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

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

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

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

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 2nd Neuron: 1. Clarke’s column 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 r Tract Anterior Spinocerebellar r 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 2nd Neuron: 1. Clarke’s column 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 r Tract Anterior Spinocerebellar r Tract Termination: Cerebellar Cortex Termination: Cerebellar Cortex Spinal Cord Ascending Tracts Spinal Cord Ascending Tracts

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

Spinocerebellar Tract

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 Tract - Lateral and Anterior Corticospinal Tract - Lateral and Anterior 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 Tract - Lateral and Anterior Corticospinal Tract - Lateral and Anterior Termination: Spinal Gray (Rexed IV-IX) Termination: Spinal Gray (Rexed IV-IX) Spinal Cord Descending Tracts Spinal Cord Descending Tracts

- 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

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

ventromedial pathway dorolateral pathway DescendingTractsfrom Brain Stem Spinal Cord Tracts Tracts

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

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

Upper Motor Neuron (UMN) vs Lower Motor Neuron (LMN) Syndrome UMN syndrome LMN Syndrome Type of Paralysis Spastic Paresis Flaccid 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

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

Spinal Cord Syndrome Spinal Cord Syndrome Syringomyelia - Initial Symptoms Syringomyelia - Initial Symptoms

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)

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