A need for a standardized cognitive outcome measure in subarachnoid hemorrhage clinical studies

Cognitive Impairment, Functional Outcome, and Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Measures such as modified Rankin Scale (mRS) may not reflect cognitive outcome following aneurysmal subarachnoid hemorrhage. The aim of this study was to assess the relationship between functional outcome, measured by mRS, and cognition, measured by mini-mental state examination (MMSE), after aSAH. A secondary analysis evaluated the impact of delayed cerebral ischemia (DCI) on the proportion of patients who had cognitive impairment.

METHODS

We performed a post hoc analysis of the Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1) trial data. MMSE and mRS scores were compared using Kruskal-Wallis equality-of-populations rank test with pairwise comparison post hoc analysis. Cognitive impairment was defined as MMSE score <27. A stepwise logistic regression model evaluated whether DCI was a predictor of cognitive impairment.

RESULTS

CONSCIOUS-1 comprised 413 patients. Of these, 337 took an MMSE at their 12-week follow-up. Mean MMSE score was 27 with a median of 29 (range, 0-30; SD 5.4). There were no significant differences between MMSE scores of patients who had 12-week mRS scores of 0-2. On multivariate analysis, DCI was independently associated with cognitive impairment after aSAH.

CONCLUSIONS

Patients considered to have a good outcome on mRS had varying degrees of cognitive function on MMSE, whereas development of DCI was an independent predictor of cognitive impairment after aSAH. MMSE may not be sensitive enough to discern subtle defects in cognition, as the median score was 29 out of 30.

Cognitive Sequelae of Unruptured and Ruptured Intracranial Aneurysms and their Treatment: Modalities for Neuropsychological Assessment

BACKGROUND

Cognitive sequelae frequently follow subarachnoid hemorrhage (SAH) and include deficits across multiple domains of executive function. This factor affects overall functional outcomes negatively, especially in younger patients. Several clinical correlates predict development and severity of cognitive dysfunction after SAH. Hypothetical mechanisms of cognitive dysfunction in the absence of radiographic lesion include cerebral hypoperfusion and blood breakdown products, resulting in perturbed interneuronal communication and network synchrony, excitotoxicity, and altered microRNA expression.

METHODS

The PubMed database was searched for articles discussing cognitive outcomes in patients with unruptured and ruptured intracranial aneurysmal disease, sequelae of treatment, and modalities for neuropsychologic testing.

RESULTS

Treatment of unruptured intracranial aneurysms, although capable of preventing SAH, comes with its own set of complications and may also affect cognitive function. Neuropsychological tests such as the Montreal Cognitive Assessment, Mini-Mental Status Examination, and others have proved useful in evaluating cognitive decline. Studies using functional neurologic imaging modalities have identified regions with altered activation patterns during various cognitive tasks. The sum of research efforts in this field has provided useful insights and an initial understanding of cognitive dysfunction after aneurysm treatment and SAH that should prove useful in guiding and rendering future investigations more fruitful.

CONCLUSIONS

Development of finer and more sensitive neuropsychological tests in evaluating the different domains of cognitive function after aneurysm treatment and SAH in general will be useful in accurately determining outcomes after ictus and comparing efficacy of different therapeutic strategies.

Effects of preventive surgery for unruptured intracranial aneurysms on attention, executive function, learning and memory: a prospective cohort study

BACKGROUND

We prospectively evaluated the effects of preventive surgery for unruptured intracranial aneurysms on attention, executive function, learning and memory.

METHODS

Between March 2012 and June 2013, 56 patients were recruited for this study. Fifty-one patients met the inclusion criteria and were enrolled. Inclusion criteria were as follows: (1) age ≤65 years and (2) planned microsurgery or endovascular surgery for unruptured intracranial aneurysm. Exclusion criteria were as follows: (1) preoperative intelligence quotient <80 (n = 3); (2) initial modified Rankin scale ≥1 (n = 1); (3) loss to follow-up (n = 1). An auditory controlled continuous performance test (ACCPT), word-color test (WCT) and verbal learning test (VLT) were performed before and after (6 months) preventive surgery.

RESULTS

ACCPT (attention), WCT (executive function) and VLT (learning and memory) scores did not change significantly between the pre- and postoperative evaluations. The ACCPT, WCT, total VLT scores (verbal learning) and delayed VLT scores (memory) did not differ significantly between patients undergoing microsurgery and those undergoing endovascular surgery. However, ACCPT, WCT and delayed VLT scores decreased postoperatively in patients with leukoaraiosis on preoperative FLAIR images (OR 9.899, p = 0.041; OR 11.421, p = 0.006; OR 2.952, p = 0.024, respectively).

CONCLUSIONS

Preventive surgery for unruptured intracranial aneurysms did not affect attention, executive function, learning or memory. However, patients with leukoaraiosis on FLAIR images might be prone to deficits in attention, executive function and memory postoperatively, whereas learning might not be affected.

Inflammation, negative nitrogen balance, and outcome after aneurysmal subarachnoid hemorrhage

OBJECTIVE

To analyze the impact of inflammation and negative nitrogen balance (NBAL) on nutritional status and outcomes after subarachnoid hemorrhage (SAH).

METHODS

This was a prospective observational study of SAH patients admitted between May 2008 and June 2012. Measurements of C-reactive protein (CRP), transthyretin (TTR), resting energy expenditure (REE), and NBAL (g/day) were performed over 4 preset time periods during the first 14 postbleed days (PBD) in addition to daily caloric intake. Factors associated with REE and NBAL were analyzed with multivariable linear regression. Hospital-acquired infections (HAI) were tracked daily for time-to-event analyses. Poor outcome at 3 months was defined as a modified Rankin Scale score ≥ 4 and assessed by multivariable logistic regression.

RESULTS

There were 229 patients with an average age of 55 ± 15 years. Higher REE was associated with younger age (p = 0.02), male sex (p < 0.001), higher Hunt Hess grade (p = 0.001), and higher modified Fisher score (p = 0.01). Negative NBAL was associated with lower caloric intake (p < 0.001), higher body mass index (p < 0.001), aneurysm clipping (p = 0.03), and higher CRP:TTR ratio (p = 0.03). HAIs developed in 53 (23%) patients on mean PBD 8 ± 3. Older age (p = 0.002), higher Hunt Hess (p < 0.001), lower caloric intake (p = 0.001), and negative NBAL (p = 0.04) predicted time to first HAI. Poor outcome at 3 months was associated with higher Hunt Hess grade (p < 0.001), older age (p < 0.001), negative NBAL (p = 0.01), HAI (p = 0.03), higher CRP:TTR ratio (p = 0.04), higher body mass index (p = 0.03), and delayed cerebral ischemia (p = 0.04).

CONCLUSIONS

Negative NBAL after SAH is influenced by inflammation and associated with an increased risk of HAI and poor outcome. Underfeeding and systemic inflammation are potential modifiable risk factors for negative NBAL and poor outcome after SAH.