Lesions of the Spinal Cord Learning Module Click to Begin

Used with permission of the Academy of Neurologic Physical Therapy of the APTA Do not duplicate without acknowledging Learning Activity author Michael McKeough, PT, EdD

Contents Overview Introduction Learning Objectives Instructions Legend Read these Instructions! Review of functional systems in the spinal cord Lateral corticospinal tract Dorsal column-medial lemniscal system Lateral spinothalamic tract Lesion lessons Dorsal column lesion Fasciculus gracilis lesion Fasciculus cuneatus lesion Lateral corticospinal tract lesion Lateral spinothalamic tract lesion Patient Cases Case 1 Case 2 Case 3 Transverse cord lesion Hemicord lesion Central cord syndrome Anterior cord syndrome Posterior cord syndrome ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Overview Introduction Learning Objectives Instructions Legend ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Introduction This module reviews lesions of the spinal cord Module organization consists of three components. Review of functional systems in the spinal cord (lateral corticospinal tract, DCML, and lateral spinothalamic tract), lesion lessons (9 interactive lesions with feedback), and patient cases (3 interactive cases with feedback). At the bottom of each page, a navigation bar contains options to move throughout the module. Material is presented at both the behavioral level and the neuroanatomical level. The behavioral level is presented first and depicts a patient’s clinical presentation. The neuroanatomical level depicts the detailed anatomy of first- order, second-order and third-order neurons. The neuroanatomical level accounts for the patient’s behavioral presentation on examination under normal and lesioned conditions. ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Learning Objectives After completing this module you should be able to: 1.describe the signs and symptoms caused by a lesion of the spinal cord (fasciculus gracilis and fasciculus cuneatus, lateral corticospinal tract, and lateral spinothalamic tract). 2.given a patient case (examination results and chief complaint), identify the functional systems causing the sensory and motor impairments. 3.correlate neurology information between the behavioral and neuroanatomical levels. ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Instructions This module contains 9 interactive lesion lessons with animation. Lesson lessons begin with a question about the symptoms produced by that particular lesion. Clicking the answer button will reveal the answer to the question. Clicking the explanation button will lead to both behavioral and neuroanatomical explanations of the lesion. Each presentation is launched by clicking the animation button. The same button serves to replay the animation if desired. Any of the lessons may be accessed by simply clicking on the lesion title on the Contents page. Please refer to the Legend that defines the symbols used throughout the module. ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Legend First-order neuron Second-order neuron Third-order neuron Pain stimulus Mechanism of injury Lesion Sensory impairment Function intact Function lost Light touch stimulus ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Review of Functional Systems in the Spinal Cord Lateral corticospinal tract Dorsal column-medial lemniscal system Lateral spinothalamic tract ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Lateral Corticospinal Tract Voluntary Knee Extension: Behavioral Description Voluntary movement is controlled by a system of brain and spinal motor centers linked by neuronal pathways. The primary motor pathway (Corticospinal tract) is crossed such that the left hemisphere controls movement of the right half of the body and vise versa. Motor pathways consist of upper and lower motor neurons. Upper motor neurons originate in the precentral gyrus, decussate in the medulla, descend in the lateral column of the spinal cord, and terminate on lower motor neurons in the ventral horn. Lower motor neurons exit the CNS and innervate skeletal muscles via the peripheral nervous system. Click to animate Neuroanatomical Explanation Stimulus UMN LMN ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Lateral Corticospinal Tract Voluntary Knee Extension: Neuroanatomical Description The cell body of the upper motor neuron is located in he precentral gyrus (somatotopically organized). The axon descends through the internal capsule, decussates in the medulla, descends through the lateral column of the spinal cord and terminates in the ventral horn. The cell body of the lower motor neuron is located in the ventral horn. The axon exits the CNS via ventral rootlets of spinal nerves and innervates skeletal muscle via a peripheral nerve. Skeletal muscles contract to produce the force to extend the knee. Behavioral Explanation Stimulus UMN LMN ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

The cell body of the upper motor neuron is located in he precentral gyrus (somatotopically organized). The axon descends through the internal capsule, decussates in the medulla, descends through the lateral column of the spinal cord and terminates in the ventral horn. The cell body of the lower motor neuron is located in the ventral horn. The axon exits the CNS via spinal nerves and innervates skeletal muscle via a peripheral nerve. Skeletal muscles contract to produce the force to extend the knee. Behavioral Explanation Stimulus UMN LMN Lateral Corticospinal Tract Voluntary Knee Extension: Neuroanatomical Description ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Thalamus Fasciculus Gracilis Fasciculus Cuneatus Nucleus Gracilis Nucleus Cuneatus Primary sensory cortex Dorsal Column-Medial Lemniscal System Discriminative touch, vibration, and position information from the body is conveyed by the dorsal column-medial lemniscal system (DCML). The DCML is a crossed system. It originates from mechano-receptors (sensory receptors sensitive to mechanical deformation) located in the body wall and projects to the contralateral cerebral hemisphere via a three neuron projection system. The DCML is comprised of the fasciculus gracilis and fasciculus cuneatus. Fasciculus gracilis Fasciculus cuneatus First-order neuron Second-order neuron Third-order neuron Stimulus ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Thalamus Fasciculus Gracilis Nucleus Gracilis Primary sensory cortex Fasciculus Gracilis: Behavioral Description Click to animate Fasciculus gracilis: light touch, vibration, and position sense from the contralateral leg and lower trunk Consists of a 3-neuron projection system extending from receptors in the periphery to the primary somatosensory cortex (Click neuroanatomical explanation) Fasciculus gracilis Neuroanatomical Explanation Fasciculus cuneatus First-order neuron Second-order neuron Third-order neuron Stimulus ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Click to animate Fasciculus Gracilis : Neuroanatomical Description First-order neurons Cell body: dorsal root ganglion (DRG) Distal axon: innervates mechanoreceptors in leg and lower trunk via peripheral nerves Proximal axon: enter dorsal column (fasciculus gracilis), ascend ipsilaterally and terminate in the nucleus gracilis Second-order neurons Cell body: nucleus gracilis Axon: decussates in the medulla and projects to the contralateral thalamus (ventral posterior lateral nucleus, VPL) via the medial lemniscus Third-order neurons Cell body: VPL of thalamus Axon: ascends via the posterior limb of the internal capsule and terminates in the primary somatosensory cortex DRG Behavioral Explanation Fasciculus cuneatus ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Fasciculus cuneatus: light touch, vibration, and position sense from the contralateral arm and upper trunk Consists of a 3-neuron projection system extending from receptors in the periphery to the primary somatosensory cortex (Click neuroanatomical explanation) Thalamus Nucleus Cuneatus Primary sensory cortex Fasciculus Cuneatus Fasciculus cuneatus: Click to animate Fasciculus Cuneatus: Behavioral Description Neuroanatomical Explanation First-order neuron Second-order neuron Third-order neuron Stimulus ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Click to animate First-order neurons Cell body: dorsal root ganglion (DRG) Distal axon: innervates mechanoreceptors in arm and upper trunk via peripheral nerves Proximal axon: enter dorsal column (fasciculus cuneatus), ascend ipsilaterally and terminate in the nucleus cuneatus Second-order neurons Cell body: nucleus cuneatus Axon: decussates in the medulla and projects to the contralateral thalamus (ventral posterior lateral nucleus, VPL) via the medial lemniscus Third-order neurons Cell body: VPL of thalamus Axon: ascends via the posterior limb of the internal capsule and terminates in the primary somatosensory cortex Fasciculus Cuneatus: Neuroanatomical Description DRG Behavioral Explanation ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Thalamus Primary sensory cortex Lateral spinothalamic tract Lateral Spinothalamic Tract: Behavioral Description Information about pain and temperature from the body is conveyed via several spinal tracts collectively known as the anterolateral system. The lateral spinothalamic tract (LSTT) is the most prominent among these. The LSTT is a crossed system. It originates from nociceptors (free nerve endings and chemo-receptors) and projects to the opposite (contralateral) cerebral hemisphere via a three neuron projection system. Click to animate Neuroanatomical Explanation First-order neuron Second-order neuron Third-order neuron Stimulus ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

The Lateral Spinothalamic Tract: Neuroanatomical Description First-order neurons Cell body: dorsal root ganglion (DRG) Distal axon: innervates nociceptors via peripheral nerves Proximal axon: enter the spinal cord, diverge 1-3 levels and terminate on second-order neurons in the dorsal horn Second-order neurons Cell body: dorsal horn Axon: decussates at or about the level of entry and projects to the contralateral thalamus (ventral posterior lateral nucleus, VPL) via the lateral spinothalamic tract Third-order neurons Cell body: VPL of thalamus Axon: ascends via the posterior limb of the internal capsule and terminates in the primary somatosensory cortex DRG Click to animate Behavioral Explanation Lateral spinothalamic tract ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Lesion Lessons Dorsal column lesion Fasciculus gracilis lesion Fasciculus cuneatus lesion Lateral corticospinal tract lesion Lateral spinothalamic tract lesion Transverse cord lesion Hemicord lesion Central cord syndrome Anterior cord syndrome Posterior cord syndrome ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Lesion of the right dorsal column at L1 produces what impairment? Click for answer Damage to the right dorsal column at L1 causes the absence of light touch, vibration, and position sensation in the right leg. Only fasciculus gracilis exists below T6. Click for explanation RL ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Right Dorsal Column Lesion Dorsal column lesion Ipsilateral loss of light touch, vibration, and position sense generalized below the lesion level Below T6 only the fasciculus gracilis is present. RL DRG L1 Common causes include MS, penetrating injuries, and compression from tumors. Click to animate ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Lesion of the left fasciculus gracilis at T8 produces what impairment? Click for answer Damage to the left fasciculus gracilis at T8 causes the absence of light touch, vibration, and position sensation in the left leg and lower left trunk. Only the fasciculus gracilis exists below T6. Click for explanation ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Thalamus Fasciculus Gracilis Fasciculus Cuneatus Nucleus Gracilis Nucleus Cuneatus Primary sensory cortex Lesion of the fasciculus gracilis on the left: Behavioral Explanation Sensory impairment: left leg and lower left trunk. Click to animate Sensory impairment: absence of light touch, vibration, and position sensation in the left leg and lower left trunk. Neuroanatomical Explanation Lesion Lost function Impairment ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Lesion of the fasciculus gracilis on the left: Neuroanatomical Explanation Because the tract has not yet decussated, impairment is ipsilateral to the lesion. Lesion of first-order neurons interrupts ascending information so light touch, vibration, and position sensation is impaired in the left leg and lower left trunk. Receptors and reflex connections below the lesion level remain intact. Click to animate Behavioral Explanation ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Lesion of the right fasciculus cuneatus at C3 produces what impairment? Click for answer Damage to the right fasciculus cuneatus at C3 causes the absence of light touch, vibration, and position sensation in the right arm and upper trunk. Click for explanation RL ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Right Fasciculus Cuneatus Lesion Fasciculus cuneatus lesion Ipsilateral loss of light touch, vibration, and position sense In the right arm and upper trunk RL DRG C3 Common causes include MS, penetrating injuries, and compression from tumors. Click to animate ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Lesion of the right lateral corticospinal tract at L1 produces what impairment? Click for answer Damage to the right lateral corticospinal tract at L1 causes upper motor neurons signs (weakness or paralysis, hyperreflexia, and hypertonia) in the right leg. Click for explanation RL ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

R L UMN Lateral corticospinal tract lesion Ipsilateral upper motor neurons signs generalized below the lesion level UMN signs Weakness (Spastic paralysis) Hyperreflexia (+ Babinski, clonus) Hypertonia Right Lateral Corticospinal Tract Lesion L1 Common causes include penetrating injuries, lateral compression from tumors, and MS. Click to animate ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Click for answer Damage to the right lateral spinothalamic tract at L1 causes the absence of pain and temperature sensation in the left leg. Click for explanation Lesion of the right lateral spinothalamic tract at L1 produces what impairment? R L ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

R L DRG Lateral spinothalamic tract lesion Contralateral loss of pain and temperature sense Right Lateral Spinothalamic Tract Lesion L1 Common causes include MS, penetrating injuries, and compression from tumors. Click to animate ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Click for answer Damage to the anterior gray and white commissures at C5-C6 causes the absence of pain and temperature sensation in the C5 and C6 dermatomes in both upper extremities. Click for explanation Lesion of the anterior gray and white commissures (central cord syndrome) at C5-C6 produces what impairment? RL ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

C5-C6 Central Cord Syndrome Lateral Spinothalamic Tract Impaired pain and temperature sensation, C5-C6 dermatomes, bilaterally DRG R L Common causes include posttraumatic contusion and syringomyelia, and intrinsic spinal cord tumors. Click to animate ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Click for answer Damage to the right dorsal columns at L1 causes the absence of light touch, vibration, and position sense in the right leg. Damage to the lateral corticospinal tract causes upper motor neuron signs in the right leg (Monoplegia), and damage to the lateral spinothalamic tract causes the absence of pain and temperature sensation in the left leg. Click for explanation Complete transection of the right half the spinal cord (Hemicord or Brown-Sequard syndrome) at L1 produces what impairments? RL ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

RL Hemicord Lesion (Brown-Sequard Syndrome) Dorsal column lesion Ipsilateral loss of light touch, vibration, and position sense Lateral corticospinal tract lesion Ipsilateral upper motor neurons signs Lateral spinothalamic tract lesion Contralateral loss of pain and temperature sense Hemicord lesion Build the lesion L1 Common causes include penetrating injuries, lateral compression from tumors, and MS. Click to animate

Hemicord Lesion (Brown-Sequard Syndrome) Dorsal column lesion Ipsilateral loss of light touch, vibration, and position sense Lateral corticospinal tract lesion Ipsilateral upper motor neurons signs Lateral spinothalamic tract lesion Contralateral loss of pain and temperature sense UMN Hemicord lesion RL DRG L1 Click to animate ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Click for answer Damage to the dorsal columns, bilaterally, causes the absence of light touch, vibration, and position sense in the both legs. Damage to the lateral corticospinal tracts, bilaterally, cause upper motor neuron signs in the both legs (Paraplegia), and damage to the lateral spinothalamic tracts, bilaterally, cause the absence of pain and temperature sensation in the both legs. Click for explanation Complete transection of the spinal cord (Transverse cord lesion) at L1 would produce what impairments? RL ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

RL Dorsal column lesion Bilateral loss of light touch, vibration, and position sense Lateral corticospinal tract lesion Bilateral upper motor neurons signs Lateral spinothalamic tract lesion Bilateral loss of pain and temperature sense Transverse Cord Lesion Transverse cord lesion Build the lesion Common causes include trauma, tumors, transverse myelitis, and MS. Click to animate ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

R L Transverse Cord Lesion UMN DRG Transverse cord lesion Dorsal column lesion Ipsilateral loss of light touch, vibration, and position sense Lateral corticospinal tract lesion Ipsilateral upper motor neurons signs Lateral spinothalamic tract lesion Contralateral loss of pain and temperature sense Click to animate ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Click for answer Damage to the dorsal columns (fasciculus gracilis and cuneatus), bilaterally, causes the absence of light touch, vibration, and position sense, bilaterally, from the neck down (below the lesion level). Click for explanation Complete transection of the dorsal columns, bilaterally, (posterior cord syndrome) in the cervical region would produce what impairments? RL ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

R L Posterior Cord Syndrome DRG Dorsal column lesion (bilateral) Bilateral loss of light touch, vibration, and position sense, generalized below lesion level Common causes include trauma, compression from posteriorly located tumors, and MS. Click to animate ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Click for answer Damage to the lateral corticospinal tracts cause upper motor neuron signs, bilaterally, below the lesion level. Damage to lower motor neurons in the ventral horns cause lower motor neuron signs, bilaterally, at the lesion level. Damage to the lateral spinothalamic tracts cause absence of pain and temperature sensation, bilaterally, below the lesion level. Sparing of the dorsal columns leaves light touch, vibration, and position sense intact throughout. Click for explanation Complete transection of the lateral corticospinal and lateral spinothalamic tracts with sparing of the dorsal columns, bilaterally, (anterior cord syndrome) in the cervical region would produce what impairments? RL ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

UMN DRG UMN DRG R L Anterior cord lesion Lateral corticospinal tract lesion Ipsilateral upper motor neurons signs Contralateral loss of pain and temperature sense Lateral spinothalamic tract lesion Anterior Cord Syndrome Common causes include anterior spinal artery infarct, trauma, and MS. Click to animate ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Patient Cases Read these instructions! Patient Case 1 Patient Case 2 Patient Case 3 ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Case Instructions These patient cases are intended to facilitate the integration and clinical application of information about lesions of the spinal cord by coupling the findings on examination and patient interview with their neuroanatomical correlates. Each case begins with the patient’s chief complaint and significant examination findings. Then, the question is asked, Damage to what system(s) is causing this patient’s problems? Clicking the Answer button will reveal the answer and clicking the Show lesion button will reveal the neuroanatomic lesion along with the patient’s behavioral impairments. Cases are presented from two perspectives. What lesion would account for a given set of examination results and patient history? For a given lesion, what signs and symptoms would be expected on examination? Click on a case number to begin the exercise. ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Case 1 The patient complains of “clumsiness” of her left leg due to uncertainty of the limb’s position in space. Active and passive ROM and strength are within normal limits (WNL) throughout. Light touch, two-point discrimination, proprioception, and vibration sense are intact in the right lower extremity but absent in all dermatomes below the umbilicus in the left lower extremity. She is able to distinguish sharp from dull WNL in lower extremities, bilaterally. Damage to what system(s) is causing this patient’s problems? Lesion of the left dorsal column (fasciculus gracilis) at approximately T10. Lateral corticospinal tracts are intact, bilaterally: AROM and strength are WNL Lateral spinothalamic tracts are intact, bilaterally: sharp/dull is WNL Dorsal column is intact on the right: light touch, two-point discrimination, proprioception, and vibration are WNL Dorsal column is absent on the left: light touch, two-point discrimination, proprioception (limb position in space), and vibration are absent in all dermatomes below the umbilicus Lesion level, T10: the umbilicus is located in the T10 dermatome Answer Show lesion ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

R L Left Dorsal Column Lesion DRG Dorsal column lesion Ipsilateral loss of light touch, vibration, and position sense Click to animate T10 ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Case 2 After a fall from his horse, the patient was alert and oriented but unable to move anything but his head. He was unable to sense light touch or pain from the neck down. He could turn his head but shoulder shrug was weak. Speech was normal but respiration was labored and required a respirator. Damage to what system(s) is causing this patient’s problems? Complete transection of the spinal cord (transverse lesion ) at approximately C3 (Tetroplegia, Christopher Reeve) Lateral corticospinal tracts absent, bilaterally, below C3: unable to move any body part except head and shoulder shrug (C3-5) Dorsal columns absent, bilaterally, below C3: unable to sense light touch below neck Lateral spinothalamic tracts absent, bilaterally, below C3: unable to sense pain below neck Lesion level, C3: patient was alert and oriented (cortex and reticular activating system intact), he could turn his head (spinal accessory nerve), shoulder shrug and respiration were weak (shoulder elevator and respiratory muscles C3-5) Answer Show lesion ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

R L Transverse Cord Lesion UMN DRG Transverse cord lesion Dorsal column lesion Ipsilateral loss of light touch, vibration, and position sense Lateral corticospinal tract lesion Ipsilateral upper motor neurons signs Lateral spinothalamic tract lesion Contralateral loss of pain and temperature sense Click to animate C3 ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Case 3 Following surgical repair of a knife wound the patient is unable to stand or walk because he is unable to move or bear weight on his right leg. Light touch, position and vibration sense are WNL in the left lower extremity but absent in the right below the crest of the ilium. Active range of motion and strength are normal in the left lower extremity but absent in the right (hip, knee, and ankle). Pain and temperature sensation are intact in the right lower extremity but absent in the left below T12. Damage to what system(s) is causing this patient’s problems? Hemisection of the spinal cord on the right at approximately L1 Dorsal column is intact on the left but absent on the right: light touch, position and vibration sense are WNL in the left lower extremity but absent in the right Lateral corticospinal tract is intact on the left but absent on the right: active range of motion and strength are normal in the left lower extremity but absent in the right Lateral spinothalamic tract is intact on the left but absent on the right: pain and temperature sensation are intact in the right lower extremity but absent in the left Lesion level, approximately L1: hip flexion absent on right (L2), pain and temperature sense absent below T12 Answer Show lesion ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

Hemicord Lesion (Brown-Sequard Syndrome) Dorsal column lesion Ipsilateral loss of light touch, vibration, and position sense Lateral corticospinal tract lesion Ipsilateral upper motor neurons signs Lateral spinothalamic tract lesion Contralateral loss of pain and temperature sense UMN Hemicord lesion RL DRG T12 Click to animate ContentsContents Functional SystemsLesionsPatient Cases ExitFunctional SystemsLesionsPatient Cases Exit

The End D. Michael McKeough, PT, EdD  2015