Objective: Although multiple pieces of evidence have suggested that there are different mechanisms in periventricular white matter hyperintensities (PWMHs) and deep white matter hyperintensities (DWMHs), the exact mechanism remains uncertain.Methods: We reviewed clinical and imaging data of old participants from a local She Ethnic group. We assessed the cerebral blood flow of white matter (WM-CBF) on arterial spin-labeling, deep medullary veins (DMVs) visual score on susceptibility-weighted imaging, and index for diffusion tensor image analysis along the perivascular space (ALPS index), indicating glymphatic function on diffusion tensor imaging. Furthermore, we investigated their relationships with volumes of PWMHs and DWMHs.Results: A total of 152 subjects were included, with an average age of 63 ± 8 years old. We found that higher age and history of hypertension were independently related to higher volumes of both PWMHs and DWMHs (all p < 0.05). Lower ALPS index was independently associated with higher PWMHs volumes (β = 0.305, p < 0.001), and this relationship was accounted for by the indirect pathway via DMVs score (β = 0.176, p = 0.017). Both lower ALPS index and WM-CBF were independent risk factors for higher DWMHs volumes (β = −0.146, p = 0.041; β = −0.147, p = 0.036).Conclusions: Our study indicated that there were different mechanisms in PWMHs and DWMHs. PWMHs were mainly attributed to the damage of veins due to the dysfunction of the glymphatic pathway, while DWMHs could be affected by both ischemia-hypoperfusion and dysfunction of the glymphatic pathway.Advances in knowledge: The relationship between glymphatic dysfunction and PWMHs might be accounted for by the indirect pathway via venous abnormalities, a glymphatic dysfunction, and lower CBF in white matter were independent risk factors for DWMHs.

BACKGROUND AND PURPOSE: Parenchymal hemorrhage is a severe complication following mechanical recanalization in patients with acute ischemic stroke with large-vessel occlusion. This study aimed to assess whether the metallic hyperdensity sign on noncontrast CT performed immediately after mechanical thrombectomy can predict parenchymal hemorrhage at 24 hours. MATERIALS AND METHODS: We included consecutive patients with acute ischemic stroke with large-vessel occlusion who underwent noncontrast CT immediately after mechanical thrombectomy between January 2014 and September 2018. The metallic hyperdensity sign was defined as a nonpetechial intracerebral hyperdense lesion (diameter, ≥1 cm) in the basal ganglia and a maximum CT density of >90 HU. The sensitivity, specificity, and positive and negative predictive values of the metallic hyperdensity sign in predicting parenchymal hemorrhage were calculated. RESULTS: A total of 198 patients were included. The metallic hyperdensity sign was found in 59 (29.7%) patients, and 51 (25.7%) patients had parenchymal hemorrhage at 24 hours. Patients with the metallic hyperdensity sign are more likely to have parenchymal hemorrhage than those without it (76.3% versus 4.3%, P < .001). The sensitivity, specificity, positive predictive value, and negative predictive value of the metallic hyperdensity sign in predicting parenchymal hemorrhage were 88.2%, 90.5%, 76.3%, and 95.7%, respectively. CONCLUSIONS: The presence of the metallic hyperdensity sign on noncontrast CT performed immediately after mechanical thrombectomy in patients with large-vessel occlusion could predict the occurrence of parenchymal hemorrhage at 24 hours, which might be helpful in postinterventional management within 24 hours after mechanical thrombectomy.

Background: Early neurological deterioration occurs in approximately 10% acute ischemic stroke patients after thrombolysis. Over half of the early neurological deterioration occurred without known causes and is called unexplained early neurological deterioration. Aims: We aimed to explore the development of early neurological deterioration at 24 h after thrombolysis, and whether it could be predicted by the presence of baseline hypoperfusion in lenticulostriate arteries territory in acute ischemic stroke patients. Methods: We retrospectively reviewed our prospectively collected database of acute ischemic stroke patients in the unilateral middle cerebral artery territory who had baseline perfusion image and received thrombolysis. Unexplained early neurological deterioration was defined as ≥ 2 points increase of National Institutes of Health Stroke Scale (NIHSS) from baseline to 24 h, without known causes. Hypoperfusion lesions in different territories were identified on perfusion maps. Results: A total of 306 patients were included in analysis. Patients with pure lenticulostriate arteries hypoperfusion (defined as the presence of hypoperfusion in lenticulostriate artery territory, but not in middle cerebral artery terminal branch territory) were more likely to have unexplained early neurological deterioration than others (27.6% vs. 6.1%; OR, 5.974; p = 0.001), after adjusting for age, baseline NIHSS and onset to treatment time. Conclusions: Patients presenting hypoperfusion in pure lenticulostriate arteries territory were easier to experience unexplained early neurological deterioration.

BACKGROUND AND PURPOSE: Thrombus permeability assessed on conventional CTA is associated with neurologic outcome in patients with acute ischemic stroke. We aimed to investigate whether dynamic CTA can improve the accuracy of thrombus permeability assessment and its predictive value for outcome. MATERIALS AND METHODS: We reviewed consecutive patients with acute ischemic stroke who had occlusion of the M1 segment of the middle artery cerebral artery and underwent pretreatment perfusion CT. Thrombus permeability, determined by thrombus attenuation increase (TAI), was assessed on 26-phase dynamic CTA derived from perfusion CT. TAI_max was defined as the maximum TAI among phases; TAI_peak, as TAI of peak arterial phase; TAI_con, as TAI on phase 13. Good outcome was defined as a 3-month mRS score of ≤2. RESULTS: One hundred four patients were enrolled in the final analysis. The median TAI_max, TAI_peak, and TAI_con were 30.1 HU (interquartile range, 13.0–50.2 HU), 9.5 HU (interquartile range, −1.6–28.7 HU), and 6.6 HU (interquartile range, −5.1–24.4 HU), respectively. Multivariable regression analyses showed that TAI_max (OR = 1.027; 95% CI, 1.007–1.048; P = .008), TAI_peak (OR = 1.029; 95% CI, 1.005–1.054; P = .020), and TAI_con (OR = 1.026; 95% CI, 1.002–1.051; P = .037) were independently associated with good outcome. The areas under the ROC curve of TAI_max, TAI_peak, and TAI_con in predicting good outcome were 0.734, 0.701, and 0.658, respectively. CONCLUSIONS: Thrombus permeability assessed on dynamic CTA could be a better predictor of outcome after reperfusion therapy than that assessed on conventional single-phase CTA.