Middle cerebral artery doppler

BACKGROUND: Carotid atherosclerosis is often mentioned as one of the main causes of stroke. Currently, embolization is considered the most common mechanism that causes ischemic strokes due to atherosclerotic lesions in the carotid artery. Transcranial Doppler (TCD) ultrasound provides relatively inexpensive, noninvasive, real-time measurement of blood flow characteristics and cerebrovascular hemodynamics within brain arteries. The pulsatile index measured by transcranial Doppler is a parameter that indicates the degree of elasticity of the blood vessels of the brain...

OBJECTIVES: Antenatal management of monochorionic pregnancies complicated by twin anemia polycythemia sequence (TAPS) remains sub-optimally defined. Our objective was to evaluate the safety and efficacy of fetoscopic selective laser photocoagulation with respect to fetal and neonatal survival. METHODS: A case series is reported with patients referred to the Texas Children's Fetal Center for evaluation and management of suspected spontaneous TAPS without concomitant twin-to-twin syndrome from 2014 to 2023...

INTRODUCTION: Cerebral blood flow (CBF) declines with age and abnormalities in CBF are associated with age-related cerebrovascular disease and neurodegeneration. Women have higher CBF than men, although this sex-difference diminishes to some extent with age in healthy subjects. The physiological drivers of these age/sex differences are uncertain, but might be secondary to age and sex-differences in haemoglobin (Hb) level. Hb levels are inversely correlated with CBF, are lower in women, and decline with age in men, but the interrelations between these factors have not been explored systematically either in healthy subjects or across the full age-range in patients with vascular risk factors...

BACKGROUND: Subarachnoid hemorrhage (SAH) patients with cerebral autoregulation (CA) impairment at an early post-SAH period are at high risk of unfavorable outcomes due to delayed cerebral ischemia (DCI) or other complications. Limited evidence exists for an association between early-stage CA impairments and SAH patient outcomes. The objective of this prospective study was to explore associations between CA impairments detected in early post-SAH snapshot examinations and patient outcomes...

The efficacy of extracranial-intracranial (EC-IC) bypass in preventing ischemic stroke progression and recurrence is controversial. As per the current hypothesis, EC-IC bypass is most beneficial for patients with persistent hemodynamic insufficiency. Hence, various approaches have been used to evaluate hemodynamic insufficiency, including repeated single photon emission CT (SPECT) imaging or continuous monitoring of cerebral flow with transcranial Doppler ultrasound (TCD). However, both modalities are time- and resource-intensive...

Wearable technology and neuroimaging equipment using photoplethysmography (PPG) have become increasingly popularized in recent years. Several investigations deriving pulse rate variability (PRV) from PPG have demonstrated that a slight bias exists compared to concurrent heart rate variability (HRV) estimates. PPG devices commonly sample at ~20-100 Hz, where the minimum sampling frequency to derive valid PRV metrics is unknown. Further, due to different autonomic innervation, it is unknown if PRV metrics are harmonious between the cerebral and peripheral vasculature...

OBJECTIVE: To investigate the early prediction value of transcranial Doppler ultrasound (TCD) combined with serum melatonin level for delayed cerebral ischemia (DCI) caused by subarachnoid hemorrhage (SAH). METHODS: This paper is a prospective study. A total of 120 patients with SAH treated were included. The patients were divided into the DCI group (40 cases) and non-DCI group (80 cases) according to whether DCI occurred 14 days after SAH (DCI usually occurs 4 to 14 d after bleeding)...

Mechanisms behind the protective effects of aerobic exercise on brain health remain elusive but may be vascular in origin and relate to cerebral pulsatility. This pilot study investigated the effects of 12 wks aerobic exercise training on cerebral pulsatility and its vascular contributors (large artery stiffness, characteristic impedance) in at-risk middle-aged adults. 28 inactive middle-aged adults with elevated blood pressure or stage 1 hypertension were assigned to either moderate/vigorous aerobic exercise training (AET) for 3 d/wk or no-exercise control (CON) group...

Atrial fibrillation (AF) and hypertension (HTN) are both associated with impaired cerebrovascular carbon dioxide reactivity (CVRCO2 ), an indicator of cerebral vasodilatory reserve. We hypothesised that CVRCO2 would be lower in patients with both AF and HTN (AF + HTN) compared to normotensive AF patients, due to an additive effect of AF and HTN on CVRCO2 . Forty AF (68 ± 9 years) and fifty-seven AF + HTN (68 ± 8 years) patients underwent transcranial Doppler ultrasound measurement of middle cerebral artery blood velocity (MCA Vm ) during stepped increases and decreases in end-tidal carbon dioxide (PET CO2 )...

BACKGROUND AND PURPOSE: Cerebral vasomotor reactivity (VMR) is vital for regulating brain blood flow and maintaining neurological function. Impaired cerebral VMR is linked to a higher risk of stroke and poor post-stroke outcomes. This study explores the relationship between statin treatment intensity and VMR in patients with ischemic stroke. METHODS: Seventy-four consecutive patients (mean age 69.3 years, 59.4% male) with recent ischemic stroke were included. VMR levels were assessed 4 weeks after the index stroke using transcranial Doppler, measuring the breath-holding index (BHI) as an indicator of the percentage increase in middle cerebral artery blood flow (higher BHI signifies higher VMR)...

INTRODUCTION: Stroke interventions that increase collateral flow have the potential to salvage penumbral tissue and increase the number of patients eligible for reperfusion therapy. We compared the efficacy of two different collateral therapeutics during transient middle cerebral artery occlusion (tMCAO) in normotensive and hypertensive rats. METHODS: The change in collateral and core perfusion was measured using dual laser Doppler in response to either a pressor agent (phenylephrine, 10 mg/kg iv or vehicle) or a collateral vasodilator (TM5441, 5 mg/kg iv or vehicle) given 30 min into tMCAO in male Wistar and spontaneously hypertensive rats (SHRs)...

The time constant of the cerebral arterial bed (τ) represents an estimation of the  transit time of flow from the point of insonation at the level of the middle cerebral artery to the arteriolar-capillary boundary, during a cardiac cycle. This study assessed differences in τ among healthy volunteers across different age groups. Simultaneous recordings of transcranial Doppler cerebral blood flow velocity (CBFV) and arterial blood pressure (ABP) were performed on two groups: young volunteers (below 30 years of age), and older volunteers (above 40 years of age)...

BACKGROUND: The current management of patients with stroke with intravenous thrombolysis and endovascular thrombectomy is effective only when it is timely performed on an appropriately selected but minor fraction of patients. The development of novel adjunctive therapy is highly desired to reduce morbidity and mortality with stroke. Since endothelial dysfunction is implicated in the pathogenesis of stroke and is featured with suppressed endothelial nitric oxide synthase (eNOS) with concomitant nitric oxide deficiency, restoring endothelial nitric oxide represents a promising approach to treating stroke injury...

BACKGROUND: Carotid endarterectomy (CEA) has been associated with both cognitive decline and improvement, but the underlying neurovascular mechanisms are unclear. The aim of this study was to investigate the relationship between neurovascular indices and cognitive changes after CEA. METHODS: We studied 55 patients with severe (≥70%) symptomatic or asymptomatic carotid stenosis before and six months after CEA. A wide array of neuropsychological tests was arranged in eight cognitive domains and cognitive functions specific to hemisphere ipsilateral to operation...

BACKGROUND: IIH is a severe form of headache that often has superimposed migraine and often it is very difficult to distinguish the two forms of headache. Intracranial hemodynamics is a relatively unexplored means of distinguishing between the two forms of headache. OBJECTIVES: We aimed to study intracranial flow dynamics using Transcranial Doppler in patients with IIH, migraine, and normal controls. MATERIALS AND METHODS: It was a hospital-based observational study that included 51 people with IIH, 87 people with migraine, and 101 healthy controls and all were subjected to TCD study after detailed clinical examination...

OBJECTIVE: The purpose of this study is to analyze the distribution characteristics of atherosclerotic lesions and the risk factors of recurrence in patients with ischemic stroke. METHODS: A total of 505 patients diagnosed with ischemic stroke from October 2016 to October 2022 were included. Divide 505 patients with ischemic stroke into old stroke group and new stroke group. Patients without old cerebral infarction were included in the first ischemic stroke group (first group), while patients with old cerebral infarction were included in the recurrent ischemic stroke group (recurrence group)...

BACKGROUND: Despite advances in imaging techniques and treatment modalities, tools to predict recovery after stroke remain limited. The objective of the study was to determine if transcranial Doppler (TCD) mean flow velocities were predictive of functional recovery following ischemic stroke. METHODS: Data were collected from patients with stroke admitted to an academic tertiary care facility in the southeastern region of the United States between 2012 and 2019 who had a middle cerebral artery distribution ischemic stroke, TCD, and were discharged to our inpatient rehabilitation facility...

OBJECTIVE: Our aim was to investigate the significance of cerebro-placento-uterine ratio CPUR, a new Doppler index, and fetal cardiac parameters (Mod MPI, EFT) in early-onset preeclampsia (EOPE) and to examine whether these parameters are related to perinatal outcome. STUDY DESIGN: Forty participants diagnosed with EOPE (preeclampsia cases diagnosed before 34 weeks of gestation) and 40 healthy pregnant women were included in this study. Demographic data were recorded...

G3P2L1, 28+4 weeks of gestation rhesus (Rh) isoimmunised pregnant women, was referred with trichorionic triamniotic triplet pregnancy with Rh antibody titres of 1:32. Nuchal translucency and anomaly scan were within normal limits with no major malformation for any of the fetuses. Obstetric colour Doppler with middle cerebral artery peak systolic volume revealed foetal anaemia in all three fetuses having velocities corresponding to around 1.5 times the median. Decision of intrauterine transfusion of blood to all three fetuses was taken...

OBJECTIVE: To assess the association of the umbilicocerebral ratio (UCR) with adverse perinatal outcome in late preterm small-for-gestational age (SGA) fetuses and to investigate the effect on perinatal outcomes of immediate delivery. DESIGN: Multicentre cohort study with nested randomised controlled trial (RCT). SETTING: Nineteen secondary and tertiary care centres. POPULATION: Singleton SGA pregnancies (estimated fetal weight [EFW] or fetal abdominal circumference [FAC] <10th centile) from 32 to 36+6  weeks...