Comparison of postoperative cognitive function in patients undergoing surgery for ruptured and unruptured intracranial aneurysm

Relationship between Deep White Matter Hyperintensities on Magnetic Resonance Imaging and Postoperative Cognitive Function Following Clipping of Unruptured Intracranial Aneurysm

To evaluate the effects on cognitive function of deep white matter hyperintensities (DWMHs) on magnetic resonance imaging (MRI) in patients treated surgically for unruptured intracranial aneurysms (UIAs). The subjects were 106 patients in whom a Wechsler adult intelligence scale-revised (WAIS-R) examination was performed 1 week before and 1 month after clipping surgery for asymptomatic UIAs. DWMH severity was evaluated on preoperative MR images by Fazekas scale, as follows: none (absence), mild (punctate foci), moderate (beginning confluence of foci), or severe (large confluent areas). A decrease of 7 or more points in intelligence quotient (IQ) postoperatively was considered deterioration. Fazekas score was none in 41 (none group), mild in 42 (mild group), moderate in 21, and severe in 2 patients (moderate/severe group). Patient characteristics, surgical factors, IQ change, and abnormal findings on postoperative MRI were compared among the groups. Although there was no statistically significant deterioration in IQ postoperatively in any group, the percentage of deteriorated patients was significantly higher in the moderate/severe group (34.8%) than in the other groups (4.9% in the none group, 7.1% in the mild group; p <0.01, p <0.05, respectively). Brain injury was observed more frequently on postoperative MR images in the moderate/severe group (17.4%) compared with the none group (2.4%; p = 0.052). The presence of moderate/severe DWMHs was an independent prognostic factor for postoperative cognitive dysfunction. In conclusion, the presence of moderate/severe DWMHs was a prognostic factor for postoperative cognitive dysfunction after surgery for UIAs.

The neuropsychological assessment battery (NAB) is a valuable tool for evaluating neuropsychological outcome after aneurysmatic subarachnoid hemorrhage

Background

Detecting and treating neuropsychological deficits after aneurysmatic subarachnoid hemorrhage (aSAH) play a key role in regaining independence; however, detecting deficits relevant to social and professional reintegration has been difficult and optimal timing of assessments remains unclear. Therefore, we evaluated the feasibility of administering the Neuropsychological Assessment Battery screening module (NAB-S) to patients with aSAH, assessed its value in predicting the ability to return to work and characterized clinical as well as neuropsychological recovery over the period of 24 months.

Methods

A total of 104 consecutive patients treated for aSAH were recruited. After acute treatment, follow up visits were conducted at 3, 12 and 24 months after the hemorrhage. NAB-S, Montreal Cognitive Assessment (MoCA) and physical examination were performed at each follow up visit.

Results

The NAB-S could be administered to 64.9, 75.9 and 88.9% of the patients at 3, 12 and 24 months, respectively. Moderate impairment of two or more neuropsychological domains (e.g speech, executive function, etc.) significantly correlated with inability to return to work at 12 and 24 months as well as poor outcome assessed by the extended Glasgow Outcome Scale (GOSE) at 3, 12 and 24 months. The number of patients with favorable outcomes significantly increased from 25.5% at discharge to 56.5 and 57.1% at 3 and 12 months, respectively, and further increased to 74.1% after 24 months.

Conclusion

The NAB-S can be administered to the majority of patients with aSAH and can effectively detect clinically relevant neuropsychological deficits. Clinical recovery after aSAH continues for at least 24 months after the hemorrhage which should be considered in the design of future clinical trials.

Computerized 4-choice reaction time test for the measurement of psychomotor recovery after general anesthesia

The recovery of patients after general anesthesia is usually estimated by using clinical scores. Since there is a lack of objective methods for assessing psychomotor recovery, the aim of this study was to evaluate three psychological tests for this purpose. Patients, scheduled for ambulatory gynecological surgery, underwent 3 standard psychological tests before (T1), 15 min after the surgery (T2) and on discharge from the recovery room (T3). The tests used were Wechsler memory scale (test 1, working memory capacity), d2-test (test 2, concentration endurance) and computer-based 4-choice-reaction time (4CRT, test 3, reaction time) as well as Postanesthesia Discharge Scoring System (PADSS). The same test battery was used in healthy female volunteers, all test results were compared at the different time points. In 109 patients, working memory capacity and concentration (tests 1 and 2) decreased, the reaction time (test 3) was prolonged at T2 in comparison with T1 and T3 (P < 0.01). PADSS increased from 8 (T2) to 10 (T3) (medians, P < 0.001). Fifty-seven healthy volunteers demonstrated a practice effect in all 3 tests through the course of the study (P <0.01). 4CRT test had shortest duration and enabled computerized data processing. All three tests objectively assess the recovery of psychomotor function in patients after general anesthesia, the computer-based 4CRT seems to be the most convenient for the clinical routine.

RECOVERY OF MEMORY AFTER CEREBRAL ARTERY ANEURYSM SURGERY

The principal study objective was to define whether memory deficits (numerical, working, verbal-mechanical, verbal-logical and visual memory) occurred in patients submitted to surgery for brain artery aneurysm and whether significant recovery of memory took place with time. The study sample included 92 patients, i.e. 35 (38%) male and 57 (62%) female patients aged 27 to 76 years. Neuropsychological testing was conducted at Zagreb University Hospital Centre, Department of Neurosurgery, from 1998 to 2012, in two time intervals: first within 11 months following surgery, and then 12 to 48 months after surgery. The obtained results showed that verbal-mechanical, verbal-logical, and visual memory deficits were present in the first testing interval. In the second testing, the verbal-logical and visual memory deficits were still present, while the tests of verbal-mechanical memory showed deficits in capacity and learning curve, but the results for short- and long-term memory were within the normal ranges. Neither the first nor the second testing showed deficits of numerical and working memory. Based on our results, we can conclude that long-term verbal-mechanical and visual short- and long-term memory had recovered to a statistically significant level, whereas other types of memory showed no significant recovery.

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.

Towards use of MRI-guided ultrasound for treating cerebral vasospasm

Cerebral vasospasm is a major cause of morbidity and mortality in patients with subarachnoid hemorrhage (SAH), causing delayed neurological deficits in as many as one third of cases. Existing therapy targets induction of cerebral vasodilation through use of various drugs and mechanical means, with a range of observed efficacy. Here, we perform a literature review supporting our hypothesis that transcranially delivered ultrasound may have the ability to induce therapeutic cerebral vasodilation and, thus, may one day be used therapeutically in the context of SAH. Prior studies demonstrate that ultrasound can induce vasodilation in both normal and vasoconstricted blood vessels in peripheral tissues, leading to reduced ischemia and cell damage. Among the proposed mechanisms is alteration of several nitric oxide (NO) pathways, where NO is a known vasodilator. While in vivo studies do not point to a specific physical mechanism, results of in vitro studies favor cavitation induction by ultrasound, where the associated shear stresses likely induce NO production. Two papers discussed the effects of ultrasound on the cerebral vasculature. One study applied clinical transcranial Doppler ultrasound to a rodent complete middle cerebral artery occlusion model and found reduced infarct size. A second involved the application of pulsed ultrasound in vitro to murine brain endothelial cells and showed production of a variety of vasodilatory chemicals, including by-products of arachidonic acid metabolism. In sum, nine reviewed studies demonstrated evidence of either cerebrovascular dilation or elaboration of vasodilatory compounds. Of particular interest, all of the reviewed studies used ultrasound capable of transcranial application: pulsed ultrasound, with carrier frequencies ranging between 0.5 and 2.0 MHz, and intensities not substantially above FDA-approved intensity values. We close by discussing potential specific treatment paradigms of SAH and other cerebral ischemic disorders based on MRI-guided transcranial ultrasound.

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.

Unruptured intracranial aneurysm treatment effects on cognitive function: a meta-analysis

OBJECTIVE

The treatment of an unruptured intracranial aneurysm (UIA) is not free of morbidity and mortality, and the decision is made by weighing the risks of treatment complications against the risk of aneurysm rupture. This meta-analysis quantitatively analyzed the literature on the effects of UIA treatment on cognition.

METHODS

MEDLINE, Embase, and PsycInfo were systematically searched for studies that reported on the cognitive status of UIA patients before and after aneurysm treatment. The search was restricted to prospective cohort and case-control studies published between January 1, 1998, and January 1, 2013. The analyses focused on the effect of treatment on general cognitive functioning, with an emphasis on 4 specific cognitive domains: executive functions, verbal and visual memory, and visuospatial functions.

RESULTS

Eight studies, with a total of 281 patients, were included in the meta-analysis. Treatment did not affect general cognitive functioning (effect size [ES] -0.22 [95% CI -0.78 to 0.34]). Executive functions and verbal memory domains trended toward posttreatment impairment (ES -0.46 [95% CI -0.93 to 0.01] and ES -0.31 [95% CI -1.24 to 0.61]), and performance of visual memory tasks trended toward posttreatment improvement (ES 1.48 [95% CI -0.36 to 3.31]). Lastly, treatment did not significantly affect visuospatial functions (ES -0.08 [95% CI -0.30 to 0.45]).

CONCLUSIONS

The treatment of an UIA does not seem to affect long-term cognitive function. However, definitive conclusions were not possible due to the paucity of studies addressing this issue.

Behavioral profile of unruptured intracranial aneurysms: a systematic review

Objectives

To systematically review the literature on the neuropsychological, psychosocial, and functional profiles of patients with unruptured intracranial aneurysms.

Methods

This review was limited to peer-reviewed research articles that reported cognitive, psychosocial, and/or functional profiles of patients with unruptured intracranial aneurysms. Studies were identified through Medline and PsychINFO by searching “(unruptured [intracranial OR cerebral] aneurysm) AND (cogniti* OR neuropsycholog* OR anxiety OR depression OR [quality of life] OR work OR employment OR [activities of daily living] OR [instrumental activities of daily living]).” Only articles that were published since January 1997 were considered. Reference lists of included articles were inspected for additional studies. Only articles in English were included. Case studies were excluded. Twenty-two articles were included in this review.

Results

The literature demonstrates that although treatment for unruptured intracranial aneurysms allays anxiety, it also results in an observable, though transient decline in cognition and daily functioning. Even before treatment, preliminary evidence hints that these patients are not free of such impairments.

Conclusions

The algorithm that underlies the decision to treat an unruptured intracranial aneurysm ought to add more weight to the neuropsychological, psychosocial, and functional profiles of these patients. The clinical relevance of these patients does not begin and end with their risk of rupture.

SAHIT Investigators--on the outcome of some subarachnoid hemorrhage clinical trials

Outcome of patients with aneurysmal subarachnoid hemorrhage (SAH) has improved over the last decades. Yet, case fatality remains nearly 40% and survivors often have permanent neurological, cognitive and/or behavioural sequelae. Other than nimodipine drug or clinical trials have not consistently improved outcome. We formed a collaboration of SAH investigators to create a resource for prognostic analysis and for studies aimed at optimizing the design and analysis of phase 3 trials in aneurysmal SAH. We identified investigators with data from randomized, clinical trials of patients with aneurysmal SAH or prospectively collected single- or multicentre databases of aneurysmal SAH patients. Data are being collected and proposals to use the data and to design future phase 3 clinical trials are being discussed. This paper reviews some issues discussed at the first meeting of the SAH international trialists (SAHIT) repository meeting. Investigators contributed or have agreed to contribute data from several phase 3 trials including the tirilazad trials, intraoperative hypothermia for aneurysmal SAH trial, nicardipine clinical trials, international subarachnoid aneurysm trial, intravenous magnesium sulphate for aneurysmal SAH, magnesium for aneurysmal SAH and from prospectively-collected data from four institutions. The number of patients should reach 15,000. Some industry investigators refused to provide data and others reported that their institutional research ethics boards would not permit even deidentified or anonymized data to be included. Others reported conflict of interest that prevented them from submitting data. The problems with merging data were related to lack of common definitions and coding of variables, differences in outcome scales used, and times of assessment. Some questions for investigation that arose are discussed. SAHIT demonstrates the possibility of SAH investigators to contribute data for collaborative research. The problems are similar to those already documented in other similar collaborative efforts such as in head injury research. We encourage clinical trial and registry investigators to contact us and participate in SAHIT. Key issues moving forward will be to use common definitions (common data elements), outcomes analysis, and to prioritize research questions, among others.

Cognitive Outcome and Clinically Silent Thromboembolic Events After Coiling of Asymptomatic Unruptured Intracranial Aneurysms

BACKGROUND:

Thromboembolic events are the most common complication after coiling of unruptured intracranial aneurysms (UIAs). However, it remains unclear whether these clinically silent ischemic lesions (CSILs) have any clinical significance.

OBJECTIVE:

To evaluate cognitive outcome after coil embolization of asymptomatic UIAs and its relationship with CSILs after the procedure.

METHODS:

We prospectively enrolled 40 UIA patients who showed no new focal neurological deficit after coil embolization. CSILs were assessed with diffusion-weighted imaging (DWI) within 1 day after the procedure. A battery of neuropsychological tests was performed 3 times: preoperatively and postoperatively at 1 and 4 weeks after coil embolization.

RESULTS:

The incidence of cognitive impairment after coiling in patients with UIAs was 44% (17 of 39) at 1 week and 19% (7 of 37) at 4 weeks after coil embolization. DWI within 1 day after coil embolization revealed that 60% of patients (24 of 40) showed CSILs. However, no significant difference was found in any mean cognitive scores or in the number of cognitively impaired variables between patients with and without CSILs at weeks 1 and 4. Additional correlation analysis revealed no correlations between the number of CSILs on DWI and the cognitive sum z score at both 1 and 4 weeks.

CONCLUSION:

Exhaustive neuropsychological evaluation of UIA patients who underwent coil embolization demonstrated recovery or improvements from baseline cognitive function after 4 weeks, although some patients still showed cognitive deficits at 4 weeks after the procedure. However, we found no statistically significant relationship between the presence and number of CSILs on DWI and cognitive changes after the procedure.

Cognitive Function of Korean Neurosurgical Patients: Cross-sectional Study Using the Korean Version of the Mini-mental Status Examination

Objective

As interest in life quality and expectancy increases, cognitive dysfunction is becoming an important topic. Although there are many foreign articles on this topic, they require cultural interpretation to be applicable to Koreans. The purpose of this study was to assess cognitive function in Korean neurosurgical patients.

Methods

We recruited 214 adult Korean patients with various cerebral pathologies and treatments from an outpatient clinic. The male-to-female ratio was 88:126, and their ages ranged from 28 to 81 years (mean: 57.9 years). The Korean version of the mini-mental status examination (K-MMSE) was adopted as an instrument for measuring cognitive function, and a score ≤23 was defined as cognitive dysfunction. K-MMSE scores were analyzed considering the patients' gender, age, time elapsed since treatments, pathology and treatment modality. A serial analysis was performed for 59 patients who completed the K-MMSE more than once.

Results

The mean K-MMSE score of 214 patients was 22.3, and 133 patients (62.1%) had a score ≤23. Cognitive dysfunction was common regardless of age, gender, pathology or treatment modality. Serial analysis revealed K-MMSE score improvement in 45 of 59 patients (76.3%). The mean time interval between two tests was 11.9 months, and the mean K-MMSE score improvement was 2.7, which was statistically significant (P = 0.000). However, many still had cognitive impairment.

Conclusion

Most Korean neurosurgical patients showed cognitive dysfunction despite improvement after several months. Patients with trauma or ischemic disease were more vulnerable. More attention should be paid to neuropsychological complications such as cognitive dysfunction.

Operative and nonoperative linguistic outcomes in brain injury patients

OBJECTIVE AND BACKGROUND

Linguistic function is one of vulnerable aspects of traumatic brain injury (TBI) which may have destructive effects on patients' communicative activities and daily life, years following trauma. This paper attempts to answer the controversy whether surgery affects increase and decrease of linguistic impairment or not.

MATERIALS AND METHODS

Two hundred forty-one TBI patients aged 18-65 with abnormal CT findings and at least 20 minute post-trauma amnesia (PTA), who were conscious at discharge, participated in this study. Based on operative intervention, the samples were divided into two groups: operative and nonoperative. Cognitive and aphasic deficits were inspected formally and pragmatic disorder was informally appraised at discharge.

RESULTS

The groups had no significant differences in aphasia incidence and language pragmatic impairment, though they were significantly distinctive in aphasia subcategories and cognitive deficit after trauma. Fluent aphasia was more common in both groups alike. In aphasia subcategories, however, transcortical sensory aphasia (TSA) in operative and anomia in nonoperative group were the most prevalent. Several variables appeared strikingly related to higher aphasia in operative groups as follows: moderate to severe injury, 18-35 and over 50 years of age, more than 1 week PTA, intracranial surgery of multiple lesions in left or bilateral hemisphere fronto-temporal cortex plus post-trauma cognitive and pragmatic impairments, and diffuse axonal injuries.

DISCUSSION

Almost certainly, meaningful drop of cognitive function post surgery roots back in significant loss of initial consciousness level. Related factors to postoperative aphasia suggest taking policies through surgery intervention. Discerning the indispensable contributions of neurosurgeons, neurolinguists, and neuroscientists, results inspire more clinical future studies.