Clinical Evaluation of Spinal Cord

Question 1

Myelopathy definition

Answer 1

Disorder resulting in spinal cord dysfunction

Question 2

Nerve root definition

Answer 2

Combined sensory and motor rami of the spinal cord (e.g. L5)

Question 3

Spinal tracts definition

Answer 3

Axons that travel in the spinal cord to relay information. (e.g. corticospinal tract).

Question 4

Dermatome definition

Answer 4

Cutaneous area served by an individual sensory root.

Question 5

Myotome definition

Answer 5

Muscles innervated by an individual motor root.

Question 6

Radiculopathy definition

Answer 6

Sensory and/or motor dysfunction due to injury to a nerve root.

Question 7

Intervertebral foramen definition

Answer 7

Opening formed by 2 adjacent vertebral bodies through which the nerve roots travel.

Question 8

Paresthesia definition

Answer 8

An abnormal sensation, can include burning, pricking, tickling, or tingling

Question 9

Dysesthesia definition

Answer 9

Impairment of sensation short of anesthesia

Question 10

Hyperesthesia definition

Answer 10

Abnormal acuteness of sensitivity to touch, pain, or other sensory stimuli

Question 11

Step-by-step approach to clinical evaluation of the spinal cord

Answer 11

1. sx from hx and PE
2. define UMN vs. LMN
3. define tracts involved
4. define anatomic sites involved
5. differential dx
6. workup

Question 12

Spinothalamic tract: fxn and crossing point

Answer 12

• -Function: Sensory modalities of pain (pinprick) and temperature-cold/hot
• -Cross: 2-3 segments above root entry level in anterior spinal cord

Question 13

Posterior/Dorsal Column: fxn and crossing point

Answer 13

• -Function: Sensory modalities of vibration, position, and 2-pt discrim
• -Cross: medulla (brain stem)

Question 14

Corticospinal tract: fxn and crossing point

Answer 14

• -Function: Motor function
• -Cross: Lower medulla (brain stem)

Question 15

Nerve root levels

Answer 15

• 8 cervical
• 12 thoracic
• 5 lumbar
• 5 sacral
• 1 coccyx

Question 16

Conus medullaris level/definition

Answer 16

• located @~L1-L2 vertebrae where the spinal cord ends
• made up of S2-S5 spinal cord segments

Question 17

Cauda equina definition

Answer 17

• formed by LS roots
• begins @ ~L1/L2 where the

Question 18

Exit of nerve roots along spinal column

Answer 18

• -C1, 2, 3, 4, 5, 6, 7 roots exit above same numbered vertebra (e.g. C7 exits above C7).
• -C8 below C7 and all other roots exit below same numbered vertebra (e.g. T1 exits below T1).

Question 19

Vertebral body vs. underlying cord segment @ cervical spine

Answer 19

• Upper cervical: vertebra # overlies same cord segment # (C2 bone, C2 cord)
• Lower cervical: vertebra # overlies cord segment # + 1 (C6 bone, C7 cord)

Question 20

Vertebral body vs. underlying cord segment @ thoracic & lumbar spine

Answer 20

• Upper thoracic: vertebra # overlies cord segment # + 2 (T4 bone, T6 cord)
• Lower thoracic/lumbar: vertebra # overlies cord segment # +2- 3 (T 11bone, L1-2 cord)
• Lower edge of the L1 vertebral body overlies the cord tip (conus medullaris)

Question 21

UMN injuries

Answer 21

• Corticospinal tract lesions in the spinal cord affect DTRs (deep tendon reflexes), strength, bulk, and tone in muscles AT or BELOW lesion on SAME SIDE of lesion.
• bulk: normal or disuse atrophy
• fasciculations: none
• tone: increased tone/spasticity
• DTR: hyperreflexia
• Plantar response: increased; extensor or babinski sign

Question 22

DTRs of the arm and leg

Answer 22

• Arm: Biceps (C5, C6), Brachioradialis (C6, C7), Triceps (C6,C7), Fingers (C8).
• Leg: Quadriceps (L3, L4), Gastrocnemius (Achilles reflex, S1).

Question 23

LMN injury characteristics

Answer 23

• bulk: decreased; significant atrophy
• fasciculations: present
• tone: decreased; flaccid
• DTRs: decreased or absent
• plantar response: decreased; flexor

Question 24

Radiculopathy: sx, exam findings, localization

Answer 24

• “spinal root syndrome”
• Pain:
  
  • quality is variable: “shooting,” “burning,” “tingling,” “numb.”
  • often radiates into a dermatome or myotome.
• Exam: possible LMN signs (reduced or absent reflexes +/- weakness).
• Localization: determine which root the abnormal muscles(s) and dermatome(s) have in common.

Question 25

Radiculopathy: exacerbating and relieving factors, common causes

Answer 25

* Exacerbation by Exam: Neck flexion/extension/rotation, shoulder movements, cough, etc. * Relieving Factors: Rest, immobilization, graded therapy, NSAIDS +/- muscle relaxants. * Common causes: Compression by degenerative joint disease (causing bony proliferation) or herniated disc near intervertebral foramen.

Question 26

Lherrmitte's sign

Answer 26

* Neck flexion ==\> "electric shock" sensation down the back and/or into arms. * Attributed to posterior column disease * MS, disc, B12 deficiency, mass

Question 27

Spinal cord pain syndromes

Answer 27

1. Complete Cord Transection 2. Central Lesions 3. Posterior Column Syndrome 4. Combined Anterior Horn Cell-Pyramidal Tract Syndrome 5. Brown-Sequard (Hemi-Section) 6. Posterolateral Column Syndrome 7. Anterior Horn Cell Syndrome 8. Anterior Spinal Artery Occlusion 9. Pyramidal Tract Syndrome 10. Myelpathy w/Radiculopathy

Question 28

Complete Cord Transection: tracts & deficits

Answer 28

* Tracts: All ascending sensory & descending motor/autonomic tracts. * Deficit: Sensory + motor levels below lesion; may also have root signs at site. * Note: Spinal shock followed by UMN signs.

Question 29

Central Lesions: tracts & deficits

Answer 29

* Tracts: Initially involve crossing ST * E.g.s: Syringomyelia (fluid-filled cavity in cord), ependymomas, cord contusion. * Deficit: PP/Temp loss at level of lesion, with sparing of position sensation. * Note: Cape-like distribution if in C-spine.

Question 30

Posterior Column Syndrome: tracts, e.g., deficits

Answer 30

* Tracts: PC * E.g.s. Tabes dorsalis (form of neurosyphilis) * Deficit: Bilateral loss of position & vibration sensation.

Question 31

Combined Anterior Horn Cell-Pyramidal Tract Syndrome: tracts, e.g., deficits

Answer 31

* Tracts: CS and LMN cells in cord. * E.g.s: Amyotrophic lateral sclerosis * Deficit: Loss of bilateral strength. * Note: Fasciculations, atrophy, increased or decreased DTR, normal sensation.

Question 32

Brown-Sequard (hemi-section): tracts, e.g., deficits

Answer 32

* Tracts: Crossed ST + uncrossed PC + crossed CS * E.g.: Compression by herniated discs, tumor, extramedullary abscess, etc. * Deficit: Below lesion, loss of: * CL PP/Temp * IL Position * IL strength.

Question 33

Posterolateral Column Syndrome: tracts, e.g., deficits

Answer 33

* Tracts: PC + CS * E.g.: B12 deficiency (aka subacute combined degeneration) * Deficit: Bilateral loss of position & vibration, and strength.

Question 34

Anterior Horn Cell Syndrome: tracts, e.g., deficits

Answer 34

* Tracts: None - lower motor neuron (cell). * E.g.: Spinal muscular atrophy, polio virus * Deficit: Bilateral loss of strength. * Note: Fasciculations, decreased tone + decreased DTRs with sparing of all sensory tracts and bladder functions.

Question 35

Anterior Spinal Artery Occlusion: tracts, e.g., deficits

Answer 35

* Tracts: ST + CS * E.g.: Anterior spinal artery occlusion. * Deficit: Bilateral loss of strength + PP/Temp, with sparing position sense.

Question 36

Pyramidal Tract Syndrome: tracts, e.g., deficits

Answer 36

* Tracts: CS * E.g.: Primary lateral sclerosis. * Deficit: Bilateral UMN weakness with spastic gait, increased DTRs, but complete sparing of all sensory tracts and bladder function.

Question 37

Myelopathy with Radicolpathy: tracts, e.g., deficits

Answer 37

* Tracts: Any or all 3 tracts (esp. CS) * E.g.s: Cervical spinal stenosis, may be congenital or degenerative. * Deficit: Bilateral UMN syndrome with spastic gait, increased DTRs + IL or CL root signs + possible bladder dysfunction.

Question 38

Signs/sx of conus medullaris (S2-S5) syndrome

Answer 38

* -Late pain in thighs & buttocks * -Pelvic floor muscle weakness * -SYMMETRIC "saddle" anesthesia * -EARLY bladder dysfunction * -EARLY bowel & sexual dysfunction

Question 39

Signs/sx of cauda equina (L1-L5 roots) syndrome

Answer 39

* -EARLY root pain radiating to legs * -Leg weakness & decreased DTRs (LMN) * -Patchy, asymmetric "saddle" numb. * -Late bladder dysfunction * -Late bowel & sexual dysfunction

Question 40

Neuronal control of micturition

Answer 40

* most micturition related axons run in or along the LCST * brain/brainstem send axons through spinal cord ==\> preganglionic parasympathetic neurons @ S2, S3, S4 * pregang parasym axons ==\> ventral roots of S2, S3, S4 ==\> postganglionic parasympathetic neruons @ ganglia near bladder * postgang parasym innervate detrussor * pregang sympathetic neurons @ T11-L1 =\> contraction of internal urethral sphincter * external sphincter = voluntary * frontal cortex ==\> descending inputs * alpha motorneurons @ anterior horn from S3-S4

Question 41

Spinal lesion impact on micturition

Answer 41

* @ sacral level: * if sensory is intact ==\> urgency w/out good detrussor contraction * ==\> ~LMN sx = weakness, atrophy, hyporeflexia * above sacral level: * bladder fxn is only affected w/bilateral lesion * ~UMN sx = initially flaccid bladder ==\> spastic bladder

Question 42

Dematome @ nipple line, xyphoid, umbilicus

Answer 42

* T4 = nipple line * T6 = xyphoid * T10 = umbilicus

Question 43

Sensory territory of C5, C6, C7

Answer 43

* C5 = @ level of clavicles; extends lateral and ventral along arms * C6 = most lateral portion of arms * C7 = middle of dorsal aspect of arms + middle palm and fingers 2,3

Question 44

Sensory territories of L4, L5, S1

Answer 44

* L4/L5/S1 = foot * most of ventral lower leg + lateral part of upper leg