Clinical Case

1. 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.

2. 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 ?

3. 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

4. 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.

5. 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.

6. Somatosensory Pathway(Dorsal Colum)

7. 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.

8. dorsal cloumn pathway Dorsal Colum tracts

9. Left spinal cord injury dorsal column pathway • Loss of sense of: • touch • proprioception • vibration • in left leg

10. Dorsal Colum Lesions • Sensory ataxia • Patient staggers; cannot perceive position or movement of legs • Visual clues help movement • Rombergism

12. 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

13. 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

14. Clinical Case Spinal cord A patient displays a symmetrical loss of pain and temperature on the shoulder area on bothSides of the body with no loss of tactile sensation. Pain and temperature and tactile sensationAre normal over the rest of the body. This condition would be due mostly likely to lesion of :

15. Clinical Case Spinal cord cont… • 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

16. 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

17. 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.

18. 1. Which of the following in not characteristic of the Brown-Sequard syndrome. • Contralateral paralysis below the lesion level. • Contralateral loss of temperature sensation 2-3 segments below the lesion. • Ipsilateral loss of position and vibratory sense below the lesion level. • An ipsilateral segmental area of atrophy and reflex loss at the segmental lesion region. • Contralateral loss of pain sensation 2-3 segments below the lesion.

19. Brown-Sequard Syndrome • Ipsilateral paresis accompanied by ipsilateral impairment of touch and vibration sense, and contralateral loss of pain and temperature sense.

20. 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.

21. Anterolateral system

22. The Anterolateral Pathway Provides sensations of “crude” touch, pressure, pain, and temperature Ascend within the anterior or lateral spinothalamic tracts:

23. Left spinal cord injury spinothalamic pathway • Loss of sense of: • Touch • Pain • Warmth/cold • in right leg Anterolateral System (Pain &Temp)

25. 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 somato-topically arranged, with those for the lower limb lying most superficially and those for the upper limb lying deeply

26. 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

27. 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

28. 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

29. 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

30. 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

31. 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

32. 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

33. Spino - olivary Tract • Indirect spinocerebellar pathway (spino-olivo-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

34. Spinoreticular Tract • Originates in laminae IV-VIII • 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

35. Spino-Olivary Tracts • Project to accessory olivary nuclei and cerebellum. • Contribute to movement coordination associated primarily with balance.

36. Spinotectal Tracts • Project to superior colliculi of midbrain. • Involved in reflexive turning of the head and eyes toward a point of cutaneous stimulation.

37. Spinoreticular Tracts • Involved in arousing consciousness in the reticular activating system through cutaneous stimulation.

40. 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.

41. 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.

42. 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

43. 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 

44. 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.

45. 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.

46. Pain and temperature sensation is lost below the lesion, on the opposite sidebeginning 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.

47. 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.

48. Hemisection of Spinalcord

49. 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) Anterior cord syndrome

50. 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. Posterior cord syndrome