title: MRI detection of cerebral lesions in post-traumatic anisocoria: specificity and prognostic significance.
abstract: OBJECTIVE
  To identify whether increased numbers of brainstem lesions are found in the presence of a post-traumatic pupillary function disturbance and classify them anatomically.
  
  
  METHODS
  In this study, a diagnostic magnetic resonance imaging (MRI) examination was performed within 8 days after traumatic brain injury (TBI) in patients who had been unconscious for more than 24 hours post-TBI. The Glasgow Outcome Scale was evaluated 6 months after TBI. The data obtained from 140 consecutively enrolled patients between 2005 and 2011 were analysed. The clinical study parameter comprised the development of post-traumatic anisocoria at least once over the course between onset of trauma and diagnostic MRI, as a yes/no decision. Significance was presumed at p≤0.05.
  
  
  RESULTS
  A total of 57 patients (41%) were found to have a lesion at MRI without involvement of the brainstem; in 83 (59%) the brainstem was (multiple) affected. Of the latter, 66 (46%) of patients had lesions in the midbrain, 38 (27%) in the pons, and seven (5%) in the medulla oblongata. By the time of MRI, anisocoria had been diagnosed in 45 (32%) patients. Mortality was highest, at 58%, in patients with anisocoria and a midbrain lesion, whilst it was 23% in those with anisocoria and no lesion in the midbrain. Mortality was 33% in relation to a midbrain lesion without anisocoria.
  
  
  CONCLUSIONS
  Overall, the study demonstrated that there is a significant correlation between midbrain lesions and post-traumatic anisocoria in unconscious trauma patients. A brainstem lesion in this case can be assumed to be a pathomorphological correlate of anisocoria. The rate of damage to the midbrain was approximately 50% in cases of transient anisocoria. It can be assumed in this situation that there are functional disorders of the peripheral oculomotor nerve or identifiable/unidentifiable lesions of the brainstem.
authors.affiliation: Department of Neurosurgery, Hospital Landshut, Robert-Koch-Straße 1, 84034 Landshut, Germany. Electronic address: Dieter.Woischneck@klinikum-landshut.de.
authors.forename: D
authors.initials: D
authors.lastname: Woischneck
authors.affiliation: Section Neuroradiology, University Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany. Electronic address: Bernd.Schmitz@uniklinik-ulm.de.
authors.forename: B
authors.initials: B
authors.lastname: Schmitz
authors.affiliation: Department of Neurosurgery, University Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany. Electronic address: Thomas.Kapapa@uniklinik-ulm.de.
authors.forename: T
authors.initials: T
authors.lastname: Kapapa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015875:Anisocoria / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000473:pathology; D000070642:Brain Injuries, Traumatic / Q000150:complications*; D001933:Brain Stem / Q000000981:diagnostic imaging / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008636:Mesencephalon / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult