Clinical Case A 45 year old woman complained of pain in her right breast and progressive weakness of her right lower limb for a period of two months, she contacted her Family physician, Her Family physician referred her to a neurologist. The neurologic evaluation revealed weakness in the right lower limb. This was associated with spasticity (increased tone), hyperreflexia (increased deep tendon reflexes) at the knee and ankle, which also demonstrated clonus. On the right side there was loss of two-point discrimination, touch ,vibratory sense and proprioception at levels below the hip. The left side showed a loss of pain and temperature sensation below dermatome T-7. Clinical Case Of Spinal Cord cont.. MRI of a patient indicated to have an extramedullary tumor expanding from the dorsal roots at spinal cord levels T-5,6. Based on the symptoms and clinical findings what is your diagnosis ? 1. This patient noticed ulcers on the fingers of both of his hands. They were associated with no pain and appeared to be the residua of burns. The probable site of damage responsible for this defect is the a. Posterior column b. Anterior horn c. Clarke’s column d. Spinothalamic tract e. Spinocerebellar tract A 45 year old man noticed a weakness of his right hand which was progressing and causing him problems. He decided to see his doctor. On examination he demonstrated bilateral weakness, atrophy, and fasciculations of the intrinsic muscles of his hands and shoulders. Upper motor neuron syndrome signs, i.e., weakness, hypertonia, hyperreflexia, positive Babinski, were evident in both lower extremities. Dermatomes C-2 through T-6 demonstrated bilateral loss of pain and temperature sensation. There was bilateral impairment of position and vibratory sense below the hips. MRI investigation showed a central cavitation at C-2 through T-7 which expanded symmetrically in all directions. It involved the anterior white commissure (spinothalamic fibers) and included portions of the posterior white columns, lateral white funiculus, and anterior gray horns. Somatosensory Pathway(Dorsal Colum) Somatosensory Pathway Posterior column pathway carries sensation of highly localized touch, pressure, vibration. Posterior column pathway includes: Fasciculus cuneatus tract Fasciculus gracilus tract Carries fine touch, pressure, vibration, sterognosis and conscious Proprioceptive sensations. Dorsal Colum tracts dorsal cloumn pathway dorsal column pathway Left spinal cord injury Loss of sense of: •touch •proprioception •vibration in left leg Dorsal Colum Lesions Sensory ataxia Patient staggers; cannot perceive position or movement of legs Visual clues help movement Rombergism An 85-year-old man is being evaluated for gait difficulties. On examination it is found that joint proprioception is absent in his toes. People with impaired position sense will usually fall if they stand with their feet together and do which of the following? Flex the neck Extend their arms in front of them Flex the knees Turn the head Close their eyes Case cont…. The ability to recognize an unseen familiar object placed in the hand depends on the integrity of which pathway Ventral spinocerebellar tract Dorsal column Dorsal spinocerebellar tract Vestibulospinal tract Spinothalamic tract Clinical Case Spinal cord A patient displays a symmetrical loss of pain and temperature on the shoulder area on both Sides of the body with no loss of tactile sensation. Pain and temperature and tactile sensation Are normal over the rest of the body. This condition would be due mostly likely to lesion of : Clinical Case Spinal cord cont… A. B. C. D. anterior white commissure from C2 to C4 anterior white commissure from T1 to T5 Anterolateral system on right at C2 paracentral lobule on the left Clinical Case Spinal cord cont.. A 54 year old male presents with complaints of loss of pain and temperature sensation in his arms and chest only. What is the lesion causing these symptoms Complete cord transection at C5 Central cavitation of the cervical spinal cord Demyelination of the dorsal columns Disc herniation Clinical case A 45 yr old man is brought to ER complaining of inability to move his left leg HPI- He was stabbed in the back Hr ago while defending his girlfriend from a mugger PE-Moderate bleeding; Stab wound at the posterior cervical spinous prominence (c7)on the left side; Weakness on finger flexion; extension of left finger; inability to sense of vibration of tuning fork along left lower limb; loss of pain and temperature sense in contralateral limb. Imaging: MRI: Haematoma at the level of C-T1 in the left of the spinal cord. 1. Which of the following in not characteristic of the BrownSequard syndrome. A. Contralateral paralysis below the lesion level. B. Contralateral loss of temperature sensation 2-3 segments below the lesion. C. Ipsilateral loss of position and vibratory sense below the lesion level. D. An ipsilateral segmental area of atrophy and reflex loss at the segmental lesion region. E. Contralateral loss of pain sensation 2-3 segments below the lesion. Brown-Sequard Syndrome Ipsilateral paresis accompanied by ipsilateral impairment of touch and vibration sense, and contralateral loss of pain and temperature sense. Case An old 52 African-American man presented to the ER with a one week history of "unable to stand". This was progressively worsening over the week and more marked on the left lower extremity. The patient also stated that he was unable to feel anything (numbness) in his legs. He also complained of inability to feel when he urinated as well as mild urinary incontinence. The patient had a spinal tumor (meningioma) removed from the upper thoracic spine 7 months prior to this presentation. At that time he presented with a Brown Sequard type syndrome (left lower extremity weakness) and a T4 sensory level. After the tumor resection, the patient's symptoms improved significantly to the extent that he was ambulating with a cane. However, on presentation he was now wheelchair-bound. Anterolateral system The Anterolateral Pathway Provides sensations of “crude” touch, pressure, pain, and temperature Ascend within the anterior or lateral spinothalamic tracts: Anterolateral System (Pain &Temp) spinothalamic pathway Left spinal cord injury Loss of sense of: •Touch •Pain •Warmth/cold in right leg Spinothalamic Tracts Located lateral and ventral to the ventral horn Carry impulses concerned with pain and thermal sensations (lateral tract) and also non- discriminative touch and pressure (medial tract) Fibers of the two tracts are intermingled to some extent In brain stem, constitute the spinal lemniscus Fibers are highly somatotopically arranged, with those for the lower limb lying most superficially and those for the upper limb lying deeply Lateral Spinothalamic Tract Carries impulses concerned with pain and thermal sensations. Axons of 1st order neurons terminate in the dorsal horn Axons of 2nd order neuron (mostly in the nucleus proprius), decussate within one segment of their origin, by passing through the ventral white commissure & terminate on 3rd order neurons in ventral posterior nucleus of the thalamus Thalamic neurons project to the somatosensory cortex Anterior Spinothalamic Tract Carries impulses concerned with non- discriminative touch and pressure Axons of 1st order neurons enter cord terminate in the dorsal horn Axons of 2nd order neuron (mostly in the nucleus proprius) may ascend several segments before crossing to opposite side by passing through the ventral white commissure & terminate on 3rd order neurons in ventral posterior nucleus of the thalamus Thalamic neurons project to the somatosensory cortex Spino-reticulo-thalamic System The system represents an additional route by which dull, aching pain is transmitted to a conscious level Some 2nd order neurons terminate in the reticular formation of the brain stem, mainly within the medulla Reticulothalamic fibers ascend to intralaminar nuclei of thalamus, which in turn activate the cerebral cortex Spinocerebellar Tracts The spinocerebellar system consists of a sequence of only two neurons Two tracts: Posterior & Anterior Located near the dorsolateral and ventrolateral surfaces of the cord Contain axons of the second order neurons Carry information derived from muscle spindles, Golgi tendon organs and tectile receptors to the cerebellum for the control of posture and coordination of movements Posterior Spinocerebellar Tracts Present only above level L3 The cell bodies of 2nd order neuron lie in Clark’s column Axons of 2nd order neuron terminate ipsilaterally (uncrossed) in the cerebellar cortex by entering through the inferior cerebellar peduncle Ventral Spinocerebellar Tracts The cell bodies of 2nd order neuron lie in base of the dorsal horn of the lumbosacral segments Axons of 2nd order neuron cross to opposite side, ascend as far as the midbrain, and then make a sharp turn caudally and enter the superior cerebellar peduncle The fibers cross the midline for a second time within the cerebellum before terminating in the cerebellar cortex Both spinocerebellar tracts convey sensory information to the same side of the cerebellum Spinotectal Tract Ascends in the anterolateral part in close association with spinothalamic system Primary afferents reach dorsal horn through dorsal roots and terminate on 2nd order neurons The cell bodies of 2nd order neuron lie in base of the dorsal horn Axons of 2nd order neuron cross to opposite side, and project to the periaquiductal gray matter and superior colliculus in the midbrain Spino - olivary Tract Indirect spinocerebellar pathway (spinoolivo-cerebellar) Impulses from the spinal cord are relayed to the cerebellum via inferior olivary nucleus Conveys sensory information to the cerebellum Fibers arise at all level of the spinal cord Spinoreticular Tract Originates in laminae IVVIII Contains uncrossed fibers that end in medullary reticular formation & crossed & uncrossed fibers that terminate in pontine reticular formation Form part of the ascending reticular activating system Spino-Olivary Tracts Project to accessory olivary nuclei and cerebellum. Contribute to movement coordination associated primarily with balance. Spinotectal Tracts Project to superior colliculi of midbrain. Involved in reflexive turning of the head and eyes toward a point of cutaneous stimulation. Spinoreticular Tracts Involved in arousing consciousness in the reticular activating system through cutaneous stimulation. Following an automobile accident, an eighteen year old male was hospitalized for several weeks. A neurological exam at that time revealed the following: 1. Complete loss of conscious proprioception in the right lower limb. 2. Babinski sign on the right. 3. Inability to detect pain and temperature sensation on the medial side of the antecubital fossa (medialepicondyle) on both upper limbs. 4. Inability to detect pain and temperature at the apex of the left axilla, in all the intercostal spaces on the left, and in the left lower limb. 5. The patient could feel a gentle squeezing of both thumbs, right and left middle fingers, and the left little finger. 6. No sensation to squeezing could be detected in the right little finger. Based on this exam, a single lesion may be found at which of the following levels? Caudal medulla in the midline Right side of the spinal cord at C8 Left side of the spinal cord at T1 Right side of the spinal cord at C4 - C5 Left side of the spinal cord at C4 - C5 Motor Loss Ipsilateral paralysis below the lesion. Paralysis is the "Upper Motor Neuron" or spastic type; there is spasticity, slow (disuse) muscle atrophy, hypertonia, ankle clonus and a positive Babinski sign. Superficial reflexes, e.g., the abdominal and cremasteric are lost. Spastic paralysis is attributed to interruption of the lateral corticospinal tract and the accompanying lateral reticulospinal tract. Loss of these upper motor neurons deprives the anterior horn cells, i.e., lower motor neurons, of the impulses which generate contraction of skeletal muscle, hence, weakness (paresis) or paralysis. Hypertonia and hyperreflexia appear to result from loss of the inhibitory effects of these two descending motor pathways on the stretch reflexes, leaving them hyperexcitable to segmental muscle afferents It may be possible to also demonstrate a "Lower Motor Neuron Syndrome" or flaccid paralysis ipsilaterally at the level of the lesion. If the anterior horn cells supplying the skeletal muscles are injured at the level of the lesion then these muscles are denervated. This paralysis is of the flaccid type; muscles undergo rapid atrophy due to loss of the trophic influence of the nerves as well as disuse. Tone and tendon reflexes are diminished since they are reflex responses and the injured lower motor neurons are the "final common pathway" to the muscle in the stretch reflex, hence, there is no reflex. Loss of conscious proprioception, two-point discrimination and vibratory sense ipsilaterally is due to interruption of the posterior white columns (fasciculus gracilis/cuneatus). This is frequently accompanied by a Romberg sign. A normal individual, standing erect with heels together and eyes closed, sways only slightly. Stable posture is achieve by 1) a sense of position from the vestibular system, 2) awareness of the position and status of muscles and joints by conscious proprioception and 3) visual input regarding our position. Closing the eyes has only slight effect on the normal individual's stance since the vestibular and conscious proprioception systems are sufficient. In a patient with an impaired posterior column conscious proprioception is diminished; when the eyes are closed loss of both systems renders the patient unstable and they are likely to sway or fall to the side. Pain and temperature sensation is lost below the lesion, on the opposite side beginning about one dermatomal segment below the level of the lesion. These sensations are carried by the lateral spinothalamic tract whose fibers originated on the side opposite the lesion but which crossed in the anterior white commissure. Dorsal root afferents carrying pain and temperature synapse in the dorsal gray; the second order neuron crosses in the anterior white commissure along an ascending path for a distance of about one spinal segment. Because of the oblique ascent of the crossing fibers in the anterior white commissure, injury of the spinothalamic tract is not likely to be carrying sensation from that level. A careful sensory evaluation may reveal that at the dermatomal level of the lesion there is a bilateral loss of pain and temperature sensation. Since the second order neurons from both sides cross in the midline below the central canal, a hemisection of the cord may interrupt the crossing fibers from both sides and produce this limited bilateral deficit. The pain in the left breast was the result of the pressure of the tumor on the dorsal root. Hemisection of Spinalcord At the level of lesion side Sensory disturbance Motor disturbance Reflexes On the same side Below On the Opposite side Loss of all sensation Loss of the dorsal Loss of 1-superfecial sensations column due to 1-pain & temp. 2-deep sensations damage of gracil & due to damage of cunite leading to loss lateral of spinothalamic tract. 1. fine touch 2-crude touch due 2. kinesthetic to damage of 3. vibration ventral 4. sterognosis spinothalamic tract. 1-LMNL UMNL due to 2-paralysis of muscles damage of pyramidal which its supply arising tract from damage Loss of all reflexes which its centers in damage segments On the same side 1-loss of flexor withdrawal reflex 2-increase crossed extensor reflex Above On the same side Hyperanasthesia (Hypersensitivity) increase sensitivity to 1. pain 2. touch 3. Temp. Anterior cord syndrome Loss of motor function and pain-temperature sensation below the level of the lesion Typically seen following hyperflexion injuries with impingement of bone or herniated disc tissue directly on the anterior spinal cord Due to mechanical compression of the anterior spinal artery and secondary infarction of the anterior spinal cord Rarely due to aortic dissection interrupting the blood supply to the anterior spinal arteries posterior column function is not affected (position sense and vibration sense) Posterior cord syndrome proprioceptive sensory loss. Usually due to posterior spinal artery occlusion, chronic atherosclerosis and impaired collateral circulation, tumors or discs compressing the posterior spinal cord, or vitamin B12 deficiency. Pain and temperature sensory function + motor function not affected. Brown-Sequard syndrome lateral cord syndrome due to a lesion involving half of the spinal cord Ipsilateral loss of motor function and proprioceptive sensory function + contralateral loss of paintemperature sensation. Most commonly due to traumatic hemisection of the spinal cord (eg. stabbing knife thrust) Syringomyelia the result of central cord cavitation affecting a few segments, and usually involving the cervical spinal cord frequently found in Arnold-Chiari malformations affecting the upper cervical cord and medulla mainly affects the crossing fibres of the spinothalamic tract as they decussate in the ventral white commissure => bilateral pain-temperature sensory loss over a few segments eg. only affecting the neck and upper shoulders in a cape-like distribution (or only affecting the upper limbs) with normal sensation above and below the affected dermatomes does not affect the spinothalamic tracts in the early stages => no initial lower trunk or lower limb pain-temperature sensory loss does not usually affect the dorsal columns => normal position sense ("dissociative" sensory loss) may rarely affect the lower motor neurons to the upper limbs early in the disease course, and may eventually affect the corticospinal tracts may affect the spinal extension of the trigeminal nucleus => face hypoesthesia in a characteristic balaclava helmut distribut Case Cont… A patient of yours who is now in her late 40's walks with a distinct limp. As you take her history she tells you that when she was four years old and on an outing at the zoo with her family, she got sick with an "upset stomach" and that she "couldn't walk anymore" because of pain in her legs. When she returned home her mother found that she had a fever of 103° F. The following morning the child could not move her legs, and she was taken to the hospital. Examination revealed that muscle tone was greatly reduced in the lower limbs, and the patellar and Achilles's tendon reflexes could not be elicited. Upper limbs were not affected. Clinical Case of Spinal cord cont.. • • • A 23 yr old women complained of pain in her right breast and progressive weakness of her right lower limb for a period of many months. The neurologic examination revealed weakness in the right lower limb. This was associated with spasticity (increased tone), hyperreflexia (increased deep tendon reflexes) at the knee and ankle, which also demonstrated clonus. On the right side there was loss of two-point touch, vibratory sense and proprioception at levels below the hip. The left side showed a loss of pain and temperature sensation below dermatome T-7. –Conclusion of the diagnosis that the patient was determined to have an extramedullary tumor expanding from the dorsal roots at spinal cord levels T5,6. Pure hemisection of the cord rarely occurs but it is among the best cases for illustrating the features of spinal cord injury. •spastic paralysis •lateral corticospinal tract •loss of position sense, discriminative touch and vibratory sense on the side of the lesion – -involvement of the and the posterior white column on the side of the lesion. On the side opposite the lesion there is a loss of pain and temperature due to involvement of the lateral spinothalamic tract. •At times, it is possible to also demonstrate a bilateral sensory deficit and flaccid paralysis at the level of the lesion. Syringomyelia • • A 55 year old man noticed a weakness of his left hand and loss of pain in his both arms which was progressing and causing him mental apathy and he felt he should visit neurologist . On examination he demonstrated bilateral weakness, atrophy, and fasciculations of the intrinsic muscles of his hands and shoulders. Upper motor neuron syndrome signs, i.e., weakness, hypertonia, hyperreflexia, positive Babinski, were evident in both lower extremities. Dermatomes C-2 through T-6 demonstrated bilateral loss of pain and temperature sensation. There was bilateral impairment of position and vibratory sense below the hips. MRI investigation showed a central cavitation at C-2 through T-7 which expanded symmetrically in all directions. It involved the anterior white commissure (spinothalamic fibers) and included portions of the posterior white columns, lateral white funiculus, and anterior gray horns. Syringomyelia Syringomyelia the result of central cord cavitation affecting a few segments, and usually involving the cervical spinal cord frequently found in Arnold-Chiari malformations affecting the upper cervical cord and medulla mainly affects the crossing fibres of the spinothalamic tract as they decussate in the ventral white commissure => bilateral pain-temperature sensory loss over a few segments eg. only affecting the neck and upper shoulders in a cape-like distribution (or only affecting the upper limbs) with normal sensation above and below the affected dermatomes does not affect the spinothalamic tracts in the early stages => no initial lower trunk or lower limb pain-temperature sensory loss does not usually affect the dorsal columns => normal position sense ("dissociative" sensory loss) may rarely affect the lower motor neurons to the upper limbs early in the disease course, and may eventually affect the corticospinal tracts Cauda equina syndrome Slow progressive loss; often asymmetric or unilateral Often due to chronic disc herniation May be due to spinal tumors Less severe back pain, may produce severe radicular symptoms Sensory loss affects all sensory modalities - lumbar > sacral Sensory loss may affect penis/clitoris and pubic area, and be asymmetrical Sensory loss may follow a specific dermatomal pattern Muscle weakness - lumbar > sacral Muscle weakness mainly affects glutei, hamstrings, gastrocnemius and soleus muscles Muscle atrophy and fasiculations common Tendon reflex loss - knee > ankle Late bladder involvement (flaccid bladder) Inferior cord syndrome (conus medullaris) syndrome Involvement of the terminal spinal cord Usually of rapid onset More severe back pain, less severe radicular symptoms Symmetrical defects Saddle distribution sensory loss +/- sensory dissociation Tendon reflex loss - ankle > knee Early consistent impotence +/- bladder involvement Subacute lesions may produce UMN signs - hyperreflexia of ankle jerks, increased anal tone and spastic bladder Case A 55-year-old man injured his thoracic spine in a motor vehicle accident 2 years ago. Initially he had a bilateral spastic paraparesis and urinary urgency, but this has improved. He still has pain and thermal sensation loss on part of his left body and proprioception loss in his right foot. There is still a paralysis of the right lower extremity as well. Questions In this patient, where would you expect the pain and temperature abnormalities to begin? a. Exactly at the level of the lesion b. Four or five segments above the lesion c. Four or five segments below the lesion d. One or two segments above the lesion e. One or two segments below the lesion