Cervical myelopathy cme

CERVICAL DISC DISORDER

LUNCH HOUR CME15/12/2010

Spondylosis: any or various degenerative diseases of the spine

Myelopathy: any disease or disorder of the spinal cord or bone marrow

Radicular: of, relating to, or involving a nerve root Radiculopathy: any pathological condition at the

nerve roots.

Definitions of Spinal Disorders

Cervical spondylosis Cervical radiculopathy Cervical myelopathy

A non-specific term Refers to any lesion of cervical spine of a

degenerative nature (non-inflammatory disc degeneration)

Cervical Spondylosis

Imbalance between formation & degradation of proteoglycans & collagen in disc

With aging, a -ve imbalance with subsequent loss of disc material -> degenerative changes

Factors influencing severity of degeneration◦Heredity◦Trauma◦Metabolic◦Other environmental effects, eg. smoking

Pathology

Degeneration ->◦Disc herniation◦Stenosis◦ Instability

Spine unable to withstand physiologic loads -> significant risk for neurologic injury, progressive deformity & long-term pain & disability

Not common in cervical spondylosis except those with stiffness in middle & lower segments who develop compensatory hypermobility at C3-4 or C4-5 -> myelopathy

Cervical spinal instability◦Radiographic criteria of White

>11o angulation >3.5 mm translation of adjacent subaxial segments

Most people with degenerative changes of the cervical spine remain asymptomatic.

Symptomatic patients are usually older than 40 years of age and present with symptoms that are caused by the compression of neural structures.

There are three main symptom complexes related to cervical spondylosis:

1.Neck pain2.Cervical radiculopathy3.Cervical myelopathy

Presentation

X-rays changes◦Narrowing of intervertebral disc◦Sclerosis of endplates◦Osteophyte formation

Similar changes may occur in facet joints Most frequently in C5-6 & C6-7 Incidence of spondylosis on X-rays in

asymptomatic patients◦80% in 51-60 age group◦95% in 61-70 age group

Radiological findings

Incidence of Spondylosis on MRI in asymptomatic patients

<40 yr >40yr

Cervical disc herniation

10% 5%

Degenerative disc changes

25% 60%

Cervical stenosis 4% 20%

A condition caused by compression of a nerve root in cervical spine.

Involves a specific spinal level with sparing of levels immediately above & below.

Peak age:50-54 year Disc protrusion =22% spondylosis=68% 41% had associated lumbar radiculopathy

Cervical Radiculopathy

C7 monoradiculopathy-most common,C6-7 level. Pain post. aspect of arm, posterolateral

forearm,middle finger Tricep and fingers extensor weakness Tricep reflex reduce. 90% not treated surgically were asymptomatic.

Cervical Radiculopathy

C3 radiculopathy-involving C2C3 disk. Uncommon Sensory-post.neck,suboccipital and ear No detectable muscle motor. C4 radiculopathy-neck and shoulder pain No significant motor deficit. Radiating pain-base

of the neck,midshoulder and scapula. No reflex changes.

Radiculopathy

C5 :deltoid muscle- difficulty in elevating of arm. Weakness of supraspinatus-infraspinatus Decrease bicep reflex C6:herniation bt.C5C6. top of neck,along the

bicep into lat. Aspect of the forearm and onto dorsal surface of hand between thumb and index finger.

Bicep and brachoradialis reflex decrease.

C8 radiculopathy-numbness small finger and medial half of the ring finger.

Most of intrinsic muscles of the hand. Lose fine fingertip and grip strength.

Largely secondary to mechanical compression of nerve roots.

5 articulations:1. intervertebral disc2. 2 uncovertebral3. 2 facets joints

Patho-anatomy

Innervation of the cervical intervertebral disc

ST=cervical sympathetic trunk

VA=vertebral artery; ALL=anterior longitudinal

ligament PLL=posterior

longitudinal ligament SVN=cervical sinuvertebral nerve

Half of adult population will experience neck and radicular pain.

Rarely progressed to myelopathic state (Less and Turner, 1963)

Natural history

Varies greatly-Pain, paraesthesia and weakness. Classically:significant radicular pain and refered

trapezial and periscapular pain. Only 55% had pain in a strictly radicular pattern.

(Henderson et al,1983,neurosurgery). Other studies:60%-70% motor weakness,70%

reflex changes. Often described symptoms that correlate with

various head position.

Clinical features

Exacerbation with neck hyperextension and tilted toward affected side.

Modified spurling test(combination of head extension and head tilt)

Shoulder abduction relief sign-specific for soft disc herniation.

Symptoms and examination

Acute-disc herniation:Posterolateral, mid-line and intra-foraminal

Insidious-degenerative Uncovertebral-compress nerve root anteriorly. Neuroforaminal narrowing by:osteophytes

superior facet, decrease disc height

Cervical disc herniation and degenerative spondylosis

o Three locations of focal disc protrusions:

(A) intraforaminal; (B) posterolateral; (C) midline

1. Cervical myelopathy2. Entrapment syndrome3. Thoracic outlet syndrome4. Intraspinal and extraspinal tumor

Differential diagnosis

X ray-instability and pathologic changes◦ Flexion-extension lateral films-instability◦ Loss of disc space height◦ Foraminal osteophytes◦Kyphosis◦Subluxution◦Posterior compression from facet arthropathy

CT-to evaluate transverse foramina, size and shape of spinal canal, facet and uncovetebral joints

MRI-spinal canal diameter, spinal cord, IVD and vetebral ligaments.

Imaging

Non-operative:1. Soft collar-<2 weeks2. Traction(24 degree flexion)- release pressure,

increase blood flow3. Heat and cold therapy4. Medical- opioid, Nsaids, antispasmodic

Management

Indications: significant pain or deficits after 6 weeks or progressive neurologic deficits

Approach should be determined by position & type of lesion◦Soft lateral discs easily removed by posterior approach◦Spurs & more paramedian discs via anterior approach

Surgical procedures

Options:• Anterior cervical discectomy & fusion• Anterior foraminotomy (Jho’s procedure)• Posterior foraminotomy• Cervical arthroplasty.

For unilateral osteophytes, facet hypertrophy, extruded disc causing unilateral radiculopathy

Avoids bone fusion but often does not efficiently eliminate the herniated disc materials

Posterior cervical foraminotomy

Indications for this approach:• Progressive or persistent symptoms arising from

unilateral or bilateral lateral disc herniations • Spondylotic neural foraminal compromise at one

to two levels. Sacrifice the spinal motion at the herniated disc

level. C/I-congenital stenosis, stenosis arising

predominantly from posterior structures, and disease at greater than three levels

ANTERIOR CERVICAL DISCECTOMY AND FUSION

provides an effective elimination of the compressing herniated portion of the disc or bone spurs, while preserving the remaining disc between the vertebrae and maintaining spinal motion

Anterior cervical microforaminotomy (Jho procedure)

Myelopathy = Cord dysfunction Cervical Spondylitic Myelopathy (CSM) introduced

by Brain et. al. 1952. CSM= gait abnormality and weakness or stiffness

of the legs which usually develop insidiously. > 50% CM are CSM. Other causes for myelopathy are trauma, tumour

and congenital.

Cervical Myelopathy

1.Developmental stenosis: AP diameter of spinal canal of 12 mm or less .

2.Dynamic stenosis: defined as Penning’s jaw diameter - distance from posterior inferior corner of vertebral body, to anterior margin of subjacent lamina, 12 mm or less, a/w 2 mm of retrolisthesis with neck in extension

3.Disc herniation4.Segmental OPLL (Ossification of posterior longitudinal ligament)5.Continuous OPLL6.Posterior spur7.Calcification of ligamentum flavum (CLF): tends to occur in elderly

women1 & 2 most common

Pathology

Cervical Myelopathy (Static stenosis)

Pain usually absent. Discomfort varies from aching to sharp pain.Gait disturbances,clumsy hands, spasticity,sphincter disturbances, motor weakness.

Cervical Myelopathy

The proximal motor groups of the legs are more

involved than the distal groups (which is the

opposite of the pattern with lumbar stenosis)

Clinical Presentation

Hyperreflexia, positive Hoffmann’s sign, Babinski test,

clonus, sensory and motor changes.

Myelopathic hand syndrome:

thenar atrophy, positive finger escape sign and grip

release test.

Positive Lhermitte’s sign: electric shock sensation with

neck flexion

Physical findings

Many patients have evidence of significant compression on neuroradiologic imaging but are relatively asymptomatic

No patient ever return to normal state. 75% episodic worsening. 20% slow and steady progression. 5% rapid onset with lengthy disability. Myelopathy rarely developed in patient with spondylosis. Generally, once moderate signs and symptoms of

myelopathy develop,the ultimate prognosis is poor.

Cervical Myelopathy:natural history

Scapulohumeral reflex. (tap on scapula spine-pathology above C4)

L’Hermitte’s sign. (flexion on neck Paresthesia / shock down to extremities)

Babinski sign.

Cervical Myelopathy(signs)

Plain X-ray for stenosis◦ Normal = ~17 mm◦ Absolute (AP canal diameter <10

mm) or relative (10-13 mm) stenosis are risk factors for myelopathy, radiculopathy, or both

◦ Pavlov's ratio (canal/vertebral body width) Should be 1.0, with <0.85

indicating stenosis Ratio of <0.80 is a significant risk

factor for lateral neurologic injury This identifies a congenitally

narrow canal◦ OPLL

MRI

◦Shows cervical disc prolapse well

◦Demonstrates spinal cord well

◦High intensity signal can be found in spinal cord on T2,

representing myelomalacia (necrosis/cavity formation) CT shows OPLL & bone spurs best

Cervical Myelopathy(evaluation)

Brown-Sequard syndrome. Unilateral cord lesion.◦Cross motor and sensory

dysfunction.

Cervical Myelopathy(clinical syndromes)

Central cord syndrome.◦ Typically Upper limbs are

more affected than lower limbs.

Cervical Myelopathy(clinical syndromes)

Motor system syndrome. Anterior cord syndrome.◦Spinal thalamic tract.◦Cortical spinal tract.◦Minimal sensory complaints.

Cervical Myelopathy(clinical syndromes)

Transverse lesion syndrome. Posterior cord syndrome◦Posterior Column.◦Spinal thalamic tract.◦Cortical spinal tract.◦Anterior horn cells often involved.

Cervical Myelopathy(clinical syndromes)

Mild myelopathy:o May display findings such as slight gait

disturbance and mild hyper-reflexia but may have no functional deficits and no weakness.

o Re-evaluation every 6 to 12 months to look for deterioration of neurologic function or a change in symptoms.

Non-operative treatment

Muscle relaxants Analgesics NSAID Physiotherapy Cervical support

Conservative management

◦Absolute indication = neurological deficit which is progressing

◦Patients with cord compression on MRI but no objective symptoms or findings of myelopathy best treated non-operatively

Herniation shows better improvement after surgery, older patients & those with dynamic stenosis show less improvement.

Indications for surgery

Surgical approaches◦No controlled prospective studies comparing anterior &

posterior approaches◦Approach depends on

Location of pathology Levels of involvement Stability of spine Presence of kyphotic deformity

◦ Indications: Generally recommended if disc herniation

or posterior spur causing compression at 1 or 2 levels

Also indicated if there is kyphotic deformity, so that correction can be achieved

◦ Options: Anterior discectomy & interbody fusion

with anterior spinal instrumentation With more extensive anterior

decompression involving excision of osteophytes - discectomy & corpectomy with strut graft fusion

Anterior Decompression & Fusion

◦Ant. Corpectomy strut grafting better decompression kyphotic deformity more problem if >3 level

Operative management

◦ Generally recommended if there is compression of spinal cord at 3 levels or more, in developmental stenosis or calcification of ligamentum flavum

◦ Options Laminoplasty

Directly decompresses cord posteriorly & indirectly decompresses cord anteriorly

Requirements Straight or lordotic cervical spine Stable spine Multilevel cord compression

o Laminectomy - poor outcome due to spinal instability & kyphosis

Posterior decompression +/- fusion

◦Canal expansive laminoplasty decompression of spinal canal with reduced risk for kyphotic

deformity No fusion Z-plasty (Hattori) Hemi-lateral open (Hirabayashi) Bilateral open (Kurokawa)

Operative management

Operative management

Operative management

< 7 = severe 8-12 = moderate 13-16 mild Max = 17

Cervical Myelopathy(evaluation)

Complications◦Anterior surgery

anterior structures (dysphagia, hoarseness, vocal cord, sore throat, sympathetic chain)

non union. Graft slippage (1% -2% ACDF) (6% - 29% graft)

◦Posterior surgery kyphosis (preservation of posterior structures) reduced ROM with laminoplasty

◦General complication infection (< 1%) hematoma and compression cord injury

Positive prognostic value include larger transverse area of the cord.

Younger patient age Shorter duration of symptoms, and Single rather than multiple levels of involvement

Symptoms > 6 months Canal : body ratio < 0.8 Compression ratio < 0.4 after surgery.

Cervical Myelopathy;bad prognosis