Anatomy of the Spinal Cord  Structure of the spinal cord  Tracts of the spinal cord  Spinal cord syndromes Anatomy of the Spinal Cord  Structure of the spinal cord  Tracts of the spinal cord  Spinal cord syndromes Won Taek Lee, M.D., Ph.D. تنظیم و بازنگری :دکتر مهران مرادی رزیدنت جراحی مغز و اعصاب

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

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

cervical enlargement (C8) thoracic cord (T8) cervical enlargement (C8) thoracic cord (T8) lumbal enlargement (L3) sacral cord (S1) lumbal enlargement (L3) sacral cord (S1)

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

Columnnar arrangement somatotopical arrangement

Lamina of Rexed Lamina of Rexed Lamina I posteromarginal nucleus Lamina I posteromarginal nucleus Lamina II substantia gelatinosa of Rolando Lamina II substantia gelatinosa of Rolando Lamina III, IV nucleus proprius Lamina III, IV nucleus proprius Lamina V, VI Lamina V, VI Lamina VII intermediate gray Lamina VII intermediate gray intermediolateral cell column (ILM) intermediolateral cell column (ILM) Clarke’s column (Nucleus dorsalis) Clarke’s column (Nucleus dorsalis) intermediomedial cell column (IMM) intermediomedial cell column (IMM) Lamina VIII Lamina VIII Lamina IX anterior horn (motor) cell Lamina IX anterior horn (motor) cell Lamina X gray commissure Lamina X gray commissure Lamina of Rexed Lamina of Rexed Lamina I posteromarginal nucleus Lamina I posteromarginal nucleus Lamina II substantia gelatinosa of Rolando Lamina II substantia gelatinosa of Rolando Lamina III, IV nucleus proprius Lamina III, IV nucleus proprius Lamina V, VI Lamina V, VI Lamina VII intermediate gray Lamina VII intermediate gray intermediolateral cell column (ILM) intermediolateral cell column (ILM) Clarke’s column (Nucleus dorsalis) Clarke’s column (Nucleus dorsalis) intermediomedial cell column (IMM) intermediomedial cell column (IMM) Lamina VIII Lamina VIII Lamina IX anterior horn (motor) cell Lamina IX anterior horn (motor) cell Lamina X gray commissure Lamina X gray commissure Spinal Cord Internal Structure Spinal Cord Internal Structure

Lamina of Rexed

Spinal reflexes

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

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

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

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

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