engleski

Multimodality Evoked Potentials in Patients with Whiplash Injuries from Traffic Accidents.

We have tried to evaluate the detectable dysfunction of neural pathways involved in the development of the acute and the late symptoms of Whiplash injury and propose the hypothesis how the dysfunction develops. The measurements were made on 30 patients (21 male, 9 female, mean age 37+/-7,5 yrs) with recent (less than 30 days old) Whiplash injury, treated as out-patients at the Dpt. of Neurosurgery and Dpt. of Neurology, Univ. Hospital “Sestre milosrdnice”. All of the subjects have been injured in the traffic accidents. We have compared their findings to those of the sex and age-matched group of normal controls (21 male, 9 female, mean age 38+/-9,7 yrs). We have compared the values of latencies and amplitudes of the main components of auditory (Brainstem Auditory Evoked Response, BAER), somatosensory (SSEP), visual (VEP) and cognitive (Event-related Potentials, ERP) in the group of subjects suffering from the recent Whiplash injury and the normal controls. All recordings have been done using Medelec Sensor and analyzed using Apple Macintosh computer equipment. Recordings were made immediately after the admission and again three months and one year after the injury. The evoked potentials proved to be the sensitive indicators of subtle neurophysiologic changes among patients suffering from Whiplash injury. Our results showed that the absolute latencies of waves I, III and V were significantly longer in the group of patients suffering from recent Whiplash injury (p<0.05). IPL I-III and III-V were also significantly longer in the group of patients suffering from recent Whiplash injury (p<0.05), both immediately after the admission and subsequently three months and one year after that. The amplitude of wave I was significantly lower immediately after the injury (p<0.05), while no significant differences could be observed later. We found no significant differences in SSEP latency values immediately after the admission. Some, although not statistically significant differences of the late components (N20, P25) latencies were observed three months and one year after the injury (p>0.05). No statistically significant differences of amplitudes had been observed. The values of latencies of VEP components in the group of patients suffering from recent whiplash injury and normal controls immediately after the admission showed significantly longer absolute latencies of P100 and N145 in the group of patients suffering from recent whiplash injury (p<0.05). No statistically significant differences of amplitudes were detected. While the first follow-up results, three months after the injury had seemed to indicate the rather quick progresion of the dysfunction, the results obtained one year after that remained the same and showed no further progression. We have found no significant differences of ERP latencies or amplitudes immediately after the admission, but the results obtained three months after that and again after one year showed a clear increase of parietal P300 latencies, suggesting a development of cognitive dysfunction. No significant differences of amplitude values were observed. We believe that our results show that at least two mechanisms are at work in the development of neural dysfunction after the Whiplash injury. The first is acting quickly and mostly affecting the amplitudes and the early components of the evoked potentials, and the abnormalities caused by it are reversible. This mechanism might be the direct commotion of the neural tissue. The other is acting more slowly and affecting primarily the latencies late components, mostly generated in distant neural generators. This mechanism might be the demyelination, prolonged vascular insufficiency or both.

evoked potentials; whiplash injury

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