Spinal Pathology: Striking the right “cord” with your ...€¦ · Once you find one spinal...
Transcript of Spinal Pathology: Striking the right “cord” with your ...€¦ · Once you find one spinal...
A N D R E W D . P E R R O N , M D , F A C E P P R O F E S S O R A N D R E S I D E N C Y P R O G R A M D I R E C T O R
D E P T O F E M E R G E N C Y M E D I C I N EM A I N E M E D I C A L C E N T E R
P O R T L A N D , M E
Spinal Pathology: Striking the right “cord” with your diagnostic skills
Plan?
Where are we going ? Hx and PE Studies Bad Guys
Infection Trauma Cancer
Where aren’t we going ? AAA / Pyelo / Zoster
30 Minutes!
Back Pain in the ED: Our Job
Find the few who harbor significant pathology (look for “Red Flags”). Take a real history. Do a real examination. When you find something, go after it! Don’t get complacent…there are a few needles in that
haystack. Reassure the vast majority who don’t have
pathology
Back Pain in the ED: Fun facts
Approximately 1-5 in 100 will have a specific diagnosis
Approximately 1 in 200 will need surgery By 4 weeks, 74% will be symptom free By 3 months, 93% of patients will be
without symptoms.
The History: Search for Red Flags
Presence of even 1 red flag increases chance of finding pathology up to 10%
Age < 18: It is unusual for children / teens to complain of back pain.
Etiologies include: Congenital/Developmental abnormalities Tumor Infection Stress fractures (Spondylitis)
> 50: Subject to all the usual major diseases: Cancer AAA Compression fx Pyelo etc
The History: Search for Red Flags
Immunosuppression Fever/Chills/Night Sweats IVDA (IV Drug Abuse)
Vertebral OsteoEpidural Abscess
Unexplained Weight Loss> 10 Lbs over 3 months w/o trying
Night time pain/Pain wakes patient Bowel/Bladder Dysfunction Overflow incontinence
Trauma Usually major, with exception in elderly
Recurrent GU infections Cancer history Pain duration Pain > 4-6 weeks more concerning
The History: Search for Red Flags
Red Flags - Controversy
Maybe the importance of “red flags” is less than we think?
They are not that sensitive nor specific. Many studies disagree on which ones “count most” Trauma = old age and steroids Malignancy = Hx of cancer
Downie A et al: Red flags to screen for malignancy and fracture in patients with low back pain: systematic review. BMJ 2013;347:7095.
Underwood M et al: Red flags for back pain-A popular idea that didn’t work and should be removed from guidelines. BMJ 2013;347:7432.
Physical Exam
The very obvious statement: If you are worried about a spinal problem do enough of a neurological examination to actually find it.
“Neuro WNL” is rarely sufficient Say what you test, test what you say…if they have
5/5 delt /bi/tri/grip then say that. If they can walk / heel walk / toe walk / squat and
stand say that If you find a deficit that you can’t explain then go
after it.
Physical Examination
VS - temperature. Fever, if present can be helpful. Caveat #1: 2%-10% of pts ultimately diagnosed with
mechanical LBP will have fever on presentation from unrelated illness.
Caveat #2: Lots of items on the ddx also cause feverPyelo, pneumonia, prostatitis, diverticular dz
Sensitivity of fever varies with disease process TB = 27%Osteo = 50% SEA = 83%
Physical Examination
Focal/Point Tenderness ? Utility Not studied Kappa is terrible
Evidence of trauma Evidence for alternative diagnoses Spasm (?) Studied Kappa is horrible for agreement of presence/absence, and if
present, on which side. Johnson EW: The myth of skeletal muscle spasm. Am J Phys
Med Rehabil 1989;68:1.
Neurologic Examination
A few simple tests will rule out pathology in the vast majority.
Need to assess motor/sensory/reflexes on all
Need to assess bowel/bladder function on some. Need to ask for it in all. (rectal/saddle/etc)
Bowel/Bladder complaints
Bowel: Rectal exam for tone/squeeze Anal wink S2-4 reflex
Bladder: Check Post-Void Residual. A PVR < 100 cc’s is VERY
sensitive for ruling out bladder dysfunction. (nl = 9.5 ml., and 25th and 75th percentiles equal to 2.5 and 35.4) US formula = L x W x 6 (in CC’s)
Diagnostics: Plain X-rays
In the absence of Red Flags, plain radiographs are NOT indicated in the 1st 4-6 weeks of back pain, because the VAST majority will be asymptomatic by this time. Supported by AHRQ (Agency for Healthcare
Research & Quality) 2002
The yield for significant unexpected findings on plain films in patients with LBP and no red flags is 1 in 2500.
Liang Arch Int Med 1982
Diagnostics: Plain X-rays
This “conservative” approach has recently been reaffirmed by the National Physicians Alliance Confirms “no benefit” to early imaging in the absence of
“red flags”
Cites potential harms as
Radiation
Cost
“Patient labeling”
Identification / intervention on incidental findings
Srinivas SV: Arch Int Med 2012
Imaging strategies
2009 Meta-analysis Immediate imaging vs standard care for LBP w/o red flags Even includes immediate imaging with fancy modalities
(CT / MRI) No difference in primary outcomes- pain & function in the
short term (0-3 months) or long term (6-12 months). No difference in secondary outcomes – mental health,
quality of life, pt satisfaction. No serious diagnoses missed in those not imaged
(i.e. w/o red flags)
Chou Lancet 2009
Other Radiographs
MRI - Study of choice if: Disc/Abscess/Metastases suspected. Cauda Equina (bowel/bladder dysfunction) Ligamentous injury
CT - (+/- Myelogram) Study of Choice if: Bony Injury MRI contraindicated Recent spine surgery
What about labs?
In general, felt to be extremely unhelpful in the evaluation of back pain.
Don’t let normal lab values dissuade you from the appropriate tests if you feel they are indicated…none are sensitive enough to do so.
Leukocytosis is present in 40-50% of patients with spinal infection, and 6-10% without infections etiology. “Normal” WBC does not rule out infectious process.
ESR extremely non-specific (elevation = “something is inflamed”). CRP ?
UA can identify alternative diagnoses
Can’t Miss Back Pain Pathology
Infection Spinal Epidural Abscess
Trauma Missed spinal injuries
Cancer Metastases Primary Cancers
Spinal Epidural Abscess
Spinal Epidural Abscess
The Problem with SEA They are hard to find
They are also rare, so they are not on the radar They frequently happen to challenging patient populations
(IVDU, chronic back pain s/p surgery / instrumentation) Presentation can be subtle
Nobody has the “classic triad” of fever + back pain + neuro deficits (ok, 13% do)
They generally need a big test (MRI) to find them Time / availability
They can have a really devastating outcome 5% die Up to 20% left para/ quad
Spinal Epidural Abscess
Who gets them? S/P spinal instrumentation (epidural catheters) Paraspinal injections (steroids / analgesics) IVDU DM HIV Alcoholics Tattoos / acupuncture Infection (contiguous or remote)
2/3 have an identifiable portal of entry, 1/3 do not
Spinal Epidural Abscess
4 Stages to most SEAs (can progress over a day to months) Stage 1: Back pain
We would have to MRI every back pain every time they presented to find all stage 1 SEAs
Stage 2: Back pain + Root pain Stage 3: Back pain + root pain + motor weakness, sensory
deficit, bowel / bladder dysfunction Stage 4: Paralysis
The earlier they are found and treated, the better the outcome. You generally come out of surgery with what you went intosurgery with. Plegia > 24 hours almost never reverses.
Spinal Epidural Abscess
2/3 are due to Staph Aureus (50% MRSA)
Rest due to strep (skin), E Coli (UTI). C/T/L spine can all be affected Usually at multiple levels, and can skip areas Pathology not just due to mechanical
compression…also causes micro-vascular septic thrombophlebitis resulting in occlusion.
Spinal Epidural Abscess
So how do I not miss it? Look for red flags
IVDU, Fever, Infectious Source, Spinal Instrumentation Don’t wait for classic triad (13%) Labs
WBC is NOT helpful (40-50% with elevated wbc) ESR and CRP combined may be useful (small study) They found that if both were normal in a low risk patient they
could stop the work-up. Don’t be a testing nihilist when SEA is legitimately in the Ddx Get the right study
MRI is the right study. CT with myelography ok
Spinal Epidural Abscess
Pearls: If it is high on the differential, keep everyone MOVING (MRI,
consultants). Entropy not ok.
Pitfalls: Not thinking of the disease Inadequate hx / physical (neuro) Getting the wrong test and letting it reassure you
CBC, plain films, CT Delaying imaging Delaying ABX if they have a deficit
Vanc + Flagyl + Ceftazidime (pseudomonas) a good place to start
Trauma
Why do we miss spinal injuries?1. Failure to obtain indicated films2. Inadequate films3. Misinterpretation of the films4. Films fail to adequately visualize the injuries
My suspicion/experience: We don’t miss injuries in the super-injured andneuro deficit group (they get an everything-scan). We don’t miss them in the minor mechanism group (they don’t break their back too often). We miss them in the middle group.
Trauma
2 back pain populations that should make you pause and ask yourself “am I missing something”?
Multiple fractures
Compression fractures vs burst fractures
Trauma
Multiple fractures When I find 1 spinal fracture, what is the chance that there is
another, non-contiguous spinal fracture in this patient?
IT DEPENDS WHOYOU ASK !
Overall about 10%
Trauma
Multiple non-contiguous fractures in the asymptomatic patient?: Heterogeneous populations Heterogeneous mechanisms Heterogeneous imaging Heterogeneous fractures (type and location) Heterogeneous study methodologies
And nobody ever gets an actual careful physical exam
Trauma
Multiple non-contiguous fractures in the asymptomatic patient?: Best case scenario
Terregino et al. found that in conscious patients with a normal mental status and no distracting injuries, the absence of back pain or tenderness had a 95% negative predictive value for TLS fractures
Worst case scenario Sava et al. prospectively compared physical examination findings with
plain films in 537 patients with reliable mental status examinations and found clinical examination to be only 80% sensitive in the identification of TLS fractures.
Cooper et al. reported a review of 183 TLS fractures in patients who were neurologically intact with a Glasgow Coma Scale (GCS) score between 13 and 15. 31% of these patients were recorded as having no pain or tenderness, yet all had fractures.
Trauma
Multiple non-contiguous fractures in the asymptomatic patient?: Once you find one spinal fracture, there is SOME risk of
another non-contiguous fracture. This risk is around 10% (all comers) Asymptomatic vs distracted vs inadequate exam is in the eye of
the beholder. Safest answer is to scan all levels once you find a spinal
fracture. If you are going to rely on physical examination, do a good one,
repeat it, and document it.
Trauma
Compression fractures vs burst fx
Trauma
Compression fractures vs burst fx Fall with flexion / distraction Mid-back pain Imaging obtained Is it a simple compression (stable) or a burst (unstable)? How often are we wrong?
Trauma
Compression fractures vs burst fx
Trauma
Compression fractures vs burst fx: Need a CT to figure out
Compression vs Burst Fx
Compression is a stable 1-column injury Early mobilization PT Pain control
Burst is an unstable 2-3 column injury Majority at T12-L3 10% of the time there is more than 1 burst Loss of 50% or more of canal is a bad prognostic factor Will usually get a brace and sometimes get surgery
Cancer
The spine is a great place to get metastases (80%) or primary cancers (20%).
Presentation can be pain, neurologic dysfunction, metabolic abnormalities (High Ca), or some combination.
Cancer
Vertebral metastases are most common with solid organ cancers 90% of Prostate Ca (@ autopsy) 74% of breast Ca 45% of lung Ca 29% Renal Call + Lymphoma
Resultant spinal compression is much less common, but not rare. Lung, Breast, Multiple Myeloma most common 5-6% of patients who die from their Ca will have a spinal cord
compression syndrome while alive.
20% of patients first find out they have Ca due to back pain or compression
Cancer
Can be lytic or blastic Lytic usually indicates a more aggressive cancer (lung, renal) Blastic / sclerotic usually indicates a slower/ more indolent
process. (prostate, breast)
Once cancer cells are established in the bone, tumor cells can induce a vicious cycle of bone turnover that leads to lytic destruction of good bone and promotes the survival of malignant cells
Cancer
Vertebral column is most common metastatic site Distribution mirrors vertebral volume (e.g. thoracic = most)
Nighttime pain (“red flag”) is the most common symptom. Pain is frequently described as being relieved by activity.
Pain can be local, diffuse, radicular With cord compression, 90% will report a prodrome
of pain (average = 7 weeks of pain before compression sx).
Cancer: Diagnosis
If you are looking for the possibility of metastatic / primary spine tumor, then MRI is the study of choice. Need to image whole spine. 20-30% will have multiple silent
metastases in addition to the index lesion.
If you need to know bony structural integrity, then CT is the study of choice. Mostly involved in surgical planning / prognostication
Cancer: Treatment
Cord compression from Ca is an emergency If I think they have it, they get 10mg IV Decadron before they
go to MRI
Get them a radiation oncologist and a surgeon Radiation can reduce tumor size and decrease cord
compression with many tumors Occasionally they need surgical debulking or stabilization
Wrap-Up
Most back pain is not an emergency…occasionally it is
Know the at-risk populations Know the red flags Know how to do an adequate neurological
examination Get the right test Call the right consultant Keep everyone moving forward
Questions?