Few studies have focused on the connection between glymphatic dysfunction and cerebral small vessel disease (CSVD), partially due to the lack of non-invasive methods to measure glymphatic function. We established modified index for diffusion tensor image analysis along the perivascular space (mALPS-index), which was calculated on diffusion tensor image (DTI), compared it with the classical detection of glymphatic clearance function calculated on Glymphatic MRI after intrathecal administration of gadolinium (study 1), and analyzed the relationship between CSVD imaging markers and mALPS-index in CSVD patients from the CIRCLE study (ClinicalTrials.gov ID: NCT03542734) (study 2). Among 39 patients included in study 1, mALPS-index were significantly related to glymphatic clearance function calculated on Glymphatic MRI ( r = -0.772~-0.844, p < 0.001). A total of 330 CSVD patients were included in study 2. Severer periventricular and deep white matter hyperintensities (β = -0.332, p < 0.001; β = -0.293, p < 0.001), number of lacunas (β = -0.215, p < 0.001), number of microbleeds (β = -0.152, p = 0.005), and severer enlarged perivascular spaces in basal ganglia (β = -0.223, p < 0.001) were related to mALPS-index. Our results indicated that non-invasive mALPS-index might represent glymphatic clearance function, which could be applied in clinic in future. Glymphatic clearance function might play a role in the development of CSVD.

Background: The existence of cerebral reperfusion injury in human beings remains controversial. Thus, we aimed to explore the presence of reperfusion injury in acute ischemic stroke patients with recanalization after mechanical thrombectomy and analyzed its impact on neurological outcome. Methods: We reviewed our prospectively collected database CIPPIS (Comparison Influence to Prognosis of CTP and MRP in AIS Patients, NCT03367286), and enrolled anterior circulation large artery occlusion patients with recanalization after mechanical thrombectomy who underwent (1) computed tomography (CT) perfusion on admission and immediately after recanalization to determine reperfusion region, and (2) CT and/or magnetic resonance imaging (MRI) immediately and 24 hours after recanalization to determine lesion areas. The expansion of lesion between recanalization and 24 hours within reperfusion region was potentially caused by reperfusion, thus termed as radiological observed reperfusion injury (RORI). Based on the imaging modality immediately after recanalization, RORI was further divided into RORI _CT and RORI _MRI . We first included a small cohort who had performed both CT and MRI immediately after recanalization to validate the consistency between RORI _CT and RORI _MRI (Study 1). Then the association with RORI _CT and poor outcome, defined as 3-month modified Rankin Scale score of 3 to 6, was explored in a larger cohort (Study 2). Results: Study 1 included 23 patients and good consistency was found between RORI _CT and RORI _MRI (intraclass correlation=0.97, P <0.001). Among 226 patients included in Study 2, a total of 106 (46.9%) were identified with RORI. The ratio of RORI to reperfusion region was 30.1 (16.2, 51.0)% and was independently associated with poor outcome (odds ratio=1.55 per 10% [95% CI‚ 1.30–1.84]; P <0.001). Conclusions: Our findings suggested that RORI was relatively frequent in stroke patients with recanalization after mechanical thrombectomy and associated with poor outcome despite successful recanalization. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03367286.

Background: Prior studies have investigated the clinical and imaging factors for hemorrhagic transformation (HT), especially symptomatic intracranial hemorrhage (sICH); however, whether alteplase increases the risk of HT after endovascular thrombectomy (EVT) is unknown. This study aimed to assess clinical and imaging features associated with HT, sICH, and parenchymal hematoma (PH) in patients with acute ischemic stroke after EVT, with and without intravenous alteplase in DIRECT-MT (Direct Intraarterial Thrombectomy to Revascularize Acute Ischemic Stroke Patients with Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals: a Multicenter Randomized Clinical Trial). Methods: The DIRECT-MT trial is a randomized trial of EVT alone versus intravenous thrombolysis combined with EVT. HT, sICH, and PH was evaluated on follow-up computed tomography. Multivariable ordinal logistic regression analysis was used to test the association of stepwise selected determinants with HT, sICH, and PH. Results: In total, 633 patients were analyzed; 261 (41.2%) had HT; 34 (5.4%) had sICH; and 85 (13.4%) had PH. The median age was 69, and 56.7% were men. The median National Institutes of Health Stroke Scale score was 18, and 320 patients were in combination-therapy group. Symptomatic intracranial hemorrhage was associated with higher baseline National Institutes of Health Stroke Scale score (adjusted odds ratio [OR], 1.06 [95% CI, 1.10–1.12]) and higher glucose level at hospital arrival (adjusted OR, 1.14 [95% CI, 1.00–1.29]). No association was found between alteplase treatment and HT, sICH, or PH. The independent predictor of sICH was higher baseline National Institutes of Health Stroke Scale score (adjusted OR, 1.09 [95% CI, 1.01–1.18]) in EVT alone group, and history of anticoagulant drugs (adjusted OR, 3.75 [95% CI, 1.07–13.06]), higher glucose level at hospital arrival (adjusted OR, 1.19 [95% CI, 1.03–1.38]), >3 passes of device (adjusted OR, 4.42 [95% CI, 1.36–14.32]) in combination-therapy group. Conclusions: In DIRECT-MT, independent predictors of sICH were baseline National Institutes of Health Stroke Scale score and glucose level at hospital arrival. Alteplase treatment did not increase the risk of HT, sICH, or PH after EVT. The independent predictor of sICH was different in EVT alone group and combination-therapy group. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03469206.

The glymphatic pathway, characterised as a cerebral drainage system, influences cognitive function in neurodegenerative diseases; however, evidence is limited in a normal ageing population. The aim of this study was to investigate the effect of glymphatic function on ageing-related cognitive decline. We retrospectively reviewed the Cognitive Impairment, Retinopathy, and Cerebrovascular Lesions in the Elderly (CIRCLE) study, and participants with multi-model magnetic resonance imaging (MRI) scans and Mini-Mental State Examinations (MMSE) were enrolled. Glymphatic function was evaluated via the diffusion tensor imaging along the perivascular space (DTI-ALPS) index. Regression models were used to estimate the impact of the DTI-ALPS index on cognitive decline cross-sectionally and longitudinally. We further analysed the mediation effect of the DTI-ALPS on age and cognitive function. A total of 633 participants were included in this study (48.2% female; mean age, 62.8 ± 8.9 years). The DTI-ALPS index was positively associated with cognitive function cross-sectionally (β = 0.108, P = 0.003), and was an independent protective factor for cognitive decline longitudinally (odds ratio (OR) = 0.029, P = 0.007). The DTI-ALPS index declined progressively with ageing (r = −0.319, P <0.001), and the decrease was more pronounced after 65 years of age. Furthermore, the DTI-ALPS index mediated the relationship between age and MMSE score (β = −0.016, P <0.001). The mediation effect accounted for 21.3%, which was higher in subjects aged over 65 years (25.3%) compared with those aged under 65 years (5.3%). Glymphatic function played a protective role in normal ageing-related cognitive decline, which may serve as a potential therapeutic target against cognitive decline in future.