Vehicular factors affect injury location, severity and outcome.

**Hillary, F.G., Schatz, P., Newman, H., *Chute, D.

**Kessler Medical Rehabilitation Research & Education Corp. (KMRREC), Saint Joseph's University, *Drexel University


Abstract
Collision reports, emergency room, hospital and rehabilitation records were analyzed for 147 patients involved in motor vehicle collisions between 1985 and 1998 in the city of Philadelphia, PA. 75 patients sustained a moderate-to-severe TBI (as indicated by positive CT/MRI findings and GCS<12); 38 patients sustained a Mild TBI (as indicated by brief LOC and GCS 12-15), and 30 patients who sustained only peripheral injuries (as indicated by no LOC, GCS of 15, and only peripheral injury) served as non-TBI controls. Results of collision analysis and lesion locations indicated that patients surviving lateral versus frontal collisions were significantly more likely to sustain temporal lobe lesions [36% vs, 7%; X2(1) =10.9, p<.001] and had a significantly higher likelihood of sustaining skull fractures [50% vs, 26%; X2(1) = 4.1, p<.05]. Further analysis of the effects of angle of impact on brain lesion revealed that lateral collisions were not associated with a significant increase in diffuse axonal brain injury [X2(1)=.005, p=.94] or incidence of frontal lobe lesions [X2(1) = 446, p=.336] as compared to frontal collisions. Patients surviving lateral versus frontal collisions displayed similar Glasgow Coma Scale scores to those in lateral impacts, but significantly greater duration of loss of consciousness [t(55)=2.3, p=.022]. Functional outcome, as measured by Functional Independence Level scores, was significantly lower for individuals surviving lateral collisions (x=6.8 vs. 8.6) [t(37)=2.75; p<.01]. These results suggest that vehicular factors, such as angle of impact and weight of vehicle, should be documented upon admission to the emergency room as they ultimately effect severity of injury and outcome.
Introduction
  • Investigators from distinct fields have studied TBI factors (i.e., brain injury physiology, patient outcome) and motor vehicle collision factors (i.e., crash analysis, safety device efficacy) independent of one another.
  • Biomechanical research has indicated that head rotation may be largely responsible for DAI.
  • The effects of inertial and impact energies on brain injury have also been dissociated.
  • Collision reconstruction literatures indicate lateral collisions to be associated with greater injury & seatbelt efficacy may be reduced during lateral collisions.
  • In addition, occupants of the "struck" have been shown to sustain more severe injuries.

Study Participants
 TBI
(n=67)
Mild TBI
(n=36)
No TBI
(n=29)
Age (mean) 33.9 39 39.6
Gender: Male 68% 55% 73%
Gender: Female 32% 44% 26%
Seatbelt Use 21.3% 45.5% 36.8%
Mean LOC 6.0 2.7 1.4
Mean GCS 7.0 14.5 15.0
Mean Acute Days 28.3 5.3 2.7

Results


Discussion
  • Use of seatbelts remains an important prophilaxis to brain injury.
  • The data also indicate that, when brain injury is sustained, seatbelts may reduce the severity of the injury.
  • Findings indicate that MVC factors contribute to location of brain lesion, patient injury severity, and, potentially, recovery course.
  • Data supports the hypothesis that lateral collisions are associated with more severe brain injuries.
  • These findings indicate that the efficacy of seatbelts in reducing the incidence and severity of brain injury may be reduced during lateral collisions.
  • "Struck" vehicles were associated with more significant injury to their occupants.
  • Not previously noted, is the finding that, during single car collisions, striking a fixed object is associated with greater injury severity.

Implications & Future Directions
  • A multidisciplinary approach is critical to better understand the contribution to brain injury made by motor vehicle collision factors.
  • Through prospective collision analysis, an interdisciplinary team approach may elucidate the physical parameters causing TBI.
  • Neuropsychologists may play a role in tracking the incidence and severity of brain injury for newly implemented vehicle safety devices.
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