Differential diagnosis of low back pain. Presentation enumerates various causes of low back pain

1. DR. VARUN SINGLA
MD (PGI Chandigarh)
PDCC-Pain Management (SGPGI Lucknow)
Fellow FPCI (Mumbai)
Member, Indian Society for Study of Pain
Peer Reviewer, Cochrane PaPaS, UK

2. INTRODUCTION
 Low back pain is the most common source of pain in
modern society
 Incidence of 1st episode – 6.3 – 15.4%
 Incidence of recurrent LBP – 1.5 – 36%*
 Identifying the source of the low back pain is of
paramount importance to a pain physician.
* Best Pract Res Clin Rheumatol, 2010 Dec;24 (6):769 -81

3.  One of the most common reasons for seeking medical
attention, second only to respiratory issues.
 84% of adults will have low back pain at some point
 Wide variety of approaches for treatment
 Suggests that optimal approach is unsure
 Most episodes are self-limited
 Some suffer from chronic or recurrent courses, with
substantial impact on quality of life

4. SOURCES OF LOW BACK PAIN
 Vertebral bodies
 Inter-vertebral discs
 Facet joints
 Spinal nerve roots
 Muscles & ligaments
 Referred pain- abdominal & pelvic viscera
 Sacro–iliac joint

6. DIFFERENTIAL DIAGNOSIS

7. MECHANICAL CAUSES

8. INCIDENCE
 Lumbar radicular syndrome – 12 – 40%
 Sacro iliac joint arthropathy – 15- 30%
 Disc disruption – 25 – 40%
 Herniated lumbar disk – 1- 2 %

9. Other causes of LBP
 Osteoporotic Compression fracture 3-5%
 Fibromyalgia & Myofascial Pain 2-5%
 Spinal canal stenosis 2-3%
 Spondylolisthesis 2-3%
 Tumor <1% / Infection <1% / FBSS <1%

11.  Syn : Lumbar radiculopathy; lumbar radiculitis; sciatica
 Pathology
 Pathologic involvement of the Sensory Spinal Nerve Roots
(SSNR) & Dorsal root ganglia ectopic impulse
generation  pain, numbness, tingling in a dermatomal
fashion
 Signs : Weakness + diminished reflexes + SLR positivity

12. Pathologic processes inv SSNR & DRGs:
 Inter-vertebral disc pathology
 Degenerative spinal disorders
 Neoplastic
 Traumatic – vertebral body fractures
 Infections
 Metabolic
Most common

13. Clinical features
Symptoms
 Radicular pain- sharp, shooting, lancinating pain that
travels along a narrow band.
 Paresthesias & numbness
 Weakness in territory of inv NR
Objective Signs
 Gait disturbances
 Loss of sensation
 Reduced muscle strength
 Diminished reflexes

14. TESTS TO CONFIRM NR IRRITATION
 SLR/ Lasegue test- sensitive, lower NRs.
 SLR & Ankle dorsiflexion of extended lower extremity.
 Crossed SLR/ X-SLR- more specific.
 Tripod test
 Femoral stretch test- L2 & L3 NRs.

17. Differential diagnoses
 Entrapment neuropathy of sciatic nerve
 Piriformis muscle
 Ischial tunnel syndrome
Pain & paresthesia along its distribution, often involving
multiple dermatomes
 Pain from IVD, SI joint and myofascial pain can also be
referred to LL- d/t Interneuronal Convergence within
spinal cord.
 Non dermatomal
 Deep aching
 Lacks objective signs of nerve root irritation

18. DIAGNOSTIC TESTS
 Not recommended for LBP & radicular pain of < 4-6
wks.  because of favorable natural history & often
spontaneous resolution of symptoms.
 Also, common +nce of abnormal diagnostic findings in
asymptomatic individuals.

19. IMAGING STUDIES
 MRI
 CT
 CT-Myelography
 Plain radiography
 Electro-diagnostic studies –
EMG, NCV, SSEP- routine use not recommended

21. Contents of a herniated disc

22. PATHOPHYSIOLOGY
 HD thought to be the mc cause of radicular pain.
 Mechanisms :
- Mechanical compression of the nerve root impairs
nutrition  nerve root ischemia and injury.
- Presence of inflammatory mediators in HD
material.
 Natural history favorable. Spontaneous resolution in
60%. (phagocytic process)
 L4-L5 (59) > L5-S1 (30) > L3-L4 (9).

23. Disc contents
causing nerve
irritation

24. Treatment
 Non surgical
 Systemic corticoteroids
 Bed rest
 Bracing
 Traction
 Behavioral therapy
 Physical therapy – active + passive exercises
Old school

25.  Minimally invasive
 Epidural steroid injections – interlaminar / TF
 Percutaneous disc decompression
- APLD
- IDET (Intradiscal Electrothermal therapy)
- Disc nucleoplasty(RF)
• Operative treatment
 classic diskectomy
 microdiskectomy

27. Lumbar spinal stenosis
 Syndrome : neurogenic claudication or radicular pain
2° to narrowing of spinal / NR canal  compression of
neural elements.
 Classification
ETIOLOGICAL ANATOMICAL
Congenital - achondroplasia Central canal stenosis
Acquired – metabolic,
traumatic, degenerative
Lateral / neural foraminal
stenosis
Combined

28. What happens in LCS
-Loss of disk height
-Disk bulging
-Facet joint hypertrophy
-Thickening of ligamentum flavum
-Osteophyte formation

29. Clinical features
Symptoms
 Neurogenic claudication
 Radicular pain – L5 > L4 > L3  lateral stenosis
 Axial pain - not specific
 Cauda equina syndrome  central stenosis
Signs
 Stooped gait
 Loss of lumbar lordosis
 Negative SLR
 Sensorimotor deficits are less pronounced
chronic,
slow
progress

30. Shopping cart sign

31. CAUDA EQUINA SYNDROME
Symptoms
 B/L Radicular pain
 Isolated back pain – rare
 Weakness U/L or B/L lower limbs
 Gait disturbances
 Abdominal discomfort – urinary retention
Signs
 Motor and sensory deficits
 + SLR & X-SLR
 ↓lower extremity reflexes
 Saddle anaesthesia
 ↓ Sphincter tone
 Urinary retention.

32. Neurogenic
claudication
 Evaluation after walking - ↑
weakness
 Relieved by – bending over,
sitting
 Increases upon – walking
downhill, ↑ lordosis
 Pulses – present
 Shopping cart sign – Present
Vascular
claudication
 Evaluation after walking –
unchanged
 Relieved by – stopping, rest
 Increases upon - Walking
uphill
 Pulses – absent
 Shopping cart sign – absent

33. DIAGNOSIS
 MRI - IOC
 Lumbar CT myelography

34. Treatment
 Non invasive
 Medications – NSAIDs, calcitonin
 Activity modification – avoid aggravating factors
 Bracing – short duration
 Physical therapy – flexion based exercises ↑
microcirculation
 Epidural steroid
 Invasive
 Laminectomy
 Laminotomy, laminoplasty
 Extensive decompression techniques + spinal fusion

36.  Syn : Discogenic pain, internal disk disruption (IDD),
degenerative disk disorder (DDD)
 It is a physiologic consequence of aging
 Factors predisposing to degenerative disk disease
 Diminished blood supply
 Genetic
 Mechanical stress
 End plate injury
 Vascular disease
 Obesity

37. PATHOPHYSIOLOGY
 Normal disc : innervation & vascularity is limited to the
outer 1/3rd of the AF
 Injury  annular tears  vascularised granulation
tissue that extend from the NP to AF (HIZ on MRI)
 Granulation tissue : ↑ pro inflammatory molecules
(substance P)  maintain hyperalgesia  chronic pain

38. Disc innervation

39. Discal tears

41. Clinical Features
Symptoms
 Pain – acute/chronic
 Precipitated by torsion injury
 Pain ↑ axial loading – prolonged sitting, standing
 Referred to lower limb - non dermatomal areas
Signs
 Black disc disease on MRI  dessicated discs (loss of
signal on T2 weighted images)
 Presence of HIZ in posterior annulus on T2

42. Imaging - DDD

43. HIZ

44. Treatment
 Mainly palliative
 IDET
 Disk arthroplasty
 Surgical – Diskectomy + spinal fusion

46. Lumbar facet – anatomy

47. Causes – Facet syndrome
 Inflammatory arthritides – RA, AS
 Degenerative
 Synovial cysts
 Infections
 Microtrauma
 Meniscoid & synovial entrapments
 Joint subluxation

48. Clinical features
Symptoms
 Low back pain – U/L or B/L
 Referral to groin, hip, posterior thigh
 Pain ↑ on twisting, extension, sitting, standing
 Pain ↓ on forward flexion, rest, walking
Signs
 Localized tenderness over facets
 No neurological deficits
 Normal SLR

49. Pain distribution patterns - facet

50. Influence of flexion - extension

51. What clinches diagnosis
Analgesic response to targeted, low volume LA
injections – only accepted standard for diagnosis !!

52. Treatment
Diagnostic facet injections – followed by
 Intra-articular LA + steroid
 Facet denervation – lesioning of the MB at the same
vertebral level & 1 level above

53. Medial branch block
Medial branch of
this facet is
supplied by the
SSNR of the level
above it

55. Sacro – iliac joint anatomy

56. Factors predisposing to SIJD
 Trauma
 Leg length discrepancy
 Spinal deformity
 Surgery
 Lumbar facet syndrome
 Pregnancy
 Inflammatory arthritides – AS
 Infections

57. Clinical features
Symptoms
 Pain – low back – max at the affected site
 Radiation – buttock, groin & posterior thigh
 Hypomobility
Signs
 Tender SI sulcus
 Positive clinical tests – FABER, Yeoman, Gaenslen’s
 Normal lab findings & imaging

58. Treatment
 Diagnostic confirmation – SI injection with LA
 Positive response – 75 – 90% pain relief
 Physical therapy
 Intra-articular steroid
 RF ablation
 Surgical fusion

60.  It is a regional pain syndrome characterised by the
presence of active trigger points in skeletal muscle
 Types of trigger points
 Active
 Latent

61. Diagnostic criteria
Essential Criteria
 Palpable taut band
 Exquisite spot tenderness of nodule in taut band
 Pressure on taut band  recognition of pain (active
TrP)
 Painful limitation of passive range of motion
Confirmatory
 Local twitch response
 Twitch on needling
 Pain on zone of reference
 EMG – spontaneous electrical activity

62. Various trigger points - back

65. Treatment
 Physical interventions
 Cold spray
 Massage of TrP
 Stretching of the muscle
 Needling
 Dry needling
 Wet needling - LA

66. BAASTRUP’S DISEASE
 Hyperlordosis, segmental instability, loss of disc
height  apposition of lumbar spine  degradation of
interspinous ligament  pseudoarthrosis/
pseudobursa
 Midline lumbar pain, radicular or claudicatory pain

67.  X-ray : contact between adjacent spinous processes
with sclerosis, flattening and enlargement
 MRI- edema interspinous ligament with fluid
 SPECT scan Tc : hyperemia

68. BERTOLOTTI’S SYNDROME
 Asso. of transitional LS segments with mechanical
back pain.
 Transitional segment a/w axial pain, related to
- neoarticulation
- C/L facet at level of asymmetric neoarticulation
- IDD in the at-risk disk above.