in each one of these patients , the clinical features ( an explosive headache , relapsing in three , and a normal neurological examination ) together with appropriate laboratory investigations ( cerebro-spinal fluid analysis , electroencephalography , echoencephalography , brain scan , arteriography , pneumoencephalography ) have ruled out the diagnosis of subarachnoid hemorrhage , as well as less common causes of explosive headaches such as ball-valve tumors of the ventricular system , intra-cerebral hemorrhage , hemorrhage into a tumor .
C0038525
subarachnoid hemorrhage
C0019080
hemorrhage