Online Module: Online Module: SpineSpine

Degenerative Disc Disease and Low Degenerative Disc Disease and Low Back PainBack Pain

Herniated Nucleus PulposusHerniated Nucleus Pulposus

Cervical Spinal StenosisCervical Spinal Stenosis

Lumbar Spinal StenosisLumbar Spinal Stenosis

Degenerative Disc Degenerative Disc Disease and Disease and

Low Back PainLow Back Pain

Degenerative Disc Degenerative Disc Disease (DJD)Disease (DJD)

Unfortunately, DJD seems to be sort of a Unfortunately, DJD seems to be sort of a “wastebasket term” that is often used to “wastebasket term” that is often used to describe age-related changes on MRI, describe age-related changes on MRI, etc.etc. While these changes are indeed While these changes are indeed

“degenerative,” this happens as we age and “degenerative,” this happens as we age and is not necessarily indicative of any significant is not necessarily indicative of any significant underlying pathology or condition. underlying pathology or condition.

The majority of individuals > 60 will show The majority of individuals > 60 will show some type of degenerative change(s) on some type of degenerative change(s) on lumbar imaging.lumbar imaging.

DJDDJD

Degeneration of an individual disc Degeneration of an individual disc space typically refers to loss of disc space typically refers to loss of disc height, loss of water content, height, loss of water content, fibrosis, end plate sclerosis/defects, fibrosis, end plate sclerosis/defects, osteophyte complexes, etc.osteophyte complexes, etc.

Low Back Pain (LBP)Low Back Pain (LBP)

LBP is extremely common; a majority of LBP is extremely common; a majority of individuals will experience at least one individuals will experience at least one episode of it in their life.episode of it in their life.

~85% of LBP is idiopathic, even with ~85% of LBP is idiopathic, even with workup.workup.

Most patients with LBP improve on Most patients with LBP improve on their own in time (even without their own in time (even without treatment).treatment). Physical therapy and pain meds (even Physical therapy and pain meds (even

nonprescription such as NSAIDs) are nonprescription such as NSAIDs) are appropriate mainstays of initial treatment.appropriate mainstays of initial treatment.

Taking a history in a pt. Taking a history in a pt. with LBPwith LBP

Evaluation of patients with LBP Evaluation of patients with LBP should be geared towards should be geared towards identification of those patients with identification of those patients with a potentially serious underlying a potentially serious underlying etiology.etiology. CancerCancer Infection – osteomyelitis, abscess, etc.Infection – osteomyelitis, abscess, etc. FractureFracture Cauda Equina SyndromeCauda Equina Syndrome

Things that should raise a Things that should raise a “red flag”“red flag”

Previous hx of cancer, unexplained weight lossPrevious hx of cancer, unexplained weight loss Immunosuppression, hx of steroid use, hx of IV Immunosuppression, hx of steroid use, hx of IV

drug abuse, hx of skin/other infection(s)drug abuse, hx of skin/other infection(s) Hx of recent falls or trauma (including surgery)Hx of recent falls or trauma (including surgery) Bladder dysfunction (usually urinary retention Bladder dysfunction (usually urinary retention

or overflow incontinence) or fecal incontinence, or overflow incontinence) or fecal incontinence, “saddle anesthesia”, leg weakness“saddle anesthesia”, leg weakness

Pain that doesn’t improve with rest; failure to Pain that doesn’t improve with rest; failure to improve after 4 weeks conservative improve after 4 weeks conservative managementmanagement

Other things to check Other things to check with LBPwith LBP

Social factors are important to ask about.Social factors are important to ask about. Employment statusEmployment status Any pending litigation?Any pending litigation?

Vitals can give clues (fever with infection, Vitals can give clues (fever with infection, etc).etc).

Routine labs are usually sufficient.Routine labs are usually sufficient. Good physical exam should pick up Good physical exam should pick up

neurological compromise, if present. neurological compromise, if present. Palpation of the spine looking for Palpation of the spine looking for

tenderness, etc., also important (trauma, tenderness, etc., also important (trauma, infection).infection).

RadiographyRadiography

Currently, radiographic imaging is not Currently, radiographic imaging is not recommended for patients with no “red recommended for patients with no “red flags” on history and physical if they flags” on history and physical if they have had symptoms less than 4 weeks have had symptoms less than 4 weeks duration.duration.

If red flags present, or persistent If red flags present, or persistent symptoms beyond 4 weeks, radiographic symptoms beyond 4 weeks, radiographic evaluation is recommended.evaluation is recommended. Then referral as/if appropriate.Then referral as/if appropriate.

Herniated Herniated Nucleus Nucleus PulposusPulposus

ConceptConcept Intervertebral discs can be thought of, Intervertebral discs can be thought of,

conceptually, kind of like a “jelly donut.” conceptually, kind of like a “jelly donut.” The outside is the The outside is the annulus fibrosusannulus fibrosus, and , and the inside “jelly” is the more watery the inside “jelly” is the more watery nucleus pulposusnucleus pulposus.. Intervertebral discs act as shock absorbers Intervertebral discs act as shock absorbers

between the vertebral bodies.between the vertebral bodies. Just like jelly donuts have a “weak spot” Just like jelly donuts have a “weak spot”

where the jelly squirts out if you squeeze where the jelly squirts out if you squeeze them, the annulus of discs is weak them, the annulus of discs is weak posteriorly where the nucleus pulposus can posteriorly where the nucleus pulposus can herniate through, causing symptoms.herniate through, causing symptoms.

PresentationPresentation The classic presentation of Herniated The classic presentation of Herniated

Nucleus Pulposus (HNP), both for cervical Nucleus Pulposus (HNP), both for cervical and lumbar spine, is radiculopathy.and lumbar spine, is radiculopathy. The disc herniation impinges upon a nerve The disc herniation impinges upon a nerve

root, causing characteristic pain.root, causing characteristic pain. Thoracic disc hernations are much, much Thoracic disc hernations are much, much

rarer.rarer. Though it can cause myelopathy in the Though it can cause myelopathy in the

cervical spine (see Cervical Spinal Stenosis, cervical spine (see Cervical Spinal Stenosis, later), Cauda Equina Syndrome in lumbar later), Cauda Equina Syndrome in lumbar spine (see module), etc., other presentations spine (see module), etc., other presentations won’t be discussed here.won’t be discussed here.

Lumbar HNPLumbar HNP ““Sciatica” is the classic radiculopathy of Sciatica” is the classic radiculopathy of

lumbar HNP, though the exact lumbar HNP, though the exact presentation depends upon the nerve presentation depends upon the nerve root(s) involved.root(s) involved.

Motor weakness can occur, which again is Motor weakness can occur, which again is representative of the nerve root(s) representative of the nerve root(s) involved.involved. L4 – quadriceps (knee extension)L4 – quadriceps (knee extension) L5 – tibialis anterior (foot dorsiflexion)L5 – tibialis anterior (foot dorsiflexion) S1 – gastrocnemius (foot plantar flexion)S1 – gastrocnemius (foot plantar flexion) Lower Motor Neuron signsLower Motor Neuron signs

Lumbar HNPLumbar HNP 90% of herniated discs are paracentral 90% of herniated discs are paracentral

(slightly off to one side) and affect the nerve (slightly off to one side) and affect the nerve root that corresponds to the lower vertebral root that corresponds to the lower vertebral level.level. Example: a typical L4/5 disc herniation would Example: a typical L4/5 disc herniation would

cause symptoms referrable to the L5 nerve root.cause symptoms referrable to the L5 nerve root. As many as 10% of herniated discs, however, As many as 10% of herniated discs, however,

are “far lateral” and impinge upon the nerve are “far lateral” and impinge upon the nerve root that corresponds to the upper vertebral root that corresponds to the upper vertebral level.level. A far lateral disc hernation at L4/5, then, would be A far lateral disc hernation at L4/5, then, would be

expected to cause symptoms relative to the L4 expected to cause symptoms relative to the L4 root.root.

Lumbar HNP – when to Lumbar HNP – when to operateoperate

The natural history of herniated The natural history of herniated discs is to resolve over time. If discs is to resolve over time. If conservative management can conservative management can adequately treat a patient’s pain, adequately treat a patient’s pain, this is the preferred course of action.this is the preferred course of action.

If conservative management fails to If conservative management fails to adequately control pain, surgery can adequately control pain, surgery can be performed (often times on an be performed (often times on an outpatient basis).outpatient basis).

Lumbar HNPLumbar HNP Emergent surgery – only for new or Emergent surgery – only for new or

progressive motor deficit, or Cauda Equina progressive motor deficit, or Cauda Equina Syndrome.Syndrome.

““Urgent” surgery sometimes for severe, Urgent” surgery sometimes for severe, incapacitating pain clearly referrable to a incapacitating pain clearly referrable to a disc herniation that is not being adequately disc herniation that is not being adequately treated with pain meds/conservative treated with pain meds/conservative management.management.

Diagnostic modality of choice is non-Diagnostic modality of choice is non-contrast MRI.contrast MRI. Can do myelogram in patients who can’t get Can do myelogram in patients who can’t get

MRI.MRI.

Cervical HNPCervical HNP

Classic presentation is to “wake up Classic presentation is to “wake up with it.” Usually no identifiable factor.with it.” Usually no identifiable factor. Causes painful limitation of neck motion Causes painful limitation of neck motion

and symptoms corresponding to the and symptoms corresponding to the affected nerve root(s)affected nerve root(s)

The majority of cervical herniated The majority of cervical herniated discs will catch the nerve root discs will catch the nerve root corresponding to the lower vertebral corresponding to the lower vertebral level.level. Ex: A C6/7 disc herniation will impinge Ex: A C6/7 disc herniation will impinge

upon the C7 root.upon the C7 root.

Cervical HNPCervical HNP

Just as is the case with Lumbar Just as is the case with Lumbar HNP, conservative therapy is the HNP, conservative therapy is the mainstay of treatment.mainstay of treatment.

Surgery indicated for those that Surgery indicated for those that don’t improve with conservative don’t improve with conservative management, or with management, or with new/progressive neurologic deficit.new/progressive neurologic deficit.

Cervical Spinal Cervical Spinal StenosisStenosis

Cervical Spinal Stenosis Cervical Spinal Stenosis (CSS)(CSS)

Stenosis – a constriction or Stenosis – a constriction or narrowing of a duct or passage.narrowing of a duct or passage. Cervical spinal stenosis, thus, is Cervical spinal stenosis, thus, is

narrowing of the spinal canal (within narrowing of the spinal canal (within which lies the cervical spinal cord).which lies the cervical spinal cord). This narrowing can be from any of a This narrowing can be from any of a

multitude of causes. Usually, though, this is multitude of causes. Usually, though, this is referring to more chronic types of referring to more chronic types of processes, rather than acute or sudden processes, rather than acute or sudden ones.ones.

CSSCSS

More than half of adults older than 50 More than half of adults older than 50 yrs. Will show significant degenerative yrs. Will show significant degenerative cervical spine disease on radiography cervical spine disease on radiography (CT/MRI)…(CT/MRI)… (i.e., “(i.e., “EverybodyEverybody has degenerative disc has degenerative disc

disease. And probably their dogs and cats disease. And probably their dogs and cats too.”too.”

……however, only a fraction of these however, only a fraction of these patients will actually experience any type patients will actually experience any type of significant neurological symptoms.of significant neurological symptoms.

CSS – when it causes CSS – when it causes problems…problems…

Radiculopathy – from nerve root Radiculopathy – from nerve root compression.compression. The term “radiculopathy” refers to disease of the The term “radiculopathy” refers to disease of the

nerve roots; LMN signs, pain/parasethesias.nerve roots; LMN signs, pain/parasethesias. Myelopathy – from spinal cord compression.Myelopathy – from spinal cord compression.

The term “myelopathy” refers to pathological The term “myelopathy” refers to pathological changes of the spinal cord itself.changes of the spinal cord itself.

Pain and sensory changes in the back of the Pain and sensory changes in the back of the head, neck, and shoulders.head, neck, and shoulders.

CSS - MyelopathyCSS - Myelopathy

The goal here is to avoid missing The goal here is to avoid missing patients who are myelopathic, patients who are myelopathic, because once stenosis has evolved to because once stenosis has evolved to the point that it is compressing (and the point that it is compressing (and causing damage to) the spinal cord, causing damage to) the spinal cord, the progression of symptoms may be the progression of symptoms may be variable…but it variable…but it isis going to progress. going to progress.

CSS myelopathy - HistoryCSS myelopathy - History

Some patients attribute weakness to Some patients attribute weakness to “getting old,” and because they aren’t “getting old,” and because they aren’t having neck pain (many myelopathic having neck pain (many myelopathic patients don’t), they don’t realize there’s patients don’t), they don’t realize there’s a problem that needs addressing.a problem that needs addressing. Ask about fine motor movements, like Ask about fine motor movements, like

buttoning buttons, tying shoes, signing buttoning buttons, tying shoes, signing checks, handwriting changes, using utensils, checks, handwriting changes, using utensils, etc. etc. “Clumsiness” with fine motor skills is “Clumsiness” with fine motor skills is common.common.

CSS myelopathy - CSS myelopathy - Physical ExamPhysical Exam

Hyperactive reflexes are the most Hyperactive reflexes are the most common physical exam finding in common physical exam finding in myelopathy.myelopathy. Remember the difference between Upper Remember the difference between Upper

Motor Neuron and Lower Motor Neuron Motor Neuron and Lower Motor Neuron signs.signs.

Remember symmetry – a Hoffman’s on one Remember symmetry – a Hoffman’s on one side, if not on the other, should raise a red side, if not on the other, should raise a red flag.flag.

Remember that a Babinski reflex, if present, Remember that a Babinski reflex, if present, is ALWAYS abnormal.is ALWAYS abnormal.

T2 weighted MRI, sagittal T2 weighted MRI, sagittal view; This patient has view; This patient has multilevel degenerative multilevel degenerative changes of the cervical changes of the cervical spine. The bottom two spine. The bottom two arrows show mild stenosis arrows show mild stenosis with CSF (white, fluid with CSF (white, fluid signal) still flowing around signal) still flowing around the cord. However, the top the cord. However, the top arrow is pointing to the C3/4 arrow is pointing to the C3/4 level where there is severe level where there is severe cervical spinal stenosis, no cervical spinal stenosis, no CSF around the cord CSF around the cord (compression), and signal (compression), and signal change within the spinal change within the spinal cord itself (indicating cord itself (indicating damage).damage).

SurgerySurgery

The goal of surgery is to halt the The goal of surgery is to halt the progression of myelopathy through progression of myelopathy through adequate decompression of the area(s) adequate decompression of the area(s) of stenosis. of stenosis.

Once patients are clinically Once patients are clinically myelopathic, complete return of myelopathic, complete return of function and/or remission of symptoms function and/or remission of symptoms almost never occurs.almost never occurs. This is why they need to be identified early!This is why they need to be identified early!

Clinical PearlClinical Pearl

Future anesthesiologists take note: Future anesthesiologists take note: Blood Pressure is the spinal cord’s Blood Pressure is the spinal cord’s friend! If you run these patients friend! If you run these patients hypotensive under anesthesia, they hypotensive under anesthesia, they can wake up paralyzed!can wake up paralyzed! Hypotension can induce an ischemic Hypotension can induce an ischemic

event within the cord at the area of event within the cord at the area of compression/stenosis. DON’T DO IT!compression/stenosis. DON’T DO IT!

Lumbar Spinal Lumbar Spinal StenosisStenosis

Lumbar Spinal Stenosis Lumbar Spinal Stenosis (LSS)(LSS)

Just as we discussed with Cervical Spinal Just as we discussed with Cervical Spinal Stenosis, “Lumbar Spinal Stenosis” can Stenosis, “Lumbar Spinal Stenosis” can occur secondary to anything which occur secondary to anything which narrows the lumbar spinal canal, and it narrows the lumbar spinal canal, and it can occur in conjunction with other can occur in conjunction with other conditions/diseases. But when we conditions/diseases. But when we mention it, we are usually referring to a mention it, we are usually referring to a chronic, degenerative process that chronic, degenerative process that causes spinal canal narrowing over time causes spinal canal narrowing over time (i.e. “spine aging”).(i.e. “spine aging”).

Lumbar Spinal StenosisLumbar Spinal Stenosis

Remember that the Spinal Cord ends at Remember that the Spinal Cord ends at the Conus Medullaris, which is typically the Conus Medullaris, which is typically located at the L1/2 interspace in adults.located at the L1/2 interspace in adults. L1/2 is the lumbar level least likely to be L1/2 is the lumbar level least likely to be

affected by Lumbar Spinal Stenosis.affected by Lumbar Spinal Stenosis. Thus, Lumbar Spinal Stenosis doesn’t Thus, Lumbar Spinal Stenosis doesn’t

cause myelopathy; when it affects the cause myelopathy; when it affects the motor system, lower motor neuron motor system, lower motor neuron signs are what you’ll find.signs are what you’ll find.

LSS - presentationLSS - presentation

The “classic” presentation of Lumbar The “classic” presentation of Lumbar Spinal Stenosis is Spinal Stenosis is Neurogenic Neurogenic Claudication Claudication (NC), or (NC), or “pseudoclaudication.” (~60% “pseudoclaudication.” (~60% sensitivity, but sensitivity, but >90% specificity>90% specificity).). Gradually progressive back, thigh, Gradually progressive back, thigh,

buttock, and/or leg pain that is relieved by buttock, and/or leg pain that is relieved by rest and/or, characteristically, a change in rest and/or, characteristically, a change in posture; usually through flexion at the posture; usually through flexion at the hips (sitting or squatting, etc.).hips (sitting or squatting, etc.).

Neurogenic ClaudicationNeurogenic Claudication Neurogenic ClaudicationNeurogenic Claudication is thought to is thought to

arise from compression of, irritation to, or arise from compression of, irritation to, or ischemia of the lumbosacral nerve roots.ischemia of the lumbosacral nerve roots.

This is in contrast to This is in contrast to Vascular Vascular ClaudicationClaudication (VC), which is secondary to (VC), which is secondary to insufficiency of vascular supply to meet insufficiency of vascular supply to meet demand of muscles (pain is ischemic, but demand of muscles (pain is ischemic, but from muscles).from muscles).

Differentiating between the two isn’t Differentiating between the two isn’t always easy, but you should understand always easy, but you should understand the difference!the difference!

““Anthropoid posture” Anthropoid posture” (walking bent-over (walking bent-over as though they’re as though they’re pushing a shopping pushing a shopping cart) is common in cart) is common in NC, and pain may be NC, and pain may be reproduced with reproduced with lumbar extension.lumbar extension.

Vascular Lab Studies Vascular Lab Studies may help may help differentiate between differentiate between NC and VCNC and VC Ankle-Brachial Index Ankle-Brachial Index

(ABI)(ABI) UltrasoundUltrasound

Table 14-18 adapted from Greenberg’sHandbook of Neurosurgery, 6th ed.

ManagementManagement

Unless there is severe neurological Unless there is severe neurological deficit, conservative medical deficit, conservative medical management is usually tried prior to management is usually tried prior to pursuing surgery.pursuing surgery. Pain meds, epidural steroid injections, etc.Pain meds, epidural steroid injections, etc.

If medical management is unsuccessful, If medical management is unsuccessful, surgery for Lumbar Spinal Stenosis is surgery for Lumbar Spinal Stenosis is aimed at removing the bony lamina and aimed at removing the bony lamina and soft tissue elements that are soft tissue elements that are contributing to the canal stenosis.contributing to the canal stenosis.