y s d ia d o c h K i n e s i a. d y s m e t r e a A t a x ia N y s t agm u s I n t e n s io n t r e m o r S lu r e d s p e e c h t y p o t o n ia T y p e s o f S e n s a t io n S u p e r f ic ia l D e e p C o m p le x T h e r m o r e c e p t o r s F in e t o u c h G r a p h e s t a s ia N o c ir e c e p t o r s ( P a in ) P re s s u r e S t e r e o g n o s is M u s c le t o n e T w o P o i n t d is c r e m in a t i o n M u s c le j o in t s e n s a t i o n  S o m a t o s e n s or y P a t h w a y s M e d i a l le m n is c a l ( P o s t e r i o r ) S p i n o t h a la m i c ( A n t e r o la t e r a l) Pa t h w ay P at h w a y F in e t o u c h ( m e c h a n o r e c e p t o r s , S u p e r f ic i a l ( P a in , t e m p , c r u d e t o u c h ) p r o p r io c e p t io n I s to r d e r d o r s a l r o o t g a n g l io n 1 s t o r d e r n e u r on in d o r s a l r o o t g a n g li o n 2 n d o r d e r d e c ons a t e d e v id e in t o 2 n d or d e r n e u r on ( c u r a t e o r G r a c il is ) d e c o n s a t e L a t er a l t r a c t P a in , t e m p , P r e s s u r e u n e a t e f a s ic le f o r a r m s , c h e s t A n t er ior t r a ct c r u d e t o u c h G r a c ilis ← f or t r u n k , L e g s 3 r d o r d e r n e u r o n in t h a la m u s 3 r d o r d e r n e u r on t h la m u s I n t e r n a l c a p s u le ( P o s t e r i o r 1 1 3 of P o s te r ior l im b ) P o s t c e n t r a l g y r u s R a d ia l n e r v e d a m a g e = w r is t d r op S c ia t i c s - s ig n - L a s e g u e t e s t ib i a l n e r v e d am a g e = L e g m u s c le P a r a ly s i s ( c a n n o t f le x ) P e ron e a l n e r v e d a m a g e - f o o t d rop ( c an n o t e x t e n d) c r a n ia l n e r v e s S e n s or y C N = 1 , 2 , 8 M ot o r C N = 4 , 6 , 1 1 ,1 2 M ix e d C N = 3 , 5,7 , 9 ,1 0 O lf a c t o r y n e r v e C N I = A n s o n ia ( a b s e n c e o r s m e l l f u n c t io n ) o p t ic n e r v e C N I - T e m p o r a l ( la t e r a l) r e t in a d on t c r o s s ( N a s a l v is io n f ie ld ) N a s a l ( m e d ia l) r e t in c r o s s in o p t i c c h ia s m ( t e m p o r a l v i s i o n f i e ld ) A n o p ia - f u l l v i s io n lo s s le s s io n in o p t ic n e r v e A m a u r o s is - B lin d n e s s e m ia n o p i a - P a r t i a l v is io n lo s s h e t r o m o n u s ( d is t e r e n s i d e o f e y e s) h om on y m ou s ( s a m e s id e o f e y e s , H e t e r on o m o u s H e m a n o p ia 1 - B it e m p o r a l h e m ia n o p i a → le s s i o n in m e d ia l P a r t o f c h ia s m a , H y p o p h y s i s t u m o r a d e n o m a 2 - B in a s a l h e m ia n o p i a → le s s io n in la t e r a l P a r t o f c h ia s m a H o m o n y m o u s H e m ia n o p sia → le s s io n in o p t ic t r a c t Q u a r t e r H e m ia n o p i a → u p p er e y e s , lo w e r e y e s C r o s s D o n t V e s t i b u lo c h o le. a t n e r v e C N V I S y m p t o m s H e a r lo s s ( A n a k u s is ) v e s t i b u la r a t a x ia ty p e s o f a t a x ia C e r e b e ll a r , V e s t ib u la r , S e n s i t iv e P o ly n e u r o p a t h y ( G l o v e s a n d s o c k s s y n d r om e ) lo s s o f s e n s a t io n in d is t a l l i m b s , lo w r e f le x e s a n d m u s c le t o n e M u s c le a t rop h y , d u e t o D B o r in f e c t i o n....  B r o w n s e r u ar d s y n d r om e : - D a m a g e t o o n e h a lf o f t h e s p in a l s e g m e n t S a m e s id e d a m a g e lo s s d e e p s e n s or y -m otor n e r v e s O p p o s it e s id e s u p e r f ic ia l s e n s o r y f o r u p p er lim b  O c c u lo m o t o r C N II M o t o r f u n c t io n : L R 6 , 5 0 4 , A T R } S e n s o r y ( P a r a s y m p a t h e t ic ) f u n c t io n : c i l i a r y m u s c le c o n t r o l le n s s s h a p e M io s i s L e s s io n s : L a t e r a l s q u in t ( 2 * 0 3 ) D IP LO P I A P t o s is E x o p h t h a lm o s O c u lo m o t o r n e r v e P a ls y s y m p tom s : M y d r ia s is , a c c o m i d a t io n P t o s is D IP L O P I A S t r a b is m u s ( e y e m is a lig n m e n t ) r o c h le a r n e r v e C N I V M o t or S o n L e s s io n : D ip l o p ia w h e n lo o k in g d o w n A b d u c e n s n e r v e C N V I M o to r L R G L e s s io n : M e d i a l s q u in t & * D ) tr ig e m in a l n e r v e C N V M o tor M a s t ic a t io n m u s c le s ( 3 r d b r a n c h ) S e n s o r y F a c e , o r a l c a v it y ( A ll b r a n c h e s , e s t in g m o t o r f u n c t io n J a w je r k , c o r n e a l r e f le x ( N o r e f le x - C N V / V I d y s f u n c t io n ) e s t in g s e n s o r y s a n c t io n P r e s s t h e P o i n t w h e r e 's b r an c h e s c om e o u t Facial nerve CNVII Motor Facial expressions Parasympathetic effects Lacrimal gland, submandibular gland, sublingual gland sensory Anterior ⅔ of tongue Lession: Full ipsilateral staint (facial nerve lesion, Bell's Palsy upperand lower face are denervated Partial contralateral Staint (supranuclear lession) Upper face wear, Lower race is denervated * to know which nerve caused diplopia Double vision occurs when the Patient moves his eyes toward the affected muscle torner syndrome: - Oculosympathetic Pathway is disrupted Symptoms: Sympathetic fibers Ptosis Anhydrosis Miosis Enophthalmos Argyll robertoson Pupil: Loss of light reflex response Triangle Pupil Post syphilis OPhtalmoplegia: Loss of innervation in CN III IV VI Damage to Glossopharyngeal nerve CNIX and CNX Hoarse voice CNIX, ✗ are examinated together Motor function Swallow, Raise uvula, Gag reflex Sensory function Taste on Posterior ⅓ of tongue Accessory nerve CNXI: Motor Sternocleido mastoid ms, Trapezius ms Damage Uneaven shoulders, winged scapula Hypoglossal Nerve CNXII Motor longue muscles except Palatoglossus Damage: Central Contralateral tongue deviation tongue will Push away from the lession side Peripheral ⟂ Psilateral tongue deviation and hypertrophy tongue will Push toward lession site atrophy/fibrillation will occur Symptoms will include: Dysarthria (slurred speech), Dyspnea, Dysphagia cortex hypoglossal nucleus Right supranuclear Palsy medulla Tongue will Push to the other side away from lession side LLMN Palsy At nedens level or lower Pushing to the R L same side Pseudo bulbar Palsy (central): - Due to bilateral cortico nuclear Pathway CUMNI damage in both sides - V, VIT IX, X, X I, ✗ T UMN lession signs - Gag reflex increased - Tongue is spastic - Jaw jerk increased - Dysarthria (Speech disorder) - Emotional liability (highly emotional) - contralateral tongue deviation Bulbar Palsy (Peripheral) - Due to LMN damage - K, X, XI - Lun lession signs -jaw jerk absent -Speech is nasal - Normal emotion - Aphagia dysphagia - Ipsilateral tongue deviation Abdominal reflexes - upper +7-+8 - Middle +9-+10 - Lower +11-+12 Alternating syndromes: - Due to damage to half of the stem, causing dysfunction of a cranial nerve nucleus + Corticospinal Pathways, Ipsilateral cranial nerves BUT contralateral Palsy in corticospin Broca's aphasia Impaired speech formation Wernicke's aphasia Impaired speech understanding Aphagia Inability to swallow (central damage) D y s a r t h r ia S lo w S p e e c h P e r ip h e r a l d a m a g e A n o m ic a p h a s ia c a n n o t n am e object s A u t o t o p a g n o s is I n a b il i t y t o lo c a li z e a n d o r ie n t d i f f e r e n t P a r t s o f t h e b o d y J a c k s o n ia n m ar c h F o c a l S e iz u r e s M e n in g e a l s y n d rom e : D u e t o m e n i n g i t is , s u b a r a c h n o id a l h e m o r r h a g e , t u m o r s S y m p t o m s in c lu d e N u c h a l r ig i d it y s t if f n e s s K e r n ig ' s s ig n P a in w h e n e x t e n d in g t h e k n e e B r u d z in s k i ' s s ig n N e c k f le x io n le a d s t o k n e e f l e x io n