A Prospective Study of Impairment of Cognition and Memory and Recovery after Subarachnoid Hemorrhage

Abstract

In this prospective study, a series of 89 patients with subarachnoid hemorrhage (SAH), most of whom had a "good" neurological outcome, were assessed with a range of tests of memory and cognition as inpatients and at 10 weeks and 12 months after SAH. On tests of verbal cognition and memory, most patients had scores in the normal range 12 months after SAH. However, a significant number of patients still showed impairment on tests of visuospatial construction and memory, mental flexibility, and psychomotor speed at the 12-month assessment. Statistical analyses were carried out for each test score to see whether aneurysm site, location of blood on the admission computed tomographic scan, vasospasm, ischemia, hydrocephalus, grades at admission to and at discharge from hospital, and Glasgow Outcome Scale score at follow-up were associated with test scores. Aneurysm site was not shown to be associated with performance on any test at any time, and the other complications of SAH had only minimal predictive value. The grade at discharge proved to be the best predictor of impairment of cognition and memory at both follow-up assessments. Older subjects did not recover to the same extent as younger subjects by the 12-month assessment. The authors conclude that the diffuse effects of SAH are more important than focal neuropathology in relation to cognitive impairment in this group of patients.

Prevalence and Determinants of Cognitive Complaints after Aneurysmal Subarachnoid Hemorrhage

“…Similarly, cognitive impairments most often concerned memory, and less often executive and visuospatial functioning [20,21], and rarely attention, which is in line with previous findings in SAH [6,20,21,22]. …”

Predictors for cognitive impairment one year after surgery for aneurysmal subarachnoid hemorrhage

“…But few former studies have shown that the amount of subarachnoid blood is directly related to cognitive outcome. In fact, most former studies with different assessment intervals for cognitive testing have failed to show any relationship at all [4,14,23,30,35,43]. We found only three former studies pointing out this relationship [17,19,24].…”

“…We recommend that future predictor studies separate amount of blood from location of blood. It is a problem that the Fisher grade combines degree of hemorrhage with location of subarachnoid blood as there exists some evidence that location of blood may be as important for late-outcome cognitive functioning as the amount of blood [24,30].…”

“…It has become well recognized that patients surgically treated for SAH often struggle with persisting cognitive impairments despite being neurologically intact [4,7,9,10,13,17,23,30,36,37,39,43]. Knowledge of the disease factors that influence long-term cognitive outcome after SAH is clinically important as such factors are possibly modifi-■ Abstract Objective To assess predictors for cognitive impairment one year after spontaneous subarachnoid hemorrhage (SAH).…”

“…Existing studies still lack consensus concerning which disease factors are the most influential for cognitive dysfunction after SAH and makes predictions in the present study open. Heterogeneous results are probably due to the large number of possible pre-, peri-, and post-operative factors that may influence the brain and recovery of cognitive functioning [3,10,13,23,26,30,36,37,39,[42][43][44]. Differences in methodology between cognitive studies may also produce heterogeneous results such as differences in test batteries applied for assessment of cognitive functions, small sample sizes and intra-sample heterogeneity [1,26,27,39].…”