twenty patients , who had sustained a proven subarachnoid haemorrhage ( sah ) and in whom cerebral panangiography had failed to reveal any source of the bleeding ( sah-nud ) , were subjected to a neuropsychological examination involving memory functions , spatial perceptual organization , visuoconstructive abilities , reasoning , perceptual speed and accuracy , and concept formation .
C0019080
bleeding
C0038525
sah