SHORT COMMUNICATION Sex differences in perihemorrhagic edema evolution after spontaneous intracerebral hemorrhage I. Wagner a , B. Volbers a , S. Kloska b , A. Doerfler b , S. Schwab a and D. Staykov a a Department of Neurology, University of Erlangen-Nuremberg; and b Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany Keywords: gender, intracerebral hemorrhage, perihemorrhagic edema Received 21 August 2011 Accepted 21 November 2011 Background and purpose: Clinical data on sex differences in perihemorrhagic edema (PHE) after intracerebral hemorrhage (ICH) are lacking. Methods: Patients with spontaneous supratentorial ICH who had received standard conservative treatment were identified retrospectively. PHE development was assessed over a 14-day period on follow-up CT scans (days 1, 2–4, 5–7, 8–11, and 12–14). ICH and PHE volumes were assessed semiautomatically and compared between men and women. Results: A total of 387 patients (233 men) were included. Starting at days 2–4, women showed lower PHE values (P < 0.05; days 2–4, 8–11) or a trend toward significance (P £ 0.1; days 5–7, 12–14). Conclusions: Female sex may predict lower PHE volumes. Introduction Intracerebral hemorrhage (ICH) causes immediate damage to the surrounding brain tissue by mechanical tissue disruption and mass effect of the hematoma. Blood and its breakdown products initiate a secondary cascade of neurotoxic and inflammatory processes in the tissue surrounding the hematoma, thereby leading to the development of perihemorrhagic edema (PHE) after ICH [1]. PHE has been shown to develop shortly after ICH and increases to approximately the double size of the hemorrhage within the first 7–11 days after the initial bleeding event [2] however, its clinical rele- vance has not been sufficiently established as yet [3]. Nevertheless, the additional mass effect caused by PHE may lead to clinical deterioration and even cause in- creased mortality, especially in larger ICH [2]. The pathophysiology of PHE is complex, and dif- ferent components, for example, thrombin, iron toxic- ity, inflammation, breakdown of the blood–brain barrier, and hemodynamic factors, seem to contribute to its formation [1]. We are currently not aware of any data indicating sex differences in the evolution of PHE after ICH; however, animal studies have shown that progesterone and estrogen reduce brain edema follow- ing experimental ischaemic stroke or traumatic brain injury [4–7]. Moreover, smaller injuries from equivalent insult and better functional outcomes in women have been demonstrated in animal models of focal and global cerebral ischaemia [8–11]. To investigate possible influences of biological sex on the development of PHE after ICH, we aimed to compare the course of PHE between men and women in a large retrospective cohort of patients with spontane- ous supratentorial ICH over a follow-up period of 2 weeks after symptom onset. Methods Patient selection Using data from our prospectively organized institu- tional ICH database, in which demographic, clinical, and radiological characteristics of all patients diag- nosed with ICH on admission are recorded, we included only subjects with spontaneous supratentorial ICH in this retrospective analysis. We excluded patients who were treated with prolonged moderate hypothermia, continuous hypertonic saline infusion, and patients who underwent surgery for hematoma evacuation. Further- more, patients who received <2 CT scans during the course of treatment were excluded from the analysis. The study was approved by our institutional review board. Imaging CT scans were performed on a fourth-generation scanner (Siemens Somatom, Erlangen, Germany). All Correspondence: I. Wagner, Department of Neurology, University of Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany (tel.: +49 9131 85 44530; fax: +49 9131 85 31160; e-mail: ingrid.wagner@uk-erlangen.de). Ó 2012 The Author(s) European Journal of Neurology Ó 2012 EFNS 1 European Journal of Neurology 2012 doi:10.1111/j.1468-1331.2011.03628.x