The Potential Impact of Neuroimaging and Translational Research on the Clinical Management of Lacunar Stroke.

Lacunar infarcts represent one of the most frequent subtypes of ischemic strokes and may represent the first recognizable manifestation of a progressive disease of the small perforating arteries, capillaries, and venules of the brain, defined as cerebral small vessel disease. The pathophysiological mechanisms leading to a perforating artery occlusion are multiple and still not completely defined, due to spatial resolution issues in neuroimaging, sparsity of pathological studies, and lack of valid experimental models. Recent advances in the endovascular treatment of large vessel occlusion may have diverted attention from the management of patients with small vessel occlusions, often excluded from clinical trials of acute therapy and secondary prevention. However, patients with a lacunar stroke benefit from early diagnosis, reperfusion therapy, and secondary prevention measures. In addition, there are new developments in the knowledge of this entity that suggest potential benefits of thrombolysis in an extended time window in selected patients, as well as novel therapeutic approaches targeting different pathophysiological mechanisms involved in small vessel disease. This review offers a comprehensive update in lacunar stroke pathophysiology and clinical perspective for managing lacunar strokes, in light of the latest insights from imaging and translational studies.

Insulin resistance and muscle weakness are synergistic risk factors for silent lacunar infarcts: the Bunkyo Health Study.

Insulin resistance and muscle weakness are risk factors for silent lacunar infarcts (SLI), but it is unclear whether they are still independent risk factors when adjusted for each other. In addition, the effect of their combination on SLI is completely unknown. We evaluated SLI, insulin sensitivity, and knee extensor muscle strength by magnetic resonance imaging, PREDIM, and dynamometer, respectively, in 1531 elderly people aged 65-84 years living in an urban area of Tokyo. Among the study subjects, 251 (16.4%) had SLI. Impaired insulin sensitivity (High; 1.00 [reference], Medium; 1.53 [95% confidence interval (CI) 0.94-2.48], Low; 1.86 [1.02-3.39], p for trend 0.047) and reduced muscle strength (High; 1.00 [reference], Medium; 1.40 [0.98-2.02], Low; 1.49 [1.04-2.15], p for trend 0.037) were independently associated with increased risk for SLI in the fully adjusted model. In terms of combined, subjects classified as having the lowest insulin sensitivity and lowest strength were 4.33 times (95% CI 1.64-11.45) more likely to have a SLI than those classified as having the highest insulin sensitivity and highest strength. Impaired insulin sensitivity and reduced muscle strength were independently associated with higher risk of SLI in elderly subjects, and their combination synergistically increased this risk.

Sex and Cardiovascular Function in Relation to Vascular Brain Injury in Patients with Cognitive Complaints.

BACKGROUND: Emerging evidence shows sex differences in manifestations of vascular brain injury in memory clinic patients. We hypothesize that this is explained by sex differences in cardiovascular function. OBJECTIVE: To assess the relation between sex and manifestations of vascular brain injury in patients with cognitive complaints, in interaction with cardiovascular function. METHODS: 160 outpatient clinic patients (68.8±8.5 years, 38% female) with cognitive complaints and vascular brain injury from the Heart-Brain Connection study underwent a standardized work-up, including heart-brain MRI. We calculated sex differences in vascular brain injury (lacunar infarcts, non-lacunar infarcts, white matter hyperintensities [WMHs], and microbleeds) and cardiovascular function (arterial stiffness, cardiac index, left ventricular [LV] mass index, LV mass-to-volume ratio and cerebral blood flow). In separate regression models, we analyzed the interaction effect between sex and cardiovascular function markers on manifestations of vascular brain injury with interaction terms (sex*cardiovascular function marker). RESULTS: Males had more infarcts, whereas females tended to have larger WMH-volumes. Males had higher LV mass indexes and LV mass-to-volume ratios and lower CBF values compared to females. Yet, we found no interaction effect between sex and individual cardiovascular function markers in relation to the different manifestations of vascular brain injury (p-values interaction terms > 0.05). CONCLUSION: Manifestations of vascular brain injury in patients with cognitive complaints differed by sex. There was no interaction between sex and cardiovascular function, warranting further studies to explain the observed sex differences in injury patterns.

Association of Left Ventricular Hypertrophy and Atrial Fibrillation with Hemorrhagic Evolution of Small Vessel Disease.

OBJECTIVES: Cerebral small vessel disease (SVD) is often associated with hypertension and may evolve towards intracerebral hemorrhage (ICH) or lacunar ischemic stroke. However, the factors favoring the evolution towards ICH or lacunar stroke are not well understood. MATERIALS AND METHODS: This retrospective study included 326 consecutive patients (71.1±13.2 years, 38% women): 143 with deep ICH and 183 with lacunar lesions (LL) <2 cm, which were visible in a deep location on brain CT scan. Among LL patients, 143 had a small-artery occlusion (SAO) stroke according to the TOAST classification. Clinical characteristics plus laboratory and neuroradiological variables of these patients had been prospectively collected and a subgroup underwent echocardiography. RESULTS: In multivariate analysis, ICH patients (97% hypertensive), compared to SAO patients (89% hypertensive), had greater left ventricular wall thickness (LVWT; OR 4.15, 95%CI 1.64-10.53, for those with LVWT ≥ 1.4 cm, 70% of whom were hemorrhagic) and lower prevalence of white matter lesions (OR 0.30, 95%CI 0.13-0.70), ever smokers (OR 0.39, 95%CI 0.18-0.82) and diabetics (OR 0.29, 95% CI 0.10-0.84). Moreover, ICH patients had a greater prevalence of atrial fibrillation than LL patients (OR 3.14, 95%CI 1.11-8.93), and so they were more often anticoagulated. CONCLUSIONS: Most SVD patients were hypertensive, but those evolving towards ICH were characterized by organ damage at the cardiac level (increase in LVWT and atrial fibrillation), while those evolving towards lacunar stroke were characterized by a higher prevalence of smokers and diabetics, and by organ damage at the cerebral level (white matter lesions).

Advances in Understanding the Pathogenesis of Lacunar Stroke: From Pathology and Pathophysiology to Neuroimaging.

Lacunar stroke (LS) accounts for about one-quarter of all acute ischemic strokes, represents an important marker of cerebral small vessel disease (CSVD), and has prognostic significance in terms of recurrent vascular events and vascular cognitive impairment. Our understanding of the etiology and pathogenesis of LS is largely based on the meticulous postmortem work of C. Miller Fisher in the late 1960s, with scarce subsequent pathological analysis of the "lacunar hypothesis" and no reliable approaches for direct in vivo imaging of the small intracranial vessels. The recent development of high-resolution MRI, which allows both large-vessel wall and perforating arteries to be imaged in one setting, provides the opportunity to advance understandings of the clinical mechanisms, imaging characteristics, and pathogenesis of LS. Given accumulating evidence of endothelial dysfunction and blood-brain-barrier disruption as early features of CSVD-related LS, advanced imaging may allow various underlying pathogenetic mechanisms to be defined and for better targeting of therapeutic approaches in LS. In this review, progress in understanding the pathogenesis of LS is outlined, covering pathology, pathophysiology, and imaging characteristics, with a focus toward future directions in the complex entity of LS.

PRESERVE: Randomized Trial of Intensive Versus Standard Blood Pressure Control in Small Vessel Disease.

[Figure: see text].

Cerebral Perfusion and the Burden of Small Vessel Disease in Patients Referred to a Memory Clinic.

BACKGROUND: Cerebral small vessel disease (SVD) lesions on MRI are common in patients with cognitive impairment. It has been suggested that cerebral hypoperfusion is involved in the etiology of these lesions. OBJECTIVE: The aim of the study was to determine the relationship between cerebral blood flow (CBF) and SVD burden in patients referred to a memory clinic with SVD on MRI. METHOD: We included 132 memory clinic patients (mean age 73 ± 10, 56% male) with SVD on MRI. We excluded patients with large non-lacunar cortical infarcts. Global CBF (mL/min per 100 mL of brain tissue) was derived from 2-dimensional phase-contrast MRI focused on the internal carotid arteries and the basilar artery. SVD burden was defined as the sum of (each 1 point): white matter hyperintensities (WMHs) Fazekas 1 or more, lacunes, microbleeds (MBs), or enlarged perivascular spaces (PVS) presence, and each SVD feature separately. Linear regression analyses were performed to study the association between CBF and SVD burden, age- and sex-adjusted. RESULTS: Median SVD burden score was 2, 36.4% of patients had MBs, 35.6% lacunar infarcts, 48.4% intermediate to severe enlarged PVS, and 57.6% a WMH Fazekas score 2 or more. Median WMH volume was 21.4 mL (25% quartile: 9.6 mL, 75% quartile: 32.5 mL). Mean CBF ± SD was 44.0 ± 11.9 mL/min per 100 mL brain. There was no relation between CBF and overall SVD burden (CBF difference per burden score point [95% CI]: -0.5 [-2.4; 1.4] mL/min/100 mL brain, p = 0.9). CBF did also not differ according to presence or absence or an high burden of any of the individual SVD features. Moreover, there was no significant relation between WMH volume and CBF (CBF difference per ml increase in WMH [95% CI] -0.6 [-1.5; 0.3] mL/min/100 mL brain p = 0.2). CONCLUSION: Global CBF was not related to overall SVD burden or with individual SVD features in this memory clinic cohort, indicating that in this setting these lesions were not primarily due to cerebral hypoperfusion.

Unusual manifestation of heat stroke: Isolated trochlear nerve palsy.

Heat stroke is a life-threatening disease characterized by hyperthermia and neurological dysfunction. The central nervous system is highly sensitive to hyperthermia, which causes neurological complications due to the involvement of the cerebellum, basal ganglia, anterior horn cells, and peripheral nerves. Several studies reported about clinical symptoms and brain image findings of heat stroke. Isolated cranial nerve dysfunction caused by lacunar infarction is an extremely rare condition in patient with heat stroke. We experienced a rare case of trochlear nerve palsy due to midbrain infarction caused by heat stroke.

Association between Ankle Brachial Index, Brachial-Ankle Pulse Wave Velocity, and Mild Cognitive Impairment in Patients with Acute Lacunar Infarction.

BACKGROUND: The link between arterial stiffness and mild cognitive impairment (MCI) is receiving increasing attention, and the goal of this study was to explore the relationship among the ankle brachial index (ABI), brachial-ankle pulse wave velocity (Ba-PWV), and MCI in patients with acute lacunar infarction (ALI). METHODS: A total of 103 hospitalized patients with ALI were divided into a non-MCI group (n = 41) and an MCI group (n = 62) according to their Montreal Cognitive Assessment (MoCA) scores. A binary logistic regression model was used to assess the association among ABI, Ba-PWV, and MCI after adjusting for confounding factors. Spearman correlation was utilized to analyse the correlations between ABI, Ba-PWV, and MoCA total scores and sub-scores in ALI patients. RESULTS: Participants with cognitive impairment had significantly higher Ba-PWV and lower ABI than those with normal cognition. Correlation analysis suggested that Ba-PWV (r = -0.854, p < 0.05) and ABI (r = 0.734, p < 0.05) were correlated with MoCA total scores; of all MoCA sub-scores, visuospatial/executive function was the most strongly correlated with the vascular variables. In the binary logistic regression analysis, Ba-PWV (odds ratio [OR] = 4.507, 95% confidence interval [CI] = 2.152-9.441) and ABI (OR = 1.124, 95% CI = 1.015-1.254) were significantly associated with MCI, even after adjusting for lipoprotein (a) and systolic and diastolic blood pressure. CONCLUSION: The present study suggested that a higher Ba-PWV and a lower ABI were independent risk factors for MCI in patients with ALI.

Immune-Inflammatory, Metabolic, Oxidative, and Nitrosative Stress Biomarkers Predict Acute Ischemic Stroke and Short-Term Outcome.

Immune-inflammatory, metabolic, oxidative, and nitrosative stress (IMO&NS) pathways and, consequently, neurotoxicity are involved in acute ischemic stroke (IS). The simultaneous assessment of multiple IMO&NS biomarkers may be useful to predict IS and its prognosis. The aim of this study was to identify the IMO&NS biomarkers, which predict short-term IS outcome. The study included 176 IS patients and 176 healthy controls. Modified Rankin scale (mRS) was applied within 8 h after IS (baseline) and 3 months later (endpoint). Blood samples were obtained within 24 h after hospital admission. IS was associated with increased white blood cell (WBC) counts, high sensitivity C-reactive protein (hsCRP), interleukin (IL-6), lipid hydroperoxides (LOOHs), nitric oxide metabolites (NOx), homocysteine, ferritin, erythrocyte sedimentation rate (ESR), glucose, insulin, and lowered iron, 25-hydroxyvitamin D [25(OH)D], total cholesterol, and high-density lipoprotein (HDL) cholesterol. We found that 89.4% of the IS patients may be correctly classified using the cumulative effects of male sex, systolic blood pressure (SBP), glucose, NOx, LOOH, 25(OH)D, IL-6, and WBC with sensitivity of 86.2% and specificity of 93.0%. Moreover, increased baseline disability (mRS ≥ 3) was associated with increased ferritin, IL-6, hsCRP, WBC, ESR, and glucose. We found that 25.0% of the variance in the 3-month endpoint (mRS) was explained by the regression on glucose, ESR, age (all positively), and HDL-cholesterol, and 25(OH)D (both negatively). These results show that the cumulative effects of IMO&NS biomarkers are associated with IS and predict a poor outcome at 3-month follow-up.

Functional health and white matter hyperintensities as effect modifiers of blood pressure-lowering on cognitive function and vascular events in older Secondary Prevention of Small Subcortical Strokes trial participants.

OBJECTIVE: To determine whether cerebral small vessel disease or disability modify the effect of SBP treatment on cognitive and vascular outcomes in older patients with recent lacunar stroke. METHODS: Participants aged at least 65 years of the Secondary Prevention of Small Subcortical Strokes Trial were randomized to a higher (130-149 mmHg) or lower (<130 mmHg) SBP target. The primary outcome was change in cognitive function (Cognitive Abilities Screening Instrument); secondary outcomes were incident mild cognitive impairment, stroke, major vascular events (all-stroke, myocardial infarction), and all-cause death. Results were stratified by severity of white matter hyperintensities (WMH; none/mild, moderate, severe) on baseline MRI, and by disability (no vs. at least one limitation in activities of daily living). RESULTS: One thousand, two hundred and sixty-three participants (mean age 73.8 ±â€Š5.9 years, 40% women) were included. Participants with severe WMH or disability had worse cognitive function at baseline and after a mean follow-up of 3.9 years. No significant interactions existed between treatment group and effect modifiers (WMH, disability) for change in cognitive function (P for interaction 0.42 and 0.66, respectively). A lower SBP target appeared more beneficial among those with worse WMH burden for vascular outcomes (P for interaction = 0.01 for stroke and 0.03 for major vascular events). CONCLUSION: There was no difference in the effect of lowering SBP to less than 130 mmHg on cognitive function by cerebral small vessel disease or disability among older adults with a history of lacunar stroke. Those with evidence of small vessel disease may derive greater benefit from lower SBP on prevention of subsequent vascular events. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT00059306.

Intravenously Transplanted Human Multilineage-Differentiating Stress-Enduring Cells Afford Brain Repair in a Mouse Lacunar Stroke Model.

Background and Purpose- Multilineage-differentiating stress-enduring cells are endogenous nontumorigenic reparative pluripotent-like stem cells found in bone marrow, peripheral blood, and connective tissues. Topically administered human multilineage-differentiating stress-enduring cells into rat/mouse stroke models differentiated into neural cells and promoted clinically relevant functional recovery. However, critical questions on the appropriate timing and dose, and safety of the less invasive intravenous administration of clinical-grade multilineage-differentiating stress-enduring cell-based product CL2020 remain unanswered. Methods- Using an immunodeficient mouse lacunar model, CL2020 was administered via the cervical vein in different doses (high dose=5×104 cells/body; medium dose=1×104 cells/body; low dose=5×103 cells/body) at subacute phase (≈9 days after onset) and chronic phase (≈30 days). Cylinder test, depletion of human cells by diphtheria toxin administration, immunohistochemistry, and human specific-genome detection were performed. Results- Tumorigenesis and adverse effects were not detected for up to 22 weeks. The high-dose group displayed significant functional recovery compared with the vehicle group in cylinder test in subacute-phase-treated and chronic-phase-treated animals after 6 weeks and 8 weeks post-injection, respectively. In the high-dose group of subacute-phase-treated animals, robust and stable recovery in cylinder test persisted up to 22 weeks compared with the vehicle group. In both groups, intraperitoneal injection of diphtheria toxin abrogated the functional recovery. Anti-human mitochondria revealed CL2020 distributed mainly in the peri-infarct area at 1, 10, and 22 weeks and expressed NeuN (neuronal nuclei)- and MAP-2 (microtubule-associated protein-2)-immunoreactivity. Conclusions- Intravenously administered CL2020 was safe, migrated to the peri-infarct area, and afforded functional recovery in experimental stroke.

Risk factors for infarct expansion are different between lacunar and giant lacunar infarction.

BACKGROUND AND AIMS: The precise mechanisms underlying the expansion of lacunar and giant lacunar infarction remain unclear. We aimed to determine risk factors for lacunar and giant lacunar infarction and to clarify differences in pathophysiological mechanisms for these two groups. METHODS: Patients were selected from a comprehensive stroke center with ≤24 h from onset to initial magnetic resonance imaging with lacunar and giant lacunar infarction. All patients underwent a second magnetic resonance imaging during hospitalization. Infarct size was calculated and compared by the positive region on diffusion-weighted imaging. Factors related to infarct expansion were evaluated separately in the two groups. RESULTS: We screened 1558 consecutive ischemic stroke patients, including 154 patients with small vessel disease (lacunar infarction, 81 patients; giant lacunar infarction, 73 patients). Age (odds ratio (OR), 0.899; 95% confidence interval (CI), 0.824-0.981, p = 0.016), higher cardio-ankle vascular index (OR, 6.011; 95%CI, 2.319-15.581, p < 0.001), higher uric acid (OR, 2.584; 95%CI, 1.091-6.121, p = 0.031), and lower/normal low-density lipoprotein (LDL)-cholesterol (OR, 0.718; 95%CI, 0.557-0.926, p = 0.011) were independently associated with infarct expansion in lacunar infarction patients. Concerning giant lacunar infarction, higher LDL-cholesterol (OR 1.509, 95%CI 1.083-2.103; p = 0.015) and lower/normal body mass index (OR 0.725, 95%CI 0.567-0.926; p = 0.010) were factors independently associated with infarct expansion. CONCLUSIONS: Risk factors for infarct expansion differed between lacunar and giant lacunar infarction. The underlying pathophysiological mechanisms for infarct expansion in these two groups should be recognized individually.

Imaging markers of small vessel disease and brain frailty, and outcomes in acute stroke.

OBJECTIVE: To assess the association of baseline imaging markers of cerebral small vessel disease (SVD) and brain frailty with clinical outcome after acute stroke in the Efficacy of Nitric Oxide in Stroke (ENOS) trial. METHODS: ENOS randomized 4,011 patients with acute stroke (<48 hours of onset) to transdermal glyceryl trinitrate (GTN) or no GTN for 7 days. The primary outcome was functional outcome (modified Rankin Scale [mRS] score) at day 90. Cognition was assessed via telephone at day 90. Stroke syndrome was classified with the Oxfordshire Community Stroke Project classification. Brain imaging was adjudicated masked to clinical information and treatment and assessed SVD (leukoaraiosis, old lacunar infarcts/lacunes, atrophy) and brain frailty (leukoaraiosis, atrophy, old vascular lesions/infarcts). Analyses used ordinal logistic regression adjusted for prognostic variables. RESULTS: In all participants and those with lacunar syndrome (LACS; 1,397, 34.8%), baseline CT imaging features of SVD and brain frailty were common and independently associated with unfavorable shifts in mRS score at day 90 (all participants: SVD score odds ratio [OR] 1.15, 95% confidence interval [CI] 1.07-1.24; brain frailty score OR 1.25, 95% CI 1.17-1.34; those with LACS: SVD score OR 1.30, 95% CI 1.15-1.47, brain frailty score OR 1.28, 95% CI 1.14-1.44). Brain frailty was associated with worse cognitive scores at 90 days in all participants and in those with LACS. CONCLUSIONS: Baseline imaging features of SVD and brain frailty were common in lacunar stroke and all stroke, predicted worse prognosis after all acute stroke with a stronger effect in lacunar stroke, and may aid future clinical decision-making. IDENTIFIER: ISRCTN99414122.

Pre-Existing Cerebral Small Vessel Disease Limits Early Recovery in Patients with Acute Lacunar Infarct.

BACKGROUND AND PURPOSE: To assess whether neuroimaging markers of chronic cerebral small vessel disease (cSVDm) influence early recovery after acute ischemic stroke (AIS). METHODS: Retrospective analysis of patients diagnosed with AIS and included in the Spanish Neurological Society Stroke Database. INCLUSION CRITERIA: (1) Brain MRI performed after acute stroke and (2) Premorbid modified Rankin scale (mRS) = 0. EXCLUSION CRITERIA: (1) Uncommon stroke etiologies, (2) AIS not confirmed on neuroimaging, or (3) Old territorial infarcts on neuroimaging. Patients scored from 0 to 2 according to the amount of cSVDm. Patients were divided into lacunar ischemic stroke (LIS) and nonlacunar ischemic stroke (NLIS) groups according to TOAST classification. PRIMARY OUTCOME: Distribution of mRS at discharge. SECONDARY OUTCOMES: NIHSS improvement more than or equal to 3 at 24 hours and at discharge, NIHSS worsening more than or equal to 3 points at 24 hours. RESULTS: We studied 4424 patients (3457 NLIS, 967 LIS). The presence of cSVDm increased the risk of worsening 1 category on the mRS at discharge in the LIS group ([1] cSVDm: OR 1.89 CI 95% 1.29-2.75, P = .001. [2] cSVDm: OR 1.87, CI 95% 1.37-2.56 P = .001) and was an independent factor for not achieving an improvement more than or equal to 3 points on the NIHSS at discharge for all the patients and the LIS group (all stroke patients: [1] cSVDm: OR 0.81 CI 95% .68-.97 P = .022. [2] cSVD: OR 0.58 CI95% .45-.77, P = .001./LIS: [1] cSVDm: OR 0.64, CI 95% .41-.98, P = .038. [2] cSVDm: OR 0.43, CI 95% .24-.75 P = .003). CONCLUSIONS: Pre-existing SVD limits early functional and neurological recovery after AIS, especially in LIS patients.

Low carotid endothelial shear stress associated with cerebral small vessel disease in an older population: A subgroup analysis of a population-based prospective cohort study.

BACKGROUND AND AIMS: The association between carotid wall shear stress (WSS) and cerebral small vessel disease has yet to be fully elucidated. The major purpose of this study was to investigate this association in older subjects. METHODS: Common carotid artery WSS, endothelial function, white matter hyperintensities (WMH), lacunes, and microbleeds were assessed in 1396 older adults. Participants were followed-up for an average of 69.7 months. RESULTS: Mean (M) and peak (P) WSS and changes in endothelial function were independently associated with changes in WMH volume and fraction, lacune counts, and microbleed counts (all p < 0.05). The risks of new-incident Fazekas scale ≥2 [hazard ratio (HR) with 95% confidence interval (CI): 2.141 (1.469-3.119), p = 0.005 and 1.731 (1.197-2.505), p = 0.004, respectively], lacunes [HR (95% CI): 2.034 (1.369-3.022), p < 0.001 and 1.693 (1.151-2.490), p = 0.003, respectively], and microbleeds [HR (95% CI): 2.311 (1.509-3.541), p < 0.001 and 2.208 (1.299-3.751), p < 0.001, respectively] were significantly higher in the lowest quartile group than in the higher quartile group, as classified by either MWSS or PWSS, after adjustment for confounders. CONCLUSIONS: Low carotid WSS is an independent risk factor for the progression of cerebral small vessel disease in older adults.

Effect of Heart Rate Variability on the Association Between the Apnea-Hypopnea Index and Cerebral Small Vessel Disease.

Background and Purpose- The apnea-hypopnea index (AHI) is associated with cerebral small vessel disease (cSVD), but pathogenesis of this association is elusive. We aimed to assess the effect of nighttime heart rate variability (HRV)-as a proxy of sympathetic upregulation-on the aforementioned association. Methods- Atahualpa residents aged ≥60 years undergoing brain magnetic resonance imaging, polysomnography, and 24-hour Holter monitoring (N=176) were included. The presence of moderate-to-severe white matter hyperintensities, deep cerebral microbleeds, lacunar infarcts, and >10 enlarged basal ganglia perivascular spaces were added for estimating the cSVD score. Interaction models were fitted to assess the effect modification of nighttime HRV in the association between the AHI and the cSVD score, and mediation analysis was utilized to assess the proportion of total effect by nighttime HRV on this association. Results- Generalized linear models showed a significant association between the AHI and the cSVD score (P=0.025), as well as a significant inverse association between nighttime HRV and the cSVD score (P=0.002), but no association between daytime HRV and the cSVD score (P=0.097). Interaction models showed a significant interaction of nighttime HRV on the association between AHI and the cSVD score (P=0.001), and mediation analysis found that the percent of total effect between AHI and cSVD score mediated by HRV was 30.8%. Predictive marginal means of the cSVD score were highly significant when the 10th percentile of nighttime HRV was compared across categories of 10th and 90th percentiles of the AHI (cSVD score margins, 0.61 [95% CI, 0.37-0.86] versus 1.67 [95% CI, 1.26-2.09]). Contour plots showed the effect of nighttime (but not daytime) HRV on the association between AHI and the cSVD score. Conclusions- This study shows an important effect of nighttime HRV on the association between the AHI and the cSVD score and provides further support for the role of sympathetic overactivity on this association.

Treatment Approaches to Lacunar Stroke.

Lacunar strokes are appropriately named for their ability to cavitate and form ponds or "little lakes" (Latin: lacune -ae meaning pond or pit is a diminutive form of lacus meaning lake). They account for a substantial proportion of both symptomatic and asymptomatic ischemic strokes. In recent years, there have been several advances in the management of large vessel occlusions. New therapies such as non-vitamin K antagonist oral anticoagulants and left atrial appendage closure have recently been developed to improve stroke prevention in atrial fibrillation; however, the treatment of small vessel disease-related strokes lags frustratingly behind. Since Fisher characterized the lacunar syndromes and associated infarcts in the late 1960s, there have been no therapies specifically targeting lacunar stroke. Unfortunately, many therapeutic agents used for the treatment of ischemic stroke in general offer only a modest benefit in reducing recurrent stroke while adding to the risk of intracerebral hemorrhage and systemic bleeding. Escalation of antithrombotic treatments beyond standard single antiplatelet agents has not been effective in long-term lacunar stroke prevention efforts, unequivocally increasing intracerebral hemorrhage risk without providing a significant benefit. In this review, we critically review the available treatments for lacunar stroke based on evidence from clinical trials. For several of the major drugs, we summarize the adverse effects in the context of this unique patient population. We also discuss the role of neuroprotective therapies and neural repair strategies as they may relate to recovery from lacunar stroke.