I recently saw a patient who was involved in a rear end automobile accident. She suffered from what we call an acceleration-deceleration or hyper extension-flexion injury, frequently referred to as whiplash.
With our dependence on the automobile as a mode of transportation, these types of injuries are relatively common.
The mechanism of injury is fairly straightforward. The victim is stopped at a stop sign or traffic light. Another vehicle hits them from the rear.
What occurs is that the head slams backwards, and then is whipped forward, and then back again. Why whiplash occurs can be easily understood if one looks at how the neck is constructed.
The foundation of the neck is the cervical spine. This consists of seven bones, referred to as vertebra, each of which is separated from the other by a robbery cushion, called the disk. The vertebra and the discs are stacked on top of each other. The discs do not extend all the way to the rear of the vertebra.
Each vertebra has a large hole at the rear so that when the vertebra are stacked, there is a central canal which permits the passage of the spinal cord from the brain down. At each level between the vertebra are two openings to allow nerve roots to exit from the spinal cord.
The cervical spine is held together with a complex arrangement of ligaments and also supported by a girdle of muscles.
During a whiplash injury, the ligaments supporting the cervical spine may be stretched or torn. In addition, the muscles are also traumatized.
A typical whiplash victim usually does not have much discomfort at the time of the injury. However, within 24 hours, the patient may begin to experience severe stiffness and pain. The discomfort is so severe that the patient cannot bend nor turn their head. In addition to the pain, patients may also experience headache, dizziness, or nausea.
The pain can be intense radiating to the top of the head and downwards into the upper back between the shoulder blades.
When the patient presents to the doctor, the examination will show reduced range of motion in the neck along with muscle spasm. Usually, the neurologic examination is normal.
X-rays will show evidence of muscle spasm and loss of the normal gentle curve in the neck because of the muscle spasm.
The initial treatment consists of the use of non-steroidal anti-inflammatory drugs, muscle relaxants, and a soft cervical collar. The collar should not be worn for more than a few days. Physical therapy is also recommended. Fortunately, most patients improve within 4 to 6 weeks.
Unfortunately, there are some people who will be left with chronic pain. This is a very difficult situation and patients may require other types of treatment including trigger point injections using either dry needling, lidocaine, botulinum toxin (Botox), and prolotherapy.