Presenting symptoms and signs after whiplash injury: the influence of accident mechanisms.

OBJECTIVE: To assess the relationship between accident mechanisms and initial findings after whiplash injury.

DESIGN: Cohort study.

SETTING: Outpatient department, Department of Neurology, University of Berne, Switzerland.

PATIENTS: A population-based sample of 137 consecutive patients referred by primary care physicians. Fractures or dislocations of the cervical spine, head trauma, and preexisting neurologic disorders were exclusion criteria.

MAIN OUTCOME MEASURES: Patients were interviewed and examined within 7.2 days (SD, 3.9 days) after trauma. Analyzed accident features were position in the car, use of seat belt, head restraint and its point of head contact, damage to seat, head position and state of preparedness at the moment of impact, and type of collision. Analyzed symptoms were intensity and onset delay of post-traumatic head and neck pain; pain in the shoulders, back, and anterior neck; symptoms of neurologic dysfunction according to presumed origin--cranial nerve or brainstem, radicular or myelopathic; and a score of multiple symptoms. Analyzed signs were neck muscle tenderness and restricted neck movement, and signs of cranial nerve, brainstem, or radicular dysfunction.

RESULTS: Passenger position in the car, use of seat belt, and the presence of a head restraint showed no significant relationship with findings. Rotated or inclined head position at the moment of impact was associated with a higher frequency of multiple symptoms (p = 0.045 and 0.008) with more severe symptoms and signs of musculoligamental cervical strain (p = 0.048 and 0.038) and of neural, particularly radicular (p = 0.031 and 0.019), damage. Unprepared occupants had a higher frequency of multiple symptoms (p = 0.031) and more severe headache (p = 0.046). Rear-end collision was associated with a higher frequency of multiple symptoms (p = 0.006), especially of cranial nerve or brainstem dysfunction (p = 0.00003).

CONCLUSION: Three features of accident mechanisms were associated with more severe symptoms: an unprepared occupant; rear-end collision, with or without subsequent frontal impact; and rotated or inclined head position at the moment of impact.