Back Pain. John W. Engstrom, MD December 16, Disclosures. A Clinical Approach to the Evaluation of Back Pain and Lumbar Radiculopathy

Transcription

1 Disclosures Nothing to declare --- or --- Significant ownership interests Speaker bureaus, honorarium, grants A Clinical Approach to the Evaluation of and Lumbar Radiculopathy John Engstrom, MD Acute Low : Importance/Defn Goals Annual Cost = $100 billion Most common cause of disability under 45 years 1% of population disabled from back pain Acute Low (ALBP)-Back pain < 12 weeks in duration Practical evaluation steps before the diagnosis is clear Objectives Know the risk factors by history and exam for serious causes of acute LBP Know how to use physical exam findings SLR/RSLR, Patrick s, heel percussion signs, palpation tenderness over spine Reflex, motor, sensory findings for L4- S1 radiculopathy LBP: Use of History and Examination Urgent vs. non-urgent cause Rational approach to initial patient management Stratify patients using historical and examination risk factor profiles Acute LBP: Risk Factors for Urgent Management- History Pain worse at rest or at night Prior history of cancer History of chronic infection History of trauma Age > 70 years Intravenous drug use Corticosteroid use History of rapidly progressive neurologic deficit 1

2 Acute LBP: Risk Factors for Urgent Management-Examination Unexplained, documented fever Unexplained, documented weight loss Percussion/palpation p tenderness over spine Abdominal, rectal, or pelvic mass Patrick s sign or heel percussion sign Straight-leg or reverse straight-leg raising signs Rapidly progressive focal neurologic deficit ALBP Requiring Urgent Management Tumors-metastatic most common Hx-rest/nocturnal pain, prior cancer, or focal neuro symptoms Ex-weight loss, fever, palp tenderness over spine, adenopathy, abdominal/pelvic/ rectal mass, or focal neurologic deficit Infection-osteomyelitis or epidural abscess Chronic bacteremia-lung, skin, urine, dental Hx- IV drug use, steroid use, or focal neurologic deficit Ex- fever, weight loss, or palp tenderness over spine, or focal neurologic deficit ALBP Requiring Urgent Management Trauma/fracture-context is key -History of trauma, osteoporosis, steroid use, severe focal back pain -Ex-Palpation tenderness over the spine, focal neurologic deficit Any acute or subacute progressive neurologic deficit in the setting of back or neck pain should trigger consultation with a neurosurgeon, neurologist, or orthopedic surgeon Acute LBP-Natural History/Treatment 85-90% back to functional baseline in 12 weeks; prognosis is outstanding! Treat symptoms Simple analgesics-nsaids or acetaminophen for pain Limited bed rest; progressive ambulation Muscle relaxants if back pain interferes with sleep Reassurance Low Back/Buttock Pain: Patrick s/heel Percussion Signs Patrick s Sign - Hip or buttock pain elicited by internal rotation of the hip with flexion of the leg at the knee Heel percussion - Leg extended at knee, heel percussion elicits hip/buttock pain LBP: Stretch Signs Straight-leg raising Traction on the L5 or S1 roots, or sciatic nerve (all posterior to hip) Sign must reproduce patient s usual symptoms Reverse straight-leg raising Traction on the L2-L4 roots or femoral nerve (all anterior to hip) Sign must reproduce patient s usual symptoms 2

3 Initial Approach to Acute LBP Algorithm 2 - Suspected Serious Etiology Risk factors present Acute LBP 1 Fracture Cancer Infection Rapidly progressive neurologic deficit Risks for Serious Source? Yes No Plain X-ray/CT ESR, CBC, consider consultation, imaging, other lab Immediate consultation Consider infection, tumor, fracture Symptomatic Rx x 3 months No Diagnostic Tests 1 Pain < 3 months duration Lumbosacral (L/S) Radiculopathy - Neurologic Findings (90%-L4, L5, S1) Root Motor Reflex Sensory Pain Distribution* L4 Quadriceps Knee Medial calf Medial calf (knee extension) L5 Peronei (foot evers) None Lateral calf, Lateral calf, post thigh Tibialis ant (foot dorsiflex) Dorsal foot dorsal foot Ext Hallucis (toe dorsiflex) S1 Abductor hallucis Ankle Sole foot Posterior thigh/calf (toe flexors) Sole foot * Least helpful, but most common L/S Radiculopathy-Motor Quadriceps-femoral, L4, anterior horn cells -Position leg in slight flexion at the knee, then have patient extend the leg at the knee Peronei/TA/EHL-peroneal nerve, sciatic nerve, L5 root, anterior horn cells -Dorsiflex foot (TA) at ankle -Great toe extension (EHL) -Eversion of the foot (peroneii) L/S Radiculopathy-Motor Toe Flexors-tibial nerve, sciatic nerve, S1 nerve root, anterior horn cells Tip-Overcome flexion of toes with fingers-do not test the big toe; do not test foot plantar flexion Tip-Use smallest bulk muscle to test nerve root of interest! Tip-Distinguish upper motor neuron weakness from L5 radiculopathy (spasticity, Inc reflexes) L/S Radiculopathy-Sensory Decreased sensation (negative sensory symptoms) indicates a decrease in sensory function Paresthesias/pain (positive sensory symptoms) reflect alive nerve cells firing inappropriately Elicit either a decrease in quantity or quality of sensation (decrease = loss of sensory axons) Compare light touch from side-to-side Sensation scale (0 to 10; 0=None, 10 = normal) 3

4 L/S Radiculopathy-Sensory Medial calf-saphenous, femoral, L4 Lateral calf or dorsal foot-superficial peroneal, sciatic, L5 Sole foot-tibial, sciatic, S1 Sensory loss from nerve or nerve root injury occurs in a patch Circumferential loss below the knees suggests spinal cord or brain lesion, or polyneuropathy L/S Radiculopathy-Reflexes Symmetry of the reflex is more important than absolute value (3+ throughout vs. right 3/left 2) Limbs in analagous positions to compare sides If you can t get a reflex, add stretch to the tendon and reinforcement L4-sitting or supine, knees bent if supine L5-+/- reflex, can check medial hams-symmetric? S1-strike Achilles or ball of foot with leg at rest Disk Herniation: Surgical Indications -Intractable Pain The most common and most controversial -Spinal cord compression (C/T-spine) -Cauda equina syndrome -Progressive motor weakness by exam, but define progressive and define weakness Natural History of Acute Disk-Related Radiculopathy Weber (1983)- If deficit and pain tolerable while waiting, spontaneous recovery common Saal (1989)-Focal motor deficits improve with time/rehab; pain improves over time, but not as fast as with surgery Bottom Line: If patient can function with the pain, then the long term outcome is about the same with and without surgery Acute Disk Herniation and Nerve Root Injury: Compression or Inflammation? Usually Not Compression - Mobile nerve roots - Nerve roots move during lumbar puncture - Gelatinous nucleus pulposus - Favorable response to steroids Evidence for Inflammation: Epidural nucleus pulposis inflammation demyelination FP 24 yo man with LBP at night Previously healthy man was awakened from sleep by new back pain in mid-june 2010 ER evaluation-pain meds sent home ER evaluation pain meds, sent home Persistent, right low back 2 more ER visits-symptom management Primary care MD-fluctuating weakness in office 4

5 Q1: This patient was in a low risk group for serious spine pathology until his primary care physician found weakness. A) True B) False FP-More information Meds: ibuprofen, diazepam, oxycodone, R lumbar paraspinal palpation tenderness MS/CN normal Slow R foot taps; weak R hams, TA, EHL Reflexes 3+ legs, 2+ arms No sensory deficit or level to pin/light touch Q2: Localization of exam findings best fits which of the following? A) Lesion at or proximal to the lumbar cord B) Lesion at or proximal to the cervical cord C) Lesion at or proximal to the thoracic cord D) Lesion in the thalamus E) Lesion in the cortex Spinal Cord Lesions Motor Level UMN weakness legs sparing arms and face Rostral to lumbar cord Parasagittal brain, thoracic or cervical cord Parasagittal brain, thoracic or cervical cord UMN weakness of legs and arms sparing face Rostral to C5 cervical cord Caudal to brainstem UMN weakness face, arms, and legs Rostral to medulla 5

6 FP-More Clinical Information Spine MRI-subacute epidural hematoma at T9-10; no vascular anomaly or mass Recommend follow-up imaging to exclude a vascular anomaly Patient develops new urinary retention while in the hospital Nsurg- No big deal. They all get better. Q3: What is your next step? a) Continue and increase the ibuprofen b) Surgical evacuation of the hematoma c) Spinal angiography d) Observation for further deterioration Spontan spinal epidural hematoma (SSEH)-Evacuate or not evacuate? 13 children w hemophilia conservatively Rx had complete resolution of neuro deficits 17 adults SSEH: severity of neuro deficit and coagulopathy predicted poor prognosis A vascular cause of acute radiculopathy Spinal cord compression w epidural tumor- only 2-6% recover ambulation after developing incontinence Take Home Points Use back pain history + exam risk factors to guide initial assessment and management Know the distribution of motor, sensory, and reflex findings for L4, L5, and S1 nerved root injury Think of back pain risk factors like cardiac risk factorsrisk is elevated with each, but urgent spine disease is not guaranteed using risk factors alone Back pain that is new or worse at rest is bad 6

7 7