1. The Spinal Cord  Structure of the spinal cord  Tracts of the spinal cord  Spinal cord syndromes The Spinal Cord  Structure of the spinal cord  Tracts of the spinal cord  Spinal cord syndromes Nabeel Kouka, MD, DO, MBA www.brain101.info www.brain101.info

2. - Comparable to Input-Output (IO) System of the Computer Input-Output (IO) System of the Computer - Spinal Nerve (C8, T12, L5, S5, Cx1) - Segmental Structure of Neural Tube Origin - Comparable to Input-Output (IO) System of the Computer Input-Output (IO) System of the Computer - Spinal Nerve (C8, T12, L5, S5, Cx1) - Segmental Structure of Neural Tube Origin Spinal Cord

3. Spinal segment C8, T12, L5, S5, Cx1 C8, T12, L5, S5, Cx1 Anterior (Ventral) Root Posterior (Dorsal) Root Dorsal Root (Spinal) Ganglion Dorsal Root (Spinal) Ganglion Root - Rootlets

4. Conus Medullaris (L1-2) Cauda Equina Anterior median fissure Anterolateral fissure

5. Posterior median sulcus median sulcusPosterolateral sulcus sulcusPosterior intermediate intermediate sulcus sulcus Fasciculus Fasciculus cuneatus cuneatus Fasciculus Fasciculus gracilis gracilis Posterior surface of the spinal cord

6. Periosteum of Vertebra Periosteum of Vertebra - Epidural Space ----------------- epidural anesthesia Dura Mater Spinalis Dura Mater Spinalis Arachnoid Membrane Arachnoid Membrane - Subarachnoid Space -------- Lumbar Puncture Spinal Anesthesia Spinal Anesthesia Pia Mater Spinalis - Denticulate Ligament --------- Cordotomy - Filum Terminale - Filum Terminale Periosteum of Vertebra Periosteum of Vertebra - Epidural Space ----------------- epidural anesthesia Dura Mater Spinalis Dura Mater Spinalis Arachnoid Membrane Arachnoid Membrane - Subarachnoid Space -------- Lumbar Puncture Spinal Anesthesia Spinal Anesthesia Pia Mater Spinalis - Denticulate Ligament --------- Cordotomy - Filum Terminale - Filum Terminale Spinal Cord Meninges Spinal Cord Meninges

7. Meninges of Meninges of the spinal cord the spinal cord Dura mater Dura mater Arachnoid membrane Arachnoid membrane Pia mater Pia mater Denticulate ligament - specialization of the pia mater - specialization of the pia mater - landmark for cordotomy - landmark for cordotomy

8. Meninges of the spinal cord Meninges of the spinal cord

10. Lumbar Puncture – lumbar (terminal) cistern

11. Arterial Supply - Spinal Arteries - Spinal Arteries Anterior (1) & Posterior (2) Spinal Artery Anterior (1) & Posterior (2) Spinal Artery from Vertebral artery from Vertebral artery - Radicular Arteries ----- Segmental arteries - Radicular Arteries ----- Segmental arteries from Vertebral, Ascending Cervical, Intercostal and from Vertebral, Ascending Cervical, Intercostal and Lumbar Artery Lumbar Artery Venous Drainage Venous Drainage - Longitudinal & Radicular Veins to Intervertebral veins ---- to Internal Vertebral Venous Plexus to Intervertebral veins ---- to Internal Vertebral Venous Plexus to external vertebral venous plexus ---- to segmental veins to external vertebral venous plexus ---- to segmental veins Arterial Supply - Spinal Arteries - Spinal Arteries Anterior (1) & Posterior (2) Spinal Artery Anterior (1) & Posterior (2) Spinal Artery from Vertebral artery from Vertebral artery - Radicular Arteries ----- Segmental arteries - Radicular Arteries ----- Segmental arteries from Vertebral, Ascending Cervical, Intercostal and from Vertebral, Ascending Cervical, Intercostal and Lumbar Artery Lumbar Artery Venous Drainage Venous Drainage - Longitudinal & Radicular Veins to Intervertebral veins ---- to Internal Vertebral Venous Plexus to Intervertebral veins ---- to Internal Vertebral Venous Plexus to external vertebral venous plexus ---- to segmental veins to external vertebral venous plexus ---- to segmental veins Spinal Cord Vascular Supply Spinal Cord Vascular Supply

12. anterior spinal artery segmental arteries 5. Adamkiwicz artery 5. Adamkiwicz artery

13. Spinal Cord External Figure Spinal Cord External Figure

14. Conus Medullaris (L1-2) Spinomedullary Junction Spinomedullary Junction - Foramen Magnum, Pyramidal decussation, C1 ventral root Enlargements - Cervical (C4-T1) & Lumbosacral (L1-L4) Longitudinal Fissures - anterior median fissure - anterolateral fissure - posterior median sulcus - posterolateral sulcus Conus Medullaris (L1-2) Spinomedullary Junction Spinomedullary Junction - Foramen Magnum, Pyramidal decussation, C1 ventral root Enlargements - Cervical (C4-T1) & Lumbosacral (L1-L4) Longitudinal Fissures - anterior median fissure - anterolateral fissure - posterior median sulcus - posterolateral sulcus Spinal Cord External Figure Spinal Cord External Figure

15. cervical enlargement (C8) thoracic cord (T8) cervical enlargement (C8) thoracic cord (T8) lumbar enlargement (L3) sacral cord (S1) lumbar enlargement (L3) sacral cord (S1)

16. Cervical level Cervical level - - Wide flat cord, lots of white matter, ventral horn enlargements. Lumbar level Lumbar level - Round cord, ventral horn enlargements. Sacral level Sacral level - Small round cord, lateral Horn. Tthoracic level - Notice the pointed tips which stick out between the small dorsal and ventral horns. This extra cell column is called the Intermediolateral intermediate horn (AKA: Intermediolateral Cell Column Cell Column). It is the source of all of the sympathetics in the body & occurs only in the Thoracic sections T 1 - L 2 Cervical level Cervical level - - Wide flat cord, lots of white matter, ventral horn enlargements. Lumbar level Lumbar level - Round cord, ventral horn enlargements. Sacral level Sacral level - Small round cord, lateral Horn. Tthoracic level - Notice the pointed tips which stick out between the small dorsal and ventral horns. This extra cell column is called the Intermediolateral intermediate horn (AKA: Intermediolateral Cell Column Cell Column). It is the source of all of the sympathetics in the body & occurs only in the Thoracic sections T 1 - L 2

17. White Matter White Matter Anterior Funiculus (Anterior White Column) Anterior Funiculus (Anterior White Column) Posterior Funiculus (Posterior White Column) Posterior Funiculus (Posterior White Column) Fasciculus Gracilis & Fasciculus Cuneatus Fasciculus Gracilis & Fasciculus Cuneatus Lateral Funiculus (Lateral White Column) Lateral Funiculus (Lateral White Column) Gray Matter Gray Matter Anterior Horn ---------------motor Anterior Horn ---------------motor Posterior Horn --------------sensory Posterior Horn --------------sensory Lateral Horn -----------------autonomic (sympathetic) Lateral Horn -----------------autonomic (sympathetic) Gray Commissure -------- anterior and posterior Gray Commissure -------- anterior and posterior White Matter White Matter Anterior Funiculus (Anterior White Column) Anterior Funiculus (Anterior White Column) Posterior Funiculus (Posterior White Column) Posterior Funiculus (Posterior White Column) Fasciculus Gracilis & Fasciculus Cuneatus Fasciculus Gracilis & Fasciculus Cuneatus Lateral Funiculus (Lateral White Column) Lateral Funiculus (Lateral White Column) Gray Matter Gray Matter Anterior Horn ---------------motor Anterior Horn ---------------motor Posterior Horn --------------sensory Posterior Horn --------------sensory Lateral Horn -----------------autonomic (sympathetic) Lateral Horn -----------------autonomic (sympathetic) Gray Commissure -------- anterior and posterior Gray Commissure -------- anterior and posterior Spinal Cord Internal Structure Spinal Cord Internal Structure

18. 1. posterior horn 2. anterior horn 3. intermediate zone (intermediate gray) (intermediate gray) 4. lateral horn 5. posterior funiculus 6. anterior funiculus 7. lateral funiculus 8. Lissauer's tract 9. anterior median 9. anterior median fissure fissure 10. posterior median sulcus sulcus 11. anterolateral sulcus sulcus 12. posterolateral sulcus sulcus 13. Posterior intermediate intermediate sulcus sulcus

19. Principles of Cord Organization 1) Longitudinal Arrangement 1) Longitudinal Arrangement Fibers (White Matter) ------------- White Column Fibers (White Matter) ------------- White Column Cell Groups (Gray Matter) ------- Gray Column Cell Groups (Gray Matter) ------- Gray Column 2) Transverse Arrangement Afferent & Efferent Fibers Afferent & Efferent Fibers Crossing (Commissural and Decussating) Fibers Crossing (Commissural and Decussating) Fibers 3) Somatotopical Arrangement Principles of Cord Organization 1) Longitudinal Arrangement 1) Longitudinal Arrangement Fibers (White Matter) ------------- White Column Fibers (White Matter) ------------- White Column Cell Groups (Gray Matter) ------- Gray Column Cell Groups (Gray Matter) ------- Gray Column 2) Transverse Arrangement Afferent & Efferent Fibers Afferent & Efferent Fibers Crossing (Commissural and Decussating) Fibers Crossing (Commissural and Decussating) Fibers 3) Somatotopical Arrangement Spinal Cord Internal Structure Spinal Cord Internal Structure

20. Columnar arrangement Somatotopical arrangement

21. Lamina of Rexed

22. Lamina I Posteromarginal Nucleus Lamina II Substantia Gelatinosa of Rolando Lamina III Lamina IV, V, VI ----- Nucleus Proprius Lamina VII - Intermediate Gray - Intermediolateral cell column (ILM) - Clarke’s column (Nucleus dorsalis) - Intermediomedial cell column (IMM) Lamina VIII Lamina IX ---------- Anterior Horn (Motor) Cell Lamina X ----------- Gray Commissure Lamina I Posteromarginal Nucleus Lamina II Substantia Gelatinosa of Rolando Lamina III Lamina IV, V, VI ----- Nucleus Proprius Lamina VII - Intermediate Gray - Intermediolateral cell column (ILM) - Clarke’s column (Nucleus dorsalis) - Intermediomedial cell column (IMM) Lamina VIII Lamina IX ---------- Anterior Horn (Motor) Cell Lamina X ----------- Gray Commissure Lamina of Rexed

23. lamina marginalis AKA: lamina marginalis or the layer of Waldeyer Receives incoming dorsal root fibers and collateral branches as well Larger neurons contribute axons Spinothalamic Tract to Contralateral Spinothalamic Tract lamina marginalis AKA: lamina marginalis or the layer of Waldeyer Receives incoming dorsal root fibers and collateral branches as well Larger neurons contribute axons Spinothalamic Tract to Contralateral Spinothalamic Tract Lamina I

24. Substantia Gelatinosa AKA: Substantia Gelatinosa Pain Involved in Pain interpretation incoming inputdorsal Receives incoming input from dorsal root descending input root axons & descending input from reticular formation reticular formation of the medulla Efferent axons travel up & down several segments to make contact with other areas of the dorsal horn Substantia Gelatinosa AKA: Substantia Gelatinosa Pain Involved in Pain interpretation incoming inputdorsal Receives incoming input from dorsal root descending input root axons & descending input from reticular formation reticular formation of the medulla Efferent axons travel up & down several segments to make contact with other areas of the dorsal horn Lamina II

25. Contains larger, less densely packed cells than lamina II Receives primary afferents from dorsal root dorsal root fibers Neurons considered as a part of nucleus proprius Contains larger, less densely packed cells than lamina II Receives primary afferents from dorsal root dorsal root fibers Neurons considered as a part of nucleus proprius Lamina III

26. Lamina IV Contains a variety of cell types that have more myelin more myelin than any other lamina tract cells Some tract cells originate here, axons cross the midline and enter the contralateral Spinothalamic Tract Spinothalamic Tract, also sends contacts to layers II and III Receives afferents from dorsal roots via dorsal funiculus the dorsal funiculus At rostral end of spinal cord, laminas I-IV spinal become continuous with the spinal trigeminal nucleus trigeminal nucleus

27. Lamina V - VI tract cells Origination of tract cells, similar to lamina IV, these tracts cells are Nucleus Proprius also known as the Nucleus Proprius spinal thalamic tract (e.g. spinal thalamic tract or anterolateral system anterolateral system; pain and temperature, some tactile) Receives afferent input from dorsal roots and descending fibers, Corticospinal most importantly Corticospinal

28. Laterally, gray matter at base of dorsal horn mixes with white matter from lateral funiculus, this region is called reticular formation reticular formation. It is noticeable in the cervical region Laterally, gray matter at base of dorsal horn mixes with white matter from lateral funiculus, this region is called reticular formation reticular formation. It is noticeable in the cervical region Lamina V - VI reticular formation ----------------> C7

29. 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: Clarke a. Nucleus dorsalis (Clarke) b. Intermediolateral cell column c. Intermediomedial cell column d. 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: Clarke a. Nucleus dorsalis (Clarke) b. Intermediolateral cell column c. Intermediomedial cell column d. Sacral autonomic nucleus Lamina VII

30. Nucleus dorsalisof Clark Nucleus dorsalis of Clark nucleus thoracicus AKA nucleus thoracicus is located medial & ventral to the dorsal horn in T1-L3 Composed of large neurons & axons that form the dorsal spinocerebellar tract on the ipsilateral side Nucleus dorsalisof Clark Nucleus dorsalis of Clark nucleus thoracicus AKA nucleus thoracicus is located medial & ventral to the dorsal horn in T1-L3 Composed of large neurons & axons that form the dorsal spinocerebellar tract on the ipsilateral side T5

31. Lamina VII Intermediolateral cell column is located at the lateral portion of the intermediate zone. Responsible for the formation lateral hornT1 - L2 of the lateral horn in T1 - L2 Consists of cell bodies of sympathetic sympathetic preganglionic neurons Intermediolateral cell column is located at the lateral portion of the intermediate zone. Responsible for the formation lateral hornT1 - L2 of the lateral horn in T1 - L2 Consists of cell bodies of sympathetic sympathetic preganglionic neurons T5

32. Lamina VII Intermediomedial 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 reflexes Intermediomedial 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 reflexes T5

33. Lamina VII Sacral autonomic nucleus is located in the lateral part of lamina VII in S2-S4 segments para- Consists of preganglionic para- sympathetic sympathetic neurons Sacral autonomic nucleus is located in the lateral part of lamina VII in S2-S4 segments para- Consists of preganglionic para- sympathetic sympathetic neurons S2

34. 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 vestibulospinal fibers, including the vestibulospinal reticulospinal tracts and reticulospinal 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 vestibulospinal fibers, including the vestibulospinal reticulospinal tracts and reticulospinal tracts Lamina VIII

35. Consists of columns of neurons embedded in either lamina VII or VIII alphagamma Cells include alpha and gamma motor neurons, which axons exit via the striated ventral roots and innervate striated muscleSmaller muscle. Smaller neurons contribute ventral fasciculus proprius axons to the ventral fasciculus proprius Four columns of motor neurons can be identified within this lamina; ventromedialventrolateraldorsolateral ventromedial, ventrolateral, dorsolateral central & central each has characteristic dendritic features Consists of columns of neurons embedded in either lamina VII or VIII alphagamma Cells include alpha and gamma motor neurons, which axons exit via the striated ventral roots and innervate striated muscleSmaller muscle. Smaller neurons contribute ventral fasciculus proprius axons to the ventral fasciculus proprius Four columns of motor neurons can be identified within this lamina; ventromedialventrolateraldorsolateral ventromedial, ventrolateral, dorsolateral central & central each has characteristic dendritic features Lamina IX

36. Ventral gray columns Ventral gray columns in lamina IX have somatotopic arrangement: Medial areas - Medial areas innervate the axial musculature Lateral areas - Lateral areas innervate the limbs muscles Ventral gray columns Ventral gray columns in lamina IX have somatotopic arrangement: Medial areas - Medial areas innervate the axial musculature Lateral areas - Lateral areas innervate the limbs muscles Lamina IX

37. PHRENIC NUCLEUS The phrenic nucleus is located in the ventromedial area of the ventral horn in C2-C5 segments. It receives bilateral innervation from the solitary nucleus of the medullary region, via solitary tract. This nucleus is responsible for the innervation of the diaphragm SPINAL ACCESSORY NUCLEUS The spinal accessory nucleus (cranial nerve XI) is located in the lateral area of vental horn in C1-C5 segments. Corticospinal tract innervates this nucleus bilaterally. This nucleus is also responsible for the innervation of the trapezius & sternocleidomastoid muscles (ipsilaterally)

38. Lamina 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 Onuf S2

39. central canal Surrounds the central canal, and ventral gray commissure includes the ventral gray commissure neurons Contains relatively small neurons, radial neuroglia cells radial neuroglia cells & decussating axons Some dorsal root afferents terminate here central canal Surrounds the central canal, and ventral gray commissure includes the ventral gray commissure neurons Contains relatively small neurons, radial neuroglia cells radial neuroglia cells & decussating axons Some dorsal root afferents terminate here Lamina X

40. Ascending and descending association fiber systems of the Ascending and descending association fiber systems of the spinal cord which lie deep in the anterior, lateral & posterior spinal cord which lie deep in the anterior, lateral & posterior funiculi adjacent to the gray matter. funiculi adjacent to the gray matter. Fasciculi proprii aka Flechsig's fasciculi or Ground bundles Fasciculi proprii aka Flechsig's fasciculi or Ground bundles consist of: anterior, lateralis & intersegmental fasciculi consist of: anterior, lateralis & intersegmental fasciculi Ascending and descending association fiber systems of the Ascending and descending association fiber systems of the spinal cord which lie deep in the anterior, lateral & posterior spinal cord which lie deep in the anterior, lateral & posterior funiculi adjacent to the gray matter. funiculi adjacent to the gray matter. Fasciculi proprii aka Flechsig's fasciculi or Ground bundles Fasciculi proprii aka Flechsig's fasciculi or Ground bundles consist of: anterior, lateralis & intersegmental fasciculi consist of: anterior, lateralis & intersegmental fasciculi Fasiculus Proprius

41. Dorsal Roots dorsal root Each dorsal root divides into 6 - 8 rootlets Each rootlet can be divided into lateral medial division lateral & medial division Lateral division Lateral division carries pain information related to pain temperature & temperature Medial division Medial division carries tactile information related to tactile discriminationvibration discrimination & vibration dorsal root Each dorsal root divides into 6 - 8 rootlets Each rootlet can be divided into lateral medial division lateral & medial division Lateral division Lateral division carries pain information related to pain temperature & temperature Medial division Medial division carries tactile information related to tactile discriminationvibration discrimination & vibration

42. Dorsal Roots Lateral division Lateral division axons enter dorsolateral tract of Lissauer dorsolateral tract of Lissauer, ascending and then divide into ascending descending & descending branches, each dorsal horn terminate in the dorsal horn Most terminate at same level & some fibers may travel up or down the cord up to four levels Lateral division Lateral division axons enter dorsolateral tract of Lissauer dorsolateral tract of Lissauer, ascending and then divide into ascending descending & descending branches, each dorsal horn terminate in the dorsal horn Most terminate at same level & some fibers may travel up or down the cord up to four levels

43. Dorsal Roots Medial division Medial division axons enter the white matter & then divide into ascendingdescending ascending & descending branches Descending branches Descending branches are organized into two bundles, Septomarginalis Fasiculus the Septomarginalis Fasiculus Interfascicular Fasiculus and the Interfascicular Fasiculus descending branchesterminate All descending branches terminate in the dorsal horn in the dorsal horn Medial division Medial division axons enter the white matter & then divide into ascendingdescending ascending & descending branches Descending branches Descending branches are organized into two bundles, Septomarginalis Fasiculus the Septomarginalis Fasiculus Interfascicular Fasiculus and the Interfascicular Fasiculus descending branchesterminate All descending branches terminate in the dorsal horn in the dorsal horn

44. Dorsal Roots Ascending branches Ascending branches of the enter the medial division enter the dorsal funiculus dorsal funiculus & terminate gracilecuneate in gracile & cuneate nuclei in the medulla Ascending branches Ascending branches of the enter the medial division enter the dorsal funiculus dorsal funiculus & terminate gracilecuneate in gracile & cuneate nuclei in the medulla

45. Ventral Horn Lamina IX contains two types Lamina IX contains two types of motor neurons, alpha and of motor neurons, alpha and gamma gamma Alpha motor neurons innervate Alpha motor neurons innervate extrafusal fibers of striated extrafusal fibers of striated skeletal muscles skeletal muscles Gamma motor neurons innervate Gamma motor neurons innervate intrafusal fibers of neuromuscular intrafusal fibers of neuromuscular spindles spindles Both types receive inputs from Both types receive inputs from interneurons, including the interneurons, including the inhibitory Renshaw cell inhibitory Renshaw cell Lamina IX contains two types Lamina IX contains two types of motor neurons, alpha and of motor neurons, alpha and gamma gamma Alpha motor neurons innervate Alpha motor neurons innervate extrafusal fibers of striated extrafusal fibers of striated skeletal muscles skeletal muscles Gamma motor neurons innervate Gamma motor neurons innervate intrafusal fibers of neuromuscular intrafusal fibers of neuromuscular spindles spindles Both types receive inputs from Both types receive inputs from interneurons, including the interneurons, including the inhibitory Renshaw cell inhibitory Renshaw cell

46. Spinal Cord Tracts Spinal Cord Tracts

47. Tracts of the Spinal Cord 1. Fasciculus Gracilis 2. Fasciculus Cuneatus 3. Tractus spinocerebellaris dorsalis 4. Tractus corticospinalis lateralis 5. Tractus spinothalamicus lateralis 6. Tractus spinocerebellaris ventralis 7. Tractus rubrospinalis 8. Tractus spinotectalis 9. Tractus corticospinalis anterior 10. Tractus olivospinalis 11. Tractus spinoolivaris 12. Tractus tectospinalis 13. Tractus reticulospinalis 14. Tractus vestibulospinalis 15. Tractus spinothalamicus anterior 16.Raphe-spinal & Hypothalamospinal fibers 1. Fasciculus Gracilis 2. Fasciculus Cuneatus 3. Tractus spinocerebellaris dorsalis 4. Tractus corticospinalis lateralis 5. Tractus spinothalamicus lateralis 6. Tractus spinocerebellaris ventralis 7. Tractus rubrospinalis 8. Tractus spinotectalis 9. Tractus corticospinalis anterior 10. Tractus olivospinalis 11. Tractus spinoolivaris 12. Tractus tectospinalis 13. Tractus reticulospinalis 14. Tractus vestibulospinalis 15. Tractus spinothalamicus anterior 16.Raphe-spinal & Hypothalamospinal fibers 16

48. Ascending Tracts Ascending Tracts Modality: Touch, Pain, Temperature, Kinesthesia Modality: Touch, Pain, Temperature, Kinesthesia Receptor: Exteroceptor, Interoceptor, Proprioceptor Receptor: Exteroceptor, Interoceptor, Proprioceptor Primary Neuron: Dorsal Root Ganglion (Spinal Ganglion) Primary Neuron: Dorsal Root Ganglion (Spinal Ganglion) Secondary Neuron: Spinal Cord or Brain Stem Secondary Neuron: Spinal Cord or Brain Stem Tertiary Neuron: Thalamus (Ventrobasal Nuclear Complex) Tertiary Neuron: Thalamus (Ventrobasal Nuclear Complex) Termination: Cerebral Cortex, Cerebellar Cortex, or Termination: Cerebral Cortex, Cerebellar Cortex, or Brain Stem Brain Stem Ascending Tracts Ascending Tracts Modality: Touch, Pain, Temperature, Kinesthesia Modality: Touch, Pain, Temperature, Kinesthesia Receptor: Exteroceptor, Interoceptor, Proprioceptor Receptor: Exteroceptor, Interoceptor, Proprioceptor Primary Neuron: Dorsal Root Ganglion (Spinal Ganglion) Primary Neuron: Dorsal Root Ganglion (Spinal Ganglion) Secondary Neuron: Spinal Cord or Brain Stem Secondary Neuron: Spinal Cord or Brain Stem Tertiary Neuron: Thalamus (Ventrobasal Nuclear Complex) Tertiary Neuron: Thalamus (Ventrobasal Nuclear Complex) Termination: Cerebral Cortex, Cerebellar Cortex, or Termination: Cerebral Cortex, Cerebellar Cortex, or Brain Stem Brain Stem Spinal Cord Tracts Spinal Cord Tracts

49. Ascending Tracts Ascending Tracts Posterior White Column-Medial Lemniscal Pathway Posterior White Column-Medial Lemniscal Pathway Spinothalamic Tract Spinoreticular or Spinoreticulothalamic Tract Spinocerebellar Tract Spinomedullothalamic Tract Cervicothalamic or Spinocervicothalamic Tract Spino-olivary Tract Spinotectal Tract Ascending Tracts Ascending Tracts Posterior White Column-Medial Lemniscal Pathway Posterior White Column-Medial Lemniscal Pathway Spinothalamic Tract Spinoreticular or Spinoreticulothalamic Tract Spinocerebellar Tract Spinomedullothalamic Tract Cervicothalamic or Spinocervicothalamic Tract Spino-olivary Tract Spinotectal Tract Spinal Cord Tracts Spinal Cord Tracts

51. Posterior White Column-Medial Lemniscal Pathway Modality: Discriminative Touch Sensation (include Vibration) and Modality: Discriminative Touch Sensation (include Vibration) and Conscious Proprioception (Position Sensation, Kinesthesia) Conscious Proprioception (Position Sensation, Kinesthesia) Receptor: Most receptors except free nerve endings Receptor: Most receptors except free nerve endings Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Posterior Root - Posterior White Column Posterior Root - Posterior White Column 2nd Neuron: Dorsal Column Nuclei (Nucleus Gracilis et Cuneatus) 2nd Neuron: Dorsal Column Nuclei (Nucleus Gracilis et Cuneatus) Internal Arcuate Fiber - Lemniscal Decussation Internal Arcuate Fiber - Lemniscal Decussation - Medial Lemniscus - Medial Lemniscus 3rd Neuron: Thalamus (VPLc) 3rd Neuron: Thalamus (VPLc) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata Termination: Primary Somesthetic Area (S I) Termination: Primary Somesthetic Area (S I) Posterior White Column-Medial Lemniscal Pathway Modality: Discriminative Touch Sensation (include Vibration) and Modality: Discriminative Touch Sensation (include Vibration) and Conscious Proprioception (Position Sensation, Kinesthesia) Conscious Proprioception (Position Sensation, Kinesthesia) Receptor: Most receptors except free nerve endings Receptor: Most receptors except free nerve endings Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Posterior Root - Posterior White Column Posterior Root - Posterior White Column 2nd Neuron: Dorsal Column Nuclei (Nucleus Gracilis et Cuneatus) 2nd Neuron: Dorsal Column Nuclei (Nucleus Gracilis et Cuneatus) Internal Arcuate Fiber - Lemniscal Decussation Internal Arcuate Fiber - Lemniscal Decussation - Medial Lemniscus - Medial Lemniscus 3rd Neuron: Thalamus (VPLc) 3rd Neuron: Thalamus (VPLc) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata Termination: Primary Somesthetic Area (S I) Termination: Primary Somesthetic Area (S I) Spinal Cord Ascending Tracts Spinal Cord Ascending Tracts

52. Posterior White Column - Medial Lemniscal Pathway Posterior White Column - Medial Lemniscal Pathway medial lemniscus lemniscal decussation internal arcuate fiber posterior white column posterior root - ipsilateral loss of discriminative touch sensation and conscious proprioception sensation and conscious proprioception below the level of lesion below the level of lesion

53. Spinothalamic Tract Modality: Pain & Temperature Sensation, Light Touch Modality: Pain & Temperature Sensation, Light Touch Receptor: Free Nerve Ending Receptor: Free Nerve Ending Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Posterior Root Posterior Root 2nd Neuron: Dorsal Horn (Lamina IV, V, VI) 2nd Neuron: Dorsal Horn (Lamina IV, V, VI) Spinothalamic Tract - (Spinal Lemniscus) Spinothalamic Tract - (Spinal Lemniscus) 3rd Neuron: Thalamus (VPLc, CL & POm) 3rd Neuron: Thalamus (VPLc, CL & POm) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata Termination: Primary Somesthetic Area (S I) & Termination: Primary Somesthetic Area (S I) & Diffuse Widespread Cortical Region Diffuse Widespread Cortical Region Spinothalamic Tract Modality: Pain & Temperature Sensation, Light Touch Modality: Pain & Temperature Sensation, Light Touch Receptor: Free Nerve Ending Receptor: Free Nerve Ending Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Posterior Root Posterior Root 2nd Neuron: Dorsal Horn (Lamina IV, V, VI) 2nd Neuron: Dorsal Horn (Lamina IV, V, VI) Spinothalamic Tract - (Spinal Lemniscus) Spinothalamic Tract - (Spinal Lemniscus) 3rd Neuron: Thalamus (VPLc, CL & POm) 3rd Neuron: Thalamus (VPLc, CL & POm) Internal Capsule ----- Corona Radiata Internal Capsule ----- Corona Radiata Termination: Primary Somesthetic Area (S I) & Termination: Primary Somesthetic Area (S I) & Diffuse Widespread Cortical Region Diffuse Widespread Cortical Region Spinal Cord Ascending Tracts Spinal Cord Ascending Tracts

54. Spinothalamic Tract spinothalamictract anterior white commissure posterior root decussation - contralateral loss of pain and temperature sensation below the level of lesion sensation below the level of lesion

55. Spinothalamic Tract & Spinoreticular Tract Widespread cortical region cortical region CL (intralaminar thalamic nuclei) thalamic nuclei)reticulothalamic pathways pathwaysspinoreticular tract tract Primary Motor Area (M I) Area (M I) VPLc (ventrobasal nuclear complex) nuclear complex) (spinal lemniscus) spinothalamic tract tract thalamus reticular formation NeoSTT PaleoSTT

56. Fast PainSlow Pain Fast PainSlow Pain Sharp, prickingDull, burning Group III (A  ) fiberGroup IV (C) fiber Short latencySlower onset Well localizedDiffuse Short durationLong duration Less emotional Emotional, autonomic response Not blocked by morphineBlocked by morphine Neospinothalamic TractPaleospinothalamic Tract Comparison of Fast and Slow Pain ------ Spinothalamic Tract Comparison of Fast and Slow Pain ------ Spinothalamic Tract

57. Spinocerebellar Tract Modality: Unconscious Proprioception Modality: Unconscious Proprioception Receptor: Muscle spindle, Golgi tendon organ Receptor: Muscle spindle, Golgi tendon organ Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Posterior Root, [Posterior Column] Posterior Root, [Posterior Column] 2nd Neuron: 1. Clarke’s column (Lamina VII) 2nd Neuron: 1. Clarke’s column (Lamina VII) Posterior Spinocerebellar Tract Posterior Spinocerebellar Tract 2. Accessory Cuneate Nucleus 2. Accessory Cuneate Nucleus Cuneocerebellar Tract Cuneocerebellar Tract 3. Posterior Horn 3. Posterior Horn Anterior Spinocerebellar Tract Anterior Spinocerebellar Tract Termination: Cerebellar Cortex Termination: Cerebellar Cortex Spinocerebellar Tract Modality: Unconscious Proprioception Modality: Unconscious Proprioception Receptor: Muscle spindle, Golgi tendon organ Receptor: Muscle spindle, Golgi tendon organ Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Ist Neuron: Dorsal Root Ganglion (Spinal Ganglion) Posterior Root, [Posterior Column] Posterior Root, [Posterior Column] 2nd Neuron: 1. Clarke’s column (Lamina VII) 2nd Neuron: 1. Clarke’s column (Lamina VII) Posterior Spinocerebellar Tract Posterior Spinocerebellar Tract 2. Accessory Cuneate Nucleus 2. Accessory Cuneate Nucleus Cuneocerebellar Tract Cuneocerebellar Tract 3. Posterior Horn 3. Posterior Horn Anterior Spinocerebellar Tract Anterior Spinocerebellar Tract Termination: Cerebellar Cortex Termination: Cerebellar Cortex Spinal Cord Ascending Tracts Spinal Cord Ascending Tracts

58. Spinocerebellar Tract Inferior cerebellar peduncle peduncleposterior spinocerebellar spinocerebellar tract tractClarke’s column columnposterior white column white column posterior root Posterior SCbllT Inferior cerebellar cerebellar peduncle pedunclecuneocerebellar tract tract (upper body) (upper body)posterior white column white column posterior root Anterior SCbllT (superior cerebellar cerebellar peduncle) peduncle)anterior spinocerebellar spinocerebellar tract tract anterior white commissure commissure posterior root

59. Spinocerebellar Tract

60. Corticospinal Tract Origin: Cerebral Cortex Origin: Cerebral 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 Radiata Corona Radiata lnternal Capsule, Posterior Limb lnternal Capsule, Posterior Limb Crus Cerebri, Middle Portion Crus Cerebri, Middle Portion Longitudinal Pontine Fiber Longitudinal Pontine Fiber Pyramid - pyramidal decussation Pyramid - pyramidal decussation Corticospinal Tracts: Corticospinal Tracts: - Lateral (crossed) - 85% - Anterior (Not crossed) - 15% Termination: Spinal Gray (Rexed IV-IX) Termination: Spinal Gray (Rexed IV-IX) Corticospinal Tract Origin: Cerebral Cortex Origin: Cerebral 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 Radiata Corona Radiata lnternal Capsule, Posterior Limb lnternal Capsule, Posterior Limb Crus Cerebri, Middle Portion Crus Cerebri, Middle Portion Longitudinal Pontine Fiber Longitudinal Pontine Fiber Pyramid - pyramidal decussation Pyramid - pyramidal decussation Corticospinal Tracts: Corticospinal Tracts: - Lateral (crossed) - 85% - Anterior (Not crossed) - 15% Termination: Spinal Gray (Rexed IV-IX) Termination: Spinal Gray (Rexed IV-IX) Spinal Cord Descending Tracts Spinal Cord Descending Tracts

62. - ipsilateral UMN syndrome at the level of lesion at the level of lesion Corticospinal Tract Corona Radiata lnternal Capsule, Posterior Limb Crus Cerebri, Middle Portion Longitudinal Pontine Fiber Pyramid Pyramidal Decussation Corticospinal Tract - Lateral and Anterior - Lateral and Anterior CR IC LPF Pyr PD LCST ACST

63. Descending Tracts from Brain Stem Dorsolateral (Motor) Pathway Dorsolateral (Motor) Pathway Rubrospinal Tract Rubrospinal Tract Ventromedial (Motor) Pathway Ventromedial (Motor) Pathway Tectospinal Tract Tectospinal Tract Vestibulospinal Tract Vestibulospinal Tract MLF (Medial Longitudinal Fasciculus) MLF (Medial Longitudinal Fasciculus) - interstitiospinal tract - interstitiospinal tract Sensory Modulation pathways Sensory Modulation pathways Raphespinal & Cerulospinal Pathways Raphespinal & Cerulospinal Pathways Descending Autonomic Pathways Descending Autonomic Pathways Descending Tracts from Brain Stem Dorsolateral (Motor) Pathway Dorsolateral (Motor) Pathway Rubrospinal Tract Rubrospinal Tract Ventromedial (Motor) Pathway Ventromedial (Motor) Pathway Tectospinal Tract Tectospinal Tract Vestibulospinal Tract Vestibulospinal Tract MLF (Medial Longitudinal Fasciculus) MLF (Medial Longitudinal Fasciculus) - interstitiospinal tract - interstitiospinal tract Sensory Modulation pathways Sensory Modulation pathways Raphespinal & Cerulospinal Pathways Raphespinal & Cerulospinal Pathways Descending Autonomic Pathways Descending Autonomic Pathways Spinal Cord Descending Tracts Spinal Cord Descending Tracts

64. ventromedial pathway dorsolateral pathway DescendingTractsfrom Brain Stem Spinal Cord Tracts Tracts

65. upper motor neuron UMN UMN SOMATIC MOTOR SYSTEM lower motor neuron LMN Brain Stem Brain StemDescending Pathway Pathway Final Common Pathway EFFECTORS skeletal muscle Pyramidal Tract VOLUNTARY CONTROL AUTOMATIC CONTROL Rubrospinal Tract Tectospinal Tract Vestibulospinal Tract MLF Reticulospinal Tract REFLEX

66. Spinal Cord Syndrome Spinal Cord Syndrome Location of Symptoms in Spinal Disease ipsilateral to lesion contralateral to lesion

67. Upper Motor Neuron (UMN) vs. Lower Motor Neuron (LMN) Syndrome UMN syndrome LMN Syndrome Type of Paralysis Spastic ParesisFlaccid Paralysis Atrophy No (Disuse) Atrophy Severe Atrophy Deep Tendon Reflex Increase Absent DTR Pathological Reflex Positive Babinski Sign Absent Superficial Reflex Absent Present Fasciculation and Absent Could be Fibrillation Present

68. Spinal Cord Syndrome Spinal Cord Syndrome Predominantly Motor Syndromes Predominantly 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

69. Spinal Cord Syndrome Spinal Cord Syndrome Amyotrophic Lateral Sclerosis Amyotrophic Lateral Sclerosis 1. corticospinal tract 2. lower motor neuron (LMN)

70. Spinal Cord SyndromeAmyotrophic Lateral Sclerosis (ALS) Lou Gherig’s Disease Spinal Cord SyndromeAmyotrophic Lateral Sclerosis (ALS) Lou Gherig’s Disease Lou "The Iron Horse" Gehrig (1903-41) 3.40, 2131(1925-39), 23 GSH, 147 RBI avg.

71. Spinal Cord SyndromeAmyotrophic Lateral Sclerosis (ALS) Lou Gherig’s Disease Spinal Cord SyndromeAmyotrophic Lateral Sclerosis (ALS) Lou Gherig’s Disease Stephen Haking (1946- ) British Physicist, A Brief History of Time

72. Spinal Cord Syndrome Spinal Cord Syndrome Predominantly Sensory Syndromes Predominantly Sensory Syndromes Herpes Zoster Herpes 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 Dorsalis Tabes 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 lesion proprioception below the level of lesion - posterior column ataxia - posterior column ataxia - lancinating pain (a stabbing or piercing sensation) - lancinating pain (a stabbing or piercing sensation) - loss of deep tendon reflex (DTR) - loss of deep tendon reflex (DTR)

73. Herpes Zoster (Shingles) varicella-zoster virus varicella-zoster virus reactivation from reactivation from the dorsal root ganglia the dorsal root ganglia unilateral vesicular unilateral vesicular eruption within eruption within a dermatome a dermatome T3 to L3 dermatome T3 to L3 dermatome lesions are frequent lesions are frequent zoster ophtahalmicus zoster ophtahalmicus (ophthalmic division (ophthalmic division of trigeminal n., V 1 ) of trigeminal n., V 1 ) Ramsey-Hunt syndrome Ramsey-Hunt syndrome (sensory br. of VII) (sensory br. of VII) acyclovir, antiviral agent acyclovir, antiviral agent

74. Spinal Cord Syndrome Spinal Cord Syndrome Sub-Acute Combined Degeneration Sub-Acute Combined Degeneration (Combined System Disease) (Combined System Disease) Lesion Lesion - posterior white column - posterior white column - corticospinal tract (UMN) - corticospinal tract (UMN) Symptom Symptom - loss of discriminative touch sensation and conscious - loss of discriminative touch sensation and conscious proprioception below the level of lesion proprioception below the level of lesion - ipsilateral UMN syndrome below the level of lesion - ipsilateral UMN syndrome below the level of lesion

75. Spinal Cord Syndrome Spinal Cord Syndrome Sub-Acute Combined Degeneration Sub-Acute Combined Degeneration 1. corticospinal tract 2. posterior white column

76. Spinal Cord Syndrome Spinal Cord Syndrome Syringomyelia, Hematomyelia Syringomyelia, Hematomyelia Lesion Lesion - 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 Symptom Symptom - 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 canal according to the lesion extended from central canal

77. Spinal Cord Syndrome Spinal Cord Syndrome Syringomyelia - Initial Symptoms Syringomyelia - Initial Symptoms

79. Spinal Cord Syndrome Spinal Cord Syndrome Brown-Sequard syndrome Brown-Sequard syndrome (spinal cord hemisection) (spinal cord hemisection) Major Symptoms Major Symptoms 1. ipsilateral UMN syndrome below the level of lesion 1. ipsilateral UMN syndrome below the level of lesion 2. ipsilateral LMN syndrome at the level of lesion 2. ipsilateral LMN syndrome at the level of lesion 3. ipsilateral loss of discriminative touch sensation and 3. ipsilateral loss of discriminative touch sensation and conscious proprioception below the level of lesion conscious proprioception below the level of lesion (posterior white column lesion) (posterior white column lesion) 4. contralateral loss of pain and temperature sensation 4. contralateral loss of pain and temperature sensation below the level of lesion (spinothalamic tract lesion) below the level of lesion (spinothalamic tract lesion)

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