L8: The cervical and thoracic spine and the brachial plexus

Question 1

How many cervical vertebrae are there?

Answer 1

Seven
C1, C2 and C7 are atypical
C3-C6 are typical

Question 2

Describe the anatomy of a typical cervical vertebrae?

Answer 2

VB–> small and broad from side to side
Large triangular vertebral foramen
Bifid spinuous process
Transverse foramen (foramen transversarium) in transverse process–> passage way for vertebral artery, vein and symphathetic plexus
Anterior tubercle
Posterior tuberlce
Groove for spinal nerve
Articular facets–> coronal plane at 45 degree to axial plane
Superior articular facets–> upwards and backwards
Inferior articular facets–> downwards and forwards

Question 3

What is the structure of the C1 vertebrae?

Answer 3

Atlas
Anterior and posterior arch connected by two lateral masses –> vertebral arches
Widest of cervical vertebrae
No spinous process or vertebral body
Anterior arch occupies 20% of circumference of ring–> attachment of anterior longitudinal ligament
Posterior arch 40% of ring–> attachment ligament nuchae
Articular facets on lateral masses
Superior articular facets–> cup shaped articulate with occipital condyles
Inferior articular facets–> C2 vertebrae
Transverse process with transverse foramen in them

Question 4

What are the names of the joints found between the skull and C1 and C1 and C2?

Answer 4

Atlanto-occipital joint–> permits nodding
–> 50% of flexion and extension of the head

Atlanto-axial joint–> 50% total rotation of head and neck
C2 –> provides pivot on which the atlas rotates

Question 5

What is the anatomy of the C2 vertebrae?

Answer 5

Axis
Strongest cervical vertebrae
Rugged lateral mass and large spinous processes
Odontoid process aka dens or odontoid peg–> projects upwards from body
Held in place by transverse ligament of the atlas acts as a pivot joint
Transverse process with transverse foramen in

Question 6

What are the ligaments associated with the axis (C2)?

Answer 6

Transverse ligament–> holds dens in place

Apical ligament–> Attaches between odontoid process and base of skull

Question 7

What is excessive movement between the atlas and axis called?

Answer 7

Atlantoaxial instability

Can cause neurological damage

Question 8

Describe the anatomy of the C7 vertebrae?

Answer 8

C7–> vertebra prominens
Longest spinous process–> not bifid
Foraman transversium are small–> only transmit accessory vertebral veins

Question 9

In the cervical region where does the spinal nerve run?

Answer 9

Spinal groove
Across the superior aspect of the vertebral pedicle
Between the anterior and posterior tubercles of the transverse process
Spinal nerve–> posterior to vertebral artery
Vertebral artery ascends through the foramina transvrsaria in C1-6 with vertebral vein and sympathetic plexus

Question 10

Compared to the thoracic and lumbar region how does the spinal nerve exit the cervical region?

Answer 10

Spinal nerve exits above vertebrae
Until C7/T1 junction where C8 nerve root is the exiting nerve root
Neural segments also more inline with vertebrae
Spinal nerve leave horizontally to pass through IV foramina
Clinical impact–> no traversing nerve root, exiting root compressed

Question 11

What is the ligamentum nuchae?

Answer 11

Thickening of the supraspinous ligament
Extends from the external occipital protuberance of the skull and the medial nuchal line to the spinous process of C7
Anterior border–> fibrous lamina attaches to the posterior tubercle of atlas and spinous process of vertebrae
Continuous inferiorly with the supraspinous ligament

Question 12

What are the roles of the ligamentum nuchae?

Answer 12

Maintain the secondary curvature of the cervical spine
Assist cerivical spine to support the weight of the head
Major attachment site for muscles of the neck and trunk

Question 13

What is the anterior longitudinal ligament?

Answer 13

Anterior border of the vertebral body 
From tubercle of atlas to sacrum
Continuous with periosteum of VB
Loosely adhered to the IVD
Function: prevent hyperextension of vertebral column

Question 14

What is the posterior longitudinal ligament?

Answer 14

Posterior VB
Body of axis to sacral canal
Superior to axis –> tectorial membrane of the atlanto-axial joint
Prevents hyperflexion
Clinical relevance–> disc prolapse tends to occur lateral to this

Question 15

What are the movements of the cervical spine?

Answer 15

One of most mobile segments of spine
50% of nodding flexion and extension at atlanto-occipital joint –> remainder takes place at cervical facet joints
50% rotation (shaking head)–> atlanto-axial joint –> remainder at facet joints
Permits 45 degrees of lateral flexion –> occurs at facet joints

Question 16

Describe the anatomy of the thoracic vertebrae?

Answer 16

12 thoracic vertebrae
Medium sized heart shaped VB
Vertebral foramen small and circular
Prominent transverse process with transverse costal facets (articulation with ribs)
Demi facets T2-T8 and whole facets T9-T10 on VB for articulation with head of ribs
T11-T12–> whole facets on pedicle
Long, spinous process, angulated inferiorly
Articular facets angulated at 20 degrees to coronal plane, 60 degrees to axial (transverse) plane–> superior face posterolaterally, inferior face anteromedially–> permits lateral flexion and rotation but prevents flexion and extension

Question 17

What do the ribs attach to?

Answer 17

T1-T12
–>T2-8 demi facets on side of VB, superior and inferior demi facets for articulation with rib of same number and the rib below
–>T9-10 whole facets on VB
–>T11-12 facets on pedicle
Rib 1-7 curve round insert onto sternum via costal cartilgae
Ribs 8-10 insert onto costal cartilage of superior rib
Ribs 11-12 –> no anterior attachment, terminate in abdominal musculature
Head of rib articulates with a costal facet–> cartilage lined depressions

Question 18

What does the thoracic spine, ribs and sternum do?

Answer 18

Provide stability and protection for the heart, lungs, liver and other organs
Ribs connected to T11-12–> protection of retroperitoneal kidneys

Question 19

Which of the thoracic vertebrae are atypical and posses whole facets?

Answer 19

T1: superior facet is whole, articulates with head of rib 1, inferior costal facet is demi
T9 and 10: whole costal facets, extend from head of VB to pedicule
T11 and 12: whole costal facets located on pedicule

Question 20

What changes occur to the spinous process as you go down the thoracic spine?

Answer 20

Becomes shorter and less oblique from T1-T12

T12 spinous process more similar to lumbar vertebrae

Question 21

What does the tubercle of the rib articulate with?

Answer 21

Costal demi facet on transverse process

Question 22

What angle are the facets joints at? How does this affect the movement of the thoracic spine?

Answer 22

60 degrees to transverse plane
20 degrees to coronal plane
Superior articular facets face posterolaterally
Inferior articular facets face anteromedially
Permit lateral flexion and rotation
Limits Flexion and extension

Question 23

Describe the anatomy of the lumbar vertebrae?

Answer 23

Large, kidney, shaped vertebral body 
Triangular shaped vertebral canal
Large blunt transverse processes
Short blunt spinous processes
Facet 90 degress to transverse plane, 45 degress to coronal plane 
Superior face posteromedially 
Inferior anterolaterally 
Large range of flexion and extension, small amount of rotation and lateral flexion

Question 24

What is the brachial plexus?

Answer 24

Union of anterior rami of C5-T1 spinal nerves
Commences in the neck and terminates in the axilla
(Posterior rami–> skin and musculature of intrinsic back muscles)

Question 25

What are the different parts of the brachial plexus?

Answer 25

Roots, trunks, divisions, cords and branches

Question 26

What forms the roots of the brachial plexus? Where does it pass?

Answer 26

Roots formed by the anterior rami of C5-T1 | Pass between the scalenus anterior and scalenus medius--> enter posterior triangle of the neck

Question 27

What are the trunks made up of?

Answer 27

Three trunks Convergence of the roots Named after relative anatomical locations Superior trunk: C5 and C6 Middle trunk: C7 Inferior trunk: C8 and T1 Travel inferolaterally across the posterior triangle of neck

Question 28

What are the division of the brachail plexus?

Answer 28

Trunks divide in posterior triangle Anterior division and posterior division Divisions leave posterior triangle and enter axilla - behind clavicle Anterior supplies flexor, posterior supply extensors)

Question 29

What are the cords?

Answer 29

In axilla, division recombine to form the cords Name according to position relative to axillary artery Lateral cord: union of anterior division of superior and middle trunk Posterior cord: union of posterior division of superior, middle and inferior trunks Medial cord: continuation of anterior division of inferior trunk

Question 30

What are the branches of the brachial plexus?

Answer 30

``` 5 major terminal branches Supply entire compartment of upper limb Musculocutaneous nerve C5,6,7 Axillary C5, 6 Median C6, 7, 8, T1 Radial C5, 6, 7, 8, T1 Ulnar C8, T1 ```

Question 31

Which nerves come off before the branches of the brachial plexus?

Answer 31

Long thoracic nerve (C5-7 directly from anterior rami (roots)) Medial pectoral nerve (C8-T1 from medial cord) Lateral pectoral nerve (C5-7 from lateral cord) Upper subscapular nerve Thoracodorsal nerve Lower subscapular nerve --> All three of posterior cord

Question 32

What are 6 key points about the brachial plexus

Answer 32

1. Each muscle supplied by more than one spinal cord segment 2. More distal muscles supplied by inferior cord segments 3. Divergence of fibres in plexus as both flexors and extensors are supplied 4. Needs to be re-assortment of nerve fibres 5. Number of spinal nerves contributing to the terminal branch is roughly the same as the number of joints it supplied 6. Sensory innervation to the limb bud follows loop like pattern

Question 33

What can you look for in the cadaver when dissecting to help get your bearings?

Answer 33

M shape Made from Musculocutaneous, median and ulnar nerves Lie superficial to the axillary artery

Question 34

What happens if you injury the brachial plexus?

Answer 34

Affect motor function and cutaneous sensation | Traction injuries affect upper or lower nerve roots of brachial plexus

Question 35

What happens if you get an upper brachial plexus injury?

Answer 35

Result from excessive increase in angle between neck and shoulder Result of trauma or during child birth if baby's head is pulled and the shoulders are stuck C5 and C6 damaged C5- shoulder abduction and external rotation affected C6- elbow flexion, wrist extension and supination affected

Question 36

Which muscles are affected by an upper brachial plexus injury?

Answer 36

``` Deltoid (axillary nerve C5 and 6) Teres minor (axillary nerve) Biceps Brachii (musculocutaneous C5-7) Brachioradialis (radial nerve C5-T1) Brachialis (musculocutaneous C5-7) Coracobrachialis (musculocutaneous C5-7) ```

Question 37

What is the clinical presentation of a upper brachial plexus injury?

Answer 37

``` Erb's palsy Arms hang by side Internally (medially) rotated Adducted arm Extended elbow Wrist flexed Waiters tip position ```

Question 38

What happens with lower brachial plexus injury?

Answer 38

Forced hyperextension or hyperabduction Childbirth- traction injury if arms are delivered first and used to pull baby out Klumpke's palsy Nerve roots C8 and T1 affected C8: finger flexion/ finger extension T1: Finger abduction and finger adduction

Question 39

What muscles are affected in an lower brachial plexus injury?

Answer 39

Intrinsic muscles of the hand Flexor carpi ulnaris, and ulnar half of flexor digitorium profundus Also muscles supplied by C8 and T1 fibres of medial and radial nerves

Question 40

What is the classical clinical presentation of a lower brachial plexus injury?

Answer 40

Claw hand Hyperextension of the metacarpalphalangeal joints Flexion of interphalangeal joints Abduciton of the thumb and wasting of interossei

Question 41

Where is the pectoral region?

Answer 41

Anterior chest wall

Question 42

What are the muscles of the pectorial region?

Answer 42

``` Pectoralis Major Pectoralis Minor Serratus Anterior Coracobrachialis (not really chest wall but important landmark) Subclavis Deltoid ```

Question 43

What is the origin, insertion, innervation and function of the Pectoralis Major muscle?

Answer 43

Sternal head and claviular head Origin: Sternal head--> Anterior surface of sternum, upper 6 CC, aponeurosis of external oblique muscles Clavicular head--> Anterior surface of medial clavical Insertion: Intertubercular sulcus of the humerus Fibres from the clavicular head overlap fibres of sternal head Function: - -> Abducted arm, sternocostal head pulls humeral insertion towards fixed sternocostal origin adducting the arm - -> Anatomical postion, contraction of clavicular head, flexion of arm at shoulder joint - -> Humerus externally rotated, contraction internally rotate it Innervation: - -> Medial pectoral nerve (C8-T1) - -> Lateral pectoral nerve (C5-7)

Question 44

What is the origin, insertion, innervation and function of the Pectoralis Minor?

Answer 44

Origin: 3-5th ribs Insertion: coracoid process of the scapular Function: Stabilises the scapular by drawing it anteroinferiorly against the thoracic wall Innervation: Medial pectoral nerve (C8-T1)

Question 45

What is the origin, insertion, innervation and function of the Serratus Anterior?

Answer 45

Origin: Ribs 1-8 Insertion: Medial border of costal surface of scapula Function: Protracts (abducts) the scapula, rotates medial border of the scapula anterioinferiorly so glenoid cavity rotates upwards, enables the upper limb to be abducted above 90 degrees at the shoulder Innervation: Long thoracic nerve (C5-7)

Question 46

What is winging of the scapula? How is it diagnosed?

Answer 46

Medial border of the scapula protrudes out of the back Damage to long thoracic nerve due to trauma Patient asked place palm of hand on wall and push--> force back along arm--> scapula lifts off or Patient asked to place palm of affected side on unaffected shoulder and pull it forward--> traction of scapula of affected limb so medial border elevates

Question 47

When do the pectoralis major, pectoralis minor and serratus anterior acts as accessory muscles?

Answer 47

Respiration High metabolic demand or respiratory disease Hyperventilating, severe metabolic acidosis, asthma Elevate the ribs increasing the volume of the thoracic cavity

Question 48

What is the origin, insertion, innervation and function of the coracobrachialis?

Answer 48

Deep to biceps brachii Origin: Coracoid process of scapula Insertion: Medial side of humeral shaft level of deltoid tubercle Function: Flexes the arm at the shoulder, weak adductor Innervation: Musculocutaneous nerve (C5-7)

Question 49

What is the origin, insertion, innervation and function of the subcalvius?

Answer 49

Small, located directly under the clavicle Protection to neurovasculature under the clavicle Origin: junction of the 1st rib and its costal cartilage Insertion: Inferior surface of the middle third of clavicle Function: Anchor and depress calvicle Innervation: Nerve to subclavius

Question 50

What is the origin, insertion, innervation and function of the deltoid?

Answer 50

Triangular muscle divided into anterior, middle and posterior parts Origin: Anterior border and upper surface of lateral third of clavicle, acromnion and spine of scapula Insertion: deltoid tuberosity on lateral surface of humerus Function: - -> Anterior fibres--> flex and medially rotate arm at shoulder - -> Middle fibres--> Abduct the arm from 15-90 degrees, (supraspinatus does first 15 degrees) - -> Posterior fibres--> extend and laterally rotate arm at shoulder Innervation: Axillary nerve (C5, 6)

Question 51

What is the axilla?

Answer 51

Pyramidal space at the junction of the upper limb and thorax Passageway for which neurovascular and muscular structures can enter and leave the limb Size and shape varies with amount of arm abduction Arm fully abducted axillary fascia taught, contents compressed against proximal humerus

Question 52

What are the borders of the axilla?

Answer 52

Anterior: pectoralis major and minor and subclavis Posterior: Subscapularis, teres major and latissimus dorsi Medial: Serratus anterior, ribs and intercostal muscles Lateral: Intertubercular sulcus of humerus Base: Axillary fascia, (thick layer of fascia spanning between the inferior borders of pectoralis major and latissimus dorsi) and skin Apex: lateral border of first rib, superior border of scapula and posterior border of the clavicle

Question 53

What are the contents of the axilla?

Answer 53

Axillary artery and branches Axillary vein and tributaries Cords of brachial plexus Branch of brachial plexus Intercostobrachial nerve --> cutaneous supply to upper medial arm and floor of axilla Axillary lymph nodes --> drain the arm and pectoral region Biceps brachii (short head) and coracobrachialis-->muscles originate from coracoid process tendons pass through into arm

Question 54

What are the main routes into and out of the axilla?

Answer 54

Inferiorly and laterally into upper limb Via quadrangular space to posterior arm and shoulder Via clavipectoral triangle (deltopectoral triangle)--> opening in the anterior wall of axilla bounded by pec major, deltoid and clavicle

Question 55

What are the borders of the quadrangular space? What passes through the quadrangular space?

Answer 55

Teres minor, Teres major and long head of triceps brachii Axillary nerve Posterior circumflex humeral artery encircle surgical neck of humerus

Question 56

What passes through the clavipectoral triangle?

Answer 56

Cephalic vein | Medial and lateral pectoral nerves

Question 57

How are the lymph nodes arranged in the upper limb? Where do they drain?

Answer 57

APICAL Anterior (pectoral) group--> Lower border of pectoralis minor, behind pectoralis major--> lymph from lateral breast, anterolateral abdominal wall above umbilicus Posterior (subscapular) group--> front of subscapularis muscle --> lymph from back down to iliac crest Infraclavicular (deltopectoral) group--> located outisde axilla, groove between deltoid and pectoralis major--> superficial lymph from lateral side of hand, forearm and arm Central group--> centre of axilla within the fat, lymph from anterior, posterior and lateral Apical group-->Apex of axilla, lateral border of first rib, nodes receive efferent lymph from all other axillary nodes Lateral group--> Medial side of axillary vein--> lymph from upper limb

Question 58

Where do they axillary lymph nodes drain into?

Answer 58

Converge forming the subclavian lymphatic trunk Right subclavian trunk--> right lymphatic duct--> right venous angle Left subclavian trunk--> thoracic duct--> left venous angle

Question 59

What is axillary lymphadenopathy?

Answer 59

Enlargement of the axillary lymph nodes Caused by: Infection of upper limb (lypmphangitis- inflammation of lymph vessel)--> red, warm, tender streak on arm Infection of pectoral region and breast Metastases from breast cancer Leukaemia or lymphoma Metastases from malignant melanoma in upper limb

Question 60

What is axillary node dissection?

Answer 60

Removal and analysis of axillary lymph node part of staging of breast cancer Interruption in lymphatic drainage from the upper limb--> lymphodema--> painful swelling of upper limb Risk of damage to long thoracic nerve supply--> winged scapula, or thoracodorsal nerve supply

Question 61

What is the main arterial supply to the upper limb?

Answer 61

5 main vessels--> proximal to distal - Subclavian artery - Axillary artery - Brachial artery - Radial artery - Ulnar artery

Question 62

When does the subclavian artery become the axillary artery? What are the different parts of the axillary artery called?

Answer 62

Lateral border of the first rib to the lower border of teres major First part- proximal to pectoralis minor Second part- posterior to pectoralis minor Third part- distal to pectoralis minor

Question 63

What are the main branches of the axillary artery?

Answer 63

First part--> superior thoracic artery Second part--> Thoracoacromial artery and lateral thoracic artery Third part--> Subscapular artery, anterior circumflex humeral artery and posterior circumflex humeral artery --> anterior and posterior anastomotic network around surgical head of humerus

Question 64

What is the course of the axillary vein?

Answer 64

Lower border of teres major from union of paired brachial veins and basilic vein Ascends through the axilla anteromedially to the axillary artery continuous with the subclavian at the lateral border of the first rib

Question 65

What are the different parts of the axillary vein?

Answer 65

First part--> above pectoralis minor--> receives blood from cephalic vein Second--> posterior Third--> distal Receive tributaries that correspond with the artery Thoracoacromial vein, lateral thoracic vein, subscapular vein, anterior circumflex humeral vein and posterior circumflex humeral vein

Question 66

What does the axillary vein drain?

Answer 66

Arm, axilla and superolateral chest wall

Question 67

What are the superficial veins of the upper limb?

Answer 67

Cephalic and Basilic | Form the pre-axial and post-axial borders of the arm respectively

Question 68

What is the course of the bascilic vein?

Answer 68

Dorsal venous network of the hand Ascends medial upper limb Inferior border of teres major, bascilic vein moves deep into the arm Combines with paired brachial veins--> axillary vein

Question 69

What is the course of the cephalic vein?

Answer 69

``` Dorsal venous network Ascends anterolateral aspect of arm Passes anteriorly at elbow At shoulder cephalic vein travels between the deltoid and pectoralis major muscle (in the deltopectoral groove) and enter the axialla via clavicopectoral (deltopectoral) triangle In axilla drains into axillary vein ```

Question 70

What connects the cephalic and bascili vein at the elbow?

Answer 70

The median cubital vein

Question 71

What is cervical spondylosis?

Answer 71

Chronic degenerative osteoarthritis | Affect intervertebral joints in the cervical spine

Question 72

What changes occur with cervical spondylosis?

Answer 72

Age related disc degeneration—> loss of disc height Osteophyte formation—> bony projections Facet joint osteoarthritis

Question 73

What is one of the problems of osteophyte generation in cervical spondylosis?

Answer 73

Narrowing of the intervertebral foramina—> Radiculopathy—> compression of the spinal nerves OR Narrowing of the spinal canal—> Myelopathy—> pressure on spinal cord

Question 74

What symptoms does radiculopathy and myelopathy present with?

Answer 74

Radiculopathy—> dermatome and sensory symptoms—> paraesthesia, numbness, pain and muscle weakness in area supplied by that spinal nerve Myelopathy—> global muscle weakness, gait dysfunction, loss of balance, loss of bowel and bladder control etc... depends on which part of spinal cord is compressed—> all areas below affected

Question 75

What are names of the different fractures that can occur to the cervical vertebrae?

Answer 75

Jefferon’s fracture Hangman’s fracture Fracture of the odontoid process (peg fractures)

Question 76

What is a Jefferson’s fracture? What is the mechanism of injury?

Answer 76

Fracture of the atlas Anterior and posterior arches fractured —> bursting open Axial loading—> diving into shallow water, hitting head against roof of vehicle etc...

Question 77

What does a Jefferson’s fracture result in?

Answer 77

Pain but no neurological signs Bursting open—> no impingement of spinal cord Potential arterial damage (base of skull)—> secondary neurological sequelae —> ataxia, stroke, Horner’s syndrome etc...

Question 78

What is a Hangman’s fracture? What is the mechanism of injury?

Answer 78

Fracture of Axis (C2) Pars interarticularis fractured—> region between superior and inferior articulatar processes Forcible hyperextension of head

Question 79

What does Hangman’s fracture result in?

Answer 79

Unstable fracture—> treatment required | Expands vertebral canal —> no neurological damage (no compression of spinal cord), pain

Question 80

What causes Fracture of the odontoid process?

Answer 80

Flexion or extension injuries Commonly—> elderly patient with osteoporosis falling forward and impacting forehead on pavement —> hyperextension of cervical spine—> fracture Alternative—> blow to back of head—> hyperflexion injury—> falling backwards down stairs

Question 81

How is a fracture to the odontoid process detected?

Answer 81

Open mouth AP X-ray CT scan of cervical spine Odontoid peg not easily seen on normal x-ray

Question 82

What is a whiplash injury?

Answer 82

Forceful hyperextension-hyperflexion injury of the cervical spine Tearing of the cervical muscle and ligaments Secondary oedema, haemorrhage and inflammation may occur Muscles respond—> contraction (spasm) surrounding muscle recruited in an attempt to splint the torn muscle

Question 83

What are the common signs and symptoms of Whiplash injury?

Answer 83

Pain and stiffness due to muscle spasms Arm pain and paraesthesia—> injury to spinal nerves Shoulder injury Lower back pain in 40-50% patients

Question 84

Why is the cervical spine prone to Whiplash injury?

Answer 84

7-10% body weight balanced High mobility and low stability of cervical spine Ligaments and capsule of the joints are weak and loose

Question 85

What is a secondary tissue response of Whiplash injury?

Answer 85

Myofascial pain syndrome - Secondary tissue response to disc or facet-joint injury High prevalence of chronic pain

Question 86

What is the classical mechanism of Whiplash?

Answer 86

Impact—> vehicle accelerates forward, patient torso and shoulder follow (100ms delay) induced by car seat acceleration Head—> no forces acting on it so it stays still—> forced extension of head Head accelerated forward—> neck acts as lever—> forced flexion of head Hyperextension followed by hyperflexion—> results in tearing

Question 87

What is one protective factor against spinal cord injury in the cervical region?

Answer 87

Vertebral foramen is relatively large Normal diameter - 17-18mm Spinal cord diameter- 10mm

Question 88

What is cervical disc prolapse? What is it associated with?

Answer 88

Herniation of IVD --> tear in annulus fibrosis of disc Nucleus pulpous protrudes from disc Compression of spinal nerve or spinal cord (Sometimes sequestration occurs (separation of nucleus pulpous from main body of disc) can be reabsorped and symptoms disappeared)

Question 89

What are the symptoms associated with cervical disc prolapse?

Answer 89

Exiting nerve root compressed Symptoms depend on the site of prolapse Discs not very large but little space for exiting nerves --> impingement--> pain Paracentral prolapse--> spinal nerve compression--> Reticulopathy Canal-filling prolapse--> spinal cord compression--> myelopathy

Question 90

What is a cervical myelopathy?

Answer 90

Spinal cord dysfunction due to compression of spinal cord | Casued by narrowing of the spinal canal

Question 91

What is the most common causes of cervical myelopathy?

Answer 91

Degenerative stenosis of the spinal canal Caused by cervical spondylosis (degenerative osteoarthritis) Commonly affects 50-80yr olds

Question 92

What is cervical spondylotic myelopathy?

Answer 92

Myelopathy secondary to cervical spondylosis

Question 93

What cause cervical spondylotic myelopathy?

Answer 93

Degenerative change Occur with age Ligamentum flavum hypertrophy or buckling Facet joint hypertrophy Disc protrusion and osteophyte formation Result in canal narrowing—> cord compression

Question 94

What are some of the other causes of cervical myelopathy?

Answer 94

Congential stenosis (narrowing) of spinal canal Cervical disc herniation Spondylolisthesis (anterior slippage of vertebral body on vertebrae below) Trauma Tumour Rheumatoid arthritis

Question 95

What are the symptoms associated with cervical myelopathy?

Answer 95

Range of symptoms Compression of long tract of spinal cord Damage to upper and lower limbs Usually non specific Classical presentation - Loss of balance - Poor coordination - Decrease dexterity - Weakness - Numbness - Paralysis - Pain (sometimes) Upper cervical lesions - loss of manual dexterity, difficulties writing, nonspecific alterations in am weakness and sensation, dysdiadochokinesia -impaired ability to perform rapid alternating movements Lower cervical lesions - Spasticity, lots of leg proprioception, legs feel heavy, gait disturbances and multiple falls

Question 96

What is Hoffman’s test?

Answer 96

Dr hold patient middle finger at the middle phalanx Flick the nail No movement of index finger or thumb —> patient has negative Hoffman’s sign Index finger and thumb move—> Positive Hoffman’s sign--> over reaction to stimuli shows long tract damage

Question 97

What is Hoffman’s test and Babinski sign used to show?

Answer 97

Long tract damage Normally signals in the long tracts dampen the spinal reflex’s so a person doesn’t overact to stimuli When long tract damaged —> exaggerated response to stimulation

Question 98

What is Babinski sign?

Answer 98

Lateral side of foot stroked with a blunt instrument from heel to toes Normally results in flexion (plantarflexion) of the toes —> negative Babinski —> normal If hallux dorsiflexes and toes fan out —> positive Babinski —>abnormal —> damage to spinal cord

Question 99

What is a classical sign of cervical myelopathy?

Answer 99

L’Hermitte’s phenomenon Sensation of intermittent electric shocks in the limbs—> exacerbated by neck flexion Severe compression—> sphincter dysfunction and quadriplegia

Question 100

What is thoracic cord compression?

Answer 100

Compression of the thoracic spinal cord

Question 101

What are the causes of thoracic cord compression?

Answer 101

Commonest cause—> vertebral fracture and tumours in the spinal canal Spinal cord second most common site for skeletal metastases

Question 102

What is important to remember when considering the clinical effects of thoracic cord compression?

Answer 102

Lower thoracic spine and in the lumbar spine the neural segments do not line up with their respective vertebrae E.g. Metastases in T12 vertebra will compress L4-L5 segments of spinal cord

Question 103

How can pathogens reach the bone and tissues of the spine?

Answer 103

Haemtogenous —> blood route into arterial supply to VB or retrograde venous flow into VB Direct inoculation during invasive spinal procedures Spread from adjacent soft tissue

Question 104

What is infection of the intervertebral disc called?

Answer 104

Spondylodiscitis or discitis

Question 105

How does discitis occur?

Answer 105

IVD avascular Organisms deposited in vertebral body via segmental artery—> bony ischaemic and infarction Necrosis of bone—> direct spread of organism to adjacent disc space, epidural space and adjacent vertebral bodies

Question 106

What does infection of the spinal canal lead to? How?

Answer 106

Neurological damage Via: - Septic thrombosis leading to ischeamia - Compression of neural element by abscess/ inflammatory tissue - Direct invasion of neural elements by inflammatory tissue - Mechanical collapse of bone leading to instability, particularly in chronic infections

Question 107

What are the most common infections seen in the spinal cord?

Answer 107

Staphylococcus aureus (50%) E.Coli (30%) Invasive spinal procedures—> Coagulase negative Staphylococci (Staph epidermis) become more frequent Injecting drug users potentially Pseudomonas, Candida