Natural history and medical treatment of cognitive dysfunction after spontaneous subarachnoid haemorrhage: review of current literature with respect to aneurysm treatment

2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage: A Guideline From the American Heart Association/American Stroke Association

AIM

The "2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage" replaces the 2012 "Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage." The 2023 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with aneurysmal subarachnoid hemorrhage.

METHODS

A comprehensive search for literature published since the 2012 guideline, derived from research principally involving human subjects, published in English, and indexed in MEDLINE, PubMed, Cochrane Library, and other selected databases relevant to this guideline, was conducted between March 2022 and June 2022. In addition, the guideline writing group reviewed documents on related subject matter previously published by the American Heart Association. Newer studies published between July 2022 and November 2022 that affected recommendation content, Class of Recommendation, or Level of Evidence were included if appropriate. Structure: Aneurysmal subarachnoid hemorrhage is a significant global public health threat and a severely morbid and often deadly condition. The 2023 aneurysmal subarachnoid hemorrhage guideline provides recommendations based on current evidence for the treatment of these patients. The recommendations present an evidence-based approach to preventing, diagnosing, and managing patients with aneurysmal subarachnoid hemorrhage, with the intent to improve quality of care and align with patients' and their families' and caregivers' interests. Many recommendations from the previous aneurysmal subarachnoid hemorrhage guidelines have been updated with new evidence, and new recommendations have been created when supported by published data.

Microglia activation, classification and microglia-mediated neuroinflammatory modulators in subarachnoid hemorrhage

Subarachnoid hemorrhage is a devastating disease with significant mortality and morbidity, despite advances in treating cerebral aneurysms. There has been recent progress in the intensive care management and monitoring of patients with subarachnoid hemorrhage, but the results remain unsatisfactory. Microglia, the resident immune cells of the brain, are increasingly recognized as playing a significant role in neurological diseases, including subarachnoid hemorrhage. In early brain injury following subarachnoid hemorrhage, microglial activation and neuroinflammation have been implicated in the development of disease complications and recovery. To understand the disease processes following subarachnoid hemorrhage, it is important to focus on the modulators of microglial activation and the pro-inflammatory/anti-inflammatory cytokines and chemokines. In this review, we summarize research on the modulators of microglia-mediated inflammation in subarachnoid hemorrhage, including transcriptome changes and the neuroinflammatory signaling pathways. We also describe the latest developments in single-cell transcriptomics for microglia and summarize advances that have been made in the transcriptome-based classification of microglia and the implications for microglial activation and neuroinflammation.

A Direct Correlation between Red Blood Cell Indices and Cognitive Impairment After Aneurysmal Subarachnoid Hemorrhage (aSAH)

BACKGROUND

Cognitive impairment can occur after aneurysmal subarachnoid hemorrhage (aSAH) though it commonly tends to be neglected. Red blood cell (RBC) indices are associated with long-term functional outcomes, while it is unclear whether RBC indices could be a potential predictor of cognitive decline after aSAH. We aimed to investigate the association between RBC indices and post-aSAH cognitive impairment at 1 year.

METHODS

Patients with aSAH received neuropsychological test by the Montreal Cognitive Assessment (MoCA) and underwent serum and cerebrospinal fluid (CSF) samples test. To determine the association between RBC indices and cognitive impairment after acute aSAH, we adjusted for demographic and vascular risk factors using multivariate logistic regression analysis.

RESULTS

Of the 126 patients included in this study, 33% (42/126) of them were diagnosed with cognitive impairment (MoCA＜26). After adjustment for potential confounders, increased mean corpuscular volume (MCV) (OR: 1.36, 95%CI: 1.19-1.55) and mean corpuscular hemoglobin (MCH) (OR: 1.61, 95%CI: 1.25-2.08), reflecting systemic iron status, are more likely to be associated with cognitive impairment after aSAH.

CONCLUSION

In this aSAH population, our data shows the positive association between MCH and MCV and cognitive impairment at 1 year.

Aneurysmal subarachnoid hemorrhage: A pilot study for using longitudinal cognitive and neuropsychological testing for functional outcomes

OBJECTIVES

Patients with aneurysmal subarachnoid hemorrhage (aSAH) often sustain substantial cognitive and functional impairment. Traditional outcome measures have emphasized radiographic and gross clinical outcomes, but cognitive and functional outcomes are less frequently documented. This pilot study assessed the feasibility of administering longitudinal cognitive and neuropsychological testing and tracked patterns of functional improvement in aSAH patients.

PATIENTS AND METHODS

Standardized cognitive and neuropsychological testing were administered to a prospective cohort of aSAH patients admitted for treatment to our tertiary care center. Thirty consecutive aSAH patients (Hunt and Hess score 1-3) were enrolled over 23-months and baseline evaluations were completed within 24-h after admission. Patients were followed prospectively after treatment (coiling or clipping) at 1-, 3-, 6-, and 12-months. Functional outcome measures included the Montreal Cognitive Assessment, the Neuropsychiatric Inventory-Questionnaire, and the Functional Activities Questionnaire.

RESULTS

Of the 30 patients, 23 (77%) followed-up at 3-months, 21 (70%) at 6-months, and 19 (63%) at 12-months. Improvement from baseline to follow-up at 12-months was noted for general cognitive function (p = .004), memory (p = .025), and executive function (p = .039), with the greatest improvement occurring within 6-months. Daily function also improved mostly within 6-months (p = .022) while changes in neuropsychological disturbances were insignificant from baseline to follow-up at 12-months (p = .216).

CONCLUSION

Standardized cognitive and neuropsychological testing provides metrics for evaluating functional outcomes following treatment of aSAH. The addition of a brief battery of tests to routine clinical and radiographic evaluations is feasible. The main limitations are related to practice and referral patterns, and future studies are needed to evaluate the impact of treatment modalities on functional outcomes.

Common Data Elements for Unruptured Intracranial Aneurysm and Subarachnoid Hemorrhage Clinical Research: Recommendations from the Working Group on Long-Term Therapies

OBJECTIVES

The goal for the long-term therapies (LTT) working group (WG) of the Unruptured Intracranial Aneurysm (UIA) and Subarachnoid Hemorrhage (SAH) common data elements (CDEs) was to develop a comprehensive set of CDEs, data definitions, case report forms, and guidelines for use in UIA and SAH LTT clinical research, as part of a new joint effort between the National Institute of Neurological Disorders and Stroke (NINDS) and the National Library of Medicine of the US National Institutes of Health. These UIA and SAH CDEs will join other neurological disease-specific CDEs already developed and available for use by research investigators.

METHODS

The eight LTT WG members comprised international UIA, and SAH experts reviewed existing NINDS CDEs and instruments, created new elements when needed, and provided recommendations for future LTT clinical research. The recommendations were compiled, internally reviewed by the all UIA and SAH WGs and steering committee members. The NINDS CDE team also reviewed the final version before posting the SAH Version 1.0 CDE recommendations on the NINDS CDE website.

RESULTS

The NINDS UIA and SAH LTT CDEs and supporting documents are publicly available on the NINDS CDE ( https://www.commondataelements.ninds.nih.gov/#page=Default ) and NIH Repository ( https://cde.nlm.nih.gov/home ) websites. The subcommittee members discussed and reviewed various parameters, outcomes, and endpoints in UIA and SAH LTT studies. The following meetings with WG members, the LTT WG's recommendations are incorporated into the disease/injury-related events, assessments and examinations, and treatment/intervention data domains.

CONCLUSIONS

Noting gaps in the literature regarding medication and rehabilitation parameters in UIA and SAH clinical studies, the current CDE recommendations aim to arouse interest to explore the impact of medication and rehabilitation treatments and therapies and encourage the convergence of LTT clinical study parameters to develop a harmonized standard.

Innate immunity activation in the early brain injury period following subarachnoid hemorrhage

Background

Aneurysmal subarachnoid hemorrhage (SAH) is a catastrophic disease with devastating consequences, including a high mortality rate and severe disabilities among survivors. Inflammation is induced following SAH, but the exact role and phenotype of innate immune cells remain poorly characterized. We investigated the inflammatory components of the early brain injury in an animal model and in SAH patients.

Method

SAH was induced through injection of blood in the subarachnoid space of C57Bl/6 J wild-type mice. Prospective blood collections were obtained at 12 h, days 1, 2, and 7 to evaluate the systemic inflammatory consequences of SAH by flow cytometry and enzyme-linked immunosorbent-assay (ELISA). Brains were collected, enzymatically digested, or fixed to characterize infiltrating inflammatory cells and neuronal death using flow cytometry and immunofluorescence. Phenotypic evaluation was performed at day 7 using the holding time and footprint tests. We then compared the identified inflammatory proteins to the profiles obtained from the plasma of 13 human SAH patients.

Results

Following SAH, systemic IL-6 levels increased rapidly, whereas IL-10 levels were reduced. Neutrophils were increased both in the brain and in the blood reflecting local and peripheral inflammation following SAH. More intracerebral pro-inflammatory monocytes were found at early time points. Astrocyte and microglia activation were also increased, and mice had severe motor deficits, which were associated with an increase in the percentage of caspase-3-positive apoptotic neurons. Similarly, we found that IL-6 levels in patients were rapidly increased following SAH. ICAM-1, bFGF, IL-7, IL-12p40, and MCP-4 variations over time were different between SAH patients with good versus bad outcomes. Moreover, high levels of Flt-1 and VEGF at admission were associated with worse outcomes.

Conclusion

SAH induces an early intracerebral infiltration and peripheral activation of innate immune cells. Furthermore, microglia and astrocytic activation are present at later time points. Our human and mouse data illustrate that SAH is a systemic inflammatory disease and that immune cells represent potential therapeutic targets to help this population of patients in need of new treatments.

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.

Cognitive impairment in aneurysmal subarachnoid hemorrhage patients with delayed cerebral infarction: prevalence and pattern

BACKGROUND

Cognitive deficits commonly occur after aneurysmal subarachnoid hemorrhage (aSAH) and clinical understanding is important for treatment and rehabilitation. Delayed cerebral infarction was shown to be related to poor outcome. Data on delayed cerebral infarction-related cognitive impairment were lacking.

OBJECTIVE

We investigated the prevalence and pattern of delayed cerebral infarction-associated cognitive impairment.

METHODS

We carried out a prospective observational and diagnostic accuracy study in Hong Kong in patients aged 21-75 years with aSAH who had been admitted within 96 h of ictus. The domain-specific neuropsychological assessment battery at 1 year after ictus was used for cognitive assessments. A cognitive domain deficit was defined as a cognitive domain z score less than -1.65 (below the fifth percentile). Cognitive impairment was defined by two or more cognitive domain deficits. The current study is registered at ClinicalTrials.gov of the U.S. National Institutes of Health (NCT01038193).

RESULTS

One hundred and twenty aSAH patients were recruited. Patients with delayed cerebral infarction (DCI) have cognitive impairment more frequently (22 % vs 11 %; odds ratio: 2.2, 0.6 to 7.8, p = 0.192). Cognitive domain deficits commonly affected in aSAH patients with delayed cerebral infarction were verbal memory, language, and visuospatial memory and skill domains, and were relatively uncommon in aSAH patients without delayed cerebral infarction.

CONCLUSION

In patients with aSAH, delayed cerebral infarction was associated with a specific pattern of cognitive domain deficits. The pathophysiology should be further investigated.

Increased risk of acute kidney injury associated with higher infusion rate of mannitol in patients with intracranial hemorrhage

Object

Mannitol, an osmotic agent used to decrease intracranial pressure, can cause acute kidney injury (AKI). The objectives of this study were to assess the impact of mannitol on the incidence and severity of AKI and to identify risk factors and outcome for AKI in patients with intracranial hemorrhage (ICH).

Methods

The authors retrospectively evaluated 153 adult patients who received mannitol infusion after ICH between January 2005 and December 2009 in the neurosurgical intensive care unit. Multivariate analysis was used to evaluate the risk factors for AKI after ICH. Based on the odds ratio, weighted scores were assigned to predictors of AKI.

Results

The overall incidence of AKI among study participants was 10.5% (n = 16). Acute kidney injury occurred more frequently in patients who received mannitol infusion at a rate ≥ 1.34 g/kg/day than it did in patients who received mannitol infusion at a rate < 1.34 g/kg/day. A higher mannitol infusion rate was associated with more severe AKI. Independent risk factors for AKI were mannitol infusion rate ≥ 1.34 g/kg/day, age ≥ 70 years, diastolic blood pressure (DBP) ≥ 110 mm Hg, and glomerular filtration rate < 60 ml/min/1.73 m2. The authors developed a risk model for AKI, wherein patients with a higher risk score showed a graded association with a higher incidence of AKI.

Conclusions

The incidence of AKI following mannitol infusion in patients with ICH was 10.5%. A higher mannitol infusion rate was associated with more frequent and more severe AKI. Additionally, age ≥ 70 years, DBP ≥ 110 mm Hg, and established renal dysfunction before starting mannitol therapy were associated with development of AKI.

Cognitive domain deficits in patients with aneurysmal subarachnoid haemorrhage at 1 year

BACKGROUND

Cognitive domain deficits can occur after aneurysmal subarachnoid haemorrhage (aSAH) though few studies systemically evaluate its impact on 1-year outcomes.

OBJECTIVE

We aimed to evaluate the pattern and functional outcome impact of cognitive domain deficits in aSAH patients at 1 year.

METHODS

We carried out a prospective observational study in Hong Kong, during which, 168 aSAH patients (aged 21-75 years and had been admitted within 96 h of ictus) were recruited over a 26-month period. The cognitive function was assessed by a domain-specific neuropsychological assessment battery at 1 year after ictus. The current study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193).

RESULTS

Prevalence of individual domain deficits varied between 7% to 15%, and 13% had two or more domain deficits. After adjusting for abbreviated National Institute of Health Stroke Scale and Geriatric Depressive Scale scores, unfavourable outcome (Modified Rankin Scale 3-5) and dependent instrumental activity of daily living (Lawton Instrumental Activity of Daily Living<15) were significantly associated with two or more domain deficits and number of cognitive domain deficits at 1 year. Two or more domain deficits was independently associated with age (OR, 1.1; 95% CI 1.1 to 1.2; p<0.001) and delayed cerebral infarction (OR, 6.1; 95% CI 1.1 to 33.5; p=0.036), after adjustment for years of school education.

INTERPRETATION

In patients with aSAH, cognitive domain deficits worsened functional outcomes at 1 year. Delayed cerebral infarction was an independent risk factor for two or more domain deficits at 1 year.

Comparison of montreal cognitive assessment and mini-mental state examination in evaluating cognitive domain deficit following aneurysmal subarachnoid haemorrhage

Objective

Cognitive deficits are common after aneurysmal subarachnoid haemorrhage (aSAH), and clinical evaluation is important for their management. Our hypothesis was that the Montreal Cognitive Assessment (MoCa) is superior to the Mini-Mental State Examination (MMSE) in screening for cognitive domain deficit in aSAH patients.

Methods

We carried out a prospective observational and diagnostic accuracy study on Hong Kong aSAH patients aged 21 to 75 years who had been admitted within 96 hours of ictus. The domain-specific neuropsychological assessment battery, the MoCA and MMSE were administered 2–4 weeks and 1 year after ictus. A cognitive domain deficit was defined as a cognitive domain z score <−1.65 (below the fifth percentile). Cognitive impairment was defined as two or more cognitive domain deficits. The study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193).

Results

Both the MoCA and the MMSE were successful in differentiating between patients with and without cognitive domain deficits and cognitive impairment at both assessment periods. At 1 year post-ictus, the MoCA produced higher area under the curve scores for cognitive impairment than the MMSE (MoCA, 0.92; 95% CI, 0.83 to 0.97 versus MMSE, 0.77; 95% CI, 0.66 to 0.83, p = 0.009).

Interpretation

Cognitive domain deficits and cognitive impairment in patients with aSAH can be screened with the MoCA in both the subacute and chronic phases.

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.

Effective factors on linguistic disorder during acute phase following traumatic brain injury in adults

Traumatic brain injury (TBI) has been known to be the leading cause of breakdown and long-term disability in people under 45 years of age. This study highlights the effective factors on post-traumatic (PT) linguistic disorder and relations between linguistic and cognitive function after trauma in adults with acute TBI. A cross-sectional design was employed to study 60 post-TBI hospitalized adults aged 18-65 years. Post-traumatic (PT) linguistic disorder and cognitive deficit after TBI were respectively diagnosed using the Persian Aphasia Test (PAT) and Persian version of Mini-Mental State Examination (MMSE) at discharge. Primary post-resuscitation consciousness level was determined using the Glasgow Coma Scale (GCS). Paracilinical data was obtained by CT scan technique. Multiple logistic regression analysis illustrated that brain injury severity was the first powerful significant predictor of PT linguistic disorder after TBI and frontotemporal lesion was the second. It was also revealed that cognitive function score was significantly correlated with score of each language skill except repetition. Subsequences of TBI are more commonly language dysfunctions that demand cognitive flexibility. Moderate, severe and fronto-temporal lesion can increase the risk of processing deficit in linguistic macrostructure production and comprehension. The dissociation risk of cortical and subcortical pathways related to cognitive-linguistic processing due to intracranial lesions can augment possibility of lexical-semantic processing deficit in acute phase which probably contributes to later cognitive-communication disorder.

Long-term cognitive dysfunction in patients with traumatic subarachnoid hemorrhage: prevalence and risk factors

BACKGROUND

Cognition had recently been suggested as a supplement to traditional measures of neurological outcome. However, no data were available in the literature on long-term cognitive outcomes in patients with traumatic subarachnoid hemorrhage (tSAH).

OBJECTIVE

We explored the long-term cognitive profiles of patients with tSAH who had returned to the community, and the risk factors associated with this event.

METHODS

Patients with tSAH were contacted to obtain their consent to participate in the study of cognitive profiles and outcome. Forty-seven (42%) of 111 eligible patients completed all the assessments.

RESULTS

Time from ictus to assessment ranged from 3 to 5 years. No difference in patient characteristics was observed between those who participated and those who did not. In patients with tSAH who had returned to the community, domain deficits and cognitive impairment were correlated with the extended Glasgow outcome scale (GOS-E), and were predicted by age and Glasgow coma scale (GCS) on admission. The accuracies of classifications were 79% and 81%, respectively. The number of domain deficits was also correlated with GOS-E, and was predicted by age, GCS on admission, and the extent of tSAH, with a total R (2) value of 50%.

CONCLUSIONS

Long-term cognitive dysfunction is common after tSAH. In addition to GCS on admission and follow-up GOS-E, the extent of tSAH is an independent risk factor for the number of cognitive domain deficits that occur.