Abstract
BackgroundThis study aims to determine the relationship between pupillary reactivity, midline shift and basal cistern effacement on brain computed tomography (CT) in moderate-to-severe traumatic brain injury (TBI). All are important diagnostic and prognostic measures, but their relationship is unclear.MethodsA total of 204 patients with moderate-to-severe TBI, documented pupillary reactivity, and archived neuroimaging were included. Extent of midline shift and basal cistern effacement were extracted from admission brain CT. Mean midline shift was calculated for each ordinal category of pupillary reactivity and basal cistern effacement. Sequential Chi-square analysis was used to calculate a threshold midline shift for pupillary abnormalities and basal cistern effacement. Univariable and multiple logistic regression analyses were performed.ResultsPupils were bilaterally reactive in 163 patients, unilaterally reactive in 24, and bilaterally unreactive in 17, with mean midline shift (mm) of 1.96, 3.75, and 2.56, respectively (p = 0.14). Basal cisterns were normal in 118 patients, compressed in 45, and absent in 41, with mean midline shift (mm) of 0.64, 2.97, and 5.93, respectively (p < 0.001). Sequential Chi-square analysis identified a threshold for abnormal pupils at a midline shift of 7–7.25 mm (p = 0.032), compressed basal cisterns at 2 mm (p < 0.001), and completely effaced basal cisterns at 7.5 mm (p < 0.001). Logistic regression revealed no association between midline shift and pupillary reactivity. With effaced basal cisterns, the odds ratio for normal pupils was 0.22 (95% CI 0.08–0.56; p = 0.0016) and for at least one unreactive pupil was 0.061 (95% CI 0.012–0.24; p < 0.001). Basal cistern effacement strongly predicted midline shift (OR 1.27; 95% CI 1.17–1.40; p < 0.001).ConclusionsBasal cistern effacement alone is associated with pupillary reactivity and is closely associated with midline shift. It may represent a uniquely useful neuroimaging marker to guide intervention in traumatic brain injury.
Highlights
Severe traumatic brain injury (TBI) is a major cause of mortality and morbidity
Prognostic scoring systems for brain computed tomography (CT) in TBI emphasize imaging stigmata of raised intracranial pressure (ICP), such as midline shift and basal cistern effacement [9,10,11,12], and among clinicians, there is a view that an unreactive pupil can predict a degree of supra-tentorial mass effect
Mean midline shift was significantly increased in patients with available pupillary reactivity data (2.22 vs. 1.15 mm, p = 0.023) (Table 2)
Summary
Patients with TBI require rapid neurological examination, including assessment of pupil reactivity to light and consciousness level, and diagnostic evaluation by brain computed tomography (CT). Both pupil reactivity and CT characteristics provide important information to guide definitive management in TBI. Prognostic scoring systems for brain CT in TBI emphasize imaging stigmata of raised ICP, such as midline shift and basal cistern effacement [9,10,11,12], and among clinicians, there is a view that an unreactive pupil can predict a degree of supra-tentorial mass effect. This study aims to determine the relationship between pupillary reactivity, midline shift and basal cistern effacement on brain computed tomography (CT) in moderate-to-severe traumatic brain injury (TBI). All are important diagnostic and prognostic measures, but their relationship is unclear
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
