Whiplash and Its Associated Disorders

1. Whiplash and Its Associated Disorders Patrick Soto, DO; ABPMR Spokane Spine Center 124 E Rowan Ave Spokane, WA 99207 509-487-8000 drsotossc@gmail.com www.spokanespine.com

2. Physiatry • We specialize in restoring optimal function to people with injuries to the muscles, bones, tissues and nervous system. • Understanding the prognosis, recovery process and functional impact of an illness. • Primarily a nonsurgical conservative approach when possible.

3. Physiatrist

4. Overview of Topics • Injury mechanics, phases of healing, and stages of treatment. • Real world statistics of permanent injury. • Medicolegal: • Maximum Medical Improvement (MMI) • Settling the MVC claim.

5. History • First case series on Whiplash Associated Disorder (WAD) : Gay J, Abbot K. Common Whiplash injuries of the neck. JAMA 1953;152: 1698–704. • In the 1950s and 1960s motor cars had no supporting headrests. • Ian Macnab, MD: extension-flexion injuries recognized in WWI after observations of sudden neck extension in pilots during catapult-assisted takeoffs.

8. Ralph Nader 1965. Accused car manufacturers of resistance to the introduction of safety features, like seat belts, and their general reluctance to spend money on improving safety.

9. Prevalence • Whiplash appears to be increasing in frequency despite the addition of headrests to automobiles. • In 1982 (UK), seat-belt legislation was introduced and the next year the prevalence of WAD rose 268% and continued to rise ~ 152% yearly for the next 15 years

10. No-fault vs. Tort • No-fault: entitled to benefits, regardless of fault, but they are not allowed to sue for pain and suffering. • Tort: entitled to limited benefits (such as health care and income replacement); they may also sue the driver at fault for the collision for additional expenses and for pain and suffering.

12. Annual incidence of reported WAD

13. Costs of US MVCs in 1994 • Total costs: $150.5 billion • Property damage: $52.1 billion • Lost market productivity: $42.4 billion • Medical expenses: $17 billion • Direct costs to taxpayers: $13.8 billion = $144 in added taxes to each household.

14. PIP Coverage in Washington • Basic provides the following minimum benefits: • Up to $10,000for reasonable and necessary medical expenses for each individual injured in an auto accident. This is available for up to three years from the date of the accident. • Up to $200per week for income replacement coverage. This is limited to one year after a person has been disabled for 14 days after the accident. • Up to $2,000for funeral expenses. • Up to $5,000for loss of services (payment to others for work you can't do).

15. Injury mechanics • Whiplash Associated Disorder (WAD) • Strains and sprains • Post-traumatic core muscle fatty infiltration noted on MRI • Central hypersensitivity

16. Injury Mechanics • The usual whiplash injury is a sprained neck occurring as a result of a MVA that produces stretching or occasionally tearing of soft tissues such as muscle, fascia, ligaments, joint capsule, blood vessels and nerve fibers. The upper and lower back may also be sprained. Occasional injuries to the intervertebral disc, bone or neurological system may occur in complicated cases but not in a common whiplash injury.

17. Signs and Symptoms • Pain, stiffness and impaired mobility of the cervical, thoracic and lumbar regions. • Radiating pain and paresthesias in the extremities • Headache and cognitive problems. • Nausea, dizziness, vision disturbances • Impaired sleep • Anxiety/PTSD/depression

18. Signs and Symptoms • Examination can be nonfocal and nonanatomic • X-rays, CT and MRI are seldom conclusive

19. Signs and Symptoms • Experimental studies have shown that the craniovertebral region as well as the mid- and lower cervical spine can be exposed to harmful translations and hyperflexion and extension forces by a whiplash trauma.

20. 1995Quebec Task Force (QTF) • WAD defined as the various clinical manifestations of, or the disability caused by, ‘whiplash injury’ • An acceleration-deceleration mechanism of energy transfer to the neck…which might result in bony or soft tissue injuries

21. Quebec Task Force on WAD • Grade 0: “no complaint about the neck, no physical sign(s)” • Grade 1: “neck pain, stiffness, or tenderness, with no physical sign(s)” • Grade 2: “neck pain, stiffness, or tenderness with musculoskeletal sign(s)” • Grade 3: “neck pain, stiffness, or tenderness with neurological signs” • Grade 4: “neck fracture or dislocation, SCI.”

22. Quebec Task Force on WAD • Rear-end collisions resulted in higher rates of relapse or recurrences of symptoms. • Seatbelts may increase risk for injury • Whiplash claims notably higher for women. • 21% of occupants reported 12 hr delays in symptoms • Permanent injury should not occur.

25. The cervical facet joints have been proposed as a source of chronic pain.

26. Cervical Facet Joints • Several elegantly designed studies have demonstrated the cervical facet joints to be the source of persisting symptoms • One group of authors have reported a prevalence of ~ 50% facet derangement in a selected group of patients with late whiplash symptoms

27. Cervical Facet Joints • Cadaver study of 18 specimens exposed to 2.6G-4.6G of right side impact acceleration. Found with right lateral impact, left sided injuries noted to the disc and rupture of facet joint capsule at one of the C4-T1 joints.In some cases noted fracture to the right articular process.

28. Cervical Facet Joints • Simulated in vitro low speed rear end collisions of cadavers demonstrated cervical facet joint spearing, significant stretch injury to the ALL and facet joint capsules

29. Undetectable Injuries • Seminal research by Taylor and Twomey: serious spinal injuries detected on post-mortem examination that were otherwise hidden to conventional imaging. • Found otherwise undetectable injuries including bleeding into the dorsal root ganglia, small fractures of the facet joints, bleeding into the facet joints, and rim lesions to intervertebral discs.

30. Post-Trauma Core Muscle Fatty Infiltration

31. Post-Trauma Core Muscle Fatty Infiltration • Atrophy is associated with LBP and “appears to help perpetuate an inhibitory feedback loop that begins with pain in the spine, possibly stemming from the IV disks or zygapophyseal joints, followed by reflex inhibition of the multifidus and then atrophy and fatty replacement of the muscle

32. Post-Trauma Core Muscle Fatty Infiltration • Study of 113 females (79 WAD) with rest as controls. Significantly higher fatty infiltrationseen in deep extensor muscles than controls.

33. Central Hypersensitivity • The authors used live anesthetized rats and stretched the C6-C7 cervical facet joint capsule. “The increase in neuronal firing across a range of stimulus magnitudes observed at day 7 post-injury provides the first direct evidence of neuronal modulation in the spinal cord following facet joint loading, and suggests that facet-mediated chronic pain following whiplash injury is driven, at least in part, by central sensitization.”

34. Phases of healing

35. Phases of healing • Hippocrates emphasized the importance of a prognosis 2400 years ago. • A physician should avoid giving a prognosis immediately after the injury • After 2 weeks if they are still symptomatic, it helps patients to have some idea of the prognosis.

36. Stages of treatment • Acute, Subacute, Chronic treatment • Over treatment vs. lack of treatment • Passive treatment vs. active treatment • Practioners can prolong the disability by continuing ineffective therapy and not realizing that time is critical in deciding on appropriate therapy and in preventing illness behaviors.

37. To Image or Not?

38. Canadian C-Spine Rule • GCS 15 • Medically stable • Dangerous mechanism = fall >3 ft or 5 stairs, axial load to the head, MVC@> 62mph, rollover or ejection. • Motorized recreational vehicle • Bicycle collision

39. Imaging • “There is no evidence that the degree of cervical lordosis or kyphosis can accurately identify “cervical muscle spasm” or distinguish patients with WAD from those without WAD.” • “There is no evidence that MRI accurately detects specific trauma-related findings in the cervical spine in the absence of fracture or major ligamentous disruption.”

40. Bone & Joint Decade2000–2010 Task Force on Neck Pain and ItsAssociated Disorders • Scott Haldeman, DC, MD, PhD. • Gathering of international expertise covering all relevant aspects related to neck pain and its associated disorders. • Initiative of the United Nations and the World Health Organization

41. Bone & Joint Decade2000–2010 Task Force on Neck Pain and ItsAssociated Disorders • ~32,000 research citations considered • Critical appraisals of > 1,000 research studies that were relevant to its mandate. • Systematic review and a best evidence synthesis, which resulted in a 21 chapter supplement in the 2008 Spine journal. • Focused on Grades I-III in regards to WAD

42. Bone & Joint Decade2000–2010 Task Force on Neck Pain and ItsAssociated Disorders • 50% of those with WAD will report neck pain symptoms 1 year after their injuries. • Greater initial pain, more symptoms, and greater initial disability predicted slower recovery. • Few factors related to the collision itself were prognostic.

43. Bone & Joint Decade2000–2010 Task Force on Neck Pain and ItsAssociated Disorders • Post-injury psychological factors such as passive coping style, depressed mood, and fear of movement were prognostic for slower or less complete recovery. • Preliminary evidence that the prevailing compensation system is prognostic for recovery in WAD.

44. Medical Causation • There must be a biologically plausible link between injury event and the outcome (injury-symptoms) • There must be a temporal relationship between injury event and the outcome (injury-symptoms). • There must not be any likely alternative explanation for the injury or symptoms.

45. Causation • There were no significant differences in the presence and severity of WAD between men and women at ΔV (change in velocity) 2.5 mph and 5 mph or in the duration of WAD at 5 mph. • There appears to be no connection between ΔV and long term injury risk.

46. Causation • 57 WAD cases evaluated for QTF grading and ΔV, with 56% reporting no symptoms. Of those reporting symptoms (25 cases or 44%) c/o neck pain. • QTF 1: 8 cases. QTF 2: 6 cases. QTF 4: 11 cases. • There was no ΔV threshold associated with acceptable sensitivity and specificity for the prognosis of a cervical spine injury. • Of the 57 cases, 21 involved rear impacts having a ΔV range 5.6 - 23 mph.

47. Real world statistics of permanent injury • Bone and Joint Decade 2000-2010 Task Force on Neck Pain and its Associated Disorders concluded in review of 226 papers with 47 specifically on WAD prognosis, that about 50% of WAD cases will continue to have symptoms at one year.

48. Real world statistics of permanent injury • Approximately 25% of acute whiplash injuries will become chronic. Áine Carroll. Clinical Rehabilitation 2008; 22: 513–519. • Chronic pain after whiplash injuries may occur in 12–42% of cases. Long-term disability and emotional distress is also frequent after whiplash injuries. Ruben Nieto. Disability and Rehabilitation. 2011; 33(5): 389–398

49. Real world statistics of permanent injury • In subjects who did not have any complaints before the collision, 77% still reported physical complaints four years after the actual incident (headache, neck or shoulder pain). • 42% reported to suffer from neuropsychological problems: impairments in attention and concentration, memory and cognitive flexibility. Sleep disturbances and depression. • Symptom exaggeration, especially in patients involved in medicolegal procedures, possibly resulting in somatization behavior.