Cerebral cysticercosis mimicking subarachnoid hemorrhage: a case report

BACKGROUND: Dense exudate during the calcification of cerebral cysticercosis in basal subarachnoid space was easy to be misdiagnosed as subarachnoid hemorrhage (SAH); clinical evaluation and MRI can help differentiate SAH from pseudo-SAH. CASE PRESENTATION: A case of ventricular expansion accompanied by high-density shadows in cisterna circinata cerebri was taken to the hospital for treatment due to sudden faint. This patient was diagnosed as subarachnoid hemorrhage according to computed tomography (CT) in another hospital. We believe that the high density in cisterna circinata cerebri was misdiagnosed as subarachnoid hemorrhage (SAH) 1 year ago. The main etiology of SAH is aneurysm; non-aneurysmal SAH associated with cerebral cysticercosis is extremely rare. Only 5 patients have been reported. CONCLUSION: This case indicated that although the specificity of CT for SAH is very high, the physicians should be aware of rare false positive findings, called pseudo-SAH. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s41016-021-00258-w.