A proposed definition of symptomatic vasospasm based on treatment of cerebral vasospasm after subarachnoid hemorrhage in Japan: Consensus 2009, a project of the 25(th) Spasm Symposium

BACKGROUND: There is a lack of unified information on diagnosis and treatment of cerebral vasospasm (CV) after subarachnoid hemorrhage (SAH) among the hospitals in Japan. Thus, the aim of the study was to define the current practice in this area based on a survey by Japanese neurosurgeons. METHODS: A survey on diagnosis and treatment of CV was sent to 414 hospitals each of which performs >100 neurosurgeries annually. RESULTS: Responses were received from 240 hospitals (58.0%). Because accurate criteria for diagnosis of symptomatic vasospasm (SVS) were used in only 33.8% of the hospitals, we proposed a clinical definition of SVS that was approved at the 25(th) Spasm Symposium (Consensus 2009). This definition is simplified as follows: (1) the presence of neurological worsening; (2) no other identifiable cause of neurological worsening; and (3) confirmation of vasospasm by medical examinations. The results also showed that the Fisher CT scale is used differently for patients with ICH or IVH, with 41.3% of cases with ICH/IVH based on SAH that met Fisher criteria classified into Fisher group 1, 2 or 3, and 46.3% classified into Fisher group 4. There were no major differences in prophylactic therapies of CV and therapy for cerebral ischemia among the hospitals. Endovascular treatment for vasospasm was performed in most hospitals (78.7%); however, the criteria differed among the hospitals: (1) angiographic vasospasm and SVS appeared (37.9%), (2) only when aggressive therapy was ineffective (41.4%). CONCLUSION: We established a clinical definition of SVS based on the results of this survey (Consensus 2009).