Examination of Posterior Column of Spinal Cord - Sensory Examination

Examination of Posterior Column of Spinal Cord - Sensory Examination - Dorsal Column lesions - vibration touch proprioception joint position sense

1. Short topic proprioception ,vibration ,touch Chairperson ; Dr. Prakash Kori (Neurologist) Student ; Dr. Ibin Shah

2. Proprioception or kinesthesia It’s the sense of movement, of position, and of skeletomuscular tension provided by deep mechanical receptors in muscles, joints, connective tissue, and the vestibular system Two components 1. conscious – motion ,position , vibration and pressure 2.unconscious component.- spinocerebellar pathways

3. Anatomy Receptors- muscle spindles , Pacinian corpuscles in muscles ,tendon ,joint. Stimuli - pressure, tension,stretching or contraction of muscles fibers , joint movement, changes in the position of the body or its parts. Nerves – large myelinated fibers ( Ia,Ib,II )

4. Vibration Receptors Pacinian corpuscles in skin,muscle,subcutaneous tissue ,periosteum. responds to high frequency Merckel disk and Meissner corpuscles in superficial skin layers responds to low frequency Stimuli - oscillations of tuning fork Nerve – large myelinated nerve fibers

5. Touch Receptors -free nerve endings,Merkel cell endings, Meissner’s and Pacinian corpuscles, Ruffini endings. Stimuli – touch , stretch, indentation Nerves – large and small myelinated nerves

6. Dorsal column pathway receptors large myelinated fibers first order neuron in the dorsal root ganglion (DRG) medial divison of posterior root fasiculi gracilis and cuneatus ascend to nucleus gracilis and cuneatus in lower medulla (synapse) Axon of 2 nd order neuron decussate then ascend in the medial leminiscus to the thalamus Thalamoparietal radiation go through posterior limb of internal capsule and get distributed in cortex

7. In thalamus ventroposterior complex is the main somesthetic receiving area - ventroposterior lateral nucleus and ventroposterior medial nucleus Projections are to primary somatosensory cortex on post central gyrus

8. VPL thalamic neurons carrying sensory information project in a highly specific way to the two somatic sensory areas of the cortex: somatic sensory area I (SI) in the postcentral gyrus and somatic sensory area II (SII) in the wall of the sylvian fissure.

9. Examination for proprioception Concept – examiner will passively move a part and see whether patient can 1. appreciate the movement 2.recognize the direction of movement 3.force and range of motion 4.minimum angle of movement patient can detect 5. ability to judge the position of the part in space

10. In lower extremity start at metatarsophalangeal joint of great toe In upper extremity use distal interphalangeal joint Before starting clearly explain about the test and what you expect Testing is done with patients eye closed

11. The examiner should hold the patient’s completely relaxed digit on the sides, away from the neighboring digits, parallel to the plane of movement, exerting as little pressure as possible. The part is then passively moved up or down, and the patient is instructed to indicate the direction of movement from the last position

12. Quick movements are more easily detected than very slow ones Healthy young individuals can detect great toe movements of 2 to 3 degrees; in the fingers virtually invisible movements, 1 degree or less can be detected

13. In pathological states sense of position of digit is lost first followed by sense of movement In foot small toes are affected before affecting great toe In hand also little finger will be involved first If digits are affected then examine ankle,wrist ,knee or elbow

14. Other methods Place the fingers of one of the patient’s hands in a certain position (e.g., the “OK” sign) while his eyes are closed, and then asking him to describe the position or to imitate it with the other hand. Parietal copy

15. . One of the outstretched hands may be passively raised or lowered, and the patient asked to place the other extremity at the same level

16. A test of proximal joint position sense, primarily at the shoulder, is performed by asking the patient to bring the two index fingers together with arms extended and eyes closed. Normal individuals can do this accurately, with errors of 1 cm or less

17. Romberg test Ask the Pt to stand with the feet together. Note whether the Pt sways. Then ask the Pt to close the eyes, and note whether the swaying increases. Stand behind the Pt with arms held up ready to catch the Pt, but do not touch the Pt.

18. Only a marked worsening of balance with eyes closed qualifies as a positive Romberg sign. A patient who cannot maintain balance feet together and eyes open does not have a positive Romberg.

19. Patients with severe proprioceptive deficits ( akinesthesia ) may have ataxia and incoordination, which closely resembles that seen in cerebellar disease, except that it is much worse when the eyes are closed.

20. Sensory vs cerebellar ataxia Clinical finding Sensory ataxia Cerebellar ataxia Loss of vibration and position sense + Areflexia + Nystagmus + Hypotonia + Ataxia much worse with eyes closed + Overshooting on release + Rhomberg test +

21. Gait in sensory ataxia – Steppage gait The term “ steppage gait” refers to a manner of walking in which the patient takes unusually high steps The patient takes a high step, throws out her foot, and slams it down on the floor in order to increase the proprioceptive feedback.

22. The heel may land before the toe, creating an audible “double tap.” The patient with sensory ataxia watches her feet and keeps her eyes on the floor while walking. Sensory ataxia can be differentiated from predominantly cerebellar ataxia by accentuation of the difficulty with eyes closed

23. Clinical examination of vibration Using tuning fork 128hz with weighted ends

24. Sites -great toes, the metatarsal heads, the malleoli, the tibia, anterior superior iliac spine, sacrum, spinous processes of the vertebrae, sternum, clavicle, styloid processes of the radius and ulna, and the finger joints.

25. Apply the free end of the shaft to the Pt’s fingernails and toenails or just proximal to the nail bed. If you press upward with the index finger pad of your free hand against the Pt’s finger pad, you can feel the fork nearly as long as the Pt can. Testing should compare side to side and distal to proximal sensation

26. Normally the patient can feel the fork over the great toe until it has almost stopped vibrating. If vibration is impaired, when the fork is no longer perceptible distally, it is moved to progressively more proximal locations until a level ii found that is normal. It is important to compare pallesthesia at homologous sites on the two sides

27. Gradual loss of sensation favors a peripheral nerve problem. Uniform loss of vibration beyond a certain point, for example favors myelopathy. The best control is an approximately age-matched normal

28. Loss of vibratory sensation is a sensitive indicator of dysfunction of the peripheral nervous system or the posterior columns Abnormal findings 1. Consistent asymmetry of vibratory sensation 2. feeling the vibration for more than 3 to 5 seconds on one side compared to the other is probably abnormal.

29. Quantitative vibratory testing . Rydel-Seiffer tuning fork.

30. In patients with posterior column or peripheral nerve disease, vibratory sensation is lost in the lower extremities much earlier than in the upper In localized spinal cord lesions, a “level” of vibration sensory loss may be found on testing over the spinous processes

31. Clinical examination of touch Light touch can be tested with a wisp of cotton, tissue paper, a feather, a soft brush, light stroking of the hairs, or using a very light touch of the fingertip.

32. For detailed and quantitative evaluation can be accomplished using Semmes-Weinstein filaments, an asthesiometer , or von Frey hairs. It is enough to determine whether the patient recognizes and roughly localizes light touch stimuli and differentiates intensities

33. Localization Sensory symptoms and signs can result from lesions at many different levels of the nervous system from the parietal cortex to the peripheral sensory receptor. Distribution and nature is the most important way to localize their source. Their extent, configuration, symmetry, quality, and severity are the key observations

34. Nerve and Root Sensory abnormalities focal nerve trunk lesions, can be readily mapped and generally have discrete boundaries Root (“radicular”) lesions frequently are accompanied by deep, aching pain along the course of the related nerve trunk

35. In polyneuropathies, sensory deficits are generally graded, distal, and symmetric in distribution Dysesthesias, followed by numbness, begin in the toes and ascend symmetrically. When dysesthesias reach the knees, they usually also have appeared in the fingertips. The process is nerve length–dependent, and the deficit is often described as “stocking-glove” in type

36. Most polyneuropathies are pansensory and affect all modalities of sensation, selective sensory dysfunction according to nerve fiber size may occur. Small- fiber polyneuropathies are characterized by burning, painful dysesthesias reduced pinprick and thermal sensation proprioception, motor function, and deep tendon reflexes intact

37. Large- fiber polyneuropathies are characterized by vibration and position sense deficits, imbalance, absent tendon reflexes, and variable motor dysfunction preservation of most cutaneous sensation. Dysesthesias, if present ,tend to be tingling or bandlike in quality

38. Sensory neuronopathy (or ganglionopathy) is characterized by widespread asymmetric sensory loss non-length dependent so that it may occur proximally or distally and in the arms, legs, or both Pain and numbness progress to sensory ataxia and impairment of all sensory modalities with time. Causes –paraneoplastic , autoimmune ,idiopathic

39. Spinal Cord Sensory level on the trunk Dissociated sensory loss on the trunk or limbs, sparing the face Suspended sensory loss Sacral sparing.

40. Dissociated Sensory Loss.- is seen in 1. intrinsic spinal cord lesions 2 Anterior spinal artery syndrome 3. Predominant posterior coloum deficits – tabes dorsalis, multiple sclerosis, subacute combined degeneration, Friedreich ataxia

41. Brainstem Sensory Lesions Lateral medullary syndrome

42. Medial medullary syndrome

43. Cerebral Sensory Lesions Thalamus Hemisensory disturbance with tingling numbness from head to foot Déjerine-Roussy syndrome, - contralateral hemisensory loss followed later by an agonizing, searing or burning pain in the affected areas. Cortical Lesions.- infarction of post central gyrus Primary sensations will be intact Impairment of graphesthesia , two-point discrimination, and the perception of double simultaneous stimuli contralateral hemineglect, hemi-inattention, and a tendency not to use affected hand and arm

44. References DEJONG’S THE NEURLOGICAL EXAMINATION BRADLEY’S NEUROLOGY IN CLINICAL PRACTICE 7TH EDITION ADAMS AND VICTORS PRINCIPLES OF NEUROLOGY 10TH EDITION Harrison principles of internal medicine 19 th edition

45. Thank you