Automatic bundle-specific white matter fiber tracking tool using diffusion tensor imaging data: A pilot trial in the application of language-related glioma resection.

Cerebral neoplasms like gliomas may cause intracranial pressure increasing, neural tract deviation, infiltration, or destruction in peritumoral areas, leading to neuro-functional deficits. Novel tracking technology, such as DTI, can objectively reveal and visualize three-dimensional white matter trajectories; in combination with intraoperative navigation, it can help achieve maximum resection whilst minimizing neurological deficit. Since the reconstruction of DTI raw data largely relies on the technical engineering and anatomical experience of the operator; it is time-consuming and prone to operator-induced bias. Here, we develop new user-friendly software to automatically segment and reconstruct functionally active areas to facilitate precise surgery. In this pilot trial, we used an in-house developed software (DiffusionGo) specially designed for neurosurgeons, which integrated a reliable diffusion-weighted image (DWI) preprocessing pipeline that embedded several functionalities from software packages of FSL, MRtrix3, and ANTs. The preprocessing pipeline is as follows: 1. DWI denoising, 2. Gibbs-ringing removing, 3. Susceptibility distortion correction (process if opposite polarity data were acquired), 4. Eddy current and motion correction, and 5. Bias correction. Then, this fully automatic multiple assigned criteria algorithms for fiber tracking were used to achieve easy modeling and assist precision surgery. We demonstrated the application with three language-related cases in three different centers, including a left frontal, a left temporal, and a left frontal-temporal glioma, to achieve a favorable surgical outcome with language function preservation or recovery. The DTI tracking result using DiffusionGo showed robust consistency with direct cortical stimulation (DCS) finding. We believe that this fully automatic processing pipeline provides the neurosurgeon with a solution that may reduce time costs and operating errors and improve care quality and surgical procedure quality across different neurosurgical centers.

Education level may modify the association between cardiac index and cognitive function among elders with normal ejection function.

Background: Lower cardiac index (CI) in elders has been associated with incident dementia, and higher CI has protectively effect with brain aging. In the present study, we investigated the modulating effects of education level and arterial stiffness on the association between CI and cognitive function among older adults. Methods: A total of 723 elders (≥60 years, 50.1% women) with normal left ventricular ejection fraction (≥50%) were identified from the Cardiovascular Diseases Risk Factor Two-Township Study. CI was calculated from the Doppler-derived stroke volume. We evaluated arterial stiffness by measuring carotid-femoral pulse wave velocity (CFPWV) and global cognitive function by using the Mini-Mental Short Examination (MMSE). Education level was determined by years of formal education. Results: In linear regression analysis adjusting for age, sex, formal years of education, and CFPWV, CI was significantly positively associated with MMSE (BETA=0.344±0.130, P = 0.0082). In logistic regression analysis adjusting for age, sex, formal years of education, and CFPWV, subjects with a CI≥75 percentile had a significantly lower risk of low MMSE (<26) (OR = 0.495, 95% CI = 0.274-0.896, P = 0.02). In subgroup analysis, higher CI was significantly associated with higher MMSE and lower risk of low MMSE only in elders with ≤ 9 years of formal education. Causal mediation analysis suggests that higher CI maintains higher MMSE in elders with lower education levels whereas higher CFPWV causes lower MMSE in all the elders. Conclusion: In elders with normal ejection fraction, a higher CI was associated with a lower risk of cognitive function impairment, independent of arterial stiffness, mainly in subjects with a lower education level and possibly a smaller cognitive reserve.

Associations Between Cerebral Vasoreactivity and Cognitive Function in the Middle-Aged Non-Demented Population.

BACKGROUND: Increasing evidence shows early vascular dysregulation in the pathophysiology of Alzheimer's disease (AD) in elderly population. OBJECTIVE: We wondered about the relationship between vascular health and cognitive performance in middle-aged adults. The present study aims to evaluate whether and which brain vascular hemodynamic parameters are associated with cognitive functions in a middle-aged, non-demented population. METHODS: We recruited 490 middle-aged community-based participants (30-60 years). Transcranial color-coded sonography was used to measure cerebral vascular hemodynamics, including mean flow velocity, pulsatility index, and breath-holding index (BHI) in the middle cerebral arteries (MCAs). Cognitive functions were assessed using the Montreal Cognitive Assessment (MoCA). A multivariate linear regression model was used to determine the association between the MoCA scores and each intracranial hemodynamic parameter. RESULTS: In 369 participants (median age 52 years [IQR 47-56], 48.8% men) with robust acoustic windows, the factors related to poorer MoCA scores were older age, less education extent, and the habitats of cigarette smoking or alcohol consumption. Multivariate analyses did not show a significant association between any intracranial hemodynamic parameters in both MCAs and MoCA scores in the total study population. Left MCA BHI was found to be significantly and independently correlated with the MoCA scores only in people aged 55-60 years (n = 111, B = 0.70, 95% confidence interval, 0.13-1.26, p = 0.017), however, not in people younger than 55 years. CONCLUSION: Our results emphasize the role of neurovascular abnormalities in the early pathophysiology of cognitive impairment and suggest cerebral vasoreactivity as the earliest detectable cognition-associated hemodynamic parameter.