Evaluating the recovery of cognitive impairment in subarachnoid hemorrhage taking into consideration the practice effects.

Abstract

It is not completely clear whether there are differences in the evolution of the neuropsychological outcomes between the 2 intervention procedures (surgery and endovascular coiling) used in subarachnoid aneurysmatic hemorrhage. Some studies have investigated this topic but without completely controlling the effect of learning the tests. To analyze our data using 2 different statistical procedures that attempt to solve this problem. The sample consists of 70 patients who have suffered a subarachnoid hemorrhage: 40 treated by means of surgery and 30 by means of endovascular coiling. Two cognitive evaluations were performed at 4 and 12 months after the invention. Twenty-seven healthy subjects were also evaluated twice with a delay of 8 months. The data were analyzed using 2 different statistical procedures: one by Samra et al (2007) using z scores and the other by Crawford and Garthwaite (2007) using the regbuild.exe program. The results indicate there are no important differences between the 2 treatment groups in the evolution of the cognitive alterations. Despite an improvement in cognitive scores on repeat testing at 12 months, neither of the 2 treatment groups showed the same level of test-retest learning as healthy control subjects. The recovery of neuropsychological functions after a subarachnoid hemorrhage is similar with the 2 interventions. It is important to control the learning effect produced by the repeated administration of tests.