The Spinal Cord The Spinal Cord

Structure of the spinal cordStructure of the spinal cord

Tracts of the spinal cordTracts of the spinal cord

Spinal cord syndromes Spinal cord syndromes

The Spinal Cord The Spinal Cord

Structure of the spinal cordStructure of the spinal cord

Tracts of the spinal cordTracts of the spinal cord

Spinal cord syndromes Spinal cord syndromes

Nabeel Kouka, Nabeel Kouka, MD, MBA, FABMISSMD, MBA, FABMISSwww.brain101.infowww.brain101.info

Nabeel Kouka, Nabeel Kouka, MD, MBA, FABMISSMD, MBA, FABMISSwww.brain101.infowww.brain101.info

- Comparable to- Comparable to Input-Output (IO) System of the ComputerInput-Output (IO) System of the Computer

- Spinal Nerve (C8, T12, L5, S5, Cx1)- Spinal Nerve (C8, T12, L5, S5, Cx1)

- Segmental Structure of Neural Tube Origin- Segmental Structure of Neural Tube Origin

- Comparable to- Comparable to Input-Output (IO) System of the ComputerInput-Output (IO) System of the Computer

- Spinal Nerve (C8, T12, L5, S5, Cx1)- Spinal Nerve (C8, T12, L5, S5, Cx1)

- Segmental Structure of Neural Tube Origin- Segmental Structure of Neural Tube Origin

Spinal CordSpinal CordSpinal CordSpinal Cord

Spinal segment Spinal segment

C8, T12, L5, S5, Cx1C8, T12, L5, S5, Cx1

Anterior (Ventral) RootAnterior (Ventral) RootPosterior (Dorsal) RootPosterior (Dorsal) Root Dorsal Root (Spinal) GanglionDorsal Root (Spinal) Ganglion

Root - RootletsRoot - Rootlets

Conus Medullaris Conus Medullaris (L1-2)(L1-2)

Cauda EquinaCauda Equina

Anterior median fissureAnterior median fissureAnterolateral fissureAnterolateral fissure

Posterior Posterior median sulcusmedian sulcus

PosterolateralPosterolateral

sulcussulcus

Posterior Posterior intermediate intermediate sulcussulcus

FasciculusFasciculus

cuneatuscuneatus

FasciculusFasciculus

gracilisgracilis

Posterior surface of the spinal cordPosterior surface of the spinal cord

Periosteum of VertebraPeriosteum of Vertebra

- - Epidural Space Epidural Space ----------------- ----------------- epidural anesthesiaepidural anesthesia

Dura Mater Spinalis Dura Mater Spinalis

Arachnoid MembraneArachnoid Membrane - - Subarachnoid Space --------Subarachnoid Space -------- Lumbar Puncture Lumbar Puncture

Spinal AnesthesiaSpinal Anesthesia

Pia Mater SpinalisPia Mater Spinalis - Denticulate Ligament- Denticulate Ligament --------- --------- CordotomyCordotomy

- Filum Terminale- Filum Terminale

Periosteum of VertebraPeriosteum of Vertebra

- - Epidural Space Epidural Space ----------------- ----------------- epidural anesthesiaepidural anesthesia

Dura Mater Spinalis Dura Mater Spinalis

Arachnoid MembraneArachnoid Membrane - - Subarachnoid Space --------Subarachnoid Space -------- Lumbar Puncture Lumbar Puncture

Spinal AnesthesiaSpinal Anesthesia

Pia Mater SpinalisPia Mater Spinalis - Denticulate Ligament- Denticulate Ligament --------- --------- CordotomyCordotomy

- Filum Terminale- Filum Terminale

Spinal Cord MeningesSpinal Cord Meninges Spinal Cord MeningesSpinal Cord Meninges

Meninges of Meninges of the spinal cordthe spinal cord

• Dura materDura mater• Arachnoid membraneArachnoid membrane• Pia materPia mater

Denticulate ligamentDenticulate ligament

- specialization of the pia mater- specialization of the pia mater

- landmark for cordotomy- landmark for cordotomy

Meninges of the spinal cordMeninges of the spinal cord

Meninges of the spinal cordMeninges of the spinal cord

Lumbar Puncture – lumbar (terminal) cisternLumbar Puncture – lumbar (terminal) cistern

Arterial SupplyArterial Supply

- Spinal Arteries- Spinal Arteries

Anterior (1) & Posterior (2) Spinal ArteryAnterior (1) & Posterior (2) Spinal Artery

from from Vertebral arteryVertebral artery

- Radicular Arteries ----- Segmental arteries- Radicular Arteries ----- Segmental arteries

from from Vertebral, Ascending Cervical, Intercostal andVertebral, Ascending Cervical, Intercostal and

Lumbar Artery Lumbar Artery

Venous DrainageVenous Drainage - - Longitudinal & Radicular Veins Longitudinal & Radicular Veins

toto Intervertebral veins Intervertebral veins ---- to ---- to Internal Vertebral Venous PlexusInternal Vertebral Venous Plexus

to to external vertebral venous plexus external vertebral venous plexus ---- to ---- to segmental veinssegmental veins

Arterial SupplyArterial Supply

- Spinal Arteries- Spinal Arteries

Anterior (1) & Posterior (2) Spinal ArteryAnterior (1) & Posterior (2) Spinal Artery

from from Vertebral arteryVertebral artery

- Radicular Arteries ----- Segmental arteries- Radicular Arteries ----- Segmental arteries

from from Vertebral, Ascending Cervical, Intercostal andVertebral, Ascending Cervical, Intercostal and

Lumbar Artery Lumbar Artery

Venous DrainageVenous Drainage - - Longitudinal & Radicular Veins Longitudinal & Radicular Veins

toto Intervertebral veins Intervertebral veins ---- to ---- to Internal Vertebral Venous PlexusInternal Vertebral Venous Plexus

to to external vertebral venous plexus external vertebral venous plexus ---- to ---- to segmental veinssegmental veins

Spinal Cord Spinal Cord Vascular SupplyVascular Supply Spinal Cord Spinal Cord Vascular SupplyVascular Supply

anterior spinal arteryanterior spinal artery segmental arteries segmental arteries

5. Adamkiwicz artery5. Adamkiwicz artery

Spinal Cord Spinal Cord External FigureExternal Figure Spinal Cord Spinal Cord External FigureExternal Figure

Conus Medullaris Conus Medullaris (L1-2)(L1-2)

Spinomedullary JunctionSpinomedullary Junction - Foramen Magnum, Pyramidal decussation, C1 ventral root

EnlargementsEnlargements - Cervical (C4-T1) & Lumbosacral (L1-L4)

Longitudinal FissuresLongitudinal Fissures - anterior median fissure - anterolateral fissure - posterior median sulcus - posterolateral sulcus

Conus Medullaris Conus Medullaris (L1-2)(L1-2)

Spinomedullary JunctionSpinomedullary Junction - Foramen Magnum, Pyramidal decussation, C1 ventral root

EnlargementsEnlargements - Cervical (C4-T1) & Lumbosacral (L1-L4)

Longitudinal FissuresLongitudinal Fissures - anterior median fissure - anterolateral fissure - posterior median sulcus - posterolateral sulcus

Spinal Cord Spinal Cord External FigureExternal Figure Spinal Cord Spinal Cord External FigureExternal Figure

cervical enlargement (C8)cervical enlargement (C8) thoracic cord (T8) thoracic cord (T8)

lumbar enlargement (L3)lumbar enlargement (L3) sacral cord (S1) sacral cord (S1)

• Cervical levelCervical level- Wide flat cord, lots of white matter, ventral horn enlargements.

• Lumbar levelLumbar level - Round cord, ventral horn enlargements.

• Sacral levelSacral level - Small round cord, lateral Horn.

• Tthoracic levelTthoracic level - Notice the pointed tips which stick out between the small dorsal and ventral horns. This extra cell column is called the intermediate horn (AKA: IntermediolateralIntermediolateral

Cell ColumnCell Column). It is the source of all of the sympathetics in the body & occurs only in the Thoracic sections T 1 - L 2

• Cervical levelCervical level- Wide flat cord, lots of white matter, ventral horn enlargements.

• Lumbar levelLumbar level - Round cord, ventral horn enlargements.

• Sacral levelSacral level - Small round cord, lateral Horn.

• Tthoracic levelTthoracic level - Notice the pointed tips which stick out between the small dorsal and ventral horns. This extra cell column is called the intermediate horn (AKA: IntermediolateralIntermediolateral

Cell ColumnCell Column). It is the source of all of the sympathetics in the body & occurs only in the Thoracic sections T 1 - L 2

White MatterWhite Matter Anterior Funiculus (Anterior White Column)Anterior Funiculus (Anterior White Column)

Posterior Funiculus (Posterior White Column)Posterior Funiculus (Posterior White Column) Fasciculus Gracilis & Fasciculus CuneatusFasciculus Gracilis & Fasciculus Cuneatus

Lateral Funiculus (Lateral White Column)Lateral Funiculus (Lateral White Column)

Gray MatterGray Matter Anterior Horn ------------Anterior Horn ------------------ motormotor

Posterior Horn --------------Posterior Horn -------------- sensorysensory

Lateral Horn -----------------Lateral Horn ----------------- autonomic (sympathetic)autonomic (sympathetic)

Gray Commissure -------- Gray Commissure -------- anterior and posterior anterior and posterior

White MatterWhite Matter Anterior Funiculus (Anterior White Column)Anterior Funiculus (Anterior White Column)

Posterior Funiculus (Posterior White Column)Posterior Funiculus (Posterior White Column) Fasciculus Gracilis & Fasciculus CuneatusFasciculus Gracilis & Fasciculus Cuneatus

Lateral Funiculus (Lateral White Column)Lateral Funiculus (Lateral White Column)

Gray MatterGray Matter Anterior Horn ------------Anterior Horn ------------------ motormotor

Posterior Horn --------------Posterior Horn -------------- sensorysensory

Lateral Horn -----------------Lateral Horn ----------------- autonomic (sympathetic)autonomic (sympathetic)

Gray Commissure -------- Gray Commissure -------- anterior and posterior anterior and posterior

Spinal Cord Spinal Cord Internal StructureInternal Structure Spinal Cord Spinal Cord Internal StructureInternal Structure

1. posterior horn 1. posterior horn

2. anterior horn 2. anterior horn

3. intermediate zone 3. intermediate zone

(intermediate gray) (intermediate gray)

4. lateral horn 4. lateral horn

5. posterior funiculus5. posterior funiculus

6. anterior funiculus6. anterior funiculus

7. lateral funiculus 7. lateral funiculus

8. Lissauer's tract 8. Lissauer's tract

9. anterior median 9. anterior median

fissure fissure

10. posterior median 10. posterior median

sulcus sulcus

11. anterolateral 11. anterolateral

sulcus sulcus

12. posterolateral 12. posterolateral

sulcus sulcus

13. Posterior13. Posterior

intermediate intermediate sulcus sulcus

Principles of Cord OrganizationPrinciples of Cord Organization

1) Longitudinal Arrangement1) Longitudinal Arrangement Fibers (White Matter) ------------- White ColumnFibers (White Matter) ------------- White Column

Cell Groups (Gray Matter) ------- Gray ColumnCell Groups (Gray Matter) ------- Gray Column

2) Transverse Arrangement2) Transverse Arrangement Afferent & Efferent FibersAfferent & Efferent Fibers

Crossing (Commissural and Decussating) FibersCrossing (Commissural and Decussating) Fibers

3) Somatotopical Arrangement3) Somatotopical Arrangement

Principles of Cord OrganizationPrinciples of Cord Organization

1) Longitudinal Arrangement1) Longitudinal Arrangement Fibers (White Matter) ------------- White ColumnFibers (White Matter) ------------- White Column

Cell Groups (Gray Matter) ------- Gray ColumnCell Groups (Gray Matter) ------- Gray Column

2) Transverse Arrangement2) Transverse Arrangement Afferent & Efferent FibersAfferent & Efferent Fibers

Crossing (Commissural and Decussating) FibersCrossing (Commissural and Decussating) Fibers

3) Somatotopical Arrangement3) Somatotopical Arrangement

Spinal Cord Spinal Cord Internal StructureInternal Structure Spinal Cord Spinal Cord Internal StructureInternal Structure

Columnar arrangement Somatotopical arrangementColumnar arrangement Somatotopical arrangement

Lamina of RexedLamina of RexedLamina of RexedLamina of Rexed

Lamina I Lamina I Posteromarginal NucleusPosteromarginal Nucleus

Lamina II Lamina II Substantia Gelatinosa of RolandoSubstantia Gelatinosa of Rolando

Lamina IIILamina III

Lamina IV, V, VI ----- Lamina IV, V, VI ----- Nucleus PropriusNucleus Proprius

Lamina VIILamina VII

- Intermediate Gray- Intermediate Gray

- I- Intermediolateral cell column (ILM)ntermediolateral cell column (ILM)

- - Clarke’s column (Nucleus dorsalis)Clarke’s column (Nucleus dorsalis)- I- Intermediomedial cell column (IMM)ntermediomedial cell column (IMM)

Lamina VIIILamina VIII

Lamina IX ---------- Lamina IX ---------- Anterior Horn (Motor) CellAnterior Horn (Motor) Cell

Lamina X ----------- Lamina X ----------- Gray CommissureGray Commissure

Lamina I Lamina I Posteromarginal NucleusPosteromarginal Nucleus

Lamina II Lamina II Substantia Gelatinosa of RolandoSubstantia Gelatinosa of Rolando

Lamina IIILamina III

Lamina IV, V, VI ----- Lamina IV, V, VI ----- Nucleus PropriusNucleus Proprius

Lamina VIILamina VII

- Intermediate Gray- Intermediate Gray

- I- Intermediolateral cell column (ILM)ntermediolateral cell column (ILM)

- - Clarke’s column (Nucleus dorsalis)Clarke’s column (Nucleus dorsalis)- I- Intermediomedial cell column (IMM)ntermediomedial cell column (IMM)

Lamina VIIILamina VIII

Lamina IX ---------- Lamina IX ---------- Anterior Horn (Motor) CellAnterior Horn (Motor) Cell

Lamina X ----------- Lamina X ----------- Gray CommissureGray Commissure

Lamina of RexedLamina of RexedLamina of RexedLamina of Rexed

• AKA: lamina marginalislamina marginalis or the layer of Waldeyer

• Receives incoming dorsal root fibers and collateral branches as well

• Larger neurons contribute axons to Contralateral Spinothalamic TractSpinothalamic Tract

• AKA: lamina marginalislamina marginalis or the layer of Waldeyer

• Receives incoming dorsal root fibers and collateral branches as well

• Larger neurons contribute axons to Contralateral Spinothalamic TractSpinothalamic Tract

Lamina ILamina ILamina ILamina I

• AKA: Substantia GelatinosaSubstantia Gelatinosa

• Involved in PainPain interpretation• Receives incoming inputincoming input from dorsaldorsal

rootroot axons & descending inputdescending input from

reticular formationreticular formation of the medulla • Efferent axons travel up & down several segments to make contact with other areas of the dorsal horn

• AKA: Substantia GelatinosaSubstantia Gelatinosa

• Involved in PainPain interpretation• Receives incoming inputincoming input from dorsaldorsal

rootroot axons & descending inputdescending input from

reticular formationreticular formation of the medulla • Efferent axons travel up & down several segments to make contact with other areas of the dorsal horn

Lamina IILamina IILamina IILamina II

• Contains larger, less densely packed cells than lamina II

• Receives primary afferents from dorsal rootdorsal root fibers

• Neurons considered as a part of nucleus propriusnucleus proprius

• Contains larger, less densely packed cells than lamina II

• Receives primary afferents from dorsal rootdorsal root fibers

• Neurons considered as a part of nucleus propriusnucleus proprius

Lamina IIILamina IIILamina IIILamina III

Lamina IVLamina IVLamina IVLamina IV

• Contains a variety of cell types that have more myelinmore myelin than any other lamina

• Some tract cellstract cells originate here, axons cross the midline and enter the contralateral Spinothalamic TractSpinothalamic Tract, also sends contacts to layers II and III

• Receives afferents from dorsal roots via the dorsal funiculusdorsal funiculus

• At rostral end of spinal cord, laminas I-IV become continuous with the spinal spinal trigeminal nucleustrigeminal nucleus

Lamina V - VILamina V - VILamina V - VILamina V - VI

• Origination of tract cellstract cells, similar to lamina IV, these tracts cells are also known as the Nucleus Proprius Nucleus Proprius (e.g. spinal thalamic tractspinal thalamic tract or anterolateral systemanterolateral system; pain and temperature, some tactile)

• Receives afferent input from dorsal roots and descending fibers, most importantly CorticospinalCorticospinal

Laterally, gray matter at base of dorsal horn mixes withwhite matter from lateral funiculus, this region is calledreticular formationreticular formation. It is noticeable in the cervical region

Laterally, gray matter at base of dorsal horn mixes withwhite matter from lateral funiculus, this region is calledreticular formationreticular formation. It is noticeable in the cervical region

Lamina V - VILamina V - VILamina V - VILamina V - VI

reticular formationreticular formation ---------------->---------------->

C7C7

• The largest region, occupies most of ventral horn &intermediate zone

• Projects long axons that connect to other gray matter segments of the cord

• Some columns do not fit into the lamina scheme, and have individual designations:

a. Nucleus dorsalis (ClarkeClarke)b. Intermediolateral cell columnc. Intermediomedial cell columnd. Sacral autonomic nucleus

• The largest region, occupies most of ventral horn &intermediate zone

• Projects long axons that connect to other gray matter segments of the cord

• Some columns do not fit into the lamina scheme, and have individual designations:

a. Nucleus dorsalis (ClarkeClarke)b. Intermediolateral cell columnc. Intermediomedial cell columnd. Sacral autonomic nucleus

Lamina VIILamina VIILamina VIILamina VII

Lamina VIILamina VIILamina VIILamina VII

• Nucleus dorsalisNucleus dorsalis of of ClarkClark AKA nucleus thoracicusnucleus thoracicus is located medial & ventral to the dorsal horn in T1-L3

• Composed of large neurons & axons that form the dorsal spinocerebellar tractdorsal spinocerebellar tract on the ipsilateral side

• Nucleus dorsalisNucleus dorsalis of of ClarkClark AKA nucleus thoracicusnucleus thoracicus is located medial & ventral to the dorsal horn in T1-L3

• Composed of large neurons & axons that form the dorsal spinocerebellar tractdorsal spinocerebellar tract on the ipsilateral side

T5

Lamina VIILamina VIILamina VIILamina VII

• Intermediolateral cell columnIntermediolateral cell column is located at the lateral portion of the intermediate zone.

• Responsible for the formation of the lateral hornlateral horn in T1 - L2T1 - L2

• Consists of cell bodies of sympatheticsympathetic preganglionic neurons

• Intermediolateral cell columnIntermediolateral cell column is located at the lateral portion of the intermediate zone.

• Responsible for the formation of the lateral hornlateral horn in T1 - L2T1 - L2

• Consists of cell bodies of sympatheticsympathetic preganglionic neurons

T5

Lamina VIILamina VIILamina VIILamina VII

• Intermediomedial cell columnIntermediomedial cell column is located lateral to lamina X. Not seen in all cord sections.

• Receives primary afferent fibers from dorsal root and has been implicated in visceral reflexesvisceral reflexes

• Intermediomedial cell columnIntermediomedial cell column is located lateral to lamina X. Not seen in all cord sections.

• Receives primary afferent fibers from dorsal root and has been implicated in visceral reflexesvisceral reflexes

T5

Lamina VIILamina VIILamina VIILamina VII

• Sacral autonomic nucleusSacral autonomic nucleus is located in the lateral part of lamina VII in S2-S4 segments

• Consists of preganglionic para-para- sympatheticsympathetic neurons

• Sacral autonomic nucleusSacral autonomic nucleus is located in the lateral part of lamina VII in S2-S4 segments

• Consists of preganglionic para-para- sympatheticsympathetic neurons

S2

• Located on the medial aspect of the ventral horn

• Efferent projections both ipsilaterally and contralaterally to the same and nearby segmental levels to lamina VII & IX

• Site of termination for descending fibers, including the vestibulospinalvestibulospinal and reticulospinal tractsreticulospinal tracts

• Located on the medial aspect of the ventral horn

• Efferent projections both ipsilaterally and contralaterally to the same and nearby segmental levels to lamina VII & IX

• Site of termination for descending fibers, including the vestibulospinalvestibulospinal and reticulospinal tractsreticulospinal tracts

Lamina VIIILamina VIIILamina VIIILamina VIII

• Consists of columns of neurons embedded in either lamina VII or VIII

• Cells include alphaalpha and gammagamma motor neurons, which axons exit via the ventral roots and innervate striatedstriated musclemuscle. SmallerSmaller neurons contribute axons to the ventral fasciculus propriusventral fasciculus proprius

• Four columns of motor neurons can be identified within this lamina; ventromedialventromedial, ventrolateralventrolateral, dorsolateraldorsolateral & central central each has characteristic dendritic features

• Consists of columns of neurons embedded in either lamina VII or VIII

• Cells include alphaalpha and gammagamma motor neurons, which axons exit via the ventral roots and innervate striatedstriated musclemuscle. SmallerSmaller neurons contribute axons to the ventral fasciculus propriusventral fasciculus proprius

• Four columns of motor neurons can be identified within this lamina; ventromedialventromedial, ventrolateralventrolateral, dorsolateraldorsolateral & central central each has characteristic dendritic features

Lamina IXLamina IXLamina IXLamina IX

Ventral gray columnsVentral gray columns in lamina IX have somatotopic arrangement: - Medial areasMedial areas innervate the axial musculatureaxial musculature - Lateral areasLateral areas innervate the limbs muscleslimbs muscles

Ventral gray columnsVentral gray columns in lamina IX have somatotopic arrangement: - Medial areasMedial areas innervate the axial musculatureaxial musculature - Lateral areasLateral areas innervate the limbs muscleslimbs muscles

Lamina IXLamina IXLamina IXLamina IX

PHRENIC NUCLEUSPHRENIC NUCLEUS

The The phrenic nucleusphrenic nucleus is located in the is located in the ventromedial areaventromedial area of the of theventral horn in C2-C5 segments. It receives bilateral innervation ventral horn in C2-C5 segments. It receives bilateral innervation from the from the solitary nucleussolitary nucleus of the medullary region, via of the medullary region, via solitary tractsolitary tract. . This nucleus is responsible for the innervation of the This nucleus is responsible for the innervation of the diaphragmdiaphragm

SPINAL ACCESSORY NUCLEUSSPINAL ACCESSORY NUCLEUS

The The spinal accessory nucleusspinal accessory nucleus (cranial nerve XI) is located in the (cranial nerve XI) is located in thelateral arealateral area of vental horn in C1-C5 segments. of vental horn in C1-C5 segments. Corticospinal tractCorticospinal tract innervates this nucleus bilaterally. This nucleus is also innervates this nucleus bilaterally. This nucleus is also responsible for the innervation of the responsible for the innervation of the trapeziustrapezius & & sternocleidomastoidsternocleidomastoid muscles (ipsilaterally) muscles (ipsilaterally)

Lamina IXLamina IXLamina IXLamina IX

• Located ventrolaterally in S1-S2 spinal segments

• Supplies muscles of the pelvic floor, including striated muscle sphincters for urinary and fecal continence

• Located ventrolaterally in S1-S2 spinal segments

• Supplies muscles of the pelvic floor, including striated muscle sphincters for urinary and fecal continence

Nucleus of OnufNucleus of Onuf S2

• Surrounds the central canalcentral canal, and includes the ventral gray commissureventral gray commissure

• Contains relatively small neuronsneurons, radial neuroglia cellsradial neuroglia cells & decussating axons

• Some dorsal root afferents terminate here

• Surrounds the central canalcentral canal, and includes the ventral gray commissureventral gray commissure

• Contains relatively small neuronsneurons, radial neuroglia cellsradial neuroglia cells & decussating axons

• Some dorsal root afferents terminate here

Lamina XLamina XLamina XLamina X

• Ascending and descending association fiber systems of theAscending and descending association fiber systems of the spinal cord which lie deep in the anterior, lateral & posteriorspinal cord which lie deep in the anterior, lateral & posterior funiculi adjacent to the gray matter.funiculi adjacent to the gray matter.

• Fasciculi propriiFasciculi proprii aka aka Flechsig's fasciculi Flechsig's fasciculi or or Ground bundlesGround bundles consist of: consist of: anterioranterior, , lateralislateralis & & intersegmentalintersegmental fasciculi fasciculi

• Ascending and descending association fiber systems of theAscending and descending association fiber systems of the spinal cord which lie deep in the anterior, lateral & posteriorspinal cord which lie deep in the anterior, lateral & posterior funiculi adjacent to the gray matter.funiculi adjacent to the gray matter.

• Fasciculi propriiFasciculi proprii aka aka Flechsig's fasciculi Flechsig's fasciculi or or Ground bundlesGround bundles consist of: consist of: anterioranterior, , lateralislateralis & & intersegmentalintersegmental fasciculi fasciculi

Fasiculus PropriusFasiculus PropriusFasiculus PropriusFasiculus Proprius

Dorsal RootsDorsal RootsDorsal RootsDorsal Roots

• Each dorsal rootdorsal root divides into 6 - 8 rootlets

• Each rootlet can be divided into lateral lateral & medial divisionmedial division

• Lateral divisionLateral division carries information related to painpain & temperaturetemperature

• Medial divisionMedial division carries information related to tactile tactile discriminationdiscrimination & vibrationvibration

• Each dorsal rootdorsal root divides into 6 - 8 rootlets

• Each rootlet can be divided into lateral lateral & medial divisionmedial division

• Lateral divisionLateral division carries information related to painpain & temperaturetemperature

• Medial divisionMedial division carries information related to tactile tactile discriminationdiscrimination & vibrationvibration

Dorsal RootsDorsal RootsDorsal RootsDorsal Roots

• Lateral divisionLateral division axons enter dorsolateral tract of Lissauerdorsolateral tract of Lissauer, and then divide into ascendingascending & descendingdescending branches, each terminate in the dorsal horndorsal horn

• Most terminate at same level & some fibers may travel up or down the cord up to four levels

• Lateral divisionLateral division axons enter dorsolateral tract of Lissauerdorsolateral tract of Lissauer, and then divide into ascendingascending & descendingdescending branches, each terminate in the dorsal horndorsal horn

• Most terminate at same level & some fibers may travel up or down the cord up to four levels

Dorsal RootsDorsal RootsDorsal RootsDorsal Roots

• Medial divisionMedial division axons enter the white matter & then divide into ascendingascending & descendingdescending branches

• Descending branchesDescending branches are organized into two bundles, the Septomarginalis FasiculusSeptomarginalis Fasiculus and the Interfascicular FasiculusInterfascicular Fasiculus

• All descending branchesdescending branches terminateterminate in thein the dorsal horn dorsal horn

• Medial divisionMedial division axons enter the white matter & then divide into ascendingascending & descendingdescending branches

• Descending branchesDescending branches are organized into two bundles, the Septomarginalis FasiculusSeptomarginalis Fasiculus and the Interfascicular FasiculusInterfascicular Fasiculus

• All descending branchesdescending branches terminateterminate in thein the dorsal horn dorsal horn

Dorsal RootsDorsal RootsDorsal RootsDorsal Roots

• Ascending branchesAscending branches of the medial division enter theenter the dorsal funiculusdorsal funiculus & terminate in gracilegracile & cuneatecuneate nuclei in the medulla

• Ascending branchesAscending branches of the medial division enter theenter the dorsal funiculusdorsal funiculus & terminate in gracilegracile & cuneatecuneate nuclei in the medulla

Ventral HornVentral HornVentral HornVentral Horn

• Lamina IXLamina IX contains two types contains two types of motor neurons, of motor neurons, alphaalpha and and gammagamma

• AlphaAlpha motor neurons motor neurons innervate innervate extrafusal fibersextrafusal fibers of striated of striated skeletal musclesskeletal muscles

• GammaGamma motor neurons motor neurons innervate innervate intrafusal fibersintrafusal fibers of neuromuscular of neuromuscular spindlesspindles

• Both types receive inputs from Both types receive inputs from interneurons, including theinterneurons, including the inhibitory inhibitory RenshawRenshaw cell cell

• Lamina IXLamina IX contains two types contains two types of motor neurons, of motor neurons, alphaalpha and and gammagamma

• AlphaAlpha motor neurons motor neurons innervate innervate extrafusal fibersextrafusal fibers of striated of striated skeletal musclesskeletal muscles

• GammaGamma motor neurons motor neurons innervate innervate intrafusal fibersintrafusal fibers of neuromuscular of neuromuscular spindlesspindles

• Both types receive inputs from Both types receive inputs from interneurons, including theinterneurons, including the inhibitory inhibitory RenshawRenshaw cell cell

Spinal Cord TractsSpinal Cord Tracts Spinal Cord TractsSpinal Cord Tracts

Tracts of the Spinal CordTracts of the Spinal CordTracts of the Spinal CordTracts of the Spinal Cord

1.1. Fasciculus GracilisFasciculus Gracilis2.2. Fasciculus CuneatusFasciculus Cuneatus3.3. Tractus spinocerebellaris dorsalisTractus spinocerebellaris dorsalis4.4. Tractus corticospinalis lateralisTractus corticospinalis lateralis5.5. Tractus spinothalamicus lateralisTractus spinothalamicus lateralis6.6. Tractus spinocerebellaris ventralisTractus spinocerebellaris ventralis7.7. Tractus rubrospinalisTractus rubrospinalis8.8. Tractus spinotectalisTractus spinotectalis9.9. Tractus corticospinalis anteriorTractus corticospinalis anterior10.10. Tractus olivospinalisTractus olivospinalis11.11. Tractus spinoolivarisTractus spinoolivaris12.12. Tractus tectospinalisTractus tectospinalis13.13. Tractus reticulospinalisTractus reticulospinalis14.14. Tractus vestibulospinalisTractus vestibulospinalis15.15. Tractus spinothalamicus anteriorTractus spinothalamicus anterior16.16. Raphe-spinal & Hypothalamospinal fibersRaphe-spinal & Hypothalamospinal fibers

1.1. Fasciculus GracilisFasciculus Gracilis2.2. Fasciculus CuneatusFasciculus Cuneatus3.3. Tractus spinocerebellaris dorsalisTractus spinocerebellaris dorsalis4.4. Tractus corticospinalis lateralisTractus corticospinalis lateralis5.5. Tractus spinothalamicus lateralisTractus spinothalamicus lateralis6.6. Tractus spinocerebellaris ventralisTractus spinocerebellaris ventralis7.7. Tractus rubrospinalisTractus rubrospinalis8.8. Tractus spinotectalisTractus spinotectalis9.9. Tractus corticospinalis anteriorTractus corticospinalis anterior10.10. Tractus olivospinalisTractus olivospinalis11.11. Tractus spinoolivarisTractus spinoolivaris12.12. Tractus tectospinalisTractus tectospinalis13.13. Tractus reticulospinalisTractus reticulospinalis14.14. Tractus vestibulospinalisTractus vestibulospinalis15.15. Tractus spinothalamicus anteriorTractus spinothalamicus anterior16.16. Raphe-spinal & Hypothalamospinal fibersRaphe-spinal & Hypothalamospinal fibers

1616

Ascending TractsAscending Tracts

Modality: Modality: Touch, Pain, Temperature, KinesthesiaTouch, Pain, Temperature, Kinesthesia

Receptor: Receptor: Exteroceptor, Interoceptor, ProprioceptorExteroceptor, Interoceptor, Proprioceptor

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

Secondary Neuron: Secondary Neuron: Spinal Cord or Brain StemSpinal Cord or Brain Stem

Tertiary Neuron: Tertiary Neuron: Thalamus (Ventrobasal Nuclear Complex) Thalamus (Ventrobasal Nuclear Complex)

Termination: Termination: Cerebral Cortex, Cerebellar Cortex, orCerebral Cortex, Cerebellar Cortex, or

Brain StemBrain Stem

Ascending TractsAscending Tracts

Modality: Modality: Touch, Pain, Temperature, KinesthesiaTouch, Pain, Temperature, Kinesthesia

Receptor: Receptor: Exteroceptor, Interoceptor, ProprioceptorExteroceptor, Interoceptor, Proprioceptor

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

Secondary Neuron: Secondary Neuron: Spinal Cord or Brain StemSpinal Cord or Brain Stem

Tertiary Neuron: Tertiary Neuron: Thalamus (Ventrobasal Nuclear Complex) Thalamus (Ventrobasal Nuclear Complex)

Termination: Termination: Cerebral Cortex, Cerebellar Cortex, orCerebral Cortex, Cerebellar Cortex, or

Brain StemBrain Stem

Spinal Cord TractsSpinal Cord Tracts Spinal Cord TractsSpinal Cord Tracts

Ascending TractsAscending Tracts

Posterior White Column-Medial Lemniscal PathwayPosterior White Column-Medial Lemniscal Pathway

Spinothalamic TractSpinothalamic Tract

Spinoreticular or Spinoreticulothalamic TractSpinoreticular or Spinoreticulothalamic Tract

Spinocerebellar TractSpinocerebellar TractSpinomedullothalamic TractSpinomedullothalamic Tract

Cervicothalamic or Spinocervicothalamic Tract Cervicothalamic or Spinocervicothalamic Tract

Spino-olivary TractSpino-olivary Tract

Spinotectal TractSpinotectal Tract

Ascending TractsAscending Tracts

Posterior White Column-Medial Lemniscal PathwayPosterior White Column-Medial Lemniscal Pathway

Spinothalamic TractSpinothalamic Tract

Spinoreticular or Spinoreticulothalamic TractSpinoreticular or Spinoreticulothalamic Tract

Spinocerebellar TractSpinocerebellar TractSpinomedullothalamic TractSpinomedullothalamic Tract

Cervicothalamic or Spinocervicothalamic Tract Cervicothalamic or Spinocervicothalamic Tract

Spino-olivary TractSpino-olivary Tract

Spinotectal TractSpinotectal Tract

Spinal Cord TractsSpinal Cord Tracts Spinal Cord TractsSpinal Cord Tracts

Posterior White Column-Medial Lemniscal PathwayPosterior White Column-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)

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

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

Posterior Root - Posterior White ColumnPosterior Root - Posterior White Column

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

Internal Arcuate Fiber - Lemniscal Decussation Internal Arcuate Fiber - Lemniscal Decussation

- Medial Lemniscus- Medial Lemniscus

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

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

Posterior White Column-Medial Lemniscal PathwayPosterior White Column-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)

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

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

Posterior Root - Posterior White ColumnPosterior Root - Posterior White Column

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

Internal Arcuate Fiber - Lemniscal Decussation Internal Arcuate Fiber - Lemniscal Decussation

- Medial Lemniscus- Medial Lemniscus

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

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

Spinal Cord Ascending TractsSpinal Cord Ascending Tracts Spinal Cord Ascending TractsSpinal Cord Ascending Tracts

Posterior White Column -Posterior White Column -Medial Lemniscal PathwayMedial Lemniscal PathwayPosterior White Column -Posterior White Column -

Medial Lemniscal PathwayMedial Lemniscal Pathway

medial lemniscusmedial lemniscus

lemniscal decussationlemniscal decussation

internal arcuate fiberinternal arcuate fiber

posterior white columnposterior white column

posterior rootposterior root

- - ipsilateralipsilateral loss of discriminative touchloss of discriminative touch sensation and conscious proprioceptionsensation and conscious proprioception belowbelow the level of lesionthe level of lesion

Spinothalamic TractSpinothalamic Tract Modality: Modality: Pain & Temperature Sensation, Light Touch Pain & Temperature Sensation, Light Touch

Receptor: Receptor: Free Nerve Ending Free Nerve Ending

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

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

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

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

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

Diffuse Widespread Cortical RegionDiffuse Widespread Cortical Region

Spinothalamic TractSpinothalamic Tract Modality: Modality: Pain & Temperature Sensation, Light Touch Pain & Temperature Sensation, Light Touch

Receptor: Receptor: Free Nerve Ending Free Nerve Ending

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

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

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

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

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

Diffuse Widespread Cortical RegionDiffuse Widespread Cortical Region

Spinal Cord Ascending TractsSpinal Cord Ascending Tracts Spinal Cord Ascending TractsSpinal Cord Ascending Tracts

Spinothalamic TractSpinothalamic TractSpinothalamic TractSpinothalamic Tract

spinothalamicspinothalamictracttract

anterior whiteanterior whitecommissurecommissure

posterior rootposterior root

decussationdecussation

- - contralateralcontralateral loss of pain and temperature loss of pain and temperature sensation sensation below below the level of lesionthe level of lesion

Spinothalamic TractSpinothalamic Tract& Spinoreticular Tract& Spinoreticular Tract

Widespread Widespread cortical regioncortical region

CL (intralaminarCL (intralaminar thalamic nuclei)thalamic nuclei)

reticulothalamicreticulothalamic pathwayspathways

spinoreticularspinoreticular tracttract

Primary MotorPrimary Motor Area (M I)Area (M I)

VPLc (ventrobasalVPLc (ventrobasal nuclear complex)nuclear complex)

(spinal lemniscus)(spinal lemniscus)

spinothalamicspinothalamic tracttract

thalamus

reticularformation

NeoSTTNeoSTT PaleoSTTPaleoSTT

Fast PainFast Pain Slow PainSlow Pain

Sharp, prickingSharp, pricking Dull, burningDull, burning

Group III (AGroup III (A) fiber) fiber Group IV (C) fiberGroup IV (C) fiber

Short latencyShort latency Slower onsetSlower onset

Well localizedWell localized DiffuseDiffuse

Short durationShort duration Long durationLong duration

Less emotional Less emotional Emotional, autonomic responseEmotional, autonomic response

Not blocked by morphineNot blocked by morphine Blocked by morphineBlocked by morphine

Neospinothalamic TractNeospinothalamic Tract Paleospinothalamic TractPaleospinothalamic Tract

Comparison of Fast and Slow PainComparison of Fast and Slow Pain ------ Spinothalamic Tract------ Spinothalamic Tract Comparison of Fast and Slow PainComparison of Fast and Slow Pain ------ Spinothalamic Tract------ Spinothalamic Tract

Spinocerebellar TractSpinocerebellar Tract

Modality: Modality: Unconscious Proprioception Unconscious Proprioception

Receptor: Receptor: Muscle spindle, Golgi tendon organMuscle spindle, Golgi tendon organ

Ist Neuron: Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion)Dorsal Root Ganglion (Spinal Ganglion) Posterior Root , [Posterior Column]Posterior Root , [Posterior Column]

2nd Neuron: 2nd Neuron: 1. Clarke’s column (1. Clarke’s column (Lamina VIILamina VII)) Posterior Spinocerebellar TractPosterior Spinocerebellar Tract

2. Accessory Cuneate Nucleus2. Accessory Cuneate Nucleus Cuneocerebellar Tract Cuneocerebellar Tract

3. Posterior Horn3. Posterior Horn Anterior Spinocerebellar TractAnterior Spinocerebellar Tract

Termination: Termination: Cerebellar CortexCerebellar Cortex

Spinocerebellar TractSpinocerebellar Tract

Modality: Modality: Unconscious Proprioception Unconscious Proprioception

Receptor: Receptor: Muscle spindle, Golgi tendon organMuscle spindle, Golgi tendon organ

Ist Neuron: Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion)Dorsal Root Ganglion (Spinal Ganglion) Posterior Root , [Posterior Column]Posterior Root , [Posterior Column]

2nd Neuron: 2nd Neuron: 1. Clarke’s column (1. Clarke’s column (Lamina VIILamina VII)) Posterior Spinocerebellar TractPosterior Spinocerebellar Tract

2. Accessory Cuneate Nucleus2. Accessory Cuneate Nucleus Cuneocerebellar Tract Cuneocerebellar Tract

3. Posterior Horn3. Posterior Horn Anterior Spinocerebellar TractAnterior Spinocerebellar Tract

Termination: Termination: Cerebellar CortexCerebellar Cortex

Spinal Cord Ascending TractsSpinal Cord Ascending Tracts Spinal Cord Ascending TractsSpinal Cord Ascending Tracts

Spinocerebellar TractSpinocerebellar TractSpinocerebellar TractSpinocerebellar Tract

Inferior cerebellarInferior cerebellar pedunclepeduncle

posteriorposterior spinocerebellarspinocerebellar tracttract

Clarke’sClarke’s columncolumn

posteriorposterior white columnwhite column

posterior rootposterior root

Posterior SCbllTPosterior SCbllT

Inferior Inferior cerebellarcerebellar pedunclepeduncle

cuneocerebellarcuneocerebellar tracttract (upper body)(upper body)

posteriorposterior white columnwhite column

posterior rootposterior root

Anterior SCbllTAnterior SCbllT

(superior(superior cerebellarcerebellar peduncle)peduncle)

anterioranterior spinocerebellarspinocerebellar tracttract

anterior whiteanterior white commissurecommissure

posterior rootposterior root

Spinocerebellar TractSpinocerebellar TractSpinocerebellar TractSpinocerebellar 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 Lobule) 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 Tracts: Corticospinal Tracts:

- Lateral (crossed) - 85%- Lateral (crossed) - 85%

- Anterior (Not crossed) - 15%- Anterior (Not crossed) - 15%

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 Lobule) 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 Tracts: Corticospinal Tracts:

- Lateral (crossed) - 85%- Lateral (crossed) - 85%

- Anterior (Not crossed) - 15%- Anterior (Not crossed) - 15%

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

Spinal Cord Descending TractsSpinal Cord Descending Tracts Spinal Cord Descending TractsSpinal Cord Descending Tracts

- - ipsilateralipsilateral UMN syndrome UMN syndrome

atat the level of lesion the level of lesion

Corticospinal TractCorticospinal TractCorticospinal TractCorticospinal Tract

Corona Radiata Corona Radiata

lnternal Capsule, Posterior Limblnternal Capsule, Posterior Limb

Crus Cerebri, Middle PortionCrus Cerebri, Middle Portion

Longitudinal Pontine FiberLongitudinal Pontine Fiber

Pyramid Pyramid

Pyramidal DecussationPyramidal Decussation

Corticospinal Tract Corticospinal Tract

- Lateral and Anterior- Lateral and Anterior

CR

IC

LPF

Pyr

PD LCST

ACST

Descending Tracts from Brain StemDescending Tracts from Brain Stem

Dorsolateral (Motor) PathwayDorsolateral (Motor) Pathway

Rubrospinal TractRubrospinal Tract

Ventromedial (Motor) Pathway Ventromedial (Motor) Pathway

Tectospinal TractTectospinal Tract

Vestibulospinal TractVestibulospinal Tract

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

- interstitiospinal tract- interstitiospinal tract

Sensory Modulation pathwaysSensory Modulation pathways

Raphespinal & Cerulospinal PathwaysRaphespinal & Cerulospinal Pathways

Descending Autonomic PathwaysDescending Autonomic Pathways

Descending Tracts from Brain StemDescending Tracts from Brain Stem

Dorsolateral (Motor) PathwayDorsolateral (Motor) Pathway

Rubrospinal TractRubrospinal Tract

Ventromedial (Motor) Pathway Ventromedial (Motor) Pathway

Tectospinal TractTectospinal Tract

Vestibulospinal TractVestibulospinal Tract

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

- interstitiospinal tract- interstitiospinal tract

Sensory Modulation pathwaysSensory Modulation pathways

Raphespinal & Cerulospinal PathwaysRaphespinal & Cerulospinal Pathways

Descending Autonomic PathwaysDescending Autonomic Pathways

Spinal Cord Descending TractsSpinal Cord Descending Tracts Spinal Cord Descending TractsSpinal Cord Descending Tracts

ventromedial pathway

dorsolateral pathway

DescendingDescendingTractsTractsfromfromBrain StemBrain Stem

Spinal Cord Spinal Cord TractsTracts

Spinal Cord Spinal Cord TractsTracts

upper motor neuronupper motor neuronUMNUMN

upper motor neuronupper motor neuronUMNUMN

SOMATIC MOTOR SYSTEMSOMATIC MOTOR SYSTEMSOMATIC MOTOR SYSTEMSOMATIC MOTOR SYSTEM

lower motor neuron

LMNLMN

Brain Stem Brain Stem DescendingDescending PathwayPathway

Final Common PathwayFinal Common Pathway

EFFECTORSskeletal muscle

Pyramidal Tract

VOLUNTARY CONTROL

AUTOMATIC CONTROL

Rubrospinal TractRubrospinal TractTectospinal TractTectospinal TractVestibulospinal TractVestibulospinal TractMLFMLFReticulospinal TractReticulospinal Tract

REFLEX

Spinal Cord SyndromeSpinal Cord Syndrome Spinal Cord SyndromeSpinal Cord Syndrome

Location of Location of Symptoms inSymptoms inSpinal DiseaseSpinal Disease

ipsilateral to lesion contralateral to lesion

Upper Motor Neuron (UMN) vs. Lower Motor Neuron (LMN) SyndromeUpper Motor Neuron (UMN) vs. Lower Motor Neuron (LMN) Syndrome

UMN syndromeUMN syndrome LMN SyndromeLMN Syndrome

Type of Paralysis Type of Paralysis Spastic ParesisSpastic Paresis Flaccid ParalysisFlaccid Paralysis

Atrophy Atrophy No (Disuse) Atrophy No (Disuse) Atrophy Severe Severe AtrophyAtrophy

Deep Tendon Reflex Deep Tendon Reflex Increase Increase Absent DTRAbsent DTR

Pathological Reflex Pathological Reflex Positive Positive Babinski Babinski Sign Sign AbsentAbsent

Superficial Reflex Superficial Reflex AbsentAbsent PresentPresent

Fasciculation and Fasciculation and Absent Absent Could be Could be Fibrillation Fibrillation PresentPresent

Spinal Cord SyndromeSpinal Cord Syndrome Spinal Cord SyndromeSpinal Cord Syndrome

Predominantly Motor SyndromesPredominantly Motor Syndromes

• Poliomyelitis (Infantile Paralysis)Poliomyelitis (Infantile Paralysis) - viral infection of lower motor neuron- viral infection of lower motor neuron

- LMN syndrome at the level of lesion- LMN syndrome at the level of lesion

• Amyotrophic Lateral Sclerosis (ALS)Amyotrophic Lateral Sclerosis (ALS) - combined LMN and UMN lesion- combined LMN and UMN lesion

- LMN syndrome at the level of lesion- LMN syndrome at the level of lesion

- UMN syndrome below the level of lesion- UMN syndrome below the level of lesion

- Lou Gehrig’s disease- Lou Gehrig’s disease

Spinal Cord SyndromeSpinal Cord Syndrome Spinal Cord SyndromeSpinal Cord Syndrome

Amyotrophic Lateral SclerosisAmyotrophic Lateral Sclerosis Amyotrophic Lateral SclerosisAmyotrophic Lateral Sclerosis

1. corticospinal tract

2. lower motor neuron (LMN)

Spinal CordSpinal CordSyndromeSyndrome

AmyotrophicAmyotrophicLateral SclerosisLateral Sclerosis

(ALS)(ALS)

Lou Gherig’sLou Gherig’sDiseaseDisease

Spinal CordSpinal CordSyndromeSyndrome

AmyotrophicAmyotrophicLateral SclerosisLateral Sclerosis

(ALS)(ALS)

Lou Gherig’sLou Gherig’sDiseaseDisease

Lou "The Iron Horse" Gehrig (1903-41)Lou "The Iron Horse" Gehrig (1903-41)3.40, 2131(1925-39), 23 GSH, 147 RBI avg.

Spinal CordSpinal CordSyndromeSyndrome

AmyotrophicAmyotrophicLateral SclerosisLateral Sclerosis

(ALS)(ALS)

Lou Gherig’sLou Gherig’sDiseaseDisease

Spinal CordSpinal CordSyndromeSyndrome

AmyotrophicAmyotrophicLateral SclerosisLateral Sclerosis

(ALS)(ALS)

Lou Gherig’sLou Gherig’sDiseaseDisease Stephen Haking (1946- )Stephen Haking (1946- )

British Physicist, A Brief History of Time

Spinal Cord SyndromeSpinal Cord Syndrome Spinal Cord SyndromeSpinal Cord Syndrome

Predominantly Sensory SyndromesPredominantly Sensory Syndromes

• Herpes ZosterHerpes Zoster - inflammatory reactions of spinal ganglion- inflammatory reactions of spinal ganglion - severe pain on the dermatomes of affected ganglion- severe pain on the dermatomes of affected ganglion

• Tabes DorsalisTabes Dorsalis - common variety of neurosyphilis- common variety of neurosyphilis - posterior column and spinal posterior root lesion- posterior column and spinal posterior root lesion - loss of discriminative touch sensation and conscious- loss of discriminative touch sensation and conscious proprioception below the level of lesionproprioception below the level of lesion - posterior column ataxia- posterior column ataxia - lancinating pain (- lancinating pain (a stabbing or piercing sensationa stabbing or piercing sensation)) - loss of deep tendon reflex (DTR)- loss of deep tendon reflex (DTR)

Herpes Zoster (Shingles)Herpes Zoster (Shingles)

• varicella-zoster virusvaricella-zoster virus reactivation from reactivation from the dorsal root gangliathe dorsal root ganglia

• unilateral vesicular unilateral vesicular eruption within eruption within a dermatomea dermatome

• T3 to L3 dermatome T3 to L3 dermatome lesions are frequentlesions are frequent

• zoster ophtahalmicus zoster ophtahalmicus (ophthalmic division(ophthalmic division of trigeminal n., Vof trigeminal n., V11))

• Ramsey-Hunt syndromeRamsey-Hunt syndrome (sensory br. of VII)(sensory br. of VII)

• acyclovir, antiviral agentacyclovir, antiviral agent

Spinal Cord SyndromeSpinal Cord Syndrome Spinal Cord SyndromeSpinal Cord Syndrome

Sub-Acute Combined DegenerationSub-Acute Combined Degeneration (Combined System Disease)(Combined System Disease) LesionLesion - posterior white column- posterior white column - corticospinal tract (UMN)- corticospinal tract (UMN)

SymptomSymptom - loss of discriminative touch sensation and conscious- loss of discriminative touch sensation and conscious proprioception below the level of lesionproprioception below the level of lesion - ipsilateral UMN syndrome below the level of lesion- ipsilateral UMN syndrome below the level of lesion

Spinal Cord SyndromeSpinal Cord Syndrome Spinal Cord SyndromeSpinal Cord Syndrome

Sub-Acute Combined DegenerationSub-Acute Combined Degeneration Sub-Acute Combined DegenerationSub-Acute Combined Degeneration

1. corticospinal tract

2. posterior white column

Spinal Cord SyndromeSpinal Cord Syndrome Spinal Cord SyndromeSpinal Cord Syndrome

Syringomyelia, HematomyeliaSyringomyelia, Hematomyelia LesionLesion

- central canal of spinal cord- central canal of spinal cord - gradually extended to peripheral part of the cord- gradually extended to peripheral part of the cord

SymptomSymptom

- initial symptom is bilateral loss of pain- initial symptom is bilateral loss of pain (compression of anterior white commissure)(compression of anterior white commissure)

- variety of symptoms appear- variety of symptoms appear according to the lesion extended from central canalaccording to the lesion extended from central canal

Spinal Cord SyndromeSpinal Cord Syndrome Spinal Cord SyndromeSpinal Cord Syndrome

Syringomyelia - Initial SymptomsSyringomyelia - Initial Symptoms Syringomyelia - Initial SymptomsSyringomyelia - Initial Symptoms

Spinal Cord SyndromeSpinal Cord Syndrome Spinal Cord SyndromeSpinal Cord Syndrome

Brown-Sequard syndromeBrown-Sequard syndrome (spinal cord hemisection)(spinal cord hemisection) Major SymptomsMajor Symptoms

1. ipsilateral 1. ipsilateral UMN syndromeUMN syndrome below below the level of lesionthe level of lesion

2. ipsilateral 2. ipsilateral LMN syndromeLMN syndrome at at the level of lesionthe level of lesion

3. ipsilateral loss of 3. ipsilateral loss of discriminative touch sensationdiscriminative touch sensation and and

conscious proprioceptionconscious proprioception belowbelow the level of lesion the level of lesion

(posterior white column lesion)(posterior white column lesion)

4. 4. contralateralcontralateral loss of loss of pain and temperaturepain and temperature sensation sensation belowbelow the level of lesion the level of lesion (spinothalamic tract lesion)(spinothalamic tract lesion)

Spinal Cord SyndromeSpinal Cord Syndrome Spinal Cord SyndromeSpinal Cord Syndrome

Brown-Sequard Syndrome (Spinal Cord Hemisection)Brown-Sequard Syndrome (Spinal Cord Hemisection) Brown-Sequard Syndrome (Spinal Cord Hemisection)Brown-Sequard Syndrome (Spinal Cord Hemisection)

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Good Luck !Good Luck !