Basal Ganglia (traditional concept)Basal Ganglia (traditional concept)

Corpus striatum

lenticular nucleus

putamen

globus pallidus

caudate nucleus

Amygdaloid body

Corpus striatum

lenticular nucleus

putamen

globus pallidus

caudate nucleus

Amygdaloid body

Basal GangliaBasal Ganglia

12

3

12

43

Basal GangliaBasal Ganglia

1 23

12

3

Traditional Concepts of Basal GangliaTraditional Concepts of Basal Ganglia

Corpus StriatumCorpus Striatum

Caudate NucleusCaudate Nucleus

Lenticular Nucleus PutamenLenticular Nucleus Putamen

Globus Pallidus Paleostriatum PallidumGlobus Pallidus Paleostriatum Pallidum

Corpus Amygdaloideum ArchistriatumCorpus Amygdaloideum Archistriatum

Neostriatum StriatumNeostriatum Striatum

Basal Ganglia Basal Ganglia

Introduction Introduction

Basal Ganglia Basal Ganglia

Introduction Introduction

1. Putamen1. Putamen2. Tail of caudate nucleus2. Tail of caudate nucleus3. Caudatolenticular gray 3. Caudatolenticular gray

bridgebridge4. Amygdaloid body4. Amygdaloid body5. thalamus5. thalamus

Lateral surface Lateral surface of basal gangliaof basal ganglia

Input Portion Input Portion

STRIATUM STRIATUM

(Caudate Nucleus and Putamen)(Caudate Nucleus and Putamen)

Output PortionOutput Portion

1. 1. PALLIDUM PALLIDUM (Globus Pallidus)(Globus Pallidus)

2. 2. SNr SNr (Substantia Nigra, Pars Reticulata)(Substantia Nigra, Pars Reticulata)

Basal Ganglia

Connections

Basal Ganglia

Connections

STRIATUMSTRIATUM

Afferents fromAfferents from 1. 1. Cerebral Cortex Cerebral Cortex [Corticostriatal Projection][Corticostriatal Projection] 2. 2. ThalamusThalamus (CM-PF complex) [Thalamostriatal Projection] (CM-PF complex) [Thalamostriatal Projection] 3. 3. SNcSNc (Substantia Nigra, pars compacta), (Substantia Nigra, pars compacta), Ventral Tegmental Area (VTA, AVentral Tegmental Area (VTA, A1010) )

and Aand A88(Retrorubral Area) [Nigrostriatal Projection](Retrorubral Area) [Nigrostriatal Projection]

4. Dorsal Raphe Nucleus (B4. Dorsal Raphe Nucleus (B66, B, B88) [Raphestriatal Projection]) [Raphestriatal Projection]

5. Amygdaloid Nuclear Complex [Amygdalostriatal Projection]5. Amygdaloid Nuclear Complex [Amygdalostriatal Projection]

Efferents toEfferents to 1. 1. Pallidum (GPi & GPe) Pallidum (GPi & GPe) [Striopallidal Projection][Striopallidal Projection] 2. 2. SNrSNr [Strionigral Projection] [Strionigral Projection] 3. 3. SNcSNc from striosome from striosome

Basal Ganglia

Connections

Basal Ganglia

Connections

An oblique section through the diencephalon and basal ganglia. Abbreviations: A8, 9, 10, dopaminergic cell groups; AL, ansa lenticularis; CL, centrolateral nucleus of thalamus; cm, centromedian nucleus of thalamus; EX, external pallidal segment; FS, fasciculus subthalamicus; H, H1, H2, subthalamic fields of Forel; ICV, internal cerebral veins in the transverse fissure; INT, internal pallidal segment; ITA, interthalamic adhesion; MFB, median forebrain bundle; SLIC, sublentiform internal capsule; 3, 3rd ventricle.

Connections of the striatum. The major afferent projections to the striatum are shown on the left and major efferent projections from the striatum on the righ

Major interconnections of the basal ganglia.

Input-OutputInput-OutputRelationshipRelationshipof Basal Gangliaof Basal Ganglia

1. striopallidal fiber1. striopallidal fiber2. strionigral fiber2. strionigral fiber3. strionigral fiber3. strionigral fiber from striosomefrom striosome to SNcto SNc4. ventrostrio-4. ventrostrio- ventro-pallidal fiberventro-pallidal fiber

PALLIDUM (Globus Pallidus)PALLIDUM (Globus Pallidus)Afferents fromAfferents from

1. 1. Striatum Striatum [Striatopallidal Projection][Striatopallidal Projection]

2. 2. STN <GPi & GPe> STN <GPi & GPe> [Subthalamopallidal Projection][Subthalamopallidal Projection]

Efferents toEfferents to

1. 1. Thalamus (VLo, VApc, CM) <GPi> Thalamus (VLo, VApc, CM) <GPi> [Pallidothalamic Projection][Pallidothalamic Projection]2. 2. STN <GPe>STN <GPe> [Pallidosubthalamic Projection] [Pallidosubthalamic Projection]

SNr (Substantia Nigra, Pars Reticulata)SNr (Substantia Nigra, Pars Reticulata)Afferents from Afferents from Striatum Striatum [Striatonigral Projection][Striatonigral Projection]

Efferents toEfferents to

1. 1. Thalamus (VLm, VAmc, MD) Thalamus (VLm, VAmc, MD) [Nigrothalamic Projection] [Nigrothalamic Projection]

2. Brain Stem Nucleus: Tectum (Superior Colliculus) &2. Brain Stem Nucleus: Tectum (Superior Colliculus) &

Pedunculopontine Nucleus (PPN)Pedunculopontine Nucleus (PPN)

Basal Ganglia Connections

Basal Ganglia Connections

Pallidothalamic FibersPallidothalamic Fibers from GPi to VLo, VApc, CMfrom GPi to VLo, VApc, CM

Ansa LenticularisAnsa Lenticularis from outer (lateral) portion of GPifrom outer (lateral) portion of GPi fibers sweep ventromedially and rostrally around fibers sweep ventromedially and rostrally around the posterior limb of the internal capsulethe posterior limb of the internal capsule enters enters Forel’s field HForel’s field H

Lenticular FasciculusLenticular Fasciculus from inner (medial) portion of GPifrom inner (medial) portion of GPi perforate internal capsuleperforate internal capsule enters enters Forel’s field HForel’s field H22

Thalamic fasciculusThalamic fasciculus ansa lenticularis, lenticular fasciculusansa lenticularis, lenticular fasciculus and cerebellothalamic fibersand cerebellothalamic fibers Forel’s field HForel’s field H11

Basal Ganglia

Connections

Basal Ganglia

Connections

Basal Ganglia Basal Ganglia Functional Consideration Functional Consideration Basal Ganglia Basal Ganglia Functional Consideration Functional Consideration

Functional ConsiderationFunctional Consideration

1. 1. Selection Selection of “Preprogramed (learned) motor plans”of “Preprogramed (learned) motor plans”

Basal Gangla Circuit ---- Basal Gangla Circuit ---- Selection MechanismSelection Mechanism

Selection Inability -------- Selection Inability -------- Akinesia and HypokinesiaAkinesia and Hypokinesia

Faulty Selection ----------- Faulty Selection ----------- HyperkinesiaHyperkinesia

2. 2. Generation (learning) Generation (learning) of motor programsof motor programs

Programming of several Programming of several motor fragments motor fragments intointo

complex motor routinescomplex motor routines

Cerebral Palsy Cerebral Palsy ------------- Disordered motor program ------------- Disordered motor program

SYDENHAM’S CHOREASYDENHAM’S CHOREASYDENHAM’S CHOREASYDENHAM’S CHOREA

- Complication of- Complication of Rheumatic FeverRheumatic Fever- Fine, disorganized , and - Fine, disorganized , and random movements ofrandom movements of extremities, face andextremities, face and tonguetongue- Accompanied by - Accompanied by Muscular HypotoniaMuscular Hypotonia- Typical exaggeration of- Typical exaggeration of associated movements associated movements during voluntary activityduring voluntary activity- Usually recovers- Usually recovers spontaneously spontaneously in 1 to 4 monthsin 1 to 4 months

Clinical FeatureClinical Feature

Principal Pathologic Lesion: Principal Pathologic Lesion: Corpus StriatumCorpus Striatum

Clinical FeatureClinical Feature

Principal Pathologic Lesion:Principal Pathologic Lesion: Corpus Striatum (esp. caudate nucleus)Corpus Striatum (esp. caudate nucleus) and Cerebral Cortexand Cerebral Cortex

- Predominantly - Predominantly autosomal dominantlyautosomal dominantly inherited chronic fatal diseaseinherited chronic fatal disease (Gene: chromosome 4)(Gene: chromosome 4)- Insidious onset: Usually 40-50- Insidious onset: Usually 40-50- Choreic movements in onset- Choreic movements in onset- Frequently associated with- Frequently associated with emotional disturbancesemotional disturbances- Ultimately, grotesque gait and sever- Ultimately, grotesque gait and sever dysarthria, progressive dementiadysarthria, progressive dementia ensues.ensues.

HUNTINGTON’S CHOREAHUNTINGTON’S CHOREA

HEMIBALLISMHEMIBALLISMHEMIBALLISMHEMIBALLISM

- Usually results from CVA- Usually results from CVA (Cerebrovascular Accident)(Cerebrovascular Accident) involving subthalamic nucleusinvolving subthalamic nucleus- sudden onset- sudden onset- Violent, writhing, involuntary- Violent, writhing, involuntary movements of wide excursionmovements of wide excursion confined to one half of the bodyconfined to one half of the body- The movements are continuous- The movements are continuous and often exhausting but ceaseand often exhausting but cease during sleepduring sleep- Sometimes fatal due to exhaustion- Sometimes fatal due to exhaustion- Could be controlled by- Could be controlled by phenothiazines and stereotaxicphenothiazines and stereotaxic surgery surgery

Clinical FeatureClinical Feature

Lesion: Lesion: Subthalamic NucleusSubthalamic Nucleus

Muhammad Ali in Alanta OlympicMuhammad Ali in Alanta Olympic

Parkinson’s DiseaseParkinson’s Disease

Disease of mesostriatal Disease of mesostriatal dopaminergic systemdopaminergic system

PDPD

normalnormal

Substantia Nigra, Substantia Nigra, Pars Compacta (SNc)Pars Compacta (SNc)

DOPAminergic NeuronDOPAminergic Neuron

Slowness of MovementSlowness of Movement- Difficulty in Initiation and Cessation - Difficulty in Initiation and Cessation of Movementof Movement

Clinical Feature (1)Clinical Feature (1)

Parkinson’s Disease - Paralysis AgitansParkinson’s Disease - Paralysis Agitans

Clinical Feature (2)Clinical Feature (2)

Resting TremorResting TremorParkinsonian PostureParkinsonian PostureRigidity-Cogwheel RigidityRigidity-Cogwheel Rigidity

Parkinson’s Disease Parkinson’s Disease

Paralysis AgitansParalysis Agitans