the cerebellum 陽明大學醫學院神經學系陳昌明醫師. position lies above and behind...

The Cerebellum

陽明大學醫學院神經學系

陳昌明醫師

Position

Lies above and behind the medullar and pons and occupies posterior cranial fossa

Cerebellum

Cerebellum Cerebellum External External ConfigurationsConfigurations


• Located in Located in posterior cranial fossaposterior cranial fossa• Tentorium cerebelli (cerebrum), 4Tentorium cerebelli (cerebrum), 4thth ventricle (brain stem)ventricle (brain stem)• Communicate with other structure viaCommunicate with other structure via

•superior, middle, and inferior superior, middle, and inferior cerebellar pedunclecerebellar peduncle

External features

Consists of two cerebellar hemisphere united in the midline by the vermis

External features

Three peduncles Inferior cerebellar peduncle

下小腦脚－ connect with medulla and with spinal cord, contain both afferent and efferent fibers

Middle cerebellar peduncle 中小腦脚－ connect with pons, contain afferent fibers

Superior cerebellar peduncle 上小腦脚－ connect with midbrain, contain mostly efferent fibers

Cerebellum

Longitudinal division Vermis, Paravermal Region, Cerebellar

Hemisphere Transverse division

Anterior Lobe Posterior Lobe Flocculonodular Lobe

Lobes

Primary fissure

Posterolateral fissureFlocculonodular lobe

Anterior lobe

Posterior lobe

corpus of cerebellar

Lobes Two deep fissures

Primary fissure

Posterosuperior fissure

Three lobs

Flocculonodular lobe 絨球小結葉 flocculus and nodule

Anterior lobe

Posterior lobe

Corpus of cerebellar

External features

Tonsil of cerebellum 小腦扁桃体 two elevated masses on inferior surface of hemispheral portion just nearby foramen magnum

Tonsil

Superior surface

View from below

Functional divisions of cerebellar cortex

External featuresCerebellum & Brainstem, Inferior Surface, Anterior View

Subdivision ofSubdivision of Flocculonodular Lobe Flocculonodular Lobe

Nodulus FlocculusNodulus Flocculus

Subdivision of Subdivision of Anterior LobeAnterior Lobe

Vermis HemisphereVermis Hemisphere

LingulaLingulaCentral Lobule Central Lobule Ala Central LobuleAla Central Lobule

postcentral fissurepostcentral fissure

Culmen Culmen Quadriangular LobuleQuadriangular Lobule



Subdivision of Subdivision of Posterior LobePosterior Lobe

Vermis HemisphereVermis Hemisphere

Declive Declive Simple LobuleSimple Lobule

postcentral fissurepostcentral fissure

FoliumFolium Superior Semilunar LobuleSuperior Semilunar Lobule horizontal fissurehorizontal fissure

Inferior Semilunar LobuleInferior Semilunar Lobule Tuber Tuber Gracile LobuleGracile Lobule prepyramidal fissureprepyramidal fissure

Pyramis Pyramis Biventer LobuleBiventer Lobule

secondary fissuresecondary fissure

Uvula Uvula TonsilTonsil



Cerebellar Cortex

Molecular Layer Purkinje Cell Layer Granular Layer

Corpus Medullare (Medullary Center)

Deep Cerebellar Nuclei

Fastigial Nuclei Nucleus Interpositus Emboliform Nucleus Globose Nucleus Dentate Nucleus

Cerebellum Cerebellum Internal Internal ConfigurationsConfigurations


Internal structures Gray matter Cerebellar cortex Cerebellar nuclei

Dentate nucleus 齒狀核 Fastigial nucleus 頂核 Interposed nucleus 中間核

Emboliform nucleus 栓狀核 Globose nucleus球狀核

White matter －medullary center 髓体

1. fastigial 1. fastigial

nucleusnucleus

2. globose 2. globose

nucleusnucleus

3. emboliform 3. emboliform

nucleusnucleus

4. dentate 4. dentate

nucleusnucleus

Deep NucleiDeep Nuclei

Internal structures

Cerebellar cortex

Dentate nucleus

Fastigial nucleus

Globose nucleus

Emboliform nucleus

medullary center

Cerebellar CortexInputs

Output

Interneurons

Climbing fibers•from Inferior olive

Mossy fibers

Purkinje neurons

Stellate neurons

Granule neurons

Basket neurons

Golgi neuronsMolecular

PurkinjeGranular

NTA Fig. 13-11

Cerebellar Cortex

I. Molecular Layer

Stellate Cell --- taurine (inhibitory) afferent: parallel fiber efferent: Purkinje cell dendrite Basket Cell ---- GABA (inhibitory) afferent: parallel fiber efferent: Purkinje cell soma Parallel Fiber granule cell axon Purkinje Cell Dendrite



Cerebellar Cortex

II. Purkinje Cell Layer

Purkinje Cell -- 15,000,000 in number -- GABA (inhibitory) afferent from: parallel fiber climbing fiber stellate cell basket cell efferent to: deep cortical nuclei

Bergman’s glial cell



Cerebellar Cortex

III. Granular LayerIII. Granular Layer

Granular Cell Granular Cell -- 50,000,000,000 in number-- 50,000,000,000 in number -- glutamic acid (excitatory)-- glutamic acid (excitatory) afferent: afferent: mossy fibermossy fiber efferent: efferent: Purkinje cell dendritePurkinje cell dendrite basket cell, stellate cellbasket cell, stellate cell Golgi cellGolgi cell

Golgi CellGolgi Cell -- GABA (inhibitory)-- GABA (inhibitory) afferent: parallel fiber, mossy fiber rosetteafferent: parallel fiber, mossy fiber rosette efferent: granule cell dendriteefferent: granule cell dendrite



1. Purkinje cell

2. granule cell

3. basket cell

4. Golgi cell

5. stellate cell

6. climbing fiber

7. mossy fiber

8. parallel fiber

9. inferior olivary nucleus

10. deep cerebellar nuclei

Synaptic Glomerulus

Afferent terminals on granular layerAfferent terminals on granular layer

Mossy Fiber Rosette Mossy Fiber Rosette -- afferent fibers except-- afferent fibers except inferior olivary inputinferior olivary input -- 2/3 of medullary center-- 2/3 of medullary center

Granular Cell Dendrite Granular Cell Dendrite -- main afferent input -- main afferent input

Golgi Cell Axon Golgi Cell Axon -- synapse on granule cell dendrite-- synapse on granule cell dendrite -- GABA (inhibitory)-- GABA (inhibitory)

- - Surrounded by Surrounded by AstrocyteAstrocyte Foot Process Foot Process



Synaptic GlomerulusSynaptic Glomerulus

Classification by Phylogenetic and Ontogenic Development

ArchicerebellumArchicerebellum PaleocerebllumPaleocerebllum NeocerebellumNeocerebellum

Classification by Afferent Connection

VestibulocerebellumVestibulocerebellum SpinocerebellumSpinocerebellum PontocerebellumPontocerebellum

Classification by Efferent Connection

VermisVermis Paravermal RegionParavermal Region Cerebellar HemisphereCerebellar Hemisphere

Cerebellum Cerebellum ClassificationsClassifications

Cerebellum Cerebellum ClassificationsClassifications

Archicerebellum (nodulus)

Archicerebellum (flocculus) Paleocerebellum

Neocerebellum

Spinocerebellum

Pontocerebellum

Vestibulocerebellum

Afferent Connections (1):

1. Inferior Cerebellar Peduncle1. Inferior Cerebellar Peduncle

Restiform BodyRestiform Body Posterior Spinocerebellar TractPosterior Spinocerebellar Tract Olivocerebellar tractOlivocerebellar tract Cuneocerebellar TractCuneocerebellar Tract Reticulocerebellar TractReticulocerebellar Tract

Juxtarestiform BodyJuxtarestiform Body Vestibulocerebellar TractVestibulocerebellar Tract Primary Vestyibular FiberPrimary Vestyibular Fiber

Cerebellum Cerebellum ConnectionsConnections


Afferent Connections (2):

2. Middle Cerebellar Peduncle2. Middle Cerebellar Peduncle

Pontocerebellar fiberPontocerebellar fiber Corticopontocerebellar FiberCorticopontocerebellar Fiber Reticulocerebellar FiberReticulocerebellar Fiber

3. Superior Cerebellar Peduncle3. Superior Cerebellar Peduncle

Anterior Spinocerebellar TractAnterior Spinocerebellar Tract Cerulocerebellar fiberCerulocerebellar fiber Raphecerebellar fiberRaphecerebellar fiber Rubrocerebellar fiberRubrocerebellar fiber Hypothalamocerebellar fiberHypothalamocerebellar fiber



Efferent Connections :

1. Superior Cerebellar Peduncle

Cerebellothalamic fiber - from 3 deep nuclei to VPLo, VLc, CL Cerebellorubral fiber - from nucleus interpositus and dentate nucleus ascending portion of uncinate fasciculus of Russell 2. Inferior Cerebellar Peduncle

Fastigiovestibular fiber descending portion of uncinate fasciculus of Russell



Three functional divisions Vestibulocerebellum

前庭小腦 Archicerebellum 原小

腦 Flocculonodular lobe

Spinocerebellum 脊髓小腦 Paleocerebellum 舊小

腦 Vermis and intermediate zone

Cerebrocerebellum 大腦小腦 Neocerebellum 新小腦 Lateral zone

Flocculonodular lobe

Verm

is In

termed

iate zo

ne

Lateral

zon

e

IVth vent VermisIntermediate hem.

Spinocerebellum: Vermis Intermediate hem.Spinocerebellum

(Vermis + Intermed. Hem)

Control of limbs and trunk

Lateral hem.

Cerebrocerebellum: Lateral hem.

Cerebrocerebellum(Lateral hemisphere)

Planning of movement+

Floculo-nodular lobe

Vestibulo-cerebellum(Floculo-nodular lobe)

Control of eye & head movementsBalance

Cerebellar divisions

NTA Fig. 13-1

Connections and function of cerebellum Vestibulocerebellum

Connections Afferents: receive input from vestibular nuclei and

primary vestibular Efferents: projects to the vestibular nucleus →

(1) vestibulospinal tract → motor neurons of anterior horn for reflexively control of equilibrium

(2) vestibulo-ocular tract → medial longitudinal fasciculus → CN nucleus 3, 4, 6 for EOM control.

Function: involved in eye movements and maintain balance

MLFMLF

Main Connections of the VestibulocerebellumMain Connections of the VestibulocerebellumMain Connections of the VestibulocerebellumMain Connections of the Vestibulocerebellum

lower motor neuronlower motor neuron

LMNLMN

vestibulospinal tractvestibulospinal tract

FASTIGIALFASTIGIAL NUCLEUSNUCLEUS

VestibularVestibular OrganOrgan FloculonodularFloculonodular

LobeLobe VermisVermis

ARCHICEREBELLUMARCHICEREBELLUM

VESTIBULAR NUCLEUSVESTIBULAR NUCLEUS

Main Connections of the PaleocerebellumMain Connections of the PaleocerebellumMain Connections of the PaleocerebellumMain Connections of the Paleocerebellum


SPINAL CORDSPINAL CORD

rubrospinal rubrospinal tracttract

NUCLEUSNUCLEUSINTERPOSITUSINTERPOSITUS

InferiorInferior OlivryOlivryNucleusNucleus

ANTERIOR ANTERIOR LOBELOBEPARAVERMAL PARAVERMAL ZONEZONE

PALEOCEREBELLUMPALEOCEREBELLUM

RED RED NUCLEUSNUCLEUS

spinocerebellar tractspinocerebellar tract

Spinocerebellar tracts

End mainly in the anterior lobe, the paramedian lobule, and the pyramis of the posterior lobe

Connections and function of cerebellum

Cerebrocerebellum Connection

Afferents: receives input from the cerebral cortex via a relay in pontine nuclei

Efferents: projects to dentate nucleus → VI → primary motor cortex → corticospinal tract → motor neurons of anterior horn

Function: participates in planning movements

CEREBRALCEREBRAL CORTEXCORTEX

CEREBRALCEREBRAL CORTEXCORTEX DENTATEDENTATE

NUCLEUSNUCLEUS

DENTATEDENTATENUCLEUSNUCLEUS

Main Connections of the NeocerebellumMain Connections of the Neocerebellum


LMNLMN

pyramidal pyramidal tracttract POSTERIOR POSTERIOR

LOBELOBECEREBELLARCEREBELLAR HEMISPHEREHEMISPHERE

POSTERIOR POSTERIOR LOBELOBE

CEREBELLARCEREBELLAR HEMISPHEREHEMISPHERE

THALAMUSTHALAMUSTHALAMUSTHALAMUS

NEOCEREBELLUMNEOCEREBELLUM

PontinePontineNucleusNucleusPontinePontineNucleusNucleus

upper motor neuronupper motor neuron

UMNUMN

upper motor neuronupper motor neuron

UMNUMN

BASALBASALGANGLIAGANGLIA

BASALBASALGANGLIAGANGLIA

Pyramidal Tract and Associated CircuitsPyramidal Tract and Associated CircuitsPyramidal Tract and Associated CircuitsPyramidal Tract and Associated Circuits


UMNUMN


UMNUMN

pyramidal tractpyramidal tract

CerebellumCerebellumCerebellumCerebellum

ReticularFormation

ReticularFormation

CEREBELLUMCEREBELLUM

Cerebellum and Automatic Motor ControlCerebellum and Automatic Motor ControlCerebellum and Automatic Motor ControlCerebellum and Automatic Motor Control

Lower Motor Neuron (LMN)Lower Motor Neuron (LMN)Lower Motor Neuron (LMN)Lower Motor Neuron (LMN)

Motor CortexMotor Cortex

Red NucleusRed Nucleus

Vestibular Nucleus

Vestibular Nucleus

ProprioceptorsProprioceptorsProprioceptorsProprioceptors

Cerebellum---- connection

Corticonuclear Connections

A zone ---------- fastigial nucleus medial vestibular nucleus B zone ---------- lateral vestibular nucleus C1, C3 zone --- emboliform nucleus C2 ---------------- globose nucleus D1 ---------------- parvocellular portion of dentate nucleus D2 ---------------- magnocellular portion of dentate nucleus

1. vermis

2. paravermal region

3. cerebella hemisphere

4. nodulus

5. flocculus

6. fastigial nucleus

7. globose nucleus

8. emboliform nucleus

9. dentate nucleus

10. medial vestibular nucleus

11. lateral vestibular nucleus

Olivocerebellar Connections

(1) Caudal portion of medial and dorsal accessory olivary nucleus ----------------- vermis of cerebellar cortex (A and B) fastigial nucleus vestibular nucleus

(2) Rostral portion of medial and dorsal accessory olivary nucleus ----------------- paravermal region (C1, C2, C3) nucleus interpositus

(3) Principal Inferior Olivary Nucleus ----------------- cerebellar hemisphere (D1, D2) dentate nucleus



Olivo-cerebellar system The inferior olivary complex

Principal olive, medial and dorsal accessory olive, and medial lamina. 1.5 million cells

Send climbing fibers to all cerebellar cortex in a specific topographic manner A Small area in the inferior olive is linked to a definite area of

the cerebellar output

The inferior olivary complex Receives projections from

The spinal cord crossed ventral and dorsal spino-olivary tracts

The brainstem (esp. red nuclei) Cerebellar nuclei

Interpositus & dentate nuclei exert an inhibitory effect Pretectal nuclei

Relaying optokinetic information Cerebrum

Motor cortex (area 4), premotor cortex (area 6) Visual and Vestibular areas Zona incerta of the thalamus

Relay for the projections from the motor cortex, prefrontal, cingulate, parietal and temporal area

medial and dorsal accessory olivary nucleusmedial and dorsal accessory olivary nucleus

caudal portioncaudal portion rostral portion rostral portion Principal Principal Inferior Olivary Inferior Olivary

NucleusNucleus

Functional divisions of cerebellar cortex

VermisIntermediate hem

CerebrocerebellumLateral hemisphere

Spinocerebellum

Vestibulo-cerebellumFloculo-nodularlobe

Functional divisions of cerebellar cortex --> Deep nuclei

CerebrocerebellumLateral hemisphere

Dentate

Fastigial

To medialsysetms

To frontalmotor areas

MotorPlanning +++

Motorexecution

Vestibulo-cerebellum

To vestibular nuclei

Eye mvt &balance

Reticular nuclei

Lateral reticular nuclei (lateral to inferior olive) Sent mossy fibers to bilateral cerebellum (ipsilateral

dominant) via superior cerebellar peduncle. Receive excitatory reciprocal input from the cerebellar

nuclei Receive collaterals from propiospinal neurons

Relay motor information to cerebellum

Organization of Motor Subsystems

CerebellumCerebellum FunctionFunction

CerebellumCerebellum FunctionFunction

Maintenance of Equilibrium - balance, posture, eye movement

Coordination of half-automatic movement of walking and posture maintenance - posture, gait

Adjustment of Muscle Tone

Motor Leaning – Motor Skills

Cognitive Function

BalanceBalance

Motor Skill Motor Skill

Pablo CasalsPablo CasalsPablo CasalsPablo Casals

CerebellumCerebellum Clinical Clinical SyndromesSyndromes

CerebellumCerebellum Clinical Clinical SyndromesSyndromes

Ataxia: incoordination of movement - decomposition of movement - dysmetria, past-pointing - dysdiadochokinesia - rebound phenomenon of Holmes - gait ataxia, truncal ataxia, titubationIntention TremorHypotonia, Nystagmus

Archicerebellar LesionArchicerebellar Lesion: medulloblastoma: medulloblastomaPaleocerebellar LesionPaleocerebellar Lesion: gait disturbance: gait disturbanceNeocerebellar LesionNeocerebellar Lesion: hypotonia, ataxia, tremor: hypotonia, ataxia, tremor

PosturePostureGait – AtaxiaGait – Ataxia

TremorTremor

Cerebellar Cerebellar AtaxiaAtaxia

Ataxic gait and Ataxic gait and position: position: Left cerebellar tumorLeft cerebellar tumor

a. Sways to the right ina. Sways to the right in standing positionstanding position

b. Steady on the b. Steady on the right legright leg

c. Unsteady on the c. Unsteady on the left legleft leg

d. ataxic gaitd. ataxic gait

a b c

d

Cerebellar tumors on vermisCerebellar tumors on vermis

- Truncal Ataxia- Truncal Ataxia

- Frequent Falling- Frequent Falling

The child in this picture:The child in this picture:

- would not try to stand - would not try to stand unsupportedunsupported

- would not let go of the bed rail- would not let go of the bed rail if she was stood on the floor.if she was stood on the floor.

Cerebellar Medulloblastoma

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the cerebellum 陽明大學醫學院 神經學系 陳昌明 醫師. position lies above and behind...

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the cerebellum 陽明大學醫學院神經學系陳昌明醫師. position lies above and behind...