Morphological classification of penetrating artery pontine infarcts and association with risk factors and prognosis: The SPS3 trial

Small vessel disease burden and prognosis of recent subcortical ischaemic stroke differ by parent artery atherosclerosis

BACKGROUND AND PURPOSE

Parent artery atherosclerosis is an important aetiology of recent subcortical ischaemic stroke (RSIS). However, comparisons of RSIS with different degrees of parent artery atherosclerosis are lacking.

METHODS

Prospectively collected data from our multicentre cohort (all were tertiary centres) of the Stroke Imaging Package Study between 2015 and 2017 were retrospectively reviewed. The patients with RSIS defined as a single clinically relevant diffusion-weighted imaging positive lesion in the territory of lenticulostriate arteries were categorized into three subgroups: (1) normal middle cerebral artery (MCA) on magnetic resonance angiography and high-resolution magnetic resonance imaging (HR-MRI); (2) low-grade MCA atherosclerosis (normal or <50% stenosis on magnetic resonance angiography and with MCA plaques on HR-MRI); (3) steno-occlusive MCA atherosclerosis (stenosis ≥50% or occlusion). The primary outcome was 90-day functional dependence (modified Rankin Scale score >2). The clinical and imaging findings were compared between subgroups.

RESULTS

A total of 239 patients (median age 60.0 [52.0-67.0] years, 72% male) were enrolled, including 140 with normal MCA, 64 with low-grade MCA atherosclerosis and 35 with steno-occlusive MCA atherosclerosis. Patients with steno-occlusive MCA atherosclerosis had the largest infarct volume. Low-grade MCA atherosclerosis was independently associated with cerebral microbleeding, more severe perivascular spaces in basal ganglia and higher total cerebral small vessel disease burden. Low-grade MCA atherosclerosis was an independent determinant of 90-day functional dependence (odds ratio 3.897; 95% confidence interval 1.309-11.604).

CONCLUSIONS

Our study suggested RSIS with varying severity of parent artery atherosclerosis exhibits distinctive clinical and neuroimaging characteristics, with low-grade MCA atherosclerosis associating with higher cerebral small vessel disease burden and worse prognosis.

Inhibiting Cyclin B1-treated Pontine Infarction by Suppressing Proliferation of SPP1+ Microglia

Pontine infarction is the major subtype of brainstem stroke causing severe neurological deficits. The pathophysiology and treatment of pontine infarction was rarely studied. A rat model of acute pontine infarction was established via injection of endothelin-1 in the pons. Single-cell RNA sequencing was applied to detect the cellular response in pontine infarction. Based on this finding, a potential treatment for pontine infarction targeting microglia was verified. Occlusion of penetrating artery caused by endothelin-1 led to pontine infarction. Single-cell RNA sequencing revealed a subtype of activated microglia, SPP1+ microglia, which were different from M1-like or M2-like depolarization. SPP1+ microglia interacted with oligodendrocytes and contributed to the demyelination of nerve tracts. Cyclin B1 regulated the proliferation of SPP1+ microglia. Cucurbitacin E, a cyclin B1 inhibitor, reduced the proliferation of SPP1+ microglia around the injured myelin sheath and alleviated the demyelination. Moreover, cucurbitacin E treatment decreased the ischemic infarction volume and neurological deficits after pontine infarction. SPP1+ microglia contributed to axonal demyelination in the pontine infarction, and inhibition of SPP1+ microglia provided neuroprotection for pontine infarction.

Morphological predictors of neurological deterioration in patients with acute isolated pontine infarct

OBJECTIVE

To investigate morphological predictors of neurological deterioration (ND) in patients with acute isolated pontine infarct.

METHODS

Acute isolated pontine infarct patients within 7 days after onset of stroke symptoms were included retrospectively and classified into ND and non-ND groups. Morphological phenotypes (paramedian pontine infarct [PPI], atypical PPI, small deep infarct, and other types), topographical location, and lesion size were evaluated on axial diffusion-weighted imaging.

RESULTS

There were 210 eligible patients, of whom 62 patients had ND (29.5%). The proportion of PPI was significantly higher in ND than that in non-ND (62.9% vs 39.6%). ND occurred more frequently in PPI patients than non-PPI patients (39.8% vs 20.5%). PPI located more frequently in lower pontine (20.4% vs 8.0%) and less in upper pontine (17.3% vs 30.4%, P = 0.028), and had larger ventro-dorsal length (13.8 ± 3.8 vs 9.9 ± 3.1) and width (8.3 ± 2.3 vs 6.2 ± 1.8) than non-PPI patients. The morphological phenotype of PPI was an independent risk factor for ND (OR 4.81, 95%CI 1.54-15.07, P = 0.007) in patients with isolated pontine infarct. The ventro-dorsal length of pontine infarct lesion was associated with ND (OR 1.18, 95%CI 1.01, 1.37, P = 0.034) in PPI patients.

CONCLUSIONS

The morphological phenotype of PPI was a potential predictor for ND in patients with acute isolated pontine infarct. The ventro-dorsal length of pontine infarct lesion was possibly associated with ND in PPI patients.

Anatomic and MRI bases for pontine infarctions with patients presentation

OBJECTIVES

There are scarce data regarding pontine arteries anatomy, which is the basis for ischemic lesions following their occlusion. The aim of this study was to examine pontine vasculature and its relationships with the radiologic and neurologic features of pontine infarctions.

MATERIALS AND METHODS

Branches of eight basilar arteries and their twigs, including the larger intrapontine branches, were microdissected following an injection of a 10% mixture of India ink and gelatin. Two additional brain stems were prepared for microscopic examination after being stained with luxol fast blue and cresyl violet. Finally, 30 patients with pontine infarctions underwent magnetic resonance imaging (MRI) in order to determine the position and size of the infarctions.

RESULTS

The perforating arteries, which averaged 5.8 in number and 0.39 mm in diameter, gave rise to paramedian and anteromedial branches, and also to anterolateral twigs (62.5%). The longer leptomeningeal and cerebellar arteries occasionally gave off perforating and anterolateral twigs, and either the lateral or posterior branches. Occlusion of some of these vessels resulted in the paramedian (30%), anterolateral (26.7%), lateral (20%), and combined infarctions (23.3%), which were most often isolated and unilateral, and rarely bilateral (10%). They were located in the lower pons (23.3%), middle (10%) or rostral (26.7%), or in two or three portions (40%). Each type of infarction usually produced characteristic neurologic signs. The clinical significance of the anatomic findings was discussed.

CONCLUSIONS

There was a good correlation between the intrapontine vascular territories, the position, size and shape of the infarctions, and the type of neurologic manifestations.

Higher Prevalence of Diabetes in Pontine Infarction than in Other Posterior Circulation Strokes

BACKGROUND

Pontine infarction is the major subtype of posterior circulation stroke, and diabetes is more common in pontine infarction patients than in anterior circulation stroke patients. Whether the prevalence of diabetes remains homogenous within the posterior circulation stroke population is unclear. The present study is aimed at investigating the prevalence of diabetes in pontine infarction and comparing it to other subtypes of posterior circulation stroke.

METHODS

We conducted a multicenter case-control study. Patients with posterior circulation stroke were screened. The subjects were divided into pontine infarction and nonpontine infarction groups.

RESULTS

From November 1, 2018, to February 28, 2021, a total of 6145 stroke patients were screened and 2627 patients had posterior circulation strokes. After excluding cardioembolic stroke, as well as its other determined and undetermined causes, 1549 patients with 754 pontine infarctions were included in the analysis. The prevalence of diabetes in the pontine infarction group was higher than that in the nonpontine infarction group (42.7% vs. 31.4%, P < 0.05). After adjusting for confounding factors, diabetes was an independent risk factor for pontine infarction (OR 1.63, 95% CI 1.27-2.09, P < 0.05). For small vessel occlusion, diabetes was also more common in the pontine infarction group (43.2% vs. 30.0%, P < 0.05). Multivariate analysis also showed that diabetes was an independent risk factor for pontine infarction (OR 1.80, 95% CI 1.32-2.46, P < 0.05).

CONCLUSION

In comparison with the nonpontine infarction subtype of posterior circulation stroke, patients with pontine infarction had a higher prevalence of diabetes, and diabetes was an independent risk factor for pontine infarction.

Characteristics of basilar artery atherosclerotic plaques in pontine infarctions: A high-resolution magnetic resonance imaging study

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This study used a 3.0T high-resolution magnetic resonance imaging to explore basilar artery plaque characteristics in patients suffering from acute isolated pontine infarction.

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The study also used plaque analysis software to calculate the properties of the plaques and to fully analyze and compare the differences between two types of pontine infarction.

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The result may account for the different prognosis associated with these two types of pontine infarction.

Objective

This study used a 3.0T high-resolution magnetic resonance imaging approach to explore basilar artery plaque characteristics in patients suffering from acute isolated pontine infarction.

Materials and methods

30 consecutive patients suffering from acute isolated pontine infarction were enrolled in this study and underwent examinations including high-resolution MRI assessment of the basilar artery within 7 days following infarction.

Results

The basilar artery plaque burden of 16 patients with paramedian pontine infarction was 0.26±0.085, while the reconstruction index and enhancement rate index values in these patients were 1.097±0.133 and 1.750±0.447, respectively. In the 14 patients suffering from deep pontine infarction, these three values were 0.21±0.055, 0.896±0.223, and 1.285±0.611, respectively.These values differed significantly when comparing patients suffering from paramedian pontine infarction to those suffering from deep pontine infarction.

Conclusion

This study suggests that the characteristics of basilar artery plaques differ between the two subtypes of pontine infarctions, which may account for the differences in prognosis associated with these two infarct subtypes.

Topographic location of unisolated pontine infarction

BACKGROUND

The topographic location of acute pontine infarction is associated with clinical syndromes and prognosis. Previous studies focused on isolated pontine infarction, but the topographic location of unisolated pontine infarction has remained unclear.

METHODS

This was a prospective, multicenter, longitudinal registry study. Patients with acute pontine infarction confirmed by magnetic resonance imaging (MRI) were enrolled. Based on the territory of the pontine artery, the topographic location was divided into anteromedial, anterolateral, tegmental, bilateral and unilateral multiple infarctions.

RESULTS

From May 1, 2003, to Oct 31, 2017, 1003 patients were enrolled, and 330 had unisolated pontine infarction. For isolated pontine infarction, 44.9, 19.8, 16.0, 13.1 and 6.2% of patients had anteromedial, anterolateral, tegmental, bilateral and unilateral multiple pontine infarctions, respectively. For unisolated pontine infarction, 30.3, 19.7, 24.5, 15.2 and 10.3% of patients had anteromedial, anterolateral, tegmental, bilateral and unilateral multiple pontine infarctions, respectively.

CONCLUSION

In this large series study, our data revealed fewer anteromedial infarctions and more tegmental and unilateral multiple infarctions in patients with unisolated pontine infarction than in patients with isolated pontine infarction.

Atherosclerosis Might Be Responsible for Branch Artery Disease: Evidence From White Matter Hyperintensity Burden in Acute Isolated Pontine Infarction

Objective: To investigate an MRI-based etiological classification for acute isolated pontine infarcts and to assess differences in vascular risk factors, clinical characteristics and WMH burden among the etiological subtypes.

Methods: All participants from SMART cohort with DWI-proven acute isolated pontine infarcts (AIPI) were included and categorized into 3 groups: large-artery-occlusive disease (LAOD), basilar artery branch disease (BAD), and small vessel disease (SVD), according to basilar artery atherosclerosis severity and lesion extent of the transverse axial plane. The vascular risk factors and 6-month functional outcome was analyzed among 3 groups.

Results: Of the 1129 patients enrolled, 175 had AIPI. BAD was the most frequent subtype of AIPI (46.3%), followed by SVD (36.0%) and LAOD (17.7%). Neurological impairment on admission was more severe in the LAOD group, followed by BAD. The BAD group had greater frequencies of female sex, hypertension, diabetes mellitus compared to the SVD group (P < 0.05). NIHSS on admission were significantly higher in the BAD group as compared with the SVD group (P < 0.001), but no difference was found between BAD and LAOD group. Poor outcome (mRS≥3) was found in only 13.7% of patients at 6-month post-stroke and there was no difference among 3 groups. WMH severity was significant higher in the SVD group compared to the BAD group for the deep subcortical region; however, there was no difference for the periventricualr region. There was no significant difference in either DWMH or PVWMH severity between the BAD and LAOD groups.

Conclusion: BAD is the most frequent etiology of AIPI followed by SVD and LAOD. WMH burden, vascular risk factors and clinical characteristics in BAD group were more similar to the LAOD group, rather than to the SVD group, suggesting the atherothrombotic nature of BAD.