Whiplash (medicine)

Whiplash is a non-medical term describing a range of injuries to the neck caused by or related to a sudden distortion of the neck associated with extension.

Whiplash is commonly associated with motor vehicle accidents, usually when the vehicle has been hit in the rear; however, the injury can be sustained in many other ways, including falls from stools, bicycles or horses. It stands out as one of the main injuries covered by the car insurers. In the United Kingdom, 430,000 people made a claim for whiplash in 2007 (75% of the UK's motor insurance claims), accounting for 14% of every driver's premium.

Signs and symptoms
Symptoms reported by sufferers include: pain and aching to the neck and back, referred pain to the shoulders, sensory disturbance (such as pins and needles) to the arms & legs and headaches. Symptoms can appear directly after the injury, but often are not felt until days afterwards. Whiplash is usually confined to the spinal cord, and the most common areas of the spinal cord affected by whiplash are the neck, and the mid-back (middle of the spine).

Cause
The exact injury mechanism that causes whiplash injuries is known.{Panjabi MM, Cholewicki J, Nibu K, et al. Simulation of whiplash trauma using whole cervical spine specimens. Spine 1998;23:17-24} A whiplash injury may be the result of impulsive stretching of the spine, mainly the ligament: anterior longitudinal ligament which is stretched or tears, as the head snaps forward and then back again causing a whiplash injury.

Whiplash may be caused by any motion similar to a rear-end collision in a motor vehicle, such as may take place on a roller coaster or other rides at an amusement park, sports injuries such as skiing accidents, other modes of transportation such as airplane travel, or from being hit, kicked or shaken. Shaken baby syndrome can result in a whiplash injury.

Whiplash symptoms might not always have any pathological (injury) explanation. "Volunteer studies of experimental, low-velocity rear-end collisions have shown a percentage of subjects to report short-lived symptoms", which can not be attributed to any pathogenic effect on the subjects neck.

Diagnosis
Diagnosis occurs through a patient history, head and neck examination, X-rays to rule out bone fractures and may involve the use of medical imaging to determine if there are other injuries.

Québec Task Force
The Québec Task Force (QTF) has divided whiplash-associated disorders into four grades.


 * Grade 0: no neck pain, stiffness, or any physical signs are noticed
 * Grade 1: neck complaints of pain, stiffness or tenderness only but no physical signs are noted by the examining physician.
 * Grade 2: neck complaints and the examining physician finds decreased range of motion and point tenderness in the neck.
 * Grade 3: neck complaints plus neurological signs such as decreased deep tendon reflexes, weakness and sensory deficits.
 * Grade 4: neck complaints and fracture or dislocation, or injury to the spinal cord.

Prevention
Protection efforts are hampered by lack of knowledge about the causes of whiplash injuries. The focus of preventive measures to date has been on the design of car seats, primarily through the introduction of headrestraints, often called headrests. This approach is potentially problematic given the underlying assumption that purely mechanical factors cause whiplash injuries - an unproven theory. So far the injury reducing effects of head restraints appears to have been low, approximately 5-10%, because car seats have become stiffer in order to increase crash-worthiness of cars in high-speed rear-end collisions which in turn could increase the risk of whiplash injury in low-speed rear impact collisions. Improvements in the geometry of car seats through better design and energy absorption could offer additional benefits. Active devices move the body in a crash in order to shift the loads on the car seat.

Some car manufacturers have begun to implement various whiplash protection devices in their products in order to reduce the risk for and severity of injury, such as
 * Mercedes-Benz A-Class Active Head Restraint (AHR) ,
 * Saab (Responsible for the first active head restraint), Opel, Ford, Nissan, Subaru, Hyundai, and Peugeot - Active Head restraint (SAHR) ,
 * Volvo and Jaguar - Whiplash Protection System/Whiplash Prevention System (WHIPS), and
 * Toyota - Whiplash Injury Lessening (WIL).

Whether or not such devices offer a substantial benefit over vehicles without them remains controversial. In a test undertaken by the Swedish National Road Administration and an insurance company (Folksam), one test showed that a whiplash protection device was no guarantee against injury and that the degree of protection varies between vehicles both with and without whiplash protection devices. One study found that an active head restraint system helps reduce the risk of neck injuries by up to 75% in rear-end collisions.

Treatment
According to the recommendations made by the Quebec Task Force, treatment for individuals with whiplash associated disorders grade 1-3 should include manipulation, mobilizations and range of motion exercises. Non-narcotic analgesics and non-steroidal anti-inflammatory drugs may also be prescribed in the case of WAD 2 and WAD 3, but their use should be limited to a maximum of 3 weeks. A cervical collar should not be used for longer than 72 hours as it may lead to prolonged inactivity. Return to normal activities of daily living should be encouraged as soon as possible to maximize and expediate full recovery.

A different approach is taken by the National Institute for Neurological Disorders and Stroke, who suggest that treatment for individuals with whiplash may include pain medications, nonsteroidal anti-inflammatory drugs, antidepressants, muscle relaxants, and a cervical collar (usually worn for 2 to 3 weeks). Range of motion exercises, physical therapy, and cervical traction may also be prescribed. Supplemental heat application may relieve muscle tension.

Prognosis
The consequences of whiplash range from mild pain for a few days (which is the case for most people), to severe disability caused by restricted head movement or of the cervical spine, sometimes with persistent pain.

Alterations in resting state cerebral blood flow have been demonstrated in patients with chronic pain after whiplash injury