Underlying aetiology of acute intracerebral haemorrhage and associations between outcome measures, findings on initial computed tomography scan and ICH classification systems: an observational historical cohort study

Introduction Intracerebral haemorrhage (ICH) accounts for approximately 15% of all strokes in Denmark and remains associated with high mortality and morbidity. It is challenging to distinguish neoplastic from non-neoplastic causes of ICH in the acute setting, and CT findings that may aid early differentiation have not been fully characterised.

Existing ICH-classification systems (SMASH-U, H-ATOMIC and CLAS-ICH) have not been directly compared for diagnostic accuracy in this setting. Identifying radiological and clinical factors associated with underlying aetiology may support faster diagnosis, reduce time to workup related to potential underlying cancer and facilitate early targeted treatment of the underlying cause of ICH.

Methods and analysis This study is a retrospective observational cohort including all patients admitted with acute ICH to the Department of Neurology, University Hospital of Southern Denmark, Aabenraa between January 2014 and December 2024 (estimated approximately n=610). Medical records and initial non-enhanced CT scans will be reviewed.

Two neurologists and two radiologists, blinded to final diagnosis, will independently extract clinical presentation, topographical and volumetric haemorrhage characteristics, and classify each case using the abovementioned ICH-classification systems.