Whiplash is the common term used to describe a complex syndrome more appropriately named "acceleration-deceleration injuries," according to the NeuroMuscular Therapy Center. Acceleration-deceleration injuries are the most common result of closed head injuries and car accidents are the leading cause of traumatic brain injury. Acceleration-deceleration injuries can be mild with most people recovering from a headache on their own; a severe head injury can result in disability or even death.
Anatomy
Whiplash was so named because of the head's lashing motion during the accident. Acceleration-deceleration is a more accurate description of what is happening inside the skull. During a car accident, for example, the head and extremities continue moving forward, despite the fact the car has suddenly stopped. The head, arms and legs continue accelerating until something stops them, like hitting the dashboard or simply reaching their limits. The same acceleration-deceleration action happens inside the body as well--the brain continues moving forward until it is stopped by the skull. The brain literally slides back and forth within the skull, an action called shearing.
There are two points of injury--one on the side of the brain where it hit the skull, and another on the exact opposite side of the brain where it impacted due to the oscillation, or sliding motion, of the brain. Even if the brain does not impact the skull, acceleration-deceleration injuries to the brain can still occur due to the sheer force of brain movement, causing bruising and bleeding to the brain at these two points.
Causes
Rear end collisions are the most common cause of whiplash, according to MayoClinic.com. Acceleration-deceleration injury may be caused by shaking a child violently, otherwise known as shaken baby syndrome. Contact sports and other activities may also cause this type of brain injury.
Symptoms
Acceleration-deceleration injuries cause tiny focal lesions at two points in the brain--at the point of impact and on the opposite side. Focal lesions caused by this type of trauma can affect language as well as difficulties with attention span, perception and reasoning. The patient may experience seizures. Symptoms of shaken baby syndrome may include seizures, irritability, loss of consciousness and stopped breathing.
Diagnosis
Diagnosis begins with assessing the cause of the accident. It is important that the physician knows an acceleration-deceleration injury is possible. The doctor will perform an examination, including a neurological exam where the physician tests mental status, reflexes, eye movement and pupil dilation, among other things, to test the brain's function. She will monitor the pressure inside a patient's head with a special machine. X-rays of the head, MRIs and CT scans are also ordered to help visualize the brain.
Treatment
Treatment involves reducing swelling, bruising and bleeding in the brain, which causes the brain to press against the skull, a condition known as intracranial pressure. A physician will order medicines to reduce swelling and stop bleeding, as well as decrease pressure on the brain. The amount of intracranial pressure will be monitored closely. The patient may be put on a respirator, as hyperventilation decreases intracranial pressure. A catheter may be put inside a patient's skull to drain away excess fluids. Anti-seizure medications will be ordered as a preventative measure. If the intracranial pressure cannot be reduced with medicine, a surgeon may remove a portion of the patient's skull to allow more room for his swollen brain.
