Abstract
With the increasing trend in traffic accidents, there has been a corresponding increase in whiplash injuries. As patients with whiplash injury complain of a variety of symptoms which are quite often resistant to treatment and since these injuries frequently involve litigation for compensation, there is a clear need for a precise definition of this clinical entity as well as effective methods of treatment.
Whiplash injury is often associated with vertigo, tinnitus, loss of hearing and headache. For this reason, many of these patients are first seen by otorhinologists. This study was undertaken to elucidate the otorhinological implications of this disorder. In addition, an experimental study with rabbits was conducted.
In a series of 135 cases of whiplash injuries, patients were given vestibular function and auditory tests, psychological examination with the Cornell Medical Index, and examination of the automatic functions with the Mecholyl test.
Relatively few disturbances were observed on the basis of the vestibular function tests the few that were found were predominantly central rather than peripheral in character. Central disorders were indicated in 20 to 25 per cent of the cases on the basis of tests for nystagmus, the optokinetic test and the pendular-rotation test.
Hearing was normal in 80.7 per cent of the cases. Most of those with hearing impairment showed a loss in the range of 15 to 35 dB, and in no case was a severe hearing loss found.
The psychosomatic aspects of this disorder were also investigated using both the Cornell Medical Index and the Mecholyl test because compensation, frequently involving lawsuits, is usually demanded by those injured in traffic accidents.
Personality tests employing the Cornell Medical Index showed 31.8 per cent of the patients with these traits in the III and IV categories, which reveal neurotic tendencies. In a control series the rate in these categories was 19.0 per cent. The incidence of neurotic tendencies was greater in those for those patients who were injured 1 to 3 months previously than for fresh cases of whiplash injuries.
The Mecholyl test revealed P+S reactive types in 63.3 per cent of the patients, which was almost twice as large as the number found in a control series of normal cases.
In the experimental study, whiplash injury was produced by subjecting rabbits to simulated accelerated gravitational forces of 2.13, 14.4 and 24.4 G. In two of the 33 rabbits used in this experiment, acceleration was followed by gradual deceleration.
The animals were observed for 7 to 10 days following the impact experiment but none showed any impairment of equilibrium or spontaneous nystagmus. E. N. G. recording of nystagmus induced with Mecholyl showed a tendency toward greater amplitude and frequency of nystagmus resulting from greater force of impact.
Histopathological examination revealed congestion of the labyrinth on both sides in 27 per cent of the test animals, and on only one side in the remaining animals. Congestion tended to be more marked in the animals that were subjected to greater impact.
Cochlear bleeding was observed in only one animal. Changes in the lumen of the lymphatic duct were not observable. The chief findings in the brain-stem and cerebellum were congestion and edema, which were more severe and found more frequently in test animals subjected to greater impact. In general, the main pathological changes were congestion and edema rather than hemorrhage, probably produced by circulatory disturbance due to the impact of the collision.
