Sciatica: When to image. When to refer.

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Sciatica When to image. When to refer.

• Juanita Halls M.D.
• Internal Medicine
• October 10, 2007

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• No financial disclosures

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Objectives

• Understand when to perform imaging on patients
  presenting with sciatica
• Understand when to refer patients with sciatica
  to a spine surgeon

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Case 1

• 58 yo healthy female presents January, 2007 with
  6 week history of achy LBP, RgtL with episodes of
  pain shooting down back of thighs to calves and
  occasional numbness in foot
• No preceding injury, heavy lifting, etc
• No weakness, bladder or bowel dysfn
• No systemic sx e.g. fever/sweats/weight loss

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PMH

• Hypertension on lisinopril/HCTZ
• s/p hysterectomy
• Takes MVI and Calcium/vitamin D
• Otherwise healthy, non-smoker
• Screening
• Routine PE 10/06
• mammogram 10/05, ordered 10/06 but not done
• Flex sig negative 1999, FOBT negative 10/06
  (colonoscopy not covered by insurance)

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Exam

• No spinal tenderness or deformity
• Mild decrease extension with pain
• Mild decrease flexion without pain
• Positive SLR bilaterally at 60o
• DTR 2 knee and 1 ankle bilaterally
• Motor 5/5 in LE
• Sensory Intact

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Imaging

• L/S spine films multilevel degenerative disk
  and joint disease
• No labs done

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Dx/ Rx

• Sciatica with no worrisome symptoms and negative
  spine X-ray
• Home exercises
• PT referral
• Ice or heat
• No lifting
• Naproxen and Tylenol 3
• RTC 2 months, sooner if not improving

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2 months later

• Had cancelled PT because pain resolved with home
  exercises and Naproxen
• Now 3 week history of increased right sided LBP
  radiating to right foot
• Paresthesia of right ankle
• No weakness or bladder/bowel dysfn
• ? with sitting and at night

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Exam

• No spinal tenderness
• SLR negative on left, positive at 60o on right
• DTR symmetrical
• Motor 5/5

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Plan

• MRI offered but patient declined
• Diclofenac (was having side effects with
  naproxen)
• PT referral
• Spine clinic referral

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4 weeks later (3 months after initial
presentation)

• Seen in Spine clinic
• Pain had gotten better, now worse again and
  interfering with sleep
• No systemic symptoms
• Exam
• No change except minimal tenderness
• Positive SLR/Lasegue maneuver
• DX Probable HNP
• Plan MRI

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2 Weeks later(3 ½ months after presentation)

• MRI competed and I am paged by the Spine clinic
  physician late Friday afternoon

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MRI case 1
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MRI Case 1
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MRI reading

• Large osseous mass involving right iliac wing and
  central and right portions of S1 and S2 vertebra
  with soft tissue extension obliterating right L5,
  S1 and S2 neural foramen.
• Second osseous mass in body of T12
• Most likely represents metastatic disease

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10 days later

• CT guided biopsy
• Large B cell lymphoma

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Low Back Pain

• Low back pain
• 84 of adults experience LBP
• 2.5 of medical visits
• Total cost in US 100 Billion per year
• lt5 have serious pathology
• 5 have sciatica
• Annual incidence of sciatica is 5 per 1000

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Definition of sciatica

• Pain, numbness, tingling in distribution of
  sciatic nerve
• Radiation down posterior or lateral leg to foot
  or ankle
• If radiation below knee more likely
  radiculopathy with impingement of nerve root

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Etiology of sciatica

• Mechanical
• Pyriformis syndrome
• HNP
• Spondylolisthesis
• Compression fracture
• Neoplastic (0.7 of LBP)
• Infectious (0.01 of LBP)

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Questions to ask

• Is there evidence of systemic disease?
• Is there evidence of neurological compromise?

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Clues on history to suggest systemic disease

• Hx of cancer No
• Age gt 50 Yes
• Unexplained weight loss No
• Duration gt 1 month Yes
• Night time pain Yes
• Unresponsive to conservative rx /-
• Pain not relieved by lying down /-

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Exam

• Back exam
• ROM
• Palpate for tenderness
• SLR
• Neuro exam
• If suspicious history
• Breast or prostate exam
• Lymph node exam

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Testing for lumbar nerve root compromise
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Straight leg raising

• Passive lifting of the leg with the knee extended
  produces pain radiating down the posterior or
  lateral aspect of the leg, distal to the knee and
  usually into the foot.
• Dorsiflexion of the foot (Lasegue's test) will
  exacerbate these symptoms

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SLR with Lasegue test
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LR
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Imaging indications

• Progression of neurological findings
• Constitutional symptoms
• Hx of traumatic onset
• Hx of malignancy
• lt18 or gt 50
• Infection risk (IVDU, immunocompromise, fever)
• Osteoporosis

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Imaging L/S spine films

• If risk factor or no better in 4-6 weeks
• May be able to detect
• Tumor (sensitivity 60)
• Infection (sensitivity 82)
• Spondyloarthropathy
• Spondylolisthesis
• Also consider Labs ESR and/or CRP if risk for
  infection
• If negative conservative rx for 4-6 weeks

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Imaging - MRI

• If progressive neurological deficit, high
  suspicion of cancer or infection, or 12 weeks of
  persistent pain
• May be able to detect
• Tumor (sensitivity 83-93)
• Infection (sensitivity 96)
• HNP (sensitivity 60-100)
• Spinal stenosis (sensitivity 90)

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Malignancy and sciatica

• O.7 of LBP due to malignancy
• Non-Hodgkins lymphoma
• 10 have CNS involvement
• Sciatica is uncommon and occurs late
• Very rare for sciatica to be presenting feature

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Case 2

• 49 yo healthy female presents February, 2007 with
  recurrent LBP radiating to right buttock and
  shooting to posterior thigh and lateral calf.
• Numbness of bottom of foot
• No weakness, bladder or bowel dysfn
• No systemic sx e.g. fever/sweats/weight loss
• ? prolonged sitting, getting up, bending
• ? walking, lying down

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Previous history

• 4 months previous had ER visit for acute LBP
  radiating to right buttock after bending over in
  Yoga class and treated with PT and pain meds
• 2 months previous after 6-7 PT sessions reported
  much better
• PMH No meds, non-smoker

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Exam

• DTRs 2 at knee and ankle
• Motor 5/5 in LE
• No spinal tenderness
• SLR negative bilaterally

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Treatment

• PT
• If not improving, get MRI and/or refer to spine
  clinic

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5 weeks later

• No better and MRI ordered and referred to spine
  clinic

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(No Transcript)
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MRI Case 2
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MRI Case 2
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MRI reading

• L5-S1 disk protrusion contacting right S1 nerve
  root

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Spine clinic visit next day

• Hx same plus pain increases with cough/sneeze
• Exam
• Tender inferior to right piriformis muscle
• ? sensation to light touch right S1, PP normal
• DTR 2 knees and left ankle, 1 right ankle
• Negative SLR
• Prone press up pain in buttock
• Dx Radiculopathy with HNP L5-S1

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Spine clinic treatment

• Right S1 diagnostic and therapeutic
  transforaminal steroid injection
• PT and/or chiropracter
• Oxycodone
• Neurontin

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8 weeks later (3 months after initial
presentation)

• s/p 2 injections, PT, Chiropracter
• Still severe pain and now weakness right leg with
  stairs
• Referred to spine surgeon

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Spine surgeon

• Exam
• SLR positive/ Lasegue positive on right
• DTR 1 left ankle 0 right ankle
• You should have been here within 6 weeks of
  onset of sciatica symptoms
• Recommends L5-S1 microdiskectomy
• Outpatient procedure with epidural
• 95 get relief of pain
• 3 risk of re-herniation

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When to refer to spine surgeon

• Cauda equina syndrome
• Neuro motor deficit
• Persistent severe sciatica after conservative
  treatment

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Timing of referral for diskectomy

• Optimal timing is not clear
• No consensus on how long conservative treatment
  should be tried
• Sciatica improves within 3 months in 75 of
  patients (95 at one year)

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Surgery vs Prolonged Conservative Treatment for
Sciatica

• Peul, et al NEJM May 31, 2007
• 283 patients with 6-12 wk of severe sciatica and
  HNP on MRI
• Randomized to
• early surgery (microdiskectomey) vs
• conservative therapy with surgery if needed
• Primary outcomes
• Subjective pain and disability scores
• Perceived recovery

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Outcomes of study

• Surgery grp 89 surgery at mean 2.2 weeks
• Conservative grp 36 surgery at mean 4½
  months
• At 1 year no difference in pain or disability
  score or perceived recovery (95 in both grps)
• Pain relief and perceived recovery faster in
  surgery group
• Median time to full recovery 4 vs 12 weeks
• Max difference in pain score lt20 mm on 100 mm
  scale

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Peul, et al. New Engl J Med, 20073562245-56
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Peul, et al. New Engl J Med, 20073562245-56
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Peul, et al. New Engl J Med, 20073562245-56
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Conclusions of study

• Advantage of early surgery is faster relief of
  pain and faster perceived recovery time
• Not blinded study (patient expectation bias)
• Did not look at any objective outcomes e.g. days
  of work lost

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SPORT studySurgical vs Nonoperative Treatment
for Lumbar Disk Herniation

• Weinstein, et al JAMA November, 2006
• 501 pts with radiculopathy and HNP for at least 6
  weeks
• Open diskectomy vs conservative rx
• Surgery grp 60 (50 within 3 months)
• Conserv grp 45 (30 within 3 months)
• No difference in subjective pain and disability
  scores

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BOTTOM LINE

• Risk of serious problem (e.g. cauda equina,
  neurological deterioration) is very small so most
  patients do not need urgent surgery
• Main benefit of surgery is faster perceived
  recovery and resolution of disabling pain
• No data on days of lost productivity
• No other strong reason to advocate for surgery
  except patient preference

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Bottom line

• Offer surgery to patients who
• Not able to cope with the pain
• Find natural course of recovery to slow
• Want to minimize time to recovery from pain
• Questions for patient
• How badly do you feel?
• How urgently do you wish to achieve relief at
  cost of having surgery?

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Follow up Case 1

• Treated with CHOP plus Ritoxan
• s/p 6 cycles
• PET and CT scans pending

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Follow up Case 2

• 4 months s/p microdiskectomy
• Back to work one month after surgery and doing
  well

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References

1. Jarvik, JG and Deyo, RA. Diagnostic evaluation
   of low back pain with emphasis on imaging. Ann
   Intern Med.2002137586-597.
2. Stadnik, et al. Annular tears and disk
   herniation Prevalence and contrast enhancement
   on MR images in the absence of low back pain or
   sciatica. Radiology 199820649-55.
3. ONeill, et al. Sciatica caused by isolated
   non-Hodgkin's lymphoma of the spinal epidural
   space A report of two cases. Br J Rheum
   199130385-86.
4. Peul, et al. Surgery versus prolonged
   conservative treatment for sciatica. N Engl J
   Med 20073562245-56.
5. Weinstein, et al. Surgical vs nonoperative
   treatment for lumbar disk herniation. SPORT
   trial. JAMA 20062962441-50.