title: Lateral impact in closed head injury: a substantially increased risk for diffuse axonal injury--a preliminary study.
abstract: OBJECTIVE
  Assessment, whether location of impact causing different facial fracture patterns was associated with diffuse axonal injury in patients with severe closed head injury.
  
  
  METHODS
  Retrospectively all patients referred to the Trauma Unit of the University Hospital of Zurich, Switzerland between 1996 and 2002 presenting with severe closed head injuries (Abbreviated Injury Scale (AIS) (face) of 2-4 and an AIS (head and neck) of 3-5) were assessed according to the Glasgow Coma Scale (GCS) and the Injury Severity Score (ISS). Facial fracture patterns were classified as resulting from frontal, oblique or lateral impact. All patients had undergone computed tomography. The association between impact location and diffuse axonal injury when correcting for the level of consciousness (using the Glasgow scale) and severity of injury (using the ISS) was calculated with a multivariate regression analysis.
  
  
  RESULTS
  Of 200 screened patients, 61 fulfilled the inclusion criteria for severe closed head injury. The medians (interquartile ranges 25;75) for GCS, AIS(face) AIS(head and neck) and ISS were 3 (3;13), 2 (2;4), 4 (4;5) and 30 (24;41), respectively. A total of 51% patients had frontal, 26% had an oblique and 23% had lateral trauma. A total of 21% patients developed diffuse axonal injury (DAI) when compared with frontal impact, the likelihood of diffuse axonal injury increased 11.0 fold (1.7-73.0) in patients with a lateral impact.
  
  
  CONCLUSIONS
  Clinicians should be aware of the substantial increase of diffuse axonal injury related to lateral impact in patients with severe closed head injuries.
authors.affiliation: Department of Cranio-Maxillofacial Surgery, University Hospital of Zurich, Zurich, Switzerland. roger.zwahlen@zzmk.uzh.ch
authors.forename: Roger Arthur
authors.initials: RA
authors.lastname: Zwahlen
authors.forename: Ludwig
authors.initials: L
authors.lastname: Labler
authors.forename: Otmar
authors.initials: O
authors.lastname: Trentz
authors.forename: Klaus Wilhelm
authors.initials: KW
authors.lastname: Grätz
authors.forename: Lucas M
authors.initials: LM
authors.lastname: Bachmann
mesh_terms: D020833:Diffuse Axonal Injury / Q000209:etiology*; D005147:Facial Bones / Q000293:injuries*; D005260:Female; D016489:Head Injuries, Closed / Q000150:complications*; D006801:Humans; D008297:Male; D016017:Odds Ratio; D010294:Parietal Bone; D012044:Regression Analysis; D012189:Retrospective Studies; D012887:Skull Fractures / Q000209:etiology; D013100:Sphenoid Bone; D013701:Temporal Bone; D015599:Trauma Severity Indices