title: The localizing value of asymmetry in pupillary size in severe head injury: relation to lesion type and location.
abstract: Reliable Assessment of the probability that a head injury patient harbors a surgical intracranial lesion is critical to both triage and treatment. The authors analyzed data from 608 patients with severe head injuries (Glasgow Coma Scale score, < or = 8) in the Traumatic Coma Data Bank to assess the reliability of pupillary asymmetry in predicting the presence and location of an intracranial mass lesion. Of 210 patients with pupillary asymmetry of > or = 1 mm, 63 (30%) had intracranial mass lesions, 52 (25%) of which were extra-axial in location, 38 (73%) of these located ipsilateral to the larger pupil. Of 51 patients with asymmetry of > or = 3 mm, 22 (43%) had intracranial mass lesions, 18 (35%) of which were extra-axial in location, 14 (64%) of these located ipsilateral to the larger pupil. For both asymmetry categories, strong interactions were found with age and mechanism of injury, the highest incidence of extra-axial lesions occurring in older patients injured other than as occupants of motor vehicles. The authors developed regression equations that provide a graphic means to predict the presence of an intracranial hematoma using data on pupillary asymmetry, age, and mechanism of injury. This predictive model, interpreted in a hospital- and patient-specific fashion, should be of significant use in directing triage, activating diagnostic and therapeutic resources, and evaluating the utility of exploratory trephination.
authors.affiliation: Department of Surgery, University of California-San Diego Medical Center.
authors.forename: R M
authors.initials: RM
authors.lastname: Chesnut
authors.forename: T
authors.initials: T
authors.lastname: Gautille
authors.forename: B A
authors.initials: BA
authors.lastname: Blunt
authors.forename: M R
authors.initials: MR
authors.lastname: Klauber
authors.forename: L E
authors.initials: LE
authors.lastname: Marshall
mesh_terms: D000063:Accidents, Traffic; D015875:Anisocoria / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D001930:Brain Injuries / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D001931:Brain Mapping / Q000379:methods*; D002543:Cerebral Hemorrhage / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D004292:Dominance, Cerebral / Q000502:physiology*; D015600:Glasgow Coma Scale; D016489:Head Injuries, Closed / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D009460:Neurologic Examination / Q000379:methods* / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D011336:Probability; D011446:Prospective Studies; D012025:Reflex, Pupillary / Q000502:physiology*; D012307:Risk Factors; D014057:Tomography, X-Ray Computed