Whiplash Injury Collision Research Revealing Chronic Pain Even After Therapy
Aches in the cervical spine, shoulders, head or the base of the skull that occurs after a motor vehicle collision are often known as “acceleration deceleration injury.” It’s a common term that most patients hear following an auto collision. Most patients with acceleration deceleration injury recover in a few weeks or at most, a few months. However, 15 to 20% of people develop chronic ache. Acceleration deceleration injury is not a trivial problem, because once it has occurred; only 70% have recovered completely by one year and only 82% have recovered completely by two years. In addition to cervical spine ache, there are many symptoms associated with the acceleration deceleration injury syndrome and include sleep problems, poor concentration and memory, blurry vision, ringing in the ears, fatigue, and weakness.
The therapy for acceleration deceleration injury syndromes depends on the stage and degree of the problem and which structures have been injured. Therapy can vary from chiropractic care, physical therapy, orthopedic intervention and more. In addition to soft tissue injury, ache that persists after four to six months is usually due to injury to the facet joints, one or more discs, or both. The diagnosis can usually be made by injections, MRI, and X-rays. Therapy is usually successful, but may require physical therapy, injections, and occasionally surgery.
The term whiplash is confusing to many. This is because it is both a mechanism of injury and the symptoms caused by a car accident. It is due to a traumatic event that causes the head to move suddenly in a whipping motion in one direction and then recoil in the other direction. The most common cause of whiplash is a motor vehicle accident in which one vehicle is struck from behind by another. However, it can occur when a car stops abruptly after striking a pole, a wall, or another car, and can also occur after a side impact.
Significant damage to ligaments, discs, and joints can occur even if the swings of extension and flexion are not excessive, but often the neck is forced to the extreme ends of normal range or beyond. Because the trauma is usually sudden, occupants of the car are not prepared for the impact. The muscles are relaxed, which allows more forces on the discs, ligaments and joints. Perhaps the most important fact about whiplash is that significant pain and structural damage can occur even in low velocity crashes.
It is the patient with constant pain without any other specific findings on examination or specialized tests that presents the most difficult problems for the patient himself or herself, the doctors, and the legal system in personal injury. In the first few weeks to months after motor vehicle accident, it is often impossible to determine the exact cause or causes of the pain associated with the injury. The symptoms and signs are not sufficiently specific in the case. In almost every instance, the muscles and ligaments have been strained and may be inflamed, painful, and tender. However after about three months, primary muscle or other soft tissue injuries usually have healed.
In a research study by Drs. Bogduk and Aprill, in 23% of patients, facet joints alone were the cause of pain, in 20% of patients the discs alone were the cause of pain, and in 41% of patients both the facet joints and discs were contributing. They were not able to identify the source of the pain in only 17% of their patients. The most common causes of persistent pain in whiplash are the facet joints and the discs. There is a poor correlation between the radiographic appearance of the joints and whether they are painful. Some joints which look bad are painless while other joints that look normal can be proven to be a source of pain. Only facet injections can determine whether the joint is painful.
Many acceleration deceleration injury patients have symptoms which seem unexplainable, such as headaches, ache in the shoulders, between the shoulder blades, or in one or both arms. These symptoms can significantly impact activities of daily living. There may be fatigue, dizziness, problems with vision, ringing in the ears, heaviness in the arms, and low back ache. There can be poor concentration or memory, change in emotions with irritability, depression or short temper, and sleep disturbance. Dizziness occurs in one-quarter to one-half of people with acceleration deceleration injury. Again, researchers are not sure of the cause. The most likely explanation is an injury to the part of the inner ear that regulates balance. Problems with memory and concentration can be due to the ache itself, depression, medications, or trauma to the brain. Visual disturbances occur in 10 to 30% of acceleration deceleration injury patients and blurred vision is the most common.
Fortunately, most people who suffer neck pain after a whiplash injury will recover by six months. However, a small percentage of people continue to have pain. Most patients destined to recover completely will have done so by three to four months, after which the rate of recovery slows markedly. By two years, essentially all patients have reached their individual maximum improvement. About 18% continued to have significant pain two years after the accident! Patients who did not get well tended to be older, had pain which began sooner after the accident, and/or had their head rotated to either side at the time of impact. They also found that patients who, before the accident, had a history of neck pain, arthritis of the neck, or headaches did not do as well.
Common sense would tell us the greater the ache and impairment, the larger the legal settlement or award might be. Rarely, patients may exaggerate their symptoms or be faking. However, a bigger question is whether the potential for money from a legal settlement can unconsciously prolong or worsen the ache. This is known as “secondary gain” and it is unconscious, not fraudulent. The science shows that personal injury litigation does not adversely affect outcome. In 1983, Drs. Norris and Watt reviewed 61 patients who were treated for acceleration deceleration injury injuries, 41 of whom had personal injury lawsuits. They found no change in symptoms after claims were settled. About ten years later, long after litigation had settled, only 12% had completely recovered, and 48% had ache which interfered with normal daily life. In another study from 1993, Drs. Parinar and Raymakers re-evaluated patients they had seen previously for legal opinions, not for therapy, 8 years after the initial consultation. They concluded that lawsuits did not influence the timing or degree of recovery.
Several years ago a group of patients were analyzed. They were referred for therapy by their attorneys because they were not getting better. The patients were treated with strengthening exercises, body mechanics training, medications, spinal injections and occasionally psychotherapy. No patient in this study needed surgery. Most of the patients did well with significant improvements in ache and function. Although most patients still had mild ache at the end of therapy, it was not enough to interfere with their daily lives. These very favorable results occurred although none of the lawsuits had been settled.