CAD: Cervical acceleration/deceleration trauma

Overview

Whiplash is a soft tissue injury to the neck that commonly occurs as the result of an automobile accident. It is more accurately called cervical acceleration/deceleration (CAD) trauma or syndrome. CAD may include injury to intervertebral joints, discs, and ligaments, cervical muscles, and nerve roots. About 75,000 Canadians who are involved in rear-end collisions experience whiplash in any given year.

Causes

This is one condition in which the cause is well-understood and documented. If you are in a car that is rear-ended, the vehicle is immediately pushed forward. Your body, however, will take something like 100 milliseconds to catch up. That may not sound like a lot, however, it is enough to set the scene for what's to follow. First your neck extends forward as your head tilts slightly downwards. When you react and step on the brake, the sudden stop snaps your head and neck backwards until it hits the head restraint and you end up with an injury to the vertebrae of the neck and the muscles and ligaments that support them. Similar injuries can also result from other mishaps in which the head is pushed or jerked beyond its normal range of motion.

Symptoms

Whiplash is characterized by a collection of symptoms that occur following damage to the neck, usually because of sudden extension and flexion. Symptoms such as neck pain may be present directly after the injury or may be delayed for several days. In addition to neck pain, other symptoms may include:

  • neck stiffness
  • injuries to the muscles and ligaments
  • headache
  • dizziness
  • abnormal sensations such as burning or prickling
  • shoulder or back pain
  • memory loss
  • concentration impairment
  • nervousness/irritability
  • sleep disturbances
  • fatigue
  • depression

Treatment 

Treatment for whiplash may include pain medications, nonsteroidal anti-inflammatory drugs, antidepressants, and muscle relaxants. These are all used as reviews show that "rest makes rusty," that is, that people who stop moving have worse outcomes. Cervical collars might be required with acute pain at the beginning but should not be worn for more than a few days. Range of motion exercises and active physical therapy may also be prescribed. Supplemental heat application may relieve muscle tension.

With treatment, the neck and head pain usually clears within a few days or weeks. Most patients recover within 3 months after the injury, however, some may continue to have residual neck pain and headaches.

Prevention

Researchers have shown that an increase in head restraint height and a decrease in the backset position of the car seat substantially reduce the risk whiplash.