Epidural Abscess: Red Flag Findings

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Red Flag Findings for Epidural Abscess

• Fecal incontinence or loss of bowel control
• Urinary retention or loss of bladder control
• Saddle anesthesia
• Unexplained fever
• Unexplained weight loss
• Focal neurological deficit, progressive or disabling symptoms
• No improvement after 6 weeks of conservative management
• Immunosuppression, recent infection, chronic steroid use, osteoporosis, significant trauma, or history of cancer

Diagnostic Accuracy of Individual Red Flag Findings

• Age > 50 years: sensitivity 74%, LR+ 1.1, LR- 0.79
• Recent loss of bladder control: sensitivity 22.2%, LR+ 2.31, LR- 0.86
• Recent loss of bowel control: sensitivity 13.9%, LR+ 2.78, LR- 0.91
• Unexplained weight loss: sensitivity 8.2%, LR+ 1.87, LR- 0.96
• Personal history of cancer: sensitivity 32%, LR+ 7.25, LR- 0.71
• Fever, chills, or sweating: sensitivity 11.7%, LR+ 1.71, LR- 0.95
• Recent infection: sensitivity 24.2%, LR+ 9.31, LR- 0.78

Diagnostic Accuracy of Combined Red Flag Findings

• Trauma + Age > 50 years: sensitivity 14.8%, LR+ 2.54, LR- 0.90
• Trauma + Age > 70 years: sensitivity 5.2%, LR+ 4.35, LR- 0.96
• Recent loss of bowel + bladder control: sensitivity 8.3%, LR+ 3.0, LR- 0.94
• Unexplained weight loss + personal history of cancer: sensitivity 2.5%, LR+ 10.25, LR- 0.98
• Fever, chills, or sweating + recent infection: sensitivity 7.5%, LR+ 13.15, LR- 0.93

Cauda Equina Syndrome

• Compression and disruption of function to cauda equina (L3-L5 nerve roots)
• Classical symptoms: new urinary retention or overflow incontinence, fecal incontinence, progressive motor or sensory loss, saddle anesthesia, lower motor neuron weakness, and significant deficits that encompass multiple nerve roots
• Diagnosis: imaging (MRI) is diagnostic gold standard
• Urgent ER referral; requires surgical decompression within 24-48 hours

Spinal Malignancy: Metastases

• Most common tumors of the spine are metastases of other primary cancers (breast, lung, prostate, renal, gastrointestinal, and thyroid)
• Personal history of cancer, back pain, unexplained weight loss, possibly sensory loss, weakness, or radiculopathy
• Diagnosis: imaging (x-ray or MRI) and blood work (incl CBC) and symptoms depend on type of primary cancer
• Urgent referral back to oncologist or palliative care

Vertebral Fracture

• A break in one or more spinal vertebrae that can result from trauma and metastatic disease but, in most cases, are the result of osteoporosis (at T11-L2)
• Low bone density, female > 50 years, prolonged use of corticosteroids, trauma/fall, personal history of vertebral fracture
• Back pain (acute or chronic, localized)

LBP with Radiculopathy: Epidemiology

• Lumbosacral radiculopathy is common: 3-5% of population
• Male > 40 years, female > 50 years, 3:2
• L5 radiculopathy is the single most common lumbar radiculopathy

LBP with Radiculopathy: Risk Factors

• Social history: repetitive lifting and twisting motions, chronic overloading of disc, driving occupations, heavy industry work, military, smoking, overweight, sedentary
• Medical history: prior trauma, multiple pregnancies, history of back pain, chronic cough

LBP with Radiculopathy: History Intake

• Site: ask about the location of the back pain
• Onset: how and when the back pain developed
• Quality: pain is often described as throbbing, aching, sharp, dull, burning, pressure, numbness, tingling, or shooting
• Radiation: assess dermatomal distribution
• Time course: consider how the back pain changed over time
• Severity of pain experience: scale of 1-10
• Pain is typically worse with: increased intradiscal pressure, Valsalva, weight bearing, standing, walking, sitting for prolonged periods
• Pain is typically better with: extension of the lumbar spine, recumbent position (knees flexed)
• Associated signs and symptoms: motor or sensory disturbances, suggestive of nerve root or spinal cord compression

Physical Exam Findings associated with Lumbar Disc Herniation

• Weak ankle dorsiflexion: sensitivity 54%, LR+ 4.9, LR- 0.5
• Calf wasting: sensitivity 29%, LR+ 5.2, LR- 0.8
• Leg sensation abnormal: sensitivity 16%, LR+ NS, LR- NS
• Abnormal ankle reflex: sensitivity 48%, LR+ 4.3, LR- 0.6
• • Straight Leg Raise (SLR) test: sensitivity 73-98%, LR+ NS, LR- 0.2
• • Crossed SLR test: sensitivity 23-43%, LR+ 4.3, LR- 0.8

Hancock Rule: Clinical Prediction Rule for Lumbar Disc Herniation

• The diagnostic accuracy of multiple neurologic findings improves clinician ability to determine level of disc herniation if at least 3 of 4 findings are in concordance with a specific nerve root:
  • dermatomal pain location
  • sensory deficit
  • reduced reflex
  • motor weakness
• Findings: score ≥ 3 for L3/L4 disc herniation, sensitivity 50%, LR+ 5.0, LR- 0.56
• Findings: score ≥ 3 for L4/L5 disc herniation, sensitivity 37%, LR+ 2.18, LR- 0.76
• Findings: score ≥ 3 for L5/S1 disc herniation, sensitivity 28%, LR+ 4.67, LR- 0.77

LBP with Radiculopathy: Epidemiology

• 3-5% of population has lumbosacral radiculopathy, with males (40+ years) more common than females (50+ years) at a 3:2 ratio
• L5 radiculopathy is the single most common lumbar radiculopathy
• Pain experience: often described as tingling, electric, burning, or sharp
• Paresthesia: 63-72% of patients, radiation of pain into lower limb: 35%, numbness (anesthesia): 27%, and muscle weakness: up to 37%

LBP with Radiculopathy: Risk Factors

• Social History:
  • Repetitive lifting and twisting motions
  • Chronic overloading of disc: driving occupations, heavy industry work, military
  • Lifestyle: smoking, overweight, sedentary
• Medical History:
  • Prior trauma (fall, motor vehicle accident)
  • Multiple pregnancies
  • History of back pain
  • Chronic cough

LBP with Radiculopathy: History Intake

• Site: ask about the location of the back pain
• Onset: how and when the back pain developed
• Quality: pain is often described as throbbing, aching, sharp, dull, burning, pressure, numbness, tingling, or shooting
• Radiation: assess dermatomal distribution
• Time Course: consider how the back pain changed over time

LBP with Radiculopathy: Associated Signs and Symptoms

• Motor or sensory disturbances: suggestive of nerve root or spinal cord compression
• Ask specifically about saddle anesthesia if cauda equina syndrome is a possibility
• Urinary retention or incontinence: typical features of cauda equina syndrome
• Hematuria (blood in urine): may occur secondary to back trauma

LBP with Radiculopathy: History Intake

• Associated Signs and Symptoms:
  • Fever: typically associated with urinary tract infection, pneumonia, and discitis
  • Malaise: associated with a wide range of pathology but in the context of back pain, consider discitis or malignancy
  • Weight loss: associated with malignancy
  • Early morning stiffness: associated with inflammatory arthritis (e.g., rheumatoid arthritis, ankylosing spondylitis)
  • Muscular spasms: may be associated with spinal fracture or primary muscular injury

LBP with Radiculopathy: Key Medical History

• History of malignancy
• Recent bacterial infections
• Recent history of epidural or spinal surgical procedures
• Medications: history of or current corticosteroid use
• Assess ability to function in daily life

Disc Herniation

• Displacement of intervertebral disc material (nucleus pulposus or annulus fibrosis) beyond the intervertebral disc space
• 1-3% of patients with acute LBP; age 30-40, male: female 2:1
• Acute-chronic pain, paresthesia, sensory change, loss of strength or reflexes (depends on affected nerve root)
• Diagnosis: SLR + Hancock rule

S1 Radiculopathy

• Distribution of Pain:
  • S1 radiculopathy will cause radiation of sacral or buttock pain into the posterior aspect of the patient's leg, into the foot, or the perineum
• Physical Exam:
  • Motor Weakness: plantar flexion
  • Paresthesia/Sensory Changes: sole, lateral foot and ankle, fourth and fifth toes
  • Absent Reflexes: ankle reflex (S1)

S1 Radiculopathy: Physical Exam Findings

• Weak ankle plantar flexion: 26-45% sensitivity
• Ipsilateral calf wasting: 43% sensitivity
• Sensory loss in S1 distribution: 32-49% sensitivity
• Asymmetric achilles reflex: 45-91% sensitivity

Serious Disorders Affecting the Lumbar Spine

• Spondylosis: an umbrella term for age-related degeneration of the spinal column (often involves degenerative disc disease and facet arthropathy)
• Spinal stenosis: narrowing of the spinal canal, neural foramen, and lateral recess which can lead to compression of the nerve roots and neurogenic claudication
• Spondylolysis: weakness or stress fracture through the pars interarticularis
• Spondylolisthesis: the slippage of one vertebral body with respect to the adjacent vertebral body

Spinal Stenosis

• Narrowing of the spinal canal, neural foramen, and lateral recess which can lead to compression of the nerve roots and neurogenic claudication
• 3% with mechanical low back pain (LBP), 19.4% aged 60-69 years
• LBP with B/L lower extremity pain, numbness or loss of strength (depends on affected nerve root) aggravated by ambulation, standing, and lumbar extension
• Neurogenic claudication: pain/discomfort with walking or prolonged standing that radiates into one or both lower extremities (relieved by rest/sitting, lumbar flexion)
• Diagnosis: imaging is diagnostic

Vertebral Infection: Osteomyelitis

• Most common vertebral infection, particularly the vertebral body
• Often caused by hematogenous spread of Staphylococcus aureus
• Rare, approx. 4.8 cases per 100,000 in US, 3-5% of all cases of osteomyelitis
• Risk factors: recent spinal procedure/surgery, recent infection, wound in spinal region, Hx IV drug use, immunosuppression
• Symptoms: back pain, fever, sensory loss, weakness or radiculopathy
• Diagnosis: imaging (MRI) is preferred, CBC often normal, ESR elevated, CRP elevated, blood cultures
• Urgent ER referral, requires antibiotic therapy (IV and oral)

LBP with Radiculopathy: Etiology

• L4-L5 (L5 nerve root) and L5-S1 (S1 nerve root) are most susceptible to injury
• Particularly flexible part of lumbar spine, bears more impact than thoracic and cervical spine

LBP with Radiculopathy: Epidemiology

• Lumbosacral radiculopathy is common: 3 - 5% of population
• Male (40yr+) > female (50yr+): 3:2
• L5 radiculopathy is the single most common lumbar radiculopathy

LBP with Radiculopathy: Risk Factors

• Social History: repetitive lifting and twisting motions, chronic overloading of disc, smoking, overweight, sedentary
• Medical History: prior trauma, multiple pregnancies, history of back pain, chronic cough

LBP with Radiculopathy: History Intake

• Site: ask about the location of the back pain
• Onset: how and when the back pain developed
• Quality: pain is often described as throbbing, aching, sharp, dull, burning, pressure, numbness, tingling, or shooting
• Radiation: assess dermatomal distribution
• Time Course: consider how the back pain changed over time
• Pain experience: scale of 1-10, pain is typically worse with increased intradiscal pressure, pressure increases with coughing, sneezing, straining, forward flexion of the lumbar spine

LBP with Radiculopathy: Physical Exam

• Motor Weakness: plantar flexion
• Paresthesia/Sensory Changes: sole, lateral foot and ankle, fourth and fifth toes
• Absent Reflexes: ankle reflex (S1)

Spinal Stenosis

• Pain/discomfort with walking or prolonged standing that radiates into one or both lower extremities (relieved by rest/sitting, lumbar flexion)
• Diagnosis: imaging is diagnostic
• Subjective + Physical Findings associated with Spinal Stenosis:
  • No pain when seated
  • Unexplained urinary disturbance
  • Symptoms improve with bend forward
  • Bilateral buttock or leg pain
  • Neurogenic claudication
  • Wide-based gait
  • Abnormal rhomberg test

Spondylolysis

• Unilateral or bilateral defect through the pars interarticularis (most commonly affects L5, 90%)
• 6-18% population (14+); up to 50% young athletes (male:female, 2:1)
• Risk associated with excessive lumbar lordosis, genetics (fHx)
• Asymptomatic (90% of patients); insidious onset, recurrent axial low back pain exacerbated with activity or lumbar hyperextension, +/- radiculopathy

Spondylolisthesis

• Slippage of one vertebral body with respect to the adjacent vertebral body
• 3-4% of patients with mechanical LBP
• Adults, female > male, obesity, fHx (spondylolisthesis, scoliosis, spina bifida)
• Intermittent and localized low back pain that radiates into buttock or posterior thigh; paresthesia, sensory change, loss of strength or reflexes (depends on affected nerve root)

Evaluation - Imaging

• Initial imaging is not indicated in the majority of patients with low back pain
• Conservative management for 6 weeks is typically recommended before considering imaging (radiography, MRI, CT)
• UNLESS presenting with severe symptom intensity or red flag findings for conditions that require timely diagnosis to prevent serious consequences