Nabeel Kouka, MD, DO, MBA

Nabeel Kouka, MD, DO, MBANabeel Kouka, MD, DO, MBAwww.brain101.infowww.brain101.info

Nabeel Kouka, MD, DO, MBANabeel Kouka, MD, DO, MBAwww.brain101.infowww.brain101.info

Basic Basic Strucrure ofStrucrure ofBrain StemBrain Stem

1. Roof Plate1. Roof Plate

2. Tegmentum2. Tegmentum

3. Basal Portion3. Basal Portion

Basilar (Basal) PortionBasilar (Basal) PortionBasilar (Basal) PortionBasilar (Basal) Portion

Descending Fibers from Cerebral CortexDescending Fibers from Cerebral Cortex

1. Corticospinal Tract1. Corticospinal Tract2. Corticobulbar Tract2. Corticobulbar Tract

3. Corticopontocerebellar Fiber3. Corticopontocerebellar Fiber Corticopontine FiberCorticopontine Fiber Pons Proper (Ventral Pons)Pons Proper (Ventral Pons) Pontocerebellar FiberPontocerebellar Fiber

Pyramidal TractPyramidal Tract

Corticospinal TractCorticospinal Tract

Origin: Origin: Cerebral CortexCerebral Cortex Brodmann Area 4 (Primary Motor Area, M I)Brodmann Area 4 (Primary Motor Area, M I)

Brodmann Area 6 (Premotor Area, PM )Brodmann Area 6 (Premotor Area, PM )

Brodmann Area 3,1,2 (Primary Somesthetic Area, S I) Brodmann Area 3,1,2 (Primary Somesthetic Area, S I)

Brodmann Area 5 (Anterior Portion of Sup. Parietal Brodmann Area 5 (Anterior Portion of Sup. Parietal Lobule)

Corona RadiataCorona Radiata

lnternal Capsule, Posterior Limblnternal Capsule, Posterior Limb

Crus Cerebri, Middle PortionCrus Cerebri, Middle Portion

Longitudinal Pontine FiberLongitudinal Pontine Fiber

Pyramid - pyramidal decussationPyramid - pyramidal decussation

Corticospinal Tract - Lateral and AnteriorCorticospinal Tract - Lateral and Anterior

Termination: Termination: Spinal Gray (Rexed IV-IX)Spinal Gray (Rexed IV-IX)

Corticospinal TractCorticospinal Tract

Origin: Origin: Cerebral CortexCerebral Cortex Brodmann Area 4 (Primary Motor Area, M I)Brodmann Area 4 (Primary Motor Area, M I)

Brodmann Area 6 (Premotor Area, PM )Brodmann Area 6 (Premotor Area, PM )

Brodmann Area 3,1,2 (Primary Somesthetic Area, S I) Brodmann Area 3,1,2 (Primary Somesthetic Area, S I)

Brodmann Area 5 (Anterior Portion of Sup. Parietal Brodmann Area 5 (Anterior Portion of Sup. Parietal Lobule)

Corona RadiataCorona Radiata

lnternal Capsule, Posterior Limblnternal Capsule, Posterior Limb

Crus Cerebri, Middle PortionCrus Cerebri, Middle Portion

Longitudinal Pontine FiberLongitudinal Pontine Fiber

Pyramid - pyramidal decussationPyramid - pyramidal decussation

Corticospinal Tract - Lateral and AnteriorCorticospinal Tract - Lateral and Anterior

Termination: Termination: Spinal Gray (Rexed IV-IX)Spinal Gray (Rexed IV-IX)

Basal Portion Descending TractsBasal Portion Descending Tracts Basal Portion Descending TractsBasal Portion Descending Tracts

Corticobulbar TractCorticobulbar Tract

- Corticofugal fibers projecting to, and terminating in,- Corticofugal fibers projecting to, and terminating in,

portions of lower brainstemportions of lower brainstem - Termination:- Termination:

1) motor nuclei (upper motor neuron pathway)1) motor nuclei (upper motor neuron pathway)

hypoglossal, ambiguus, facial motor,hypoglossal, ambiguus, facial motor,

trigeminal motor, abducens, trochleartrigeminal motor, abducens, trochlear

and oculomotor nucleusand oculomotor nucleus

2) sensory relay nuclei2) sensory relay nuclei

nuclei gracilis and cuneatus, trigeminalnuclei gracilis and cuneatus, trigeminal

sensory nucleus, solitary tract nucleussensory nucleus, solitary tract nucleus

3) reticular formation 3) reticular formation (corticoreticular fiber)(corticoreticular fiber)



Corticobulbar Tract - UMN PathwayCorticobulbar Tract - UMN Pathway

- Corticofugal fibers projecting to - Corticofugal fibers projecting to cranial motor nucleicranial motor nuclei

GSE - GSE - hypoglossal (XII), abducens (VI), hypoglossal (XII), abducens (VI),

trochlear (IV) and oculomotor (III) nucleustrochlear (IV) and oculomotor (III) nucleus

SVE -SVE - ambiguus (IX, X, XI), facial motor (VII),ambiguus (IX, X, XI), facial motor (VII),

trigeminal motor (V) nucleustrigeminal motor (V) nucleus

- largely - largely bilateralbilateral

laryngeal, pharyngeal, palatal and upper faciallaryngeal, pharyngeal, palatal and upper facial

muscles of mastication and extraocular musclesmuscles of mastication and extraocular muscles

- - unilateralunilateral

lower facial musculature (facial palsy)lower facial musculature (facial palsy)

SCM and trapezius (uncrossed) --- spinal accessorySCM and trapezius (uncrossed) --- spinal accessory

- - Pseudobulbar PalsyPseudobulbar Palsy --- syndrome of bilateral UMN lesion--- syndrome of bilateral UMN lesion


Corticopontocerebellar FiberCorticopontocerebellar Fiber

- Corticofugal fibers projecting to- Corticofugal fibers projecting to

cerebellar hemispherecerebellar hemisphere

- consists of 2 neuron chain- consists of 2 neuron chain

1. Corticopontine fiber projecting to 1. Corticopontine fiber projecting to pontine nucleipontine nuclei

2. Pontocerebellar fiber2. Pontocerebellar fiber crossed mudline and enter cerebellum crossed mudline and enter cerebellum as middle cerebellar peduncleas middle cerebellar peduncle

Roof PlateRoof PlateRoof PlateRoof Plate

Midbrain Midbrain

Superior ColliculusSuperior Colliculus: : visionvision

Inferior ColliculusInferior Colliculus: : hearinghearing

Closed MedullaClosed Medulla

Nucleus Gracilis et CuneatusNucleus Gracilis et Cuneatus::

discriminative touch sensationdiscriminative touch sensation

cf.cf. CerebelumCerebelum: : equilibriumequilibrium

Roof PlateRoof Plate of Hypothetized of Hypothetized Chordate AncestorChordate Ancestor

A. olfactionB. visionC. hearingD. equilibriumE. discriminative touch sensation

1. epithalamus2. superior colliculus3. inferior colliculus4. cerebellum5. nucleus gracilis et cuneatus

TegmentumTegmentumTegmentumTegmentum

Cranial nerve NucleiCranial nerve Nuclei

Precerebellar NucleiPrecerebellar Nuclei

Reticular FormationReticular Formation

TractsTracts Ascending Cortical PathwayAscending Cortical Pathway

Cerebellar CircuitsCerebellar Circuits

Descending TractDescending Tract

Composite BundleComposite Bundle

Cranial NervesCranial Nerves ColumnsColumns of ofBrain StemBrain Stem

Motor ColumnMotor Column

1. GSE1. GSE 2. SVE2. SVE 3. GVE3. GVE

Sensory ColumnSensory Column

4. VA (GVA & SVA)4. VA (GVA & SVA) 5. GSA5. GSA 6. SSA6. SSA

Components of Components of Cranial NervesCranial Nerves

General Somatic Efferent Nuclei (GSE)General Somatic Efferent Nuclei (GSE)

Hypoglossal NucleusHypoglossal Nucleus XIIXII

Abducens NucleusAbducens Nucleus VIVI

Trochlear NucleusTrochlear Nucleus IVIV

Oculomotor NucleusOculomotor Nucleus IIIIII

Special Visceral Efferent Nuclei (SVE)Special Visceral Efferent Nuclei (SVE)

Nucleus AmbiguusNucleus Ambiguus IX, X, XIIX, X, XI

Facial Motor NucleusFacial Motor Nucleus VIIVII

Trigeminal Motor NucleusTrigeminal Motor Nucleus VV

General Visceral Efferent Nuclei (GVE)General Visceral Efferent Nuclei (GVE)

Dorsal Motor Nucleus of VagusDorsal Motor Nucleus of Vagus XX

Inferior Salivatory NucleusInferior Salivatory Nucleus IXIX

Superior Salivatory NucleusSuperior Salivatory Nucleus VIIVII

Edinger-Westphal NucleusEdinger-Westphal Nucleus IIIIII

Motor NucleiMotor Nuclei of ofCranial NervesCranial Nerves

1. GSE1. GSE III, IV, VI, XIIIII, IV, VI, XII

2. SVE2. SVE V, VII, V, VII, IX, X, XIIX, X, XI

3. GVE3. GVE III, VII, IX, XIII, VII, IX, X

General Somatic Afferent Nuclei (GSA)General Somatic Afferent Nuclei (GSA)

Trigeminal Sensory Nucleus Trigeminal Sensory Nucleus V, V, VII, IX, XVII, IX, X

Mesencephalic Tract NucleusMesencephalic Tract Nucleus

Principal (Main) Sensory NucleusPrincipal (Main) Sensory Nucleus

Spinal Tract NucleusSpinal Tract Nucleus

pars oralispars oralis

pars interpolarispars interpolaris

pars caudalispars caudalis

Visceral Afferent Nuclei (VA)Visceral Afferent Nuclei (VA)

Nucleus Tractus SolitariusNucleus Tractus Solitarius VII, IX, XVII, IX, X

General Visceral Afferent (GVA)General Visceral Afferent (GVA)

Special Visceral Afferent (SVA): Special Visceral Afferent (SVA): TasteTaste

Gustatory NucleusGustatory Nucleus

Special Somatic Afferent Nuclei (SSA)Special Somatic Afferent Nuclei (SSA)

Cochlear Nucleus Cochlear Nucleus VIIIc VIIIc Dorsal Cochlear NucleusDorsal Cochlear Nucleus

Ventral Cochlear NucleusVentral Cochlear Nucleus

Vestibular NucleusVestibular Nucleus VIIIv VIIIv Medial Vestibular NucleusMedial Vestibular Nucleus

Lateral Vestibular NucleusLateral Vestibular Nucleus

Superior Vestibular NucleusSuperior Vestibular Nucleus

Inferior Vestibular NucleusInferior Vestibular Nucleus

Sensory NucleiSensory Nuclei of ofCranial NervesCranial Nerves

1. VA 1. VA

GVA --- IX, XGVA --- IX, X

SVA --- VII, IX, XSVA --- VII, IX, X 2. GSA2. GSA V,V, VII, IX, XVII, IX, X

3. SSA3. SSA VIIIc, VIIIvVIIIc, VIIIv

Precerebellar NucleiPrecerebellar Nuclei

Accessory Cuneate Nucleus Accessory Cuneate Nucleus

Inferior Olivary Nuclear ComplexInferior Olivary Nuclear Complex

Vestibular NuclusVestibular Nuclus

Red NucleusRed Nucleus

Perihypoglossal NucleusPerihypoglossal Nucleus

Precerebellar Reticular NucleiPrecerebellar Reticular Nuclei

PrecerebellarPrecerebellarNucleiNuclei

1. Red Nucleus1. Red Nucleus 2. Vestibular Nucleus2. Vestibular Nucleus

3. Inferior Olivary3. Inferior Olivary NucleusNucleus

4. Perhypoglossal4. Perhypoglossal NucleiNuclei

5. Accessory 5. Accessory Cuneate NucleusCuneate Nucleus

Reticular Reticular FormationFormation

A. Raphe NucleiA. Raphe Nuclei B. Central B. Central Nuclear GroupNuclear Group

C. LateralC. Lateral Nuclear GroupNuclear Group

D. PrecerebellarD. Precerebellar Reticular NucleiReticular Nuclei

A

B

C

D

Central Nuclear Group of Reticular FormationCentral Nuclear Group of Reticular Formation

Gigantocellular Reticular Nucleus Gigantocellular Reticular Nucleus

Caudal Reticulopontine NucleusCaudal Reticulopontine Nucleus

Oral Reticulopontine NucleusOral Reticulopontine Nucleus

Subcuneiform NucleusSubcuneiform Nucleus

Cuneiform NucleusCuneiform Nucleus

Lateral Nuclear Group of Reticular FormationLateral Nuclear Group of Reticular Formation

Central Nucleus of Medulla OblongataCentral Nucleus of Medulla Oblongata

Superficial Ventrolateral Reticular AreaSuperficial Ventrolateral Reticular Area

Parvicellular Reticular NucleusParvicellular Reticular Nucleus

Parabrachial NucleusParabrachial Nucleus

Pedunculopontine NucleusPedunculopontine Nucleus

Raphe Nuclei - Serotonergic NeuronRaphe Nuclei - Serotonergic Neuron

Nucleus Raphe Obscrus, BNucleus Raphe Obscrus, B22

Nucleus Raphe Pallidus, Nucleus Raphe Pallidus, BB11

Nucleus Raphe Magnus, Nucleus Raphe Magnus, BB33

Pontine Raphe Nucleus, Pontine Raphe Nucleus, BB55

Median Raphe or Median Raphe or Superior CentralSuperior Central Nucleus, Nucleus, BB6, 6, BB88

Dorsal Raphe Nucleus, Dorsal Raphe Nucleus, BB77

Nucleus LinealisNucleus Linealis

Norepinephrinergic & Dopaminergic NeuronNorepinephrinergic & Dopaminergic Neuron

Norepinephrinergic NeuronNorepinephrinergic Neuron

Nucleus Locus Ceruleus, ANucleus Locus Ceruleus, A66

Dopaminergic NeuronDopaminergic Neuron

Retrorubral Area, Retrorubral Area, AA88

Ventral Tegmental Area, Ventral Tegmental Area, AA1010

Substantia Nigra, Pars Compacta, Substantia Nigra, Pars Compacta, AA99

Ascending Cortical PathwayAscending Cortical PathwayAscending Cortical PathwayAscending Cortical Pathway

Posterior White Column-Medial Lemniscal PathwayPosterior White Column-Medial Lemniscal Pathwaymedial lemniscusmedial lemniscus

Spinothalamic and Spinoreticular TractSpinothalamic and Spinoreticular Tractspinal lemniscusspinal lemniscus

Ventral and Dorsal Trigeminothalamic TractVentral and Dorsal Trigeminothalamic Tracttrigeminal lemniscustrigeminal lemniscus

Auditory Pathway: Auditory Pathway: lateral lemniscuslateral lemniscus

Taste (Gustatory) Pathway: Taste (Gustatory) Pathway: central tegmental tractcentral tegmental tract

Vestibular Pathway: Vestibular Pathway: medial lemniscusmedial lemniscus

Ascending Cortical System Ascending Cortical System General SensationGeneral Sensation Ascending Cortical System Ascending Cortical System General SensationGeneral Sensation

Brain Stem Pathways for General SensationBrain Stem Pathways for General Sensation

Touch & Proprioception from bodyTouch & Proprioception from body

Posterior White Colum-Medial Lemniscal PathwayPosterior White Colum-Medial Lemniscal Pathway

Pain & Temperature from bodyPain & Temperature from body

Spinothalamic TractSpinothalamic Tract

cf. Spinoreticular or Spinoreticulothalamic Tractcf. Spinoreticular or Spinoreticulothalamic Tract

General Sensation from FaceGeneral Sensation from Face

Trigeminothalamic TractsTrigeminothalamic Tracts

Posterior White Column - medial Lemniscal PathwayPosterior White Column - medial Lemniscal Pathway& Spinothalamic Tract& Spinothalamic Tract

Posterior White Colum-Medial Lemniscal PathwayPosterior White Colum-Medial Lemniscal Pathway Posterior White Colum-Medial Lemniscal PathwayPosterior White Colum-Medial Lemniscal Pathway

Modality: Modality: Discriminative Touch Sensation (include Vibration) and Discriminative Touch Sensation (include Vibration) and Conscious Proprioception (Position Sensation, Kinesthesia)Conscious Proprioception (Position Sensation, Kinesthesia) from bodyfrom body

Receptor: Most receptors except free nerve endingsReceptor: Most receptors except free nerve endings

Ist Neuron: Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion)Dorsal Root Ganglion (Spinal Ganglion)

Posterior White ColumnPosterior White Column

2nd Neuron: 2nd Neuron: Dorsal Column NucleiDorsal Column Nuclei (Nucleus Gracilis et Cuneatus)(Nucleus Gracilis et Cuneatus)

Internal Arcuate Fiber - Lemniscal Decussation - Medial LemniscusInternal Arcuate Fiber - Lemniscal Decussation - Medial Lemniscus

3rd Neuron: 3rd Neuron: Thalamus (VPLc)Thalamus (VPLc) Internal Capsule ----- Corona RadiataInternal Capsule ----- Corona Radiata

Termination: Termination: Primary Somesthetic Area (S I)Primary Somesthetic Area (S I)

DRG: Dorsal Root GanglionDRG: Dorsal Root Ganglion

1. 1. Posterior White ColumnPosterior White Column

A. Nucleus gracilisA. Nucleus gracilis

B. Nucleus cuneatusB. Nucleus cuneatus

2. 2. Medial LemniscusMedial Lemniscus

3. 3. Corona Radiata Corona Radiata

C. Thalamus (VPLc)C. Thalamus (VPLc)

D. Cerebral Cortex (S I)D. Cerebral Cortex (S I)

Posterior White Column-Posterior White Column-

Medial Lemniscal PathwayMedial Lemniscal Pathway

DRG

D

Spinothalamic TractSpinothalamic Tract Spinothalamic TractSpinothalamic Tract

Modality: Modality: Pain & Temperature Sensation, Light Touch Pain & Temperature Sensation, Light Touch from bodyfrom body

Receptor: Receptor: Free Nerve Ending Free Nerve Ending

Ist Neuron: Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion)Dorsal Root Ganglion (Spinal Ganglion)

2nd Neuron: 2nd Neuron: Dorsal Horn Dorsal Horn (Lamina I, IV, V)(Lamina I, IV, V)

Anterior White CommissureAnterior White Commissure

Spinothalamic Tract (Spinal Lemniscus)Spinothalamic Tract (Spinal Lemniscus)

3rd Neuron: 3rd Neuron: Thalamus (VPLc & CL)Thalamus (VPLc & CL) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata


Spinoreticulothalamic Tract Spinoreticulothalamic Tract (Paleospinothalamic Tract)(Paleospinothalamic Tract) Spinoreticulothalamic Tract Spinoreticulothalamic Tract (Paleospinothalamic Tract)(Paleospinothalamic Tract)

Modality: Modality: Pain & Temperature Sensation, Light Touch Pain & Temperature Sensation, Light Touch from bodyfrom body

Receptor: Receptor: Free Nerve Ending Free Nerve Ending

Ist Neuron: Ist Neuron: Dorsal Root Ganglion Dorsal Root Ganglion (Spinal Ganglion)(Spinal Ganglion)

2nd Neuron: 2nd Neuron: Dorsal Horn Dorsal Horn (Lamina I, IV, V)(Lamina I, IV, V)

Anterior White CommissureAnterior White Commissure

Spinothalamic Tract (Spinal Lemniscus)Spinothalamic Tract (Spinal Lemniscus)

3rd Neuron: 3rd Neuron: Reticular FormationReticular Formation

4rd Neuron: 4rd Neuron: Thalamus (CL, Sm, POm)Thalamus (CL, Sm, POm) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Diffuse Cerebral CotexDiffuse Cerebral Cotex

DRG: Dorsal Root GanglionDRG: Dorsal Root Ganglion

A. Posterior (dorsal) hornA. Posterior (dorsal) horn

1. 1. Spinothalamic tractSpinothalamic tract

B. Reticular formationB. Reticular formation

2. 2. Spinoreticular tractSpinoreticular tract

C. Thalamus (VPLc, CL)C. Thalamus (VPLc, CL)

3. 3. Corona Radiata Corona Radiata

D. Cerebral Cortex (S I)D. Cerebral Cortex (S I)

Spinothalamic TractSpinothalamic Tract(Neospinothalamic Tract)(Neospinothalamic Tract)

Spinoreticular TractSpinoreticular Tract(Paleospinothalamic Tract)(Paleospinothalamic Tract)

DRG

D

Trigeminothalamic Tract Trigeminothalamic Tract Trigeminothalamic Tract Trigeminothalamic Tract

Modality: Modality: General SensationGeneral Sensation from facefrom face

Receptor: Receptor: Most receptors in the face Most receptors in the face

Ist Neuron: Ist Neuron: Trigeminal (Semilunar) GangliaTrigeminal (Semilunar) Ganglia

2nd Neuron: 2nd Neuron: Trigeminal Sensory NucleusTrigeminal Sensory Nucleus pain & temperature pain & temperature ---- pars caudalis of---- pars caudalis of

spinal tract nucleus of Vspinal tract nucleus of V

Ventral and Dorsal Trigeminothalamic TractVentral and Dorsal Trigeminothalamic Tract

3rd Neuron: 3rd Neuron: Thalamus (VPM)Thalamus (VPM) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata


Trigeminothalamic TractTrigeminothalamic Tract

A. trigeminal ganglionA. trigeminal ganglion

B. trigeminal sensory B. trigeminal sensory

nucleusnucleus

C. thalamus (VPM)C. thalamus (VPM)

D. cerebral cortexD. cerebral cortex

(S I)(S I)

1. 1. spinal tract of spinal tract of

trigeminal nervetrigeminal nerve

2. 2. ventral ventral

trigeminothalamic tracttrigeminothalamic tract

3. 3. dorsal dorsal

trigeminothalamic tracttrigeminothalamic tract

4. 4. corona radiatacorona radiata

V.V. trigeminal nerve trigeminal nerve

Ascending Cortical System Ascending Cortical System Special SensationSpecial Sensation Ascending Cortical System Ascending Cortical System Special SensationSpecial Sensation

Brain Stem Pathways for Special SensationBrain Stem Pathways for Special Sensation

Gustatory Sensation (Taste, SVA) Gustatory Sensation (Taste, SVA)

----- Taste Pathway----- Taste Pathway

Auditory Sensation (Hearing, SSA) Auditory Sensation (Hearing, SSA)

----- Auditory Pathway----- Auditory Pathway

Vestibular Sensation (Equilibrium, SSA)Vestibular Sensation (Equilibrium, SSA)

----- Vestibular Pathway----- Vestibular Pathway

Auditory PathwayAuditory Pathway Auditory PathwayAuditory Pathway

Modality: Modality: Auditory Sensation (Hearing) Auditory Sensation (Hearing) Receptor: Receptor: Organ of Coti of Cochlear DuctOrgan of Coti of Cochlear Duct Cranial Nerve: VIIIcCranial Nerve: VIIIc

1st Neuron: 1st Neuron: Spiral GanglionSpiral Ganglion 2nd Neuron: 2nd Neuron: Cochlear Nucleus, Ventral & DorsalCochlear Nucleus, Ventral & Dorsal dorsal, intermediate and ventral acoustic striaedorsal, intermediate and ventral acoustic striae trapezoid bodytrapezoid body lateral lemniscuslateral lemniscus 3rd Neuron: 3rd Neuron: Inferior Colliculus Inferior Colliculus brachium of inferior colliculusbrachium of inferior colliculus 4th Neuron: 4th Neuron: Medial Geniculate Nucleus (MG)Medial Geniculate Nucleus (MG) auditory radiationauditory radiation Termination: Termination: Primary Auditory Area (A I)Primary Auditory Area (A I) Brodmann area 31, 32Brodmann area 31, 32

Auditory PathwaysAuditory Pathways

A. spiral ganglionA. spiral ganglionB. dorsal and ventralB. dorsal and ventral cochlear nucleuscochlear nucleusC. inferior colliculusC. inferior colliculusD. medial geniculateD. medial geniculate nucleusnucleusE. Primary auditory areaE. Primary auditory areaF. superior olivary nucleusF. superior olivary nucleusG. nucleus of G. nucleus of lateral lemniscuslateral lemniscus

1. 1. acoustic striae &acoustic striae & trapezoid bodytrapezoid body2. 2. lateral lemniscuslateral lemniscus3. 3. brachium of inferiorbrachium of inferior colliculuscolliculus4. 4. auditory radiationauditory radiation5. 5. commissure ofcommissure of inferior colliculusinferior colliculusVIIIc. VIIIc. cochlear divisioncochlear division

Auditory PathwayAuditory Pathway

A. spiral ganglionA. spiral ganglion

B. dorsal cochlear nucleusB. dorsal cochlear nucleus

C. ventral cochlear nucleusC. ventral cochlear nucleus

D. superior olivary nucleusD. superior olivary nucleus

1. dorsal acoustic striae1. dorsal acoustic striae

2. intermediate2. intermediate acoustic acoustic

striaestriae

3. ventral acoustic striae3. ventral acoustic striae

4. efferent cochlear bundle4. efferent cochlear bundle

5. trapezoid body5. trapezoid body

6. lateral lemniscus6. lateral lemniscus

Vestibular PathwayVestibular Pathway Vestibular PathwayVestibular Pathway

Modality: Modality: Equilibrium Sensation Equilibrium Sensation

Receptor: Receptor: Macula & Crista Ampullaris Macula & Crista Ampullaris

Cranial Nerve: VIIIvCranial Nerve: VIIIv

Ist Neuron: Ist Neuron: Vestibular GanglionVestibular Ganglion

2nd Neuron: 2nd Neuron: Vestibular NucleusVestibular Nucleus vestibulothalamic fiber (medial lemniscus)vestibulothalamic fiber (medial lemniscus)

3rd Neuron: 3rd Neuron: Thalamus (VPLo, VPI?)Thalamus (VPLo, VPI?) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Primary Vestibular AreaPrimary Vestibular Area ----- Primary Somesthetic Area ----- Primary Somesthetic Area

(Brodmann area 3a, 2v )(Brodmann area 3a, 2v )

VestibularVestibular

Pathway Pathway

1. Vestibulocerebellar Tract1. Vestibulocerebellar Tract 2. Vestibulospinal Tract2. Vestibulospinal Tract

3. Vestibulothalamic Tract3. Vestibulothalamic Tract 4. Medial Longitudinal4. Medial Longitudinal fasciculus (MLF)fasciculus (MLF)

- ascending portion- ascending portion

- descending portion- descending portion

- interstitiospinal tractinterstitiospinal tract

Taste (Gustatory) PathwayTaste (Gustatory) Pathway Taste (Gustatory) PathwayTaste (Gustatory) Pathway

Modality: Modality: Taste Sensation Taste Sensation

Receptor: Receptor: Taste BudTaste Bud

Cranial Nerve: VII, IX, XCranial Nerve: VII, IX, X

Ist Neuron: Ist Neuron: Geniculate Ganglion (VII)Geniculate Ganglion (VII)

Inferior Ganglion (IX, X)Inferior Ganglion (IX, X)

2nd Neuron: 2nd Neuron: Nucleus Tractus SolitariusNucleus Tractus Solitarius

(Gustatory Nucleus)(Gustatory Nucleus)

solitariothalamic fiber (central tegmental tract)solitariothalamic fiber (central tegmental tract)

3rd Neuron: 3rd Neuron: Thalamus (VPMpc)Thalamus (VPMpc) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata

Termination: Termination: Gustatory AreaGustatory Area Brodmann area 43 & parainsular cortexBrodmann area 43 & parainsular cortex

Taste PathwaysTaste Pathways

A. nucleus tractusA. nucleus tractus solitariussolitarius (gustatory nucleus)(gustatory nucleus)B. thalamus (VPMpc)B. thalamus (VPMpc)C. Brodmann area 43C. Brodmann area 43D. parainsular cortexD. parainsular cortexE. parabrachialE. parabrachial nucleusnucleus

1. 1. solitariothalamicsolitariothalamic fiber (central fiber (central tegmental tract)tegmental tract) 2. 2. corona radiatacorona radiataVII. VII. facial nervefacial nerveIX. IX. glossopharyngeal glossopharyngeal nervenerveX. X. vagus nervevagus nerve

Cerebellar CircuitsCerebellar CircuitsCerebellar CircuitsCerebellar Circuits

Superior, Middle and Inferior Cerebellar PeduncleSuperior, Middle and Inferior Cerebellar Peduncle

VestibulocerebellumVestibulocerebellum - - Vestibular NucleusVestibular Nucleus

SpinocerebellumSpinocerebellum - - Red Nucleus and Spinal CordRed Nucleus and Spinal Cord

PontocerebellumPontocerebellum - - Cerebral Cortex and Pontine NucleiCerebral Cortex and Pontine Nuclei

Inferior Olivary Nuclear ComplexInferior Olivary Nuclear Complex

Afferent ConnectionsAfferent Connections of Cerebellumof Cerebellum

Inferior Cerebellar Peduncle Inferior Cerebellar Peduncle

1. posterior spinocerebellar tract1. posterior spinocerebellar tract

2. cuneocerebellar tract2. cuneocerebellar tract

3. vestibulocerebellar tract3. vestibulocerebellar tract

Middle cerebellar PeduncleMiddle cerebellar Peduncle

- corticopontocerebellar - corticopontocerebellar pathwaypathway

Superior Cerebellar PeduncleSuperior Cerebellar Peduncle - anterior spinocerebellar tract- anterior spinocerebellar tract

Efferent ConnectionsEfferent Connections of Cerebellumof Cerebellum

Superior Cerebellar PeduncleSuperior Cerebellar Peduncle

1. dentatothalamic fiber1. dentatothalamic fiber

2. interpositorubral fiber2. interpositorubral fiber

3. ascending portion of3. ascending portion of

uncinate fasciculus of Russelluncinate fasciculus of Russell

Inferior Cerebellar Peduncle Inferior Cerebellar Peduncle

1. direct fastigiovestibular fiber1. direct fastigiovestibular fiber

2. descending portion of2. descending portion of

uncinate fasciculus of Russelluncinate fasciculus of Russell

Connections ofConnections of

Inferior Olivary Inferior Olivary

Nuclear Complex Nuclear Complex

1. Olivocerebellar Tract1. Olivocerebellar Tract 2. Cortico-olivary Tract2. Cortico-olivary Tract

3. Rubro-olivary Tract3. Rubro-olivary Tract 4. Vestibulo-olivary Tract4. Vestibulo-olivary Tract

5. Spino-olivary Tract5. Spino-olivary Tract

Descending TractsDescending TractsDescending TractsDescending Tracts

Rubrospinal TractRubrospinal Tract

Tectospinal tractTectospinal tract

Vestibulospinal TractVestibulospinal Tract

Reticulospinal TractReticulospinal Tractpontine and medullarypontine and medullary

Descending Autonomic PathwayDescending Autonomic Pathway

Brain Stem Descending TractsBrain Stem Descending Tracts Brain Stem Descending TractsBrain Stem Descending Tracts

Descending Tracts from Brain StemDescending Tracts from Brain Stem

Dorsolateral (Motor) PathwayDorsolateral (Motor) Pathway

Rubrospinal TractRubrospinal Tract

Ventromedial (Motor) PathwayVentromedial (Motor) Pathway

Tectospinal TractTectospinal Tract

Vestibulospinal TractVestibulospinal Tract

MLF (Medial Longitudinal Fasciculus)MLF (Medial Longitudinal Fasciculus)

- interstitiospinal tractinterstitiospinal tract

Sensory Modulation pathwaysSensory Modulation pathways

Raphespinal & Cerulospinal PathwaysRaphespinal & Cerulospinal Pathways

Descending Autonomic PathwaysDescending Autonomic Pathways

Composite BundleComposite BundleComposite BundleComposite Bundle

Medial Longitudinal Fasciculus (MLF)Medial Longitudinal Fasciculus (MLF)

Dorsal Longitudinal Fasciculus (DLF)Dorsal Longitudinal Fasciculus (DLF)

Central Tegmental TractCentral Tegmental Tract

Components of Components of Medial Longitudinal Fasciculus (MLF)Medial Longitudinal Fasciculus (MLF)

Descending ComponentsDescending ComponentsMedial Vestibulospinal TractMedial Vestibulospinal Tract

from medial and inferior vestibular nucleusfrom medial and inferior vestibular nucleusInterstitiospinal TractInterstitiospinal Tract

from interstitial nucleus of Cajalfrom interstitial nucleus of Cajal

Ascending ComponentsAscending Components Efferents from Medial Vestibular NucleusEfferents from Medial Vestibular Nucleus contralateral contralateral III, IV, interstitial nucleusIII, IV, interstitial nucleus bilateral bilateral VI nucleusVI nucleusEfferents from Superior Vestibular Nucleus Efferents from Superior Vestibular Nucleus ipsilateralipsilateral III, IV, interstitial nucleus III, IV, interstitial nucleus

Ascending ComponentsAscending Componentssolitariohypothalamic fibersolitariohypothalamic fiber

(visceral afferent fiber)(visceral afferent fiber)

ascending serotonergic fiberascending serotonergic fiber

Descending Component Descending Component descending fibers from hypothalamusdescending fibers from hypothalamus to periaqueductal gray and to periaqueductal gray and dorsal tegmental nucleusdorsal tegmental nucleus

Components of Components of Dorsal Longitudinal Fasciculus Dorsal Longitudinal Fasciculus (DLF, fasciculus of Sch(DLF, fasciculus of Schüütz)tz)

Components of Components of Central Tegmental TractCentral Tegmental Tract

Ascending ComponentsAscending Componentsreticulothalamic fiberreticulothalamic fiber

solitariothalamic fibersolitariothalamic fiber

(secondary taste fiber)(secondary taste fiber)

Descending Component Descending Component rubro-olivary tractrubro-olivary tract

Spinomedullary Transition Spinomedullary Transition (Level of Pyramidal Decussation)(Level of Pyramidal Decussation)


Roof Plate - Roof Plate - fasciculus gracilis and fasciculus cuneatusfasciculus gracilis and fasciculus cuneatus

TegmentumTegmentum Cranial and Spinal Nerve NucleiCranial and Spinal Nerve Nuclei

Supraspinal NucleusSupraspinal NucleusSpinal Nucleus of Trigeminal Nerve, Pars CaudalisSpinal Nucleus of Trigeminal Nerve, Pars Caudalis

Reticular FormationReticular FormationCentral Nucleus of Medulla OblongataCentral Nucleus of Medulla Oblongata (Ventral Reticular Nucleus) (Ventral Reticular Nucleus)

Unclassified NucleiUnclassified NucleiRetroambiguus NucleusRetroambiguus Nucleus

TractsTractsSpinal Tracts of Trigeminal NerveSpinal Tracts of Trigeminal Nerve

Basal Part Basal Part - - Pyramid, Pyramidal DecussationPyramid, Pyramidal Decussation

Cranial & Spinal N. NucleiCranial & Spinal N. Nuclei

1. Supraspinal Nucleus1. Supraspinal Nucleus

2. Spinal Accessory Nucleus2. Spinal Accessory Nucleus

Cranial & Spinal NerveCranial & Spinal Nerve XI. XI. Accessory NucleusAccessory Nucleus

C1. C1. motor root ofmotor root of 1st cervical nerve1st cervical nerve


Lower Medulla Lower Medulla (Level of Lemniscal Decussation)(Level of Lemniscal Decussation)Lower Medulla Lower Medulla (Level of Lemniscal Decussation)(Level of Lemniscal Decussation)

Roof Plate - Roof Plate - nucleus gracilis and nucleus cuneatusnucleus gracilis and nucleus cuneatus

TegmentumTegmentum Cranial and Spinal Nerve NucleiCranial and Spinal Nerve Nuclei

Hypoglossal Nucleus, Ambiguus NucleusHypoglossal Nucleus, Ambiguus NucleusSolitary Tract Nucleus, Dorsal Motor Nucleus of XSolitary Tract Nucleus, Dorsal Motor Nucleus of X

Reticular FormationReticular FormationLateral Reticular Nucleus Lateral Reticular Nucleus

Precerebellar NucleiPrecerebellar NucleiInferior Olivary Nuclear Complex Inferior Olivary Nuclear Complex

TractsTractsVentral Trigeminothalamic TractVentral Trigeminothalamic TractInternal Arcuate Fiber, Lemniscal DecussationInternal Arcuate Fiber, Lemniscal Decussation

Basal Part Basal Part - - Pyramid, Pyramidal DecussationPyramid, Pyramidal Decussation

Lower MedullaLower Medulla(Level of Lemniscal(Level of Lemniscal

Decussation)Decussation)

Roof PlateRoof Plate A. Nucleus GracilisA. Nucleus GracilisB. Nucleus CuneatusB. Nucleus Cuneatus

Cranial Nerve NucleiCranial Nerve Nuclei1. Hypoglossal Nucleus1. Hypoglossal Nucleus

2. Nucleus Ambiguus2. Nucleus Ambiguus

3. Dorsal Motor Nucleus of X3. Dorsal Motor Nucleus of X

4. Nucleus Tractus Solitarius4. Nucleus Tractus Solitarius

5. Spinal Tract Nucleus of5. Spinal Tract Nucleus of

Trigeminal NerveTrigeminal Nerve



Precerebellar NucleusPrecerebellar Nucleus1. Inferior Olivary Nuclear Complex1. Inferior Olivary Nuclear Complex 1a. Principal Inferior1a. Principal Inferior

Olivary NucleusOlivary Nucleus 1b. Medial Accessory1b. Medial Accessory

Olivary NucleusOlivary Nucleus 1c. Dorsal Accessory1c. Dorsal Accessory Olivary NucleusOlivary Nucleus2. Nucleus Intercalatus2. Nucleus Intercalatus3. Nucleus Conterminalis3. Nucleus Conterminalis4. Arcuate Nucleus4. Arcuate Nucleus




1. Lateral Reticular Nucleus1. Lateral Reticular Nucleus

2. Central Nucleus of2. Central Nucleus of

Medulla OblongataMedulla Oblongata

2d. subnucleus dorsalis2d. subnucleus dorsalis

2v. subnucleus ventralis2v. subnucleus ventralis

Clinical Syndromes Clinical Syndromes of Lower Medullaof Lower Medulla

A. HypoglossalA. Hypoglossal Alternating HemiplegiaAlternating Hemiplegia

B. Avelis SyndromeB. Avelis Syndrome

C. Jackson SyndromeC. Jackson Syndrome

D. Tapia SyndromeD. Tapia Syndrome

1. pyramidal tract1. pyramidal tract

2. hypoglossal nerve2. hypoglossal nerve

3. spinothalamic tract3. spinothalamic tract

4. nucleus ambiguus4. nucleus ambiguus

HypoglossalHypoglossalPalsyPalsy

Lower Motor Lower Motor NeuronNeuron

SyndromeSyndrome

HypoglossalHypoglossalPalsyPalsy


SyndromeSyndrome Deviation of Tongue to affected sideDeviation of Tongue to affected side

Atrophy of Tongue MusclesAtrophy of Tongue Muscles

Open Medulla Open Medulla (Mid-olivary Level)(Mid-olivary Level) Open Medulla Open Medulla (Mid-olivary Level)(Mid-olivary Level)

TegmentumTegmentum Cranial Nerve NucleiCranial Nerve Nuclei

Medial Vestibular NucleusMedial Vestibular NucleusSpinal Tract Nucleus of V, pars interpolarisSpinal Tract Nucleus of V, pars interpolaris

Precerebellar Nuclei Precerebellar Nuclei Accessory Cuneate NucleusAccessory Cuneate NucleusNucleus of Roller, Nucleus Interfascicularis HypoglossiNucleus of Roller, Nucleus Interfascicularis Hypoglossi

Reticular FormationReticular FormationLateral Reticular Nucleus, subtrigeminal portionLateral Reticular Nucleus, subtrigeminal portion

Unclassified NucleiUnclassified NucleiArea PostremaArea Postrema

Tracts: Tracts: Inferior Cerebellar Peduncle, DLFInferior Cerebellar Peduncle, DLF

Basal Part Basal Part - - PyramidPyramid

Cranial Nerve NucleiCranial Nerve Nuclei

1. Hypoglossal Nucleus1. Hypoglossal Nucleus2. Nucleus Ambiguus2. Nucleus Ambiguus



5. Spinal Tract Nucleus, 5. Spinal Tract Nucleus,

pars interpolarispars interpolaris

6. Medial Vestibular Nucleus6. Medial Vestibular Nucleus

Open MedullaOpen Medulla(Mid-olivary Level)(Mid-olivary Level)

Open MedullaOpen Medulla(Mid-olivary Level)(Mid-olivary Level)

Precerebellar NucleusPrecerebellar Nucleus1. Accessory Cuneate Nucleus1. Accessory Cuneate Nucleus2. Inferior Olivary Nuclear Complex2. Inferior Olivary Nuclear Complex 2a. Principal Inferior Olivary Nuc. 2a. Principal Inferior Olivary Nuc. 2b. Medial Accessory Olivary Nuc. 2b. Medial Accessory Olivary Nuc. 2c. Dorsal Accessory Olivary Nuc. 2c. Dorsal Accessory Olivary Nuc.

3. Nucleus Intercalatus3. Nucleus Intercalatus4. Nucleus of Roller4. Nucleus of Roller5. Nucleus Interfascicularis 5. Nucleus Interfascicularis HypoglossiHypoglossi6. Nucleus Conterminalis6. Nucleus Conterminalis

Open MedullaOpen Medulla (Mid-olivary Level)(Mid-olivary Level)

XII. Hypoglossal NerveXII. Hypoglossal Nerve

1. Hypoglossal Nucleus1. Hypoglossal Nucleus

X. Vagus NerveX. Vagus Nerve




5. Spinal Tract Nucleus of V5. Spinal Tract Nucleus of V

A. Dejerine’s SyndromeA. Dejerine’s Syndrome

1. pyramidal tract1. pyramidal tract

2. hypoglossal nerve2. hypoglossal nerve

3. medial lemniscus3. medial lemniscus

B. Wallenberg SyndromeB. Wallenberg Syndrome

4. spinothalamic tract4. spinothalamic tract

5. spinal tract of trigeminal nerve5. spinal tract of trigeminal nerve

6. nucleus ambiguus6. nucleus ambiguus

7. 7. descending autonomicdescending autonomic pathwaypathway

Clinical Syndromes Clinical Syndromes

of Open Medullaof Open Medulla

Wallenberg SyndromeWallenberg Syndrome

Spinothalamic tractSpinothalamic tract

- contralateral loss of pain and - contralateral loss of pain and

temperature sensation at the bodytemperature sensation at the body

Spinal tract of trigeminal nerveSpinal tract of trigeminal nerve - ipsilateral loss of pain and - ipsilateral loss of pain and

temperature sensation at the facetemperature sensation at the face

Nucleus ambiguusNucleus ambiguus - dysphageia, dysarthria, hoarseness- dysphageia, dysarthria, hoarseness

DDescending autonomic pathwayescending autonomic pathway

- Horner’s syndrome - Horner’s syndrome

(meiosis, ptosis, anhydrosis)(meiosis, ptosis, anhydrosis)

Open Medulla Open Medulla (Upper Level of Medulla)(Upper Level of Medulla) Open Medulla Open Medulla (Upper Level of Medulla)(Upper Level of Medulla)


Inferior Vestibular NucleusInferior Vestibular NucleusDorsal Cochlear NucleusDorsal Cochlear Nucleus

Precerebellar Nuclei Precerebellar Nuclei Nucleus Prepositus HypoglossiNucleus Prepositus Hypoglossi

Reticular FormationReticular FormationGigantocellular Reticular NucleusGigantocellular Reticular NucleusParagigantocellular Reticular NucleusParagigantocellular Reticular NucleusParvocellular Reticular NucleusParvocellular Reticular NucleusRaphe NucleiRaphe Nuclei

Unclassified NucleiUnclassified Nucleiretrofacial, supravestibular nucleus, nucleus interpositusretrofacial, supravestibular nucleus, nucleus interpositus

Tracts: Tracts: stria medullaris of 4th ventriclestria medullaris of 4th ventricle








5. Inferior Vestibular Nucleus5. Inferior Vestibular Nucleus

6. Dorsal Cochlear Nucleus6. Dorsal Cochlear Nucleus

Open MedullaOpen Medulla(Upper Level of Medulla)(Upper Level of Medulla)


Precerebellar NucleusPrecerebellar Nucleus

1. Inferior Olivary Nuclear Complex1. Inferior Olivary Nuclear Complex 2a. Principal Inferior Olivary Nuc. 2a. Principal Inferior Olivary Nuc. 2b. Medial Accessory Olivary Nuc. 2b. Medial Accessory Olivary Nuc. 2c. Dorsal Accessory Olivary Nuc. 2c. Dorsal Accessory Olivary Nuc.

2. Nucleus Prepositus Hypoglossi2. Nucleus Prepositus Hypoglossi

3. Pontobulbar Body3. Pontobulbar Body

4. Arcuate Nucleus4. Arcuate Nucleus




Reticular FormationReticular Formation 1. Paramedian reticular Nucleus1. Paramedian reticular Nucleus2. Gigantocellular Reticular Nucleus2. Gigantocellular Reticular Nucleus3. paragigantocellular 3. paragigantocellular Reticular NucleusReticular Nucleus4. Parvocellular Reticular Nucleus4. Parvocellular Reticular Nucleus5. Nucleus raphe Obscrus (B5. Nucleus raphe Obscrus (B22))

6. Nucleus Raphe Pallidus (B6. Nucleus Raphe Pallidus (B11))

7. Nucleus Raphe Magnus (B7. Nucleus Raphe Magnus (B33))

Unclassifiied NucleiUnclassifiied NucleiA. Nucleus RetrofacialisA. Nucleus RetrofacialisB. Supravestibular NucleusB. Supravestibular NucleusC. Nucleus Interpositus C. Nucleus Interpositus

IX. glossopharyngeal IX. glossopharyngeal NerveNerve


2. Inferior Salivatory Nucleus2. Inferior Salivatory Nucleus



Open Medulla Open Medulla (Upper Level of Medulla)(Upper Level of Medulla)

Pontomedullary JunctionPontomedullary Junction Pontomedullary JunctionPontomedullary Junction


Facial Motor NucleusFacial Motor NucleusVentral Cochlear NucleusVentral Cochlear Nucleus

Precerebellar Nuclei Precerebellar Nuclei Reticular FormationReticular Formation Unclassified NucleiUnclassified Nuclei

nucleus ovalisnucleus ovalis TractsTracts


Cranial Nerve -Cranial Nerve - Vestibulocochlear Nerve (VIII)Vestibulocochlear Nerve (VIII)

Facial Nerve (VII)Facial Nerve (VII)


1. Facial Motor Nucleus 1. Facial Motor Nucleus





5. Inferior Vestibular Nucleu5. Inferior Vestibular Nucleu

ss

6. Ventral Cochlear Nucleus6. Ventral Cochlear Nucleus

PontomedullaryPontomedullaryJunctionJunction


Precerebellar NucleusPrecerebellar Nucleus

1. Principal Inferior1. Principal Inferior Olivary NucleusOlivary Nucleus

2. Nucleus Prepositus2. Nucleus Prepositus HypoglossiHypoglossi

3. Pontobulbar Body3. Pontobulbar Body

4. Arcuate Nucleus4. Arcuate Nucleus




Reticular FormationReticular Formation 1. Paramedian reticular Nucleus1. Paramedian reticular Nucleus2. Gigantocellular2. Gigantocellular Reticular NucleusReticular Nucleus3. paragigantocellular 3. paragigantocellular Reticular NucleusReticular Nucleus4. Parvocellular Reticular Nucleus4. Parvocellular Reticular Nucleus7. Nucleus Raphe Magnus (B7. Nucleus Raphe Magnus (B33))

Unclassifiied NucleiUnclassifiied NucleiA. Nucleus InterpositusA. Nucleus InterpositusB. Nucleus OvalisB. Nucleus Ovalis

Lower Pons Lower Pons (Level of Abducens Nucleus)(Level of Abducens Nucleus) Lower Pons Lower Pons (Level of Abducens Nucleus)(Level of Abducens Nucleus)


Abducens Nucleus, Main Sensory Nucleus of VAbducens Nucleus, Main Sensory Nucleus of V Nuclei of Auditory PathwayNuclei of Auditory Pathway

Superior Olivary Nuclear ComplexSuperior Olivary Nuclear Complex Reticular FormationReticular Formation

Caudal Pontine Reticular & Subceruleus NucleusCaudal Pontine Reticular & Subceruleus Nucleus TractsTracts

Trapezoid Body, lateral Lemniscus, Trapezoid Body, lateral Lemniscus, Central tegmental TractCentral tegmental Tract

Basal Part: Pons Proper:Basal Part: Pons Proper: Pontine NucleiPontine Nuclei,,Transverse Pontine Fiber, Transverse Pontine Fiber, Longitudinal Pontine Fiber (Pyramidal Tract)Longitudinal Pontine Fiber (Pyramidal Tract)

Lower PonsLower Pons (Level of Abducens Nucleus)(Level of Abducens Nucleus)


1. Abducens Nucleus1. Abducens Nucleus

2. Main Sensory Nucleus of V2. Main Sensory Nucleus of V

3. Lateral vestibular Nucleus3. Lateral vestibular Nucleus

4. Superior Vestibular Nucleus4. Superior Vestibular Nucleus

Auditory Relay NucleiAuditory Relay Nuclei A. Superior Olivary NucleusA. Superior Olivary Nucleus

B. Nucleus of Trapezoid bodyB. Nucleus of Trapezoid body

Lower PonsLower Pons (Level of Abducens Nucleus)(Level of Abducens Nucleus)


1. Gigantocellular1. Gigantocellular

Reticular NucleusReticular Nucleus

2. Caudal Pontine2. Caudal Pontine

Reticular Nucleus Reticular Nucleus

3. Parvocellular 3. Parvocellular

Reticular NucleusReticular Nucleus

4. Nucleus Subceruleus4. Nucleus Subceruleus

VII. Facial NerveVII. Facial Nerve

1. Facial Motor Nucleus1. Facial Motor Nucleus

2. Superior Salivatory Nucleus2. Superior Salivatory Nucleus



VI. Abducens NerveVI. Abducens Nerve

5. Abducens Nucleus 5. Abducens Nucleus

A. Facial PalsyA. Facial PalsyB. A + B. A + decreased salivationdecreased salivationC. A + B + C. A + B + hyperacusishyperacusisD. A + B + C + D. A + B + C + decrased decrased lacrimal secretionlacrimal secretionE. Central Type Facial PalsyE. Central Type Facial Palsy

1. Facial Motor Nucleus1. Facial Motor Nucleus2. Superior Salivatory Nucleus2. Superior Salivatory Nucleus3. Solitary Nucleus3. Solitary Nucleus4. Spinal Tract Nucleus of4. Spinal Tract Nucleus of Trigeminal NerveTrigeminal Nerve

FacialFacial PalsyPalsy

(Bell’s Palsy)(Bell’s Palsy)

Lower MotorLower MotorNeuronNeuron

SyndromeSyndrome

FacialFacial PalsyPalsy

(Bell’s Palsy)(Bell’s Palsy)

Lower MotorLower MotorNeuronNeuron

SyndromeSyndromeTriple W SignTriple W Sign - Wrinkle, Wink, Whistle - Wrinkle, Wink, Whistle

Right facial paralysisRight facial paralysis

FacialFacial Palsy (Bell’s Palsy)Palsy (Bell’s Palsy)

Central TypeCentral TypeFacialFacial PalsyPalsy

Upper MotorUpper MotorNeuronNeuron

SyndromeSyndrome

Central TypeCentral TypeFacialFacial PalsyPalsy

Upper MotorUpper MotorNeuronNeuron

SyndromeSyndromefacial motor nucleus neuronsfacial motor nucleus neuronssupplying forehead musclesupplying forehead muscle

Bilateral Corticobulbar TractBilateral Corticobulbar Tract

AbducensAbducensPalsyPalsy


SyndromeSyndrome

AbducensAbducensPalsyPalsy


SyndromeSyndrome Lateral Gaze ParalysisLateral Gaze Paralysis

Upper Pons Upper Pons (Level of Trigeminal Motor Nucleus)(Level of Trigeminal Motor Nucleus)Upper Pons Upper Pons (Level of Trigeminal Motor Nucleus)(Level of Trigeminal Motor Nucleus)


Trigeminal Motor Nucleus,Trigeminal Motor Nucleus,Mesencephalic Tract Nucleus of Trigeminal NerveMesencephalic Tract Nucleus of Trigeminal Nerve

Nuclei of Auditory PathwayNuclei of Auditory PathwayNucleus of Lateral LemniscusNucleus of Lateral Lemniscus

Reticular FormationReticular FormationReticular Tegmental NucleusReticular Tegmental Nucleus

Unclassified NucleusUnclassified NucleusPontine Central Gray: Ch6Pontine Central Gray: Ch6

TractsTractsTrigeminal Nerve FiberTrigeminal Nerve Fiber

Basal Part: Pons ProperBasal Part: Pons Proper

Upper Pons Upper Pons (Level of Trigeminal Motor Nucleus)(Level of Trigeminal Motor Nucleus)


1. Trigeminal Motor Nucleus1. Trigeminal Motor Nucleus

2. Main Sensory Nucleus of V2. Main Sensory Nucleus of V

3. Mesencephalic Tract3. Mesencephalic Tract

Nucleus of VNucleus of V

4. Superior Vestibular Nucleus4. Superior Vestibular Nucleus

Auditory Relay NucleiAuditory Relay Nuclei A. Nucleus of Lateral LemniscusA. Nucleus of Lateral Lemniscus

Upper Pons Upper Pons (Level of Trigeminal Motor Nucleus)(Level of Trigeminal Motor Nucleus)


1. Caudal Pontine1. Caudal Pontine

Reticular Nucleus Reticular Nucleus

2. Nucleus Subceruleus2. Nucleus Subceruleus

3. Reticular Tegemntal3. Reticular Tegemntal

Nucleus of BekhterewNucleus of Bekhterew

(Nucleus Papilloformis of(Nucleus Papilloformis of

Olszewski and Baxter)Olszewski and Baxter)

A. Millard-Gubler SyndromeA. Millard-Gubler SyndromeB. Raymond SyndromeB. Raymond SyndromeC. Foville SyndromeC. Foville SyndromeD. Raymond-Cestan SyndromeD. Raymond-Cestan SyndromeE. Marie-Poix SyndromeE. Marie-Poix Syndrome

1. pyramidal tract1. pyramidal tract2.2. MLFMLF3. 3. medial lemniscusmedial lemniscus4. spinothalamic tract4. spinothalamic tract5. trigeminal motor nucleus5. trigeminal motor nucleus6. main sensory nucleus of V6. main sensory nucleus of V7. spinal tract of trigeminal nerve7. spinal tract of trigeminal nerve8. 8. middle cerebellar pedunclemiddle cerebellar peduncle

Clinical Syndromes Clinical Syndromes of Ponsof Pons

Trigeminal NeuralgiaTrigeminal Neuralgia(tic douloureux)(tic douloureux)

- - excruciating episodic painexcruciating episodic pain

in the area supplied by in the area supplied by

trigeminal nerve, especiallytrigeminal nerve, especially

second and third divisionsecond and third division

- - trigger pointtrigger point

- intense pain makes the- intense pain makes the

patient grimace (tic)patient grimace (tic)

- - antiepileptic drugantiepileptic drug (phenytoin, (phenytoin,

carbamazepinecarbamazepine) is effective) is effective

- surgical treatment- surgical treatment

Lower Midbrain Lower Midbrain (Level of Inferior Colliculus)(Level of Inferior Colliculus) Lower Midbrain Lower Midbrain (Level of Inferior Colliculus)(Level of Inferior Colliculus)

Roof Plate - Roof Plate - Tectum:Tectum: Inferior ColliculusInferior Colliculus


Trochlear NucleusTrochlear Nucleus Reticular FormationReticular Formation

Cuneiform, Pedunculopontine, Parabrachial Cuneiform, Pedunculopontine, Parabrachial and Median Raphe (Superior Central) Nucleusand Median Raphe (Superior Central) Nucleus

Unclassified NucleiUnclassified NucleiPeriaqueductal GrayPeriaqueductal Gray

TractsTractsDecussation of Superior Cerebellar PeduncleDecussation of Superior Cerebellar Peduncle

Basal Part Basal Part - - Crus Cerebri,Crus Cerebri, Pons ProperPons Proper

Lower MidbrainLower Midbrain (Level of Inferior(Level of Inferior

Colliculus)Colliculus)

Roof PlateRoof Plate A. Inferior ColliculusA. Inferior Colliculus


1. Mesencephalic Tract1. Mesencephalic Tract Nucleus ofNucleus of Trigeminal NerveTrigeminal Nerve

2. Trochlear Nucleus2. Trochlear Nucleus

Lower MidbrainLower Midbrain (Level of Inferior(Level of Inferior

Colliculus)Colliculus) Reticular FormationReticular Formation 1. Cuneiform Nucleus1. Cuneiform Nucleus2. Pedunculopontine Nucleus2. Pedunculopontine Nucleus3. Nucleus Locus ceruleus3. Nucleus Locus ceruleus4. Parabrachial Nucleus4. Parabrachial Nucleus5. Dorsal Raphe Nucleus5. Dorsal Raphe Nucleus6. Median Raphe Nucleus6. Median Raphe Nucleus

Unclassified NucleiUnclassified NucleiA. Periaqueductal GrayA. Periaqueductal GrayB. Dorsal Tegmental Nucleus B. Dorsal Tegmental Nucleus of Guddenof GuddenC. Interpeduncular NucleusC. Interpeduncular NucleusD. Parabigeminal NucleusD. Parabigeminal Nucleus

C

6

5

Upper Midbrain Upper Midbrain (Level of Superior Colliculus)(Level of Superior Colliculus) Upper Midbrain Upper Midbrain (Level of Superior Colliculus)(Level of Superior Colliculus)

Roof Plate - Roof Plate - Tectum:Tectum: Superior ColliculusSuperior Colliculus


Oculomotor and Edinger-Westphal NucleusOculomotor and Edinger-Westphal Nucleus Reticular Formation - Reticular Formation - Subcuneiform NucleusSubcuneiform Nucleus Precerebellar Nuclei Precerebellar Nuclei

Red NucleusRed Nucleus Unclassified NucleiUnclassified Nuclei

Substantia Nigra, Substantia Nigra, Paranigral, ParalemniscalParanigral, Paralemniscal NucleusNucleusVentral Tegmental Area (VTA)Ventral Tegmental Area (VTA)

TractsTractsBrachium of Inferior ColliculusBrachium of Inferior Colliculus

Basal Part Basal Part - - Crus CerebriCrus Cerebri

Upper MidbrainUpper Midbrain (Level of Superior(Level of Superior

Colliculus)Colliculus)

Roof PlateRoof Plate A. Superior ColliculusA. Superior Colliculus

Precerebellar NucleusPrecerebellar NucleusB. Red NucleusB. Red Nucleus

Cranial Nerve NucleiCranial Nerve Nuclei1. Mesencephalic Tract1. Mesencephalic Tract Nucleus of VNucleus of V2. Oculomotor Nucleus2. Oculomotor Nucleus3. Edinger-Westphal Nucleus3. Edinger-Westphal Nucleus

Upper MidbrainUpper Midbrain (Level of Superior(Level of Superior

Colliculus)Colliculus) Reticular FormationReticular Formation A. Cuneiform NucleusA. Cuneiform NucleusB. Subcuneiform NucleusB. Subcuneiform Nucleus

Unclassified NucleiUnclassified Nuclei1. Periaqueductal Gray1. Periaqueductal Gray2. Paralemniscal Nucleus2. Paralemniscal Nucleus 3. Substantia Nigra3. Substantia Nigra 3a. Pars Compacta3a. Pars Compacta 3b. Pars Reticulata3b. Pars Reticulata4. Paranigral Nucleus4. Paranigral Nucleus5. Ventral Tegmental Area5. Ventral Tegmental Area

Clinical Syndromes Clinical Syndromes of Upper Midbrainof Upper Midbrain A. Weber SyndromeA. Weber SyndromeB. Foix SyndromeB. Foix SyndromeC. Benedikt’s SyndromeC. Benedikt’s SyndromeD. Claude SyndromeD. Claude SyndromeE. Parinaud’s SyndromeE. Parinaud’s Syndrome

1. pyramidal tract1. pyramidal tract2. superior cerebellar peduncle2. superior cerebellar peduncle 3. red nucleus3. red nucleus4. medial lemniscus4. medial lemniscus5. superior colliculus5. superior colliculus6. cerebral aqueduct6. cerebral aqueduct7. MLF7. MLF8. oculomotor nucleus8. oculomotor nucleus

Weber SyndromeWeber Syndrome

Pyramidal tractPyramidal tract

- contralateral UMN syndrome - contralateral UMN syndrome

at the body and lower faceat the body and lower face

(contralateral hemiparesis)(contralateral hemiparesis)

Oculomotor Nerve Oculomotor Nerve - ipsilateral ocular palsy- ipsilateral ocular palsy

- external strabismus- external strabismus

- mydriasis- mydriasis

- loss of accommodation- loss of accommodation

- normal consensual light reflex- normal consensual light reflex

Documents

Nabeel Kouka, MD, DO, MBA