Descriptive analysis of pathological and therapy-relevant cranial computed tomography scan findings in patients with anisocoria

Background: Anisocoria can be a war- ning sign of life-threatening neurological conditions. Especially in critical care patients, it is difficult to differentiate these from benign causes. Unfortunately, valid data are lacking to develop recom- mendations for a diagnostic algorithm. The aim of this study was to describe the frequency and type of pathological fin- dings in cranial computed tomographies (cCTs) in patients with anisocoria and the resulting therapeutic consequences. Methods: We performed a retrospective analysis of all patients of the University Hospital Frankfurt whose cCT indication contained the keywords ,,pupillary dif- ference" or ,,anisocoria" in the period between 1 Jan. 2004 and 31 Dec. 2017. Endpoints were pathological findings in the initial cCT and the rate and type of therapeutic consequences. Results: A total of 1,241 cCT requests due to anisocoria were identified. After exclusion of control cCTs and incom- plete data sets, the data of 788 patients were evaluated. Pathological findings were described in 198 (25.1 %) cCTs. The highest rate of pathological cCTs was determined in neurological / neuro- surgical intensive care patients, closely followed by anaesthesiological-surgical critical care patients (maxillofacial, cardiac, visceral, vascular surgery and urology) with > 40 % pathological cCTs. Of the total 119 surgical procedures performed in response to a pathological cCT, 74.8 % were performed on neuro- logical/neurosurgical patients. Conclusion: Valid data on the therapeu- tic relevance of cCT for anisocoria are highly relevant, as these would allow differential assessment, especially in emergency situations. Overall, we found a high proportion of pathological cCT findings, especially in intensive care patients. Further studies are needed to develop a risk -adjusted diagnostic algo- rithm especially in unconscious patients.