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Cervical and low back pain and radiculopathy
Cervical and low back pain and radiculopathy
Jenice Robinson, MD
Assistant Professor of Neurology
Penn State College of Medicine
NBS725 January 12, 2009
Jenice Robinson, MD
Assistant Professor of Neurology
Penn State College of Medicine
NBS725 January 12, 2009
Learning Objectives:After reviewing the content of the lecture, the student will be able to:1) Distinguish somatic and radicular neck and low back pain by mechanism of
pain and by associated clinical symptoms and signs2) Describe the anatomy of the ventral and dorsal nerve roots, the location of
the cell bodies in the ventral horn and dorsal root ganglia, and the formation of the spinal nerves
3) List common symptoms and signs of cervical and lumbosacral disk herniation causing nerve root compression
4) Draw the anatomy of the nerve roots at the L4-L5 and L5-S1 levels and demonstrate how a disk herniation at these levels may compress the nerve roots
5) Describe diagnostic imaging methods for use to evaluate radicular pain6) Describe basic treatment of radiculopathy caused by disc herniation7) List ‘red flags’ in the evaluation of neck and low back pain indicating
increased risk for a possible serious underlying cause of the pain
Back and neck pain:• Very common• Up to 50% of working
adults have had a back injury in the past year
• Back symptoms most common cause of disability in patients <45
• Neck pain also very common
• Societal cost of back pain estimated to be > $20 billion dollars per year
Somatic pain:
• Most cervical and low back pain fall into the category of somatic pain
• Somatic pain arises from the stimulation of A (small myelinated) and C (unmyelinated) nociceptive nerve endings– Activation can be chemical via tissue damage – Direct mechanical stimulation
Pain sensitive structures:
• Muscles• Ligaments
Pain sensitive structures:
• Muscles• Ligaments• Facet joints
(zygapophyseal)• Dura mater• Intravertebral discs:
annulus fibrosis• Epidural veins
Somatic pain:• Aching/expanding pressure• Felt locally in area of injury, but also my be
referred to other areas• Referred to areas innervated by the same
spinal cord segment• Mechanism is convergence in spinal cord
and thalamus– Afferents from the primary source of pain
converge with afferents from the site of referral
Referred pain from stimulation of zygapophyseal joints
Somatic pain: Summary• Aching/pressure quality• Occurs in broad areas reflecting areas of
referral from the same spinal segment, severe could radiate to limbs
• Otherwise known as back strain and etc.• Does NOT:
– Travel in bands– Have a lancinating or electric shock quality– Have associated neurologic signs on
examination
Radicular pain:
• Less common than somatic pain• The hallmark of radiculopathy, any
pathologic condition affecting the nerve roots
• Arises from the nerve roots or dorsal root ganglia
• Herniated disk is by far the most common cause
Radicular pain:• Inflammation is important as a pain
mechanism:– Phospholipase A and E, NO, TNF, other
pro-inflammatory mediators are released by a herniated disk
– The dura surrounding the ventral and dorsal nerve root is bathed in this exudate
– Inflammation or prior injury to nerve root is necessary to cause compression to generate continued pain
dura
Radicular pain:• Lancinating or electric quality• Moves in bands and usually radiates down
the limbs• Associated symptoms of paresthesias are
very helpful determining the identity of the involved nerve root better than site of pain
• Symptoms of weakness and objective findings of sensory loss, weakness and reflex loss may occur
Dermatome
• Each nerve root supplies cutaneous sensation to a specific area of skin, known as a dermatome
Overlaps somewhat, so won’t loseAll sensation, but will feel paresthesia
Myotome
• If radicular pain sever could affect myotome
• Each nerve root supplies motor innervation to certain muscles,
known as a myotome
Types of peripheral nerve injury:• Neurapraxia: Segmental loss of myelin
coating on nerve root/nerve– Weakness, but no atrophy
• Axonotmesis: Loss of axons and myelin but at least some supporting structures are preserved– Weakness and muscle atrophy if severe
• Neurotmesis: Loss of axons, myelin, and complete disruption of supporting structures (transection) weakness and atrophy
Radiculopathy: Summary• Pain and paresthesias radiating in the
distribution of a nerve root, often associated with sensory loss and paraspinal muscle spasm
• Sensory loss (often vague or ill defined)
• Weakness (often subjective, not present, or mild)
• Reflex loss (may be present or absent)
Radiculopathy: Provocative maneuvers
• Valsalva– Cough, laughter, voluntary contraction of abdominal wall
muscles, when straining, make radicular pain worse
• Stretching the involved nerve root—L1S1—sitting worsens, C5C6—abduct arm over head relieves
• Straight leg raise—L5L6 worsens
Reflexes:
• C5-C6 Biceps• C5-C6 Brachioradialis• C7 Triceps• L3-L4
Quadriceps/patellar• S1 Ankle
60s—no ankle jerks—could be normal if on both sides, but if only on one side With pertinent symptoms on that side--significant
• In the cervical spine:– Nerve roots exit above
their named vertebral body– I.e., C7 exits below C6 and
above C7-so lateral disk herniation here gets C7
• In the lumbar spine:– Spinal cord ends at L1 or
L2– Nerve roots travel long
distances then exit below their named vertebral body
– The lumbosacral nerve roots are susceptible to injury at multiple locations
– T11-L1—anterior horn
• L4-L5 lateral disk herniation– Usually will compress the
L5 nerve root
• L5-S1 lateral disk herniation– Usually will compress the
S1 nerve root
• These are the general rules and anatomy to remember for the cervical and lumbosacral spine…
But in the LS spine there are exceptions!
Large disk herniation, far lateral,
Nerve roots
Cauda equina and conus medullaris syndromes:
Severe radiating pay, L4L5 lvl herniated midline, all nerve roots are pinched
Cauda equina and conus medullaris syndromes:
• Large midline disk herniation can cause symptoms in both legs in the distribution of multiple nerve roots, bilateral, large full bladder– Cauda equina syndrome:
• multiple nerve roots bilaterally are affected below the end of the spinal cord at L1-2
– Conus medullaris syndrome: • the end of the spinal cord from about T11-L1
Cauda equina and conus medullaris syndromes:
• Both are potentially surgical emergencies depending on the cause
• Warning signs that one of these may be present are: – Rapidly progressive bilateral lower extremity
weakness– Saddle anesthesia– Loss of ability to urinate voluntarily with a large
bladder and overflow incontinence– Loss of rectal tone
Cauda equina and conus medullaris
• Differentiating the two is difficult, and they may coexist:– Cauda equina: More pain, asymmetric at onset, bladder
dysfunction not initially as severe– Conus medullaris: Often little pain, symmetric at onset,
severe bladder dysfunction
• Key points: – Emergent imaging with MRI is essential – Make sure to image high enough to see the full conus! To
at least T10
Root Pain (*less reliable for localization)
Paresthesias/Numbness (*more reliable for localization)
Weakness Reflex loss
L2 Groin Anterolateral thigh Hip flexion None L3 Anterior thigh
to knee Medial thigh and knee Hip flexion
and adduction, knee extension
Quadriceps
L4 Anterior thigh to medial leg
Medial leg to medial ankle
Hip adduction, knee extension, foot dorsiflexion
Quadriceps
L5 Lateral thigh and leg to dorsum of foot
Lateral leg, dorsum of foot and great toe
Hip abductors, ankle inversion, eversion, foot and toe dorsiflexion
None
S1 Posterior thigh, calf and heel
Sole and lateral foot and ankle, lateral 2 toes
Hip extension, knee flexion, foot plantarflexion and toe flexion
Ankle
Summary: Neurologic features of LS radiculopathy
Summary: Neurologic features of cervical radiculopathy
C7 most common
Radiculopathy: Etiology besides herniate disk which is most
common
• Structural– Disk (MC)– Spondylosis (degenerative changes)– Tumor (mass lesion)– Abscess– Hematoma
Radiculopathy: Etiology
• Non-structural, or infiltrative– Tumor (carcinomatous or lymphomatous
meningitis)– Granulomatous tissue (e.g., sarcoid)– Infection (e.g., Lyme disease, herpes zoster,
cytomegalovirus, herpes simplex). – Acute inflammatory demyelinating neuropathy– Infarction
• Vasculitic neuropathy• Diabetic polyradiculopathy
Severe radicular pain in All extermities, lime diseaseWhite over everything
Differential diagnosis of radiculopathy:
• I do not expect you to know these next two slides in detail, however, please be familiar with the concepts
• Radiculopathy always must be distinguished from other peripheral nerve or plexus problems
• Root lesion (radiculopathy) vs plexus lesion– C5/6 vs Upper trunk– C8 vs Lower trunk– L3/4 vs Lumbar plexus– L5/S1 vs Sacral plexus
Differential diagnosis of radiculopathy:
• Root lesion (radiculopathy) vs entrapment neuropathy– C6/7 vs carpal tunnel syndrome (med. n. at wrist)– C8 vs ulnar neuropathy at the elbow– L3/4 vs femoral neuropathy– L5 vs peroneal n. at the fibular neck
• Bilateral L5-S1 radiculopathy vs early peripheral polyneuropathy
• Could be appropriate by EMG/NSV
Imaging: Indications
• Somatic back and neck pain:– Often not helpful and not indicated unless
the patient has risk factors for a serious underlying cause of back pain
• Incidence of spine abnormalities such as disk bulges/minor herniations is about 25-50% in asymptomatic people!
• Current techniques are not helpful in identifying the source of the somatic pain
Imaging: Indications
• Imaging is appropriate in the following patients:– Trauma– Risk factors for serious underlying etiology – Symptoms present for >4 weeks– Neurologic deficit
Imaging: Modalities
• X-rays: most useful in trauma to exclude fracture, not sensitive for nerve root or spinal cord pathology
• CT: most useful study for bony anatomy• MRI: most useful study for imaging disk, nerve
root and spinal cord pathology– Contrast is used if patient has had prior spine surgery in
the affected area b/c can light up scar tissue, or if tumor, infection, or other inflammatory etiology is suspected
• CT myelogram, CT/w dye injected into spine: in patients who cannot obtain MRI, often the best study for imaging the nerve roots of a selected area
‘Red flags’:• Risk factors for a possible serious underlying cause of low back or neck pain include (b/c <1% of ppl with neck/back pain have underlying etiology except these):– Age >50 years– Prior diagnosis of cancer
• Lung, breast, colon, prostate, lymphoma, renal cancers especially– History of serious medical condition (i.e., AIDS, TB, artificial heart valve,
severe COPD, etc.)– Use of glucocorticosteroids – Chronic/frequent pulmonary or urinary infections– History of intravenous drug use– Duration of pain > 1 month– Urinary or bowel urgency or incontinence
• Risk factors for a possible serious underlying cause of low back pain additionally include:– Pain is worsened or not improved by lying down
• Signs associated with a potentially serious etiology of low back or neck pain:– Unexplained weight loss– Percussion tenderness over the spine– Rapidly progressive neurologic deficit
Treatment of radiculopathy:• Natural history of lumbosacral and cervical
radiculopathy:– Up to 75% spontaneously improve– Length of time required for improvement may
be several weeks or up to years!
• If there is a progressive neurologic deficit or intractable pain, surgical referral is appropriate
• Otherwise, most patients can avoid surgery
Empiric treatment of radiculopathy:
• Medications:– Pain control with NSAIDS and narcotic
medications as necessary– Short course of corticosteroids in selected
patients; justification is to decrease inflammation around the nerve root
Empiric treatment of radiculopathy:
• Gentle physical therapy (mobilization and stretching)
• Bed rest• TENS unit, heating pads, ultrasound,
gentle massage• Traction for the cervical spine• Epidural steroid injections for the LS spine
– Risks are higher in cervical spine
• Transforaminal steroid injections for the LS spine