Hrev_master [Emergency Care Journal 2017; 13:6681] [page 51] Subarachnoid haemorrhage? Think again Cjien-Ting Liu,1 Chien-Chin Hsu,1,2 Kuo-Tai Chen1,3 1Emergency Department, Chi-Mei Medical Center, Tainan; 2Department of Biotechnology, Southern Tainan University of Technology; 3Department of Emergency Medicine, Taipei Medical University, Taipei A 69-year-old male patient was admit- ted to a hospital for acute cerebral infarc- tion. During hospitalisation, he developed pneumonia, septic shock, bowel ischemia, and acute renal failure, and was transferred to our hospital for further treatment. On arrival, he underwent another non-contrast enhanced cranial computed tomography (CT), which suspected the presence of sub- arachnoid haemorrhage (SAH) (Figure 1). We then consulted a neurosurgeon urgently but additional image studies were avoided to prevent contrast agent-related nephrotox- icity. Subsequent radiology confirmed that the cranial CT displayed pseudo-SAH, which may have resulted from hypoxic encephalopathy-induced severe cerebral oedema. The patient was administered broad- spectrum antibiotics, aggressive haemody- namic support for septic shock, and manni- tol infusion for the cerebral oedema. However, the sepsis progressed and he died 6 days after admission from multiple organ failure. Marked cerebral oedema may develop in patients with hypoxic encephalopathy, severe head trauma, meningitis, postradia- tion therapy, and hypervolemia.1,2 Several studies have reported that cranial CT of such patients sometimes reveals increased attenuation along the basal cisterna or corti- cal sulci, which mimics SAH.1-3 The key to differentiating true and pseu- do-SAH is identifying the presence of severe cerebral oedema in the absence of a large amount of subarachnoid blood or a substantial parenchymal haematoma on a cranial CT scan. Cranial CT of pseudo-SAH will show the marked effacement of sulci and basal cisterns, slit-like ventricles, and poor grey-white matter differentiation.1,2 Furthermore, the distribution of blood along the fissure and sulci exhibits irregular hyperdensity in true SAH, whereas it dis- plays a smoother line in pseudo-SAH. References 1. Avrahami E, Katz R, Rabin A, Friedman V. CT diagnosis of non-traumatic haem- orrhage in patients with brain edema. Eur J Radiol 1998;28:222-5. 2. Rabinstein AA, Pittock SJ, Miller GM, et al. Pseudosubarachnoid haemorrhage in subdural haematoma. J Neurol Neurosurg Psychiatry 2003;74:1131-2. 3. Yuzawa H, Higano S, Mugikura S, et al. Pseudo-subarachnoid haemorrhage found in patients with postresuscitation encephalopathy: characteristics of CT findings and clinical importance. Am J Neuroradiol 2008;29:1544-9. Emergency Care Journal 2017; volume 13:6681 Correspondence: Kuo-Tai Chen, Emergency Department, Chi-Mei Medical Center 901 Chung-Hwa Road, Yung Kang, Tainan 710, Taiwan. E-mail: 890502@mail.chimei.org.tw Key words: subarachnoid haemorrhage; pseu- dosubarachnoid haemorrhage; cerebral oede- ma; computed tomography; misdiagnosis. Contributions: CTL: manuscript drafting. CCH: art work of the figure. KTC: manuscript revision. Conflict of interest: the authors declare no potential conflict of interest. Received for publication: 3 March 2017. Revision received: 20 September 2017. Accepted for publication: 22 September 2017. This work is licensed under a Creative Commons Attribution 4.0 License (by-nc 4.0). ©Copyright C-T. Liu et al., 2017 Licensee PAGEPress, Italy Emergency Care Journal 2017; 13:6681 doi:10.4081/ecj.2017.6681 Figure 1. Cranial computed tomography scan revealing increased attenuation along the basal cisterna or cortical sulci, which mimics SAH. In the absence of a large amount of subarachnoid blood or a parenchymal haematoma, images of pseudo-SAH show the marked effacement of sulci and basal cisterns, invisible ventricles, and poor grey-white matter differentiation. Non -co mmerc ial us e o nly