Diagnostic considerations on whiplash associated disorders

Abstract

Whiplash is caused by an acceleration-/deceleration transfer of energy to the neck. It commonly occurs in motor vehicle accidents. The force may result in lesions of the cervical spine and soft tissues, which may result in many clinical manifestations: whiplash associated disorders (WAD), according to the Quebec classification. However, the extent of coincident brainstem injury is still unknown. The symptoms of WAD vary, the commonest being: neck pain, concentration difficulties, headache, radicular symptoms, dizziness and visual disturbances. The difficulty of obtaining a documentation on the symptoms described by the patients is well known.

In Sweden every year about 10 000 persons suffer whiplash trauma. Six to 9 months after the accident 350 - 400 (i.e., 3.5 - 4 %) still have symptoms. They will be given the diagnosis of WAD. The aims of the study were: 1) to develop and evaluate an objective test to diagnose WAD; 2) to perform an otoneurologic examination of a series of patients having WAD with the purpose of finding extent of coincident brainstem injury; 3) to make an audiological study of speech reception; and 4) to investigate some cognitive performances - i.e., reading ability, simultaneous capacity and learning.

The investigation took the form of prospective clinical studies of consecutive patients. One series consisted of patients with tension-type headache, and the other series of WAD and various control groups. All patients and controls were examined with a method developed for this purpose, the smooth pursuit neck torsion (SPNT) test. Moreover, all patients with WAD underwent caloric, saccadic eye movement, auditory brainstem response tests, and pure tone audiometry. One selected group took the speech recognition-in-noise test. Another study group underwent a comprehensive neuropsychological test battery, including special tests for reading ability.

Results: The investigation of patients with tension-type headache showed that they had a distinct pattern in the SPNT test. Patients with WAD also had abnormal SPNT test results, but with a different pattern. The sensitivity of the SPNT test in WAD patients with dizziness was about 90 %, and in patients without dizziness 60 %. The specificity was about 80 %. Neck proprioception was affected in most of the patients. In most patients with WAD the neck, but seldom the brainstem cerebellum was affected. The audiological investigation showed that about 6 % might have had an accident-related bearing loss. However, 40 % of WAD patients with normal/subnormal hearing had self-reported hearing problems. Thirty percent of the WAD patients with normal/subnormal hearing in this study had abnormal speech recognition-in-noise. Patients with WAD also showed a considerably poorer reading level than matched controls. A significant relation was found between various reading parameters and the SPNT test. The neuropsychological test battery documented difficulties in simultaneous capacity and learning.

Conclusion The SPNT test proved to be valuable for documentation of WAD and the neck seems to be the major organ injured. The brainstem/cerebellum seldom seems to be damaged. Speech reception and reading difficulties were common. Moreover, simultaneous capacity and learning ability are probably reduced in patients with WAD.