Gray-to-white matter ratio predicts long-term recovery potential of patients with aneurysmal subarachnoid hemorrhage

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.

Secondary White Matter Injury and Therapeutic Targets After Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is one of the special stroke subtypes with high mortality and mobility. Although the mortality of SAH has decreased by 50% over the past two decades due to advances in neurosurgery and management of neurocritical care, more than 70% of survivors suffer from varying degrees of neurological deficits and cognitive impairments, leaving a heavy burden on individuals, families, and the society. Recent studies have shown that white matter is vulnerable to SAH, and white matter injuries may be one of the causes of long-term neurological deficits caused by SAH. Attention has recently focused on the pivotal role of white matter injury in the pathophysiological processes after SAH, mainly related to mechanical damage caused by increased intracerebral pressure and the metabolic damage induced by blood degradation and hypoxia. In the present review, we sought to summarize the pathophysiology processes and mechanisms of white matter injury after SAH, with a view to providing new strategies for the prevention and treatment of long-term cognitive dysfunction after SAH.

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.

Transpulmonary thermodilution monitoring-guided hemodynamic management improves cognitive function in patients with aneurysmal subarachnoid hemorrhage: a prospective cohort comparison

BACKGROUND

The effects of goal-directed hemodynamic management using transpulmonary thermodilution (TPT) monitor on the cognitive function of patients with aneurysmal subarachnoid hemorrhage (aSAH) remain unclear. The present study aimed to determine whether hemodynamic management with TPT monitor provides better cognitive function compared with standard hemodynamic management.

METHODS

Patients with aSAH who were admitted to the intensive care unit in 2016 were assigned to cohort 1, and those admitted in 2017 were assigned to cohort 2. In cohort 1, hemodynamic and fluid management was performed in accordance with the traditional pressure-based hemodynamic parameters and clinical examination, whereas in cohort 2, it was performed in accordance with the TPT monitor-measured flow-based parameters. The incidence of delayed cerebral ischemia (DCI) and pulmonary edema (PE) was determined. The functional outcome of patients was assessed using the modified Rankin scale (mRS) score and Montreal cognitive assessment (MoCA) test at 1 year following aSAH.

RESULTS

Cohort 1 included 45 patients and cohort 2 included 39 patients who completed the trial. The incidence of DCI (38% versus 26%) and PE (11% versus 3%) was comparable between the cohorts (p > 0.05). The mRS score was similar between the cohorts (p = 0.11). However, the MoCA score was 20.2 (19.2-21.4) and 23.5 (22.2-24.8) in cohort 1 and cohort 2, respectively (p < 0.001). Accordingly, the occurrence of poor MoCA score (38% versus 18%) was significantly lower in cohort 2 (p = 0.045).

CONCLUSIONS

TPT monitor-based hemodynamic management provides better cognitive outcome than standard hemodynamic management in patients with aSAH.