Clinical Evaluation of the Spine and Spinal Cord

Question 1

What is Paresthesia?

Answer 1

An abnormal sensation, can include burning,

pricking, tickling, or tingling

Question 2

What is Dysesthesia?

Answer 2

Impairment of sensation short of anesthesia

Question 3

What is Paresis?

Answer 3

partial loss of movement or impaired movement

Question 4

What is a Dermatome?

Answer 4

Cutaneous area served by an individual sensory root.

Question 5

What is a Myotome?

Answer 5

Muscles innervated by an individual motor root.

Question 6

What is Radiculopathy?

Answer 6

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

root.

Question 7

What is Myelopathy?

Answer 7

Disorder resulting in spinal cord dysfunction.

Question 8

What are the 3 major spinal tracts?

Answer 8

1) spinothalamic tract (pain and temperature)
2) posterior columns (vibration and position)
3) corticospinal tract (motor)

Question 9

What are the functions of the spinothalamic tract and where do they cross?

Answer 9

Function: sensory modalities of pain and temperature (cold/hot)

Cross: 2 -3 segments above root entry level in the anterior spinal cord

Question 10

What are the functions of the posterior columns and where do they cross?
3) corticospinal tract (motor)

Answer 10

Function: sensory modalities of vibration, position, and 2-point discrimination

Cross: medulla (brain stem)

Question 11

What are the functions of the corticospinal tract and where do they cross?

Answer 11

Function: motor function

Cross: lower medulla (brain stem)

Question 12

Know where the nerve roots exit

e.g. C6 root exits between C5-C6; T2 between T2-T3

Answer 12

C1, 2, 3, 4, 5, 6, 7 roots exit above same numbered vertebra

C8 exits below C7 vertebra

All other nerve roots exit below same number vertebra

Question 13

Know the spinal cord level that each vertebral body overlies (C6 bone overlies C7 cord.)

Answer 13

• Upper cervical: vertebra number overlies cord segment of same number
• Lower cervical: vertebra number overlies cord segment number + 1 (C6 bone, C7 cord)
• Upper thoracic: vertebra number overlies cord segment number + 2 (T4 bone, T6 cord)
• Lower thoracic/lumbar: vertebra number overlies cord segment number + 2/3 (T11 bone, L1-2 Cord)
• Lower edge of the L1 vertebral body overlies the cord tip (conus medullaris)

Question 14

Recognize the symptoms of a radiculopathy.

Answer 14

Radiculopathy: sensory and/or motor dysfunction due to an injury to a nerve root. Pain is variable: “shooting”, “burning”, “tingling”, “numb”. Pain radiates into a dermatome or myotome.

Exam: possible LMN signs (reduced or absent reflexes +/- weakness)

Localization: determine which root the abnormal muscles and dermatome have in common

Exacerbation by exam: neck flexion/extension/rotation, shoulder movements, cough

Relieving factors: rest, immobilization, graded therapy, NSAIDs +/- muscle relaxants

Common causes: compression by degenerative joint disease (causing bony proliferation) or herniated disc near invertebral foramen.

Question 15

Know the neurologic signs used to distinguish lesions affecting the lower motor neurons versus those affecting the upper motor neurons.

Answer 15

LMN signs:

• Atrophy
• Fasiculations
• Flaccidity (decreased muscle tone)
• Decreased or absent DTRs
• Downward plantar response

UMN signs:

• Spasticity (increased muscle tone)
• Hyperreflexia
• Up-going plantar response (Babinski sign)

Question 16

How do you distinguish conus medullaris syndrome from cauda equina syndrome?

Answer 16

Conus medullaris syndrome (S2 – S5):

• Late pain in thighs & buttocks
• Pelvic floor muscle weakness
• Symmetric saddle anesthesia numb
• Early bladder dysfunction
• Early loss of bowel and sexual functioning

Cauda equina syndrome (L1 – S5):

• Early root pain radiating to legs
• Leg weakness and ↓ DTRs (LMNs)
• Patchy, asymmetric “saddle”
• Late bladder dysfunction
• Late loss of bowel & sexual dysfunction

Question 17

Understand the basic neural pathways involved in the control of micturition.

Answer 17

Controlled by areas of the brain and brainstem that send axons down the spinal cord, traveling just medial to the LCST. These bilateral projections terminate on preganglionic parasympathetic neurons at S2, S3 and S4. The preganglionic parasympathetic neurons send their axons out the ventral roots of the S2, S3, and S4 to synapse on postganglionic parasympathetic cells in ganglia near the bladder. These postganglionic parasympathetic cells in turn innervate the detrussor (smooth) muscle of the bladder for voiding.

There are muscle spindles, nociceptors, and other sensory receptors in the detrussor muscle & bladder wall whose cell bodies lie in the dorsal root ganglia at S2, S3 and S4.

Question 18

Know the thoracic dermatomes that typically cover the nipple line, xyphoid, and umbilicus.

Answer 18

Nipple line: T4

Xyphoid: T7

Umbilicus: T10

Question 19

Understand ALL of the material presented in neuroexam.com under “reflexes” (except
the material on “reflexes tested in special situations”).

Answer 19

x

Question 20

Learning objectives from the Spinal cord powerpoint exercise from last exam

Answer 20

x

Question 21

Understand Lhermitte’s symptom.

Answer 21

Neck flexion results in “electric shock” sensation down the back and/or arms. Attributed to posterior column disease (MS, disc, B12 deficiency, mass)

Question 22

Tracts and deficits associated with Complete Cord Transection

Answer 22

Tracts: All ascending sensory and descending motor/autonomic tracts

Deficits: Sensory + motor levels below the lesions

May also have root signs at the site

Question 23

Tracts and deficits associated with Central Lesions

Answer 23

Tracts: Initially involve crossing spinalthalamic tract

Deficits: Pain/temp loss at level of lesion, with sparing of position sense

Cape-like distribution if in C-spine

Question 24

Tracts and deficits associated with Posterior Column Syndrome

Answer 24

Tracts: PCML

Deficits: Bilateral loss of position and vibration sense

Question 25

Tracts and deficits associated with Combined anterior horn cell-pyramidal tract syndrome

Answer 25

Tracts: Corticospinal tract and LMN cells in the cord

Deficits: Loss of bilateral strength

Question 26

Tracts and deficits associated with Brown-Sequard

Answer 26

Tracts: Crossed spinalthalamic tract
Uncrossed PCML
Crossed Corticospinal tract

Deficits: Below lesion: contralateral pain and temp + ipsilateral position and strength

Question 27

Tracts and deficits associated with Posteriolateral Column Syndrome

Answer 27

Tracts: PMCL and Corticospinal tract

Deficits: Bilateral loss of position, vibration, and strength

Question 28

Tracts and deficits associated with Anterior Horn Cell Syndrome

Answer 28

Tracts: No tracts, just LMNs

Deficits: Bilateral loss of strength

Question 29

Tracts and deficits associated with Anterior Spinal Artery Occlusion

Answer 29

Tracts: Spinalthalamic tract and corticospinal tract

Deficits: Bilateral loss of strength, pain, and temp

Sparing of position sense

Question 30

Tracts and deficits associated with Pyramidal Tract Syndrome

Answer 30

Tracts: Corticospinal tract

Deficits: Bilateral UMN weakness with spastic gait
Increased DTRs

Complete sparing of all sensory tracts and bladder function

Question 31

Tracts and deficits associated with Myelopathy with Radiculopathy

Answer 31

Tracts: Any of all 3 tracts, especially the corticospinal tract

Deficits: Bilateral UMN syndrome with spastic gait, increased DTRs

Ipsilateral or contralateral root signs

Possible bladder dysfunction

Question 32

Recognize that injuries at different levels can result in a flaccid or spastic bladder

Answer 32

PNS LMNs are injured → weakness, atrophy and hyporeflexia → bladder does not contract

LMN injury can occur: Anywhere from the preganglionic parasympathetic neurons at S2, S3, S4, Sacral roots of the cauda equina, pelvic nerve, Pelvic plexus, 2˚ postganglionic parasympathetic neuron that innervates the detrussor

UMN lesions

• To affect bladder function, lesions must be bilateral.
• Detrussor becomes flaccid → urinary retention → flaccid bladder

Question 33

Understand the sensory territory, unique motor territory, and reflex components of the C5 nerve root

Answer 33

Sensory territory: shoulder, upper lateral arm

Motor territory: deltoid, infraspinatus, biceps

Reflex components: biceps

Question 34

Understand the sensory territory, unique motor territory, and reflex components of the C6 nerve root

Answer 34

Sensory territory: 1st and 2nd digits of hand

Motor territory: wrist extension, biceps

Reflex components: biceps, bracioradialis

Question 35

Understand the sensory territory, unique motor territory, and reflex components of the C7 nerve root

Answer 35

Sensory territory: 3rd digit

Motor territory: triceps

Reflex components: triceps

Question 36

Understand the sensory territory, unique motor territory, and reflex components of the L4 nerve root

Answer 36

Sensory territory: knee, medial leg

Motor territory: psoas, quadriceps

Reflex components: patellar

Question 37

Understand the sensory territory, unique motor territory, and reflex components of the L5 nerve root

Answer 37

Sensory territory: dorsum of foot, great toe

Motor territory: foot dorsiflexion, big toe extension, foot eversion and inversion

Reflex components: none

Question 38

Understand the sensory territory, unique motor territory, and reflex components of the S1 nerve root

Answer 38

Sensory territory: lateral foot, small toe, sole of foot

Motor territory: foot plantarflexion

Reflex components: Achilles

Question 39

Function of Anterolateral System

Answer 39

Sensory- temperature and pain information

The body of the sensory neuron resides in the dorsal root ganglia and sends a process out to the skin. The sensory neuron may extend a process up a spinal segment or two in the dorsolateral tract (Lissauer’s tract). This sensory neuron then synapses on a second order neuron ipsilaterally in a section of the dorsal horn called the substantia gelatinosa. The second order neuron then crosses the midline at the anterior white commissure and ascends in the anterolateral (spinothalamic) tract to the ventral posterior lateral nucleus (VPL) of the

Question 40

Function of Dorsal column-medial lemniscus

Answer 40

Sensory- information on vibration, discriminative touch and proprioception

Sensory neurons with their cell bodies in the dorsal root ganglia have receptors in the skin, muscles and tendons. These sensory neurons send axons up the length of the spinal cord ipsilateral to their target. The tract in which they ascend the spinal column is called either the fasciculus gracilis (FGr) or the fasciculus cuneatus (FCu).

Question 41

Function of Corticospinal tract

Answer 41

Motor- muscle movement

This lower motor neuron may form a synapse with an upper motor neuron that has one of the following fates:

1. The upper motor neuron extends from the ventral horn on the ipsilateral side through the anterior corticospinal tract to the somatomotor cortex.
2. The upper motor neuron extends from the ventral horn on the ipsilateral side through the lateral corticospinal tract and then crosses the midline at the decussation of the pyramids in the brainstem before ending in the somatomotor cortex. (This is the most common pathway).
3. The upper motor neuron extends from the ventral horn ipsilaterally in the lateral corticospinal tract to the somatomotor cortex.

Question 42

Brown-Sequard Syndrome

Answer 42

A hemilesion of the spinal cord that results in motor paralysis and numbness to touch and vibration on the same side of the lesion and loss of pain and temperature sensation on the opposite side.

Question 43

Understand the general layout of gray matter in the spinal cord in anterior (or ventral) horn, intermediate gray and the dorsal horn

Answer 43

The anterior (ventral) horn contains cell bodies of lower motor neurons that innervate skeletal muscle. The anterior horn is found throughout the spinal cord.

The posterior (dorsal) horn contains neuronal cell bodies important for sensing pain and temperature. The dorsal horn is also found throughout the spinal cord.

The intermediate gray contains interneurons, preganglionic sympathetic neurons at spinal cord levels T1 through L2 and preganglionic parasympathetics at sacral levels 2, 3, and 4.

Question 44

Practice telling what level a section of spinal cord came from

Answer 44

x

Question 45

In representative sections of the spinal cord at different levels, identify the posterior fasciculus, and its two subdivisions: fasciculus gracilis (FGr) and fasciculus cuneatus (FCu), and the information these carry. Understand the effects of lesions of these structures

Answer 45

Recall that fasciculus gracilis and cuneatus are tracts of white matter traversing the spinal cord to the medulla in the dorsal column medial lemniscus pathway. The fasciculus cuneatus (upper extremity) is always lateral to the fasciculus gracilis (lower extremity) in the dorsal aspect of the spinal cord. The fasciculus gracilis and cuneatus are collectively called the posterior fasciculus.

• A lesion to the fasciculus gracilis (below level T6) would effect lower extremity vibration and fine touch sensation ipsilaterally.
• A lesion to the fasciculus cuneatus (above level T6) would effect upper extremity vibration and fine touch sensation ipsilaterally.

Question 46

understand the ascending flow of information from pain and temperature sensory receptors with soma in the PRG and sensory endings in the skin to spinal cord, and subsequently to thalamus

Answer 46

This pathway (sensory receptor→ PRG → dorsolateral tract → anterolateral tract → thalamus → somatosensory cortex) is described in objective 1.

Question 47

Symptoms occurring after damage of UMNs

Answer 47

Immediate muscle weakness, hypotonia and hyporeflexia

Followed by hyperreflexia in days to weeks

Spastic paresis

Question 48

Symptoms occurring after damage of LMNs

Answer 48

Muscle weakness, hypotonia and hyporeflexia are immediate and long-lasting

Flaccid paresis

Question 49

Know the location of neuron cell bodies for preganglionic parasympathetics

Answer 49

The preganglionic parasympathetics arise from the brainstem (CN III, VII, IX and X) and from the sacral levels 2, 3 and 4. At the sacral level, the cell bodies of these preganglionics are found in the intermediate grey of the spinal cord.