Early Cognitive Domain Deficits in Patients with Aneurysmal Subarachnoid Hemorrhage Correlate with Functional Status

Clinical Factors Contributing to Cognitive Function in the Acute Stage after Treatment of Intracranial Aneurysms: A Cross-Sectional Study

Background: The factors affecting cognitive function after treatment of subarachnoid haemorrhage (SAH) can be categorised into aneurysmal factors, procedural factors, and complications. The aim of this study was to investigate which of these factors has greater influence on the cognitive function. Methods: We retrospectively identified 14 patients with unruptured intracranial aneurysms (UIAs) and 34 patients with SAH with mild symptoms at disease onset (Hunt and Hess grade: >3). All patients underwent neuropsychological tests within 35 days of discharge from hospitalisation for treatment. The relationship between the clinical factors and each neuropsychological test score was evaluated using multiple linear regression analysis after controlling for age and years of education. Results: Patients with UIA showed greater cognitive impairment in visual memory and the frontal/executive domains. Hypertension was associated with cognitive impairment. Patients with SAH showed greater cognitive impairment in the visuospatial, verbal memory, and frontal/executive domains. The dome-to-neck ratio, aneurysms located in the posterior circulation, microsurgical clipping, procedure time, anaesthesia duration, and complications were associated with cognitive impairment. Conclusions: Underlying diseases, procedural factors, and complications contributed to cognitive impairment after treatment of intracranial aneurysms. Since the effect of each factor on each cognitive domain was slightly different, a more in-depth study of these effects is needed.

Topological Alterations of Working Memory Impairment in Aged Patients With Vascular Dementia

Aneurysmal subarachnoid hemorrhage (aSAH) is a common disease causing vascular dementia. Survivors often suffer from cognitive impairment especially working memory deficit. Currently, lack of theoretical support limits the improvement of cognitive intervention or rehabilitation. It is unclear how the large-scale network differs and to what extent is the brain network affected? Our study aims to provide novel information about the topological characteristics of brain organization, especially "small-world" property. A total of 62 aSAH patients are enrolled in this study. They are divided into two groups according to the syndrome of working memory deficit. Their working memory function is evaluated by TMT-B and AVLT (Chinese version). Functional MRI scan is also performed for detecting resting-state cortical plasticity. We utilized ICA to extract functional sub-networks including working memory network from imaging data. And then we establish binarized network and calculate the small-worldness property as well as local and global efficiency of networks. aSAH group with working memory deficit shows no significant difference of clustering coefficient with control group. Our study discovered significant decrease of characteristic path length indicating an increase of overall routing efficiency. We reason that patients with working memory deficit have to recruit more neuronal resources and thus develops higher overall routing efficiency of local network. This study provides novel information about the neural alterations of aSAH patients with working memory deficit. It might contribute to the understanding of neural mechanism and the improvement of current intervention for vascular dementia.

Cognitive deficits among patients surviving aneurysmal subarachnoid hemorrhage. A contemporary systematic review

BACKGROUND

Subarachnoid hemorrhage (SAH) is associated with high rates of morbidity, including neurological and cognitive deficits that may be difficult to identify and quantify. This review provides an update on the cognitive deficits that may result from spontaneous aneurysmal SAH (aSAH) and identifies factors that may help predict and manage these deficits at discharge and thereafter.

MATERIALS AND METHODS

We conducted a systematic review of PubMed and Google Scholar to identify studies published between 2010 and 2019 that assessed cognitive deficits at discharge and during follow-up in patients with aSAH. Full-text articles were assessed for information regarding cognitive testing and factors that may be associated with functional outcomes in this population.

RESULTS

We reviewed 65 studies published since 2010 that described the cognitive deficits associated with non-traumatic aSAH. Such deficits may impact functional outcomes, quality of life, and return to work and may result in cognitive impairments, such as memory difficulties, speech problems, and psychiatric disorders.

CONCLUSIONS

Patients with aSAH, even those that appear normal at the time of hospital discharge, may harbor cognitive deficits that are difficult to detect, yet can interfere with daily functioning. Further research is needed to provide additional information and to identify stronger correlations to be used in the identification, treatment, and amelioration of long-term cognitive deficits in aSAH patients, including those who are discharged with good clinical outcomes scores.

Transcranial Doppler for Early Prediction of Cognitive Impairment after Aneurysmal Subarachnoid Hemorrhage and the Associated Clinical Biomarkers

Methods

Prospective study included 40 cases with acute aSAH. Initial evaluation by Glasgow Coma Scale (GCS) and the severity of aSAH was detected by both the clinical Hunt and Hess and radiological Fisher's grading scales. TCD was done for all patients five times within 10 days measuring the mean flow velocities (MFVs) of cerebral arteries. At the 3-month follow-up, patients were classified into two groups according to Montreal Cognitive Assessment (MoCA) scale: the first group was 31 cases (77.5%) with intact cognitive functions and the other group was 9 cases (22.5%) with impaired cognition.

Results

Patients with impaired cognitive functions showed significantly lower mean GCS (p = 0.03), significantly higher mean Hunt and Hess scale grades (p = 0.04), significantly higher mean diabetes mellitus (DM) (p = 0.03), significantly higher mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) (p = 0.02 and p = 0.005, respectively), and significantly higher MFVs measured within the first 10 days. The patients with cognitive impairment were accompanied by a higher incidence of hydrocephalus (p = 0.01) and a higher incidence of delayed cerebral ischemia (DCI) (p < 0.001). Logistic regression analysis detected that MFV ≥ 86  cm/s in the middle cerebral artery (MCA), MFV ≥ 68  cm/s in the anterior cerebral artery (ACA), and MFV ≥ 45  cm/s in the posterior cerebral artery (PCA) were significantly associated with increased risk of cognitive impairment.

Conclusion

Cognitive impairment after the 3-month follow-up phase in aSAH patients was 22.5%. Acute hydrocephalus and DCI are highly associated with poor cognitive function in aSAH. Increased MFV is a strong predictor for poor cognitive function in aSAH. This trial is registered with NCT04329208.

Effect of hemorrhagic cerebrospinal fluid drainage on cognitive function after intracranial aneurysm clipping

Objective:

The effects of repeated lumbar puncture and continuous lumbar cistern drainage on the cognitive function of patients with aneurysmal subarachnoid hemorrhage were compared and analyzed.

Methods:

Retrospective analysis was performed on 59 patients with aneurysmal subarachnoid hemorrhage treated at our Neurosurgery Department between October 2017 and October 2018. According to the hemorrhagic cerebrospinal fluid drainage mode after aneurysm clipping, the patients were divided into the following two groups: the repeated lumbar puncture drainage (Group A, n = 28) and continuous lumbar cistern drainage (Group B, n = 31). Before and 1 month after surgery, the cognitive function of the patients was scored using the Montreal Cognitive Assessment Scale. Scores of 27~30 were defined as normal, and scores of < 27 as cognitive impairment.

Results:

The incidences of cognitive impairment were 46% (13/28) and 32% (10/31) for Groups A and B, respectively, before surgery, but the difference was not significant ( P > 0.05). The incidences of cognitive impairment were 35% (10/28) and 12% (4/31) for Groups A and B, respectively, at 1 month after surgery, with significant difference ( P < 0.05).

Conclusion:

Compared with repeated lumbar puncture, continuous lumbar cistern drainage for aneurysmal subarachnoid hemorrhage significantly reduced the incidence of cognitive impairment after aneurysm clipping.

Vascular Cognitive Impairment: Information from Animal Models on the Pathogenic Mechanisms of Cognitive Deficits

Vascular cognitive impairment (VCI) is the second most common cause of cognitive deficit after Alzheimer's disease. Since VCI patients represent an important target population for prevention, an ongoing effort has been made to elucidate the pathogenesis of this disorder. In this review, we summarize the information from animal models on the molecular changes that occur in the brain during a cerebral vascular insult and ultimately lead to cognitive deficits in VCI. Animal models cannot effectively represent the complex clinical picture of VCI in humans. Nonetheless, they allow some understanding of the important molecular mechanisms leading to cognitive deficits. VCI may be caused by various mechanisms and metabolic pathways. The pathological mechanisms, in terms of cognitive deficits, may span from oxidative stress to vascular clearance of toxic waste products (such as amyloid beta) and from neuroinflammation to impaired function of microglia, astrocytes, pericytes, and endothelial cells. Impaired production of elements of the immune response, such as cytokines, and vascular factors, such as insulin-like growth factor 1 (IGF-1), may also affect cognitive functions. No single event could be seen as being the unique cause of cognitive deficits in VCI. These events are interconnected, and may produce cascade effects resulting in cognitive impairment.

Progression in Vascular Cognitive Impairment: Pathogenesis, Neuroimaging Evaluation, and Treatment

Vascular cognitive impairment (VCI) defines an entire spectrum of neurologic disorders from mild cognitive impairment to dementia caused by cerebral vascular disease. The pathogenesis of VCI includes ischemic factors (e.g., large vessel occlusion and small vessel dysfunction); hemorrhagic factors (e.g., intracerebral hemorrhage and subarachnoid hemorrhage); and other factors (combined with Alzheimer's disease). Clinical evaluations of VCI mainly refer to neuropsychological testing and imaging assessments, including structural and functional neuroimaging, with different advantages. At present, the main treatment for VCI focuses on neurological protection, cerebral blood flow reconstruction, and neurological rehabilitation, such as pharmacological treatment, revascularization, and cognitive training. In this review, we discuss the pathogenesis, neuroimaging evaluation, and treatment of VCI.