Statin-treated familial hypercholesterolemia patients with coronary heart disease and pronounced atherosclerosis do not have more brain lesions than healthy controls in later middle age

Cerebrovascular Reactivity Measures Are Associated With Post-traumatic Headache Severity in Chronic TBI; A Retrospective Analysis

OBJECTIVE

To characterize the relationship between persistent post-traumatic headache (pPTH) and traumatic cerebrovascular injury (TCVI) in chronic traumatic brain injury (TBI). Cerebrovascular reactivity (CVR), a measure of the cerebral microvasculature and endothelial cell function, is altered both in individuals with chronic TBI and migraine headache disorder (Amyot et al., 2017; Lee et al., 2019b). The pathophysiologies of pPTH and migraine are believed to be associated with chronic microvascular dysfunction. We therefore hypothesize that TCVI may contribute to the underlying migraine-like mechanism(s) of pPTH.

MATERIALS AND METHODS

22 moderate/severe TBI participants in the chronic stage (>6 months) underwent anatomic and functional magnetic resonance imaging (fMRI) scanning with hypercapnia gas challenge to measure CVR as well as the change in CVR (ΔCVR) after single-dose treatment of a specific phosphodiesterase-5 (PDE-5) inhibitor, sildenafil, which potentiates vasodilation in response to hypercapnia in impaired endothelium, as part of a Phase2a RCT of sildenafil in chronic TBI (NCT01762475). CVR and ΔCVR measures of each participant were compared with the individual's pPTH severity measured by the headache impact test-6 (HIT-6) survey.

RESULTS

There was a moderate correlation between HIT-6 and both CVR and ΔCVR scores [Spearman's correlation = -0.50 (p = 0.018) and = 0.46 (p = 0.03), respectively], indicating that a higher headache burden is associated with decreased endothelial function in our chronic TBI population.

CONCLUSION

There is a correlation between PTH and CVR in chronic moderate-severe TBI. This relationship suggests that chronic TCVI may underlie the pathobiology of pPTH. Further, our results suggest that novel treatment strategies that target endothelial function and vascular health may be beneficial in refractory pPTH.

High Prevalence of Cerebral Small Vessel Disease on 7T Magnetic Resonance Imaging in Familial Hypercholesterolemia

Aim: It remains unclear whether elevated low-density lipoprotein cholesterol (LDL-C) is a risk factor for cerebral vascular disease. Familial hypercholesterolemia (FH) is the most appropriate model for understanding the effects of excess LDL-C because affected individuals have inherently high levels of circulating LDL-C. To clarify the effects of hypercholesterolemia on cerebral small vessel disease (SVD), we investigated cerebrovascular damage in detail due to elevated LDL-C using high resolution brain magnetic resonance imaging (MRI) in patients with FH.

Methods: Twenty-eight patients with FH and 35 healthy controls underwent 7T brain MRI. The prevalence of SVD and arterial structural changes were determined in each group.

Results: The prevalence of periventricular hyperintensity (PVH) was significantly higher (control, 0% vs. FH, 14.2%, p = 0.021) and deep white matter intensity tended to be more frequent in FH patients than in controls. The prevalence of SVD in patients with forms of cerebral damage, such as lacunar infarction, PVH, deep white matter hyperintensities (DWMH), microbleeding, and brain atrophy, was significantly higher among FH patients (control, n = 2, 5.7% vs. FH, n = 7, 25.0%, p < 0.001, chi-square test). The tortuosity of major intracranial arteries and the signal intensity of lenticulostriate arteries were similar in the two groups. In FH patients, as the grade of PVH progressed, several atherosclerosis risk factors, such as body mass index, blood pressure, and triglyceride level, showed ever worsening values.

Conclusion: These results obtained from FH patients revealed that persistently elevated LDL-C leads to cerebral PVH. It is necessary in the management of FH to pay attention not only to the development of coronary heart disease but also to the presence of cerebral SVD.

White matter microstructure and cognitive decline in metabolic syndrome: a review of diffusion tensor imaging

Metabolic syndrome is a cluster of cardiovascular risk factors defined by the presence of abdominal obesity, glucose intolerance, hypertension and/or dyslipidemia. It is a major public health epidemic worldwide, and a known risk factor for the development of cognitive dysfunction and dementia. Several studies have demonstrated a positive association between the presence of metabolic syndrome and worse cognitive outcomes, however, evidence of brain structure pathology is limited. Diffusion tensor imaging has offered new opportunities to detect microstructural white matter changes in metabolic syndrome, and a possibility to detect associations between functional and structural abnormalities. This review analyzes the impact of metabolic syndrome on white matter microstructural integrity, brain structure abnormalities and their relationship to cognitive function. Each of the metabolic syndrome components exerts a specific signature of white matter microstructural abnormalities. Metabolic syndrome and its components exert both additive/synergistic, as well as, independent effects on brain microstructure thus accelerating brain aging and cognitive decline.

Characterizing Deep White Matter Hyperintensities in Patients with Symptomatic Isolated Cortical Superficial Siderosis

BACKGROUND

In patient with cerebral amyloid angiopathy (CAA) presenting with lobar hemorrhage (LH), magnetic resonance imaging (MRI) white matter hyperintensities (WMH) tend to be predominant in posterior regions with the "multiple subcortical spots" WMH pattern as the most frequent topographical WMH pattern. Our aim was to analyze WMH severity and topographical distribution in patients with cortical superficial siderosis (CSS).

METHODS

We retrospectively analyzed MRIs from consecutive symptomatic isolated (i.e., without LH) CSS and LH-CAA (with or without associated CSS) patients. We analyzed baseline clinical characteristics including age, history of hypertension, diabetes, hypercholesterolemia, and pre-existing cognitive deficit. The presence of lobar microbleeds (MB) was scored on T2*. FLAIR (fluid-attenuated inversion recovery) WMH severity (using the Fazekas scale) and topographical distribution (using [slightly modified] earlier described WMH patterns) were analyzed and compared between both groups.

RESULTS

Twenty CSS and 63 LH-CAA patients were analyzed. Baseline clinical characteristics were similar between both groups, except for hypercholesterolemia less frequently present in the CSS group (P = .026). Lobar MB were significantly less frequently present in the CSS group (P < .01), and CSS was more frequently focal in the CSS group compared with LH-CAA patients with associated CSS (P = .03). Mean Fazekas scale was significantly lower in CSS patients (P = .011). WMH patterns did not differ between both groups, with the multiple subcortical spots pattern as the most frequently observed pattern.

CONCLUSIONS

Relative severe WMH scores and similar topographical distribution in CSS patients argue for WMH as a CAA-related feature in these patients with isolated CSS, adding level of evidence that isolated CSS could correspond to early manifestations of CAA.

Statins decrease the risk of stroke in individuals with heterozygous familial hypercholesterolemia: A systematic review and meta-analysis

BACKGROUND

Familial hypercholesterolemia (FH) is undoubtedly associated with premature coronary heart disease, but it is debatable whether FH increases the risk for stroke.

OBJECTIVE

To meta-analyze available evidence regarding the incidence of stroke in individuals with heterozygous (He) FH.

METHODS

We conducted a systematic review and a meta-analysis of epidemiological studies, including English-language publications until June 2015; four observational studies, with 3374 participants with HeFH, were included in the analysis. Cerebrovascular disease comprised of ischemic stroke or transient ischemic attack. Since studies did not include any control subjects, the corresponding general population of the same reference area and period of time for each HeFH study served as control group. Analyses were performed according to the period of time during which the studies were conducted: prestatin and statin era (before and after 1987 when lovastatin was launched).

RESULTS

In the prestatin era, individuals with HeFH exhibited a higher risk for stroke compared with the general population [odds ratio (OR) = 7.658, 95% confidence interval (CI): 6.059-9.678, p < 0.01]. In contrast, FH subjects had a lower odds for stroke following the generalization of statin therapy (OR = 0.251, 95% CI: 0.176-0.358, p < 0.01).

CONCLUSIONS

Taking into account the small number of studies and methodological issues, HeFH was associated with a higher risk of cerebrovascular disease compared with the general population in the prestatin era, which was significantly reduced after the introduction of statin therapy.

Treatment of carotid artery disease: endarterectomy or angioplasty?

The management of carotid stenosis has enjoyed renewed interest in the neurological community in recent years due to the advent of endovascular approaches. In concert, progress in medical treatment of these patients has rekindled the debate regarding the best management of carotid stenosis overall, both for symptomatic and asymptomatic disease. For symptomatic carotid stenosis, the major decision required is choosing the type of intervention best suited for individual patients: carotid endarterectomy versus carotid artery stenting. For patients with asymptomatic carotid stenosis, intensive medical management has evolved significantly over the past decade to decrease the risk of ischemic stroke to match surgical intervention under most circumstances. This review will examine the supporting evidence for each intervention, and discuss the recent advances in medical and endovascular therapy that provide the data for a new era in clinical decision making.

Compliance of the aorta in two diseases affecting vascular elasticity, familial hypercholesterolemia and diabetes: a MRI study

Arterial elasticity changes in familial hypercholesterolemia (FH) and diabetes mellitus (DM) with different but overlapping mechanisms. We compared aortic elasticity between 19 FH patients with the same mutation, 18 type 2 DM patients, and 30 controls, all aged 48 to 64. They underwent aortic magnetic resonance imaging, risk-factor assessment, and carotid and femoral ultrasound measurements. All patients were on adequate cardiovascular medication including statins and had established coronary heart disease (CHD). FH patients had longer-duration CHD (13.3 +/- 7.7 years) than did DM patients (5.0 +/- 3.1). Aortic compliance in the descending thoracic (DM 0.38 +/- 0.14 vs control 0.53 +/- 0.19, P = 0.032) and abdominal aorta (DM 0.45 +/- 0.20 vs control 0.66 +/- 0.25, P = 0.011) was lower in DM patients than in controls, whereas no significant difference existed between FH patients and controls. Carotid and femoral intima-media thickness was greater in FH and DM patients than in controls with no difference between patient groups. Carotid or femoral plaques appeared in 15 (79%) FH and in 10 (56%) DM patients. One control had a femoral plaque. Five FH patients showed stenosis, occlusion or both in carotid arteries. In our opinion, DM patients' lower compliance reflect mainly arterial media affecting arteriosclerosis, while FH patients' plaque status and longer duration of CHD suggest more advanced atherosclerosis. The FH patients may therefore be at increased risk for atherothrombotic events. However, due to small patient material, larger confirmatory studies are needed.