Pre-Stroke Antihypertensive Therapy Affects Stroke Severity and 3-Month Outcome of Ischemic MCA-Territory Stroke.

OBJECTIVES: Whether different antihypertensive drug classes in high blood pressure (HBP) pre-stroke treatment affect dynamic cerebral autoregulation (dCA), stroke severity, and outcome. METHODS: Among 337 consecutive ischemic stroke patients (female 102; median age 71 years [interquartile range, [IQR 60; 78]; NIHSS median 3 [IQR 1; 6]) with assessment of dCA, 183 exhibited the diagnosis of HBP. dCA parameters' gain and phase were determined by transfer function analysis of spontaneous oscillations of blood pressure and cerebral blood flow velocity. RESULTS: Patients used beta-blockers (n = 76), calcium channel blockers (60), diuretics (77), angiotensin-converting enzyme inhibitors (59), or angiotensin-1 receptor blockers (79), mostly in various combinations of two or three drug classes. dCA parameters did not differ between the non-HBP and the different HBP medication groups. Multinomial ordinal logistic regression models revealed that the use of diuretics decreased the likelihood of a less severe stroke (odds ratio 0.691, 95% CI 0.493; 0.972; p = 0.01) and that beta-blockers decreased the likelihood of a better modified Rankin score at 3 months (odds ratio 0.981, 95% CI 0.970; 0.992; p = 0.009). Other independent factors associated with stroke outcome were penumbra and infarct volume, treatment with mechanical thrombectomy, and the initial National Institute of Health Stroke Scale score. INTERPRETATION: In this cohort of ischemic minor to moderate stroke patients, pre-stroke antihypertensive treatment with diuretics was associated with a more severe neurological deficit on admission and pre-stroke treatment with beta-blockers with a poorer 3-month outcome. The antihypertensive drug class used pre-stroke did not impact dCA.

Impaired dynamic cerebral autoregulation measured in the middle cerebral artery in patients with vertebrobasilar ischemia is associated with autonomic failure.

OBJECTIVES: To assess whether vertebrobasilar artery ischemia (VBI) affects cortical cerebral blood flow (CBF) regulation. MATERIAL AND METHODS: 107 consecutive patients (mean age 65 ± 15 years; women 21) with VBI underwent structured stroke care with assessment of dynamic cerebral autoregulation (dCA) in both middle cerebral arteries (MCAs) by transfer function analysis using spontaneous oscillations of blood pressure (BP) and CBF velocity that yields by extraction of phase and gain information in the very low (0.02-0.07 Hz), low (0.07-0.15 Hz) and high frequency (0.15-0.5 Hz) ranges. Additionally, power spectrum analysis of BP and heart rate variability (HRV) was performed. The control group consists of 29 age- and sex-matched healthy persons. RESULTS: Compared to controls, phase in the VBI patients was significantly reduced and gain increased in the very low frequencies (VLF), in the low (LF), phase was significantly reduced only ipsilaterally. In the high frequencies (HF), phase reduction was only marginally significant. BP power spectral density (PSD) was much higher in the patients than in the controls across all frequencies. In the PSD of heart rate variability the controls but not the patients exhibited a strong peak around 0.11Hz, while the patients, but not the controls, exhibit a strong peak around 0.36 Hz. In regression analysis, patient's phase and gain results were not related to age, sex, arterial hypertension, diabetes mellitus, renal dysfunction, heart failure as indicated by left ventricular ejection fraction, stroke subtype, presence or absence of cerebral small vessel disease. CONCLUSION: Patients with VBI exhibit bilateral cortical autoregulation impairment in association with an autonomic nervous system disbalance. GOV IDENTIFIER: NCT04611672.

Middle cerebral artery dynamic cerebral autoregulation is impaired by infarctions in the anterior but not the posterior cerebral artery territory in patients with mild strokes.

Objective: The aim of this study was to ascertain whether dynamic cerebral autoregulation (CA) in the middle cerebral artery (MCA) is disturbed by cerebral infarctions outside the MCA territory. Methods: We estimated transfer function parameters gain and phase from simultaneous recordings of spontaneous oscillation in blood pressure and MCA cerebral blood flow velocity in 10 consecutive patients with isolated anterior cerebral artery (ACA) infarctions and in 22 consecutive patients with isolated posterior cerebral artery (PCA) infarctions. All ACA infarctions were in the motor, premotor, or supplementary motor cortex areas and presented with pronounced leg hemiparesis. Twenty-eight age- and sex-matched healthy subjects served as controls. Results: Compared to controls, phase was significantly reduced in the MCA ipsilateral to the lesion site and in the contralateral MCA (unaffected hemisphere) in the very low (0.02-0.07 Hz) and low (0.07-0.15 Hz) frequency ranges in the ACA infarctions but not in the PCA infarctions. Gain was reduced only in the very low frequency range in the MCA contralateral to the ACA lesion site. Systemic factors were unrelated to phase and gain results. Conclusion: Bilateral impairment of MCA dynamic CA in patients with a unilateral ACA infarction is frequent.

Automated Supra- and Infratentorial Brain Infarct Volume Estimation on Diffusion Weighted Imaging Using the RAPID Software.

Purpose: The present computerized techniques have limits to estimate the ischemic lesion volume especially in vertebrobasilar ischemia (VBI) automatically. We investigated the ability of the RAPID AI (RAPID) software on diffusion-weighted imaging (DWI) to estimate the infarct size in VBI in comparison to supratentorial ischemia (STI). Methods: Among 123 stroke patients (39 women, 84 men, mean age 66 ± 11 years) having undergone DWI, 41 had had a VBI and 82 a STI. The infarct volume calculation by RAPID was compared to volume calculations by 2 neurologists using the ABC/2 method. For inter-reader and between-method analysis intraclass correlation coefficient (ICC), area under the curve (AUC) estimations, and Bland-Altman plots were used. Results: ICC between the two neurologists and each neurologist and RAPID were >0.946 (largest 95% CI boundaries 0.917-0.988) in the STI group, and > 0.757 (95% CI boundaries between 0.544 and 0.982) in the VBI group. In the STI group, AUC values ranged between 0.982 and 0.999 (95% CI 0.971-1) between the 2 neurologists and between 0.875 and 1 (95% CI 0.787-1) between the neurologists and RAPID; in the VBI group, they ranged between 0.925 and 0.965 (95% CI 0.801-1) between the neurologists, and between 0.788 and 0.931 (95% CI 0.663-1) between RAPID and the neurologists. Compared to the visual DWI interpretation by the neurologists, RAPID did not recognize a substantial number of infarct volumes of ≤ 2 ml. Conclusion: The ability of the RAPID software to depict strokes in the vertebrobasilar artery system seems close to its ability in the supratentorial brain tissue. However, small lesion volumes ≤ 2 ml remain still undetected in both brain areas.

Ischemic stroke in COVID-19 patients: Mechanisms, treatment, and outcomes in a consecutive Swiss Stroke Registry analysis.

BACKGROUND: Most case series of patients with ischemic stroke (IS) and COVID-19 are limited to selected centers or lack 3-month outcomes. The aim of this study was to describe the frequency, clinical and radiological features, and 3-month outcomes of patients with IS and COVID-19 in a nationwide stroke registry. METHODS: From the Swiss Stroke Registry (SSR), we included all consecutive IS patients ≥18 years admitted to Swiss Stroke Centers or Stroke Units during the first wave of COVID-19 (25 February to 8 June 2020). We compared baseline features, etiology, and 3-month outcome of SARS-CoV-2 polymerase chain reaction-positive (PCR+) IS patients to SARS-CoV-2 PCR- and/or asymptomatic non-tested IS patients. RESULTS: Of the 2341 IS patients registered in the SSR during the study period, 36 (1.5%) had confirmed COVID-19 infection, of which 33 were within 1 month before or after stroke onset. In multivariate analysis, COVID+ patients had more lesions in multiple vascular territories (OR 2.35, 95% CI 1.08-5.14, p = 0.032) and fewer cryptogenic strokes (OR 0.37, 95% CI 0.14-0.99, p = 0.049). COVID-19 was judged the likely principal cause of stroke in 8 patients (24%), a contributing/triggering factor in 12 (36%), and likely not contributing to stroke in 13 patients (40%). There was a strong trend towards worse functional outcome in COVID+ patients after propensity score (PS) adjustment for age, stroke severity, and revascularization treatments (PS-adjusted common OR for shift towards higher modified Rankin Scale (mRS) = 1.85, 95% CI 0.96-3.58, p = 0.07). CONCLUSIONS: In this nationwide analysis of consecutive ischemic strokes, concomitant COVID-19 was relatively rare. COVID+ patients more often had multi-territory stroke and less often cryptogenic stroke, and their 3-month functional outcome tended to be worse.

Cerebral macro- and microcirculatory blood flow dynamics in successfully treated chronic hypertensive patients with and without white mater lesions.

The mechanisms of high blood pressure (HBP) -related brain pathology progression remain relatively unclear. We investigated whether lowering BP in chronic HBP patients normalizes cerebral perfusion dynamics at resistance vessel and capillary levels. Sixty-seven patients with HBP and 49 age- and sex-matched healthy controls underwent simultaneous recordings of middle cerebral artery blood flow velocity (CBFV), BP, and end-tidal CO2 concentration. Thirty-four controls and 28 patients underwent additional near-infrared spectroscopy recordings (oxygenated [O2Hb] and deoxygenated [HHb] hemoglobin). Degree of microcirculatory white matter lesions was graded by Fazekas scale. Dynamic cerebral autoregulation (dCA) was assessed by transfer function analysis. BP was successfully lowered (patients = 89 ± 15 mm Hg, controls = 87 ± 17), but cerebrovascular resistance was higher in BP patients (p < 0.05). BP-CBFV phase was lower in very low frequency (VLF) (left/right: 48 ± 20°/44 ± 17; controls: 61 ± 20/60 ± 21; p < 0.001) and low frequency (LF) (34 ± 14/35 ± 14; controls: 48 ± 20/44 ± 17; p < 0.05) ranges. Gain was higher in VLF range (in %/ mm Hg 0.56 ± 0.44/0.59 ± 0.49; controls: 0.32 ± 0.29/0.34 ± 0.32; p ≤ 0.005). BP-CBFV phase and gain did not differ across Fazekas groups. Across all patients, the capillary phases and gains (CBFV-[O2Hb], CBFV-[HHb]) were comparable to controls. Successfully treated chronic HBP results in normal brain capillary hemodynamics while the resistance vessel state is disturbed (phase decrease, gain increase).