Cerebral Hemodynamic Disturbances Research Articles

Propofol and thiopental for intravenous induction in neonates: study protocol for a dose-finding trial.

Propofol and thiopental are commonly used induction agents in neonatal anesthesia. Even though both hypnotics have been used off-label for many years, pharmacological knowledge regarding these agents is scarce in neonates. The significant variability in neonates' body composition, organ function, and maturation makes pharmacological studies highly relevant albeit challenging. As a result, there is currently limited data about the anesthetic induction dose of thiopental and propofol in neonates. In addition, a knowledge gap exists concerning the pharmacodynamics of induction doses. To determine the median effective anesthetic induction dose of propofol and thiopental in neonatal patients of different gestational and postnatal ages and evaluate the pharmacodynamics of the anesthesia induction doses on the neonatal systemic and cerebral hemodynamics. This is a single-center, prospective, open-label, interventional, dose-finding study, including neonatal patients from birth up to 28 postnatal days undergoing general anesthesia for surgical or diagnostic procedures. The patients will be stratified according to their gestational and postnatal age and allocated to one of the two trial arms: anesthesia induction with propofol or anesthesia induction with thiopental. We will use Dixon's up-and-down method to estimate the median effective anesthesia induction dose of both agents in neonates of different gestational and postnatal ages. In addition, we will study the relationship between anesthesia induction doses and changes in systemic and cerebral hemodynamics. Alterations in the systemic and cerebral regional hemodynamics secondary to anesthesia induction may be harmful in neonates, especially premature and critically ill newborns, due to their immature organ systems, reduced physiological reserves, and impaired cerebral autoregulation. Perfusion homeostasis is considered one of the significant and modifiable determinants of anesthesia-related neurocognitive outcomes. Therefore, dose-finding and safety pharmacological studies of the anesthetic induction agents in neonates are urgently needed and acknowledged as a high priority by the European Medicine Agency. Estimating adequate induction doses to ensure optimal depth of anesthesia while avoiding systemic and cerebral hemodynamic disturbances will help ensure safe anesthesia and potentially improve anesthesia-related outcomes in this group of patients. This article is protected by copyright. All rights reserved.

Transcranial Doppler ultrasonography in tuberculous meningitis: A systematic review.

Tuberculous (TB) meningitis is a common type of central nervous system infection, and may cause multifocal cerebral infarctions due to the involvement of cerebral vasculature. This systematic review aims to review and synthesize the utility of transcranial Doppler (TCD) in TB meningitis. This is a systematic review of observational studies on the use of TCD in patients diagnosed to have TB meningitis. Study outcomes included changes in TCD parameters during stages of TB meningitis, frequency of neurologic complications (such as hydrocephalus, vasculopathy, and cerebral infarction), correlation of TCD findings with neuroimaging, and functional outcomes. Five studies were included with a total of 141 participants, with ages from 4 months to 75 years. The most common neurologic complication was hydrocephalus (87.1%), cerebral infarction (29.2%), and arterial stenosis (26.3%). There was increased mean flow velocity (MFV) most commonly in the middle cerebral artery in the early stage of TB meningitis, and decreased MFV in the advanced disease stage. TCD findings of stenosis were well correlated with CT or MR angiogram. Among patients with hydrocephalus, pulsatility indices were significantly decreased after ventriculoperitoneal shunting. A considerable proportion of patients with TB meningitis develop cerebral hemodynamic disturbances which lead to cerebral ischemia and affect clinical outcomes. TCD is a reliable tool for the diagnosis of vasculopathy and increased intracranial pressure and can thus help monitor disease progression and treatment response. Future studies with larger populations and longer follow-ups are recommended to determine the association of TCD findings with functional outcomes.

Parainfectious cerebral vasculopathy complicating bacterial meningitis: Acute-short lived vasospasm followed by delayed-long lasting vasculitis.

Bacterial meningitis is a serious, life-threatening infection of the meninges. Several radiological studies highlight prominent structural alterations occurring in the cerebral vasculature, leading to significant cerebrovascular consequences during bacterial meningitis. Beginning with reflexive arterial vasospasm , cerebrovascular disease during bacterial meningitis proceeds through a orderly sequence of arterial vasculitis with inflammatory cell infiltration, medial smooth muscle migration and proliferation, medial necrosis, adventitial fibrosis and eventual intimal stenosis. As such, this review focuses on changes occurring within cerebral arteries during disease progression, highlighting the various structural modifications occurring in the arterial vessels that contribute to disturbances in cerebral hemodynamics and, ultimately, cerebrovascular consequences during bacterial meningitis.

FEATURES OF THE STRUCTURE AND SEVERITY OFCOGNITIVE DISORDERS IN PATIENTS WITH PARANOID SCHIZOPHRENIA WITH CONCOMITANT CEREBRAL AND HEMODYNAMIC DISORDERS

In the works of recent years, there has been a high comorbidity of schizophrenia and somatic diseases, the most frequent of whichwere arterial hypertension, hyperlipidemia and diabetes mellitus, diseases of the gastrointestinal tract, and for some of them, such as HIV, complications of pregnancy and childbirth, cardiovascular vascular diseases, obesity, thyroid dysfunction, there is a high-quality evidence base based on data from population studies [2, 3, 5].Keywords:cerebral hemodynamic disturbances, somatic pathology, schizophrenia, risk factors, comorbid pathology

Autoimune component in the development of celebrovascular insufficiency in children with bronchial asthma

Bronchial asthma (BA) remains one of the most serious diseases of our time. A number of studies have shown that this disease in a number of cases, especially with the threat of termination of pregnancy, acute and chronic diseases of mothers, accompanied by fetal hypoxia, originates in the ante- and postnatal period. In general, taking into account the peculiarities of the cellular tissue organization of the brain and cerebrovascular blood supply, prolonged hypoxic lesions increase the activity of the hypothalamic-diencephalic structures and the cerebral cortex. The existing respiratory disorders lead to hemodynamic and metabolic disorders of cerebral structures, emotional sphere and autonomic regulation. However, this issue in childhood requires further study. The aim is to study autoimmune processes in the pathogenesis of cerebrovascular insufficiency in children with BA. Materials and methods. We examined 121 patients with asthma aged 5 to 15 years in the period of exacerbation. To study the role of the autoimmune component in the development of cerebrovascular insufficiency and its relationship with the autoimmune process in the bronchopulmonary system in AD in children, we used a method for the quantitative determination of autoantibodies to lipopolysaccharide antigens (LA) of cerebral vessels and topographic structures of the brain, as well as to homologous LA bronchi and lung tissue. The results of the studies have shown that the first signs of cerebral hemodynamic disturbance are recorded already in patients with mild disease and are aggravated depending on the severity of BA. Conclusions. The most characteristic changes are an increase in the tone of small and medium vessels and impaired cerebral venous circulation. It was also found that the levels of autoantibodies to lipopolysaccharide antigens of cerebral vessels and cellular tissue structures of the brain correlate with an increase in the level of autoantibodies to lipopolysaccharide antigens of the trachea, bronchi and lung tissue and reflect the severity of AD in children.

Assessment of Transient Cerebral Hemodynamic Disturbance via Whole-Brain Computed Tomography Perfusion After Extracranial-Intracranial Bypass in Ischemic Moyamoya Disease

To assess the cerebral hemodynamic data associated with transient cerebral hemodynamic disturbance (TCHD), including cerebral hyperperfusion syndrome (CHS) and watershed shift ischemia (WSI), by whole-brain (WB) computed tomography perfusion (CTP) before and after revascularization for ischemic moyamoya disease. A total of 115 consecutive patients with ischemic moyamoya disease underwent revascularization. All patients underwent WB-CTP 24 hours before operation and on the day of onset of TCHD and 6 months after revascularization. The volumes of delay time (DT) >3 seconds and mismatch and relative cerebral blood flow <30% were calculated in 3 time points. Of the 115 patients, 18 115 had TCHD, comprising 10 with CHS and 8 with WSI. Compared with the brain volume of DT >3 seconds before revascularization, the volume decreased significantly (P < 0.05) on the day of CHS. The volume of mismatch in 3 time points indicated no significant differences (P > 0.05). The volume of relative cerebral blood flow <30% showed obvious differences of significance among 10 patients with CHS (P < 0.05) at 3 time points. In the WSI group, the volume of DT >3 seconds, mismatch, and DT >3 seconds showed significant differences, relatively (P < 0.05), at 3 time points. At the time of onset of TCHD, DT >3 seconds and mismatch in the CHS group were dramatically lower than those in the WSI group (P < 0.05). DT >3 seconds in the no-TCHD group showed significant differences (P < 0.05) at 3 time points. WB-CTP could be used to assess the cerebral hemodynamic characteristics before and after revascularization. DT >3 seconds and mismatch played important roles in evaluating distinct features of TCHD.

Transcranial Doppler Ultrasonography for the Management of Severe Traumatic Brain Injury After Decompressive Craniectomy

Cerebral hemodynamic transformation is a relatively common finding in patients with traumatic brain injury (TBI). Knowledge of cerebral hemodynamic disturbance may assist in predicting the management outcome. Transcranial Doppler ultrasonography (TCD) monitoring of patients with TBI can be used to reveal various pathologic hemodynamic changes. The objective of this study was to compare the clinical outcomes of postoperative routine intracranial pressure (ICP) monitoring versus ICP monitoring combined with TCD monitoring in patients with brain trauma after decompressive craniectomy. This was a retrospective study of 30 patients with TBI who underwent ICP combined with TCD monitoring (after 2015) compared with a historical control group of 30 patients who only underwent routine ICP monitoring (in 2013-2014). ICP, partial pressure of carbon dioxide, hemoglobin, and hematocrit values were monitored and recorded on a daily basis for 7 days after operation. Neuroimaging was also performed at admission. Neurologic outcome was assessed at 2 weeks and 6 months after operation using the Glasgow Outcome Score Extended (GOS-E). Unconditional multivariable logistic regression was conducted to analyze the factors for favorable clinical outcome. Two weeks after operation, there were no differences in mortality rate between the 2 groups (P=0.643). When considering the GOS-E score at 6 months, there were no differences in clinical prognosis between the 2 groups (P= 0.101), but the ICP combined with TCD monitoring group showed a higher frequency of patients with favorable outcome compared with the routine ICP monitoring group (P= 0.043). Unconditional multivariable logistic regression results showed that no factor was independently associated with GOS-E at 6 months. TCD could be helpful for the serial monitoring of cerebral hemodynamic changes after decompressive craniectomy for TBI, which could be beneficial for neurologic outcome improvement.

THE ASSESSMENT OF CEREBRAL BLOOD FLOW VELOCITIES IN PRETERM NEONATES VERY LOW BIRTH WEIGHT WITH BRAIN IMPAIRMENTS

This article investigates the value of early diagnosis and prognostic evaluation of Doppler ultrasound for preterm neonates very low birth weight in early neonatal life. The results showed that cerebral hemodynamic disturbance of intracranial carotid arterials would be associated with later brain impairments (intraventricular hemorrhage, lesions of periventricular white matter) detected by MRI.

Cerebral Perfusion Is Perturbed by Preterm Birth and Brain Injury.

Early disturbances in systemic and cerebral hemodynamics are thought to mediate prematurity-related brain injury. However, the extent to which CBF is perturbed by preterm birth is unknown. Our aim was to compare global and regional CBF in preterm infants with and without brain injury on conventional MR imaging using arterial spin-labeling during the third trimester of ex utero life and to examine the relationship between clinical risk factors and CBF. We prospectively enrolled preterm infants younger than 32 weeks' gestational age and <1500 g and performed arterial spin-labeling MR imaging studies. Global and regional CBF in the cerebral cortex, thalami, pons, and cerebellum was quantified. Preterm infants were stratified into those with and without structural brain injury. We further categorized preterm infants by brain injury severity: moderate-severe and mild. We studied 78 preterm infants: 31 without brain injury and 47 with brain injury (29 with mild and 18 with moderate-severe injury). Global CBF showed a borderline significant increase with increasing gestational age at birth (P = .05) and trended lower in preterm infants with brain injury (P = .07). Similarly, regional CBF was significantly lower in the right thalamus and midpons (P < .05) and trended lower in the midtemporal, left thalamus, and anterior vermis regions (P < .1) in preterm infants with brain injury. Regional CBF in preterm infants with moderate-severe brain injury trended lower in the midpons, right cerebellar hemisphere, and dentate nuclei compared with mild brain injury (P < .1). In addition, a significant, lower regional CBF was associated with ventilation, sepsis, and cesarean delivery (P < .05). We report early disturbances in global and regional CBF in preterm infants following brain injury. Regional cerebral perfusion alterations were evident in the thalamus and pons, suggesting regional vulnerability of the developing cerebro-cerebellar circuitry.

Cerebral hemodynamics is altered in patients with sleep apnea/hypopnea syndrome.

According to recent epidemiologic studies, patients with sleep apnea/hypopnea syndrome (SAHS) are at increased risk of cardiovascular diseases, including stroke. However, the mechanisms are not well defined. Nocturnal apneas can trigger acute cerebral ischemia in predisposed patients and impaired vasodilatation is present in SAHS, but few studies have explored vascular cerebral dysfunction and often gave inconclusive results. The aims of our study were to assess whether patients with SAHS have impairment of cerebral hemodynamics with respect to controls, and to investigate a possible relationship with clinical data. We studied two groups, one of 76 SAHS patients and another one of 76 non-SAHS subjects matched for age, sex and main cardiovascular risk factors. All participants underwent a daytime transcranial Doppler study of right middle cerebral artery to record cerebral blood flow velocity and cerebrovascular reactivity by means of breath-holding test (BHT). SAHS patients have a reduction in mean cerebral blood flow velocity (MFV) (52 ± 9 vs 60 ± 12 cms/s, p < 0.001) and BHT (31 ± 12 vs 36 ± 11 %, p = 0.005) when compared to non-SAHS controls. Moreover, MFV correlated negatively with the presence of coronary disease, and BHT with female sex and arterial pressure. On the other hand, in the SAHS group, MFV correlated negatively with oxygen desaturation severity. Patients with SAHS have impaired MFV and cerebrovascular reactivity when compared to controls. Interestingly, poorly controlled or unknown hypertension and severe nocturnal hypoxemia caused additional cerebral hemodynamic disturbances to these patients.

Вопросы и ультразвуковые ответы в терапии нарушений церебральной гемодинамики у пациентов молодого возраста c венозной энцефалопатией

Вопросы и ультразвуковые ответы в терапии нарушений церебральной гемодинамики у пациентов молодого возраста c венозной энцефалопатией

Dynamic Cerebral Autoregulation after Cardiopulmonary Bypass.

Background Cerebral hemodynamic disturbances in the peri- or postoperative period may contribute to postoperative cognitive dysfunction (POCD) in patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). We therefore examined dynamic cerebral autoregulation (dCA) post-CPB and changes in neurocognitive function in patients that had undergone CABG. Materials and Methods We assessed dCA by transfer function analysis of spontaneous oscillations between arterial blood pressure and middle cerebral artery blood flow velocity measured by transcranial Doppler ultrasound in eight patients 6 hours after the cessation of CPB; 10 healthy volunteers served as controls. Neurocognitive function was assessed by four specific tests 1 day prior to and 3 days after CPB. Results Even though patients exhibited systemic inflammation and anemic hypoxemia, dCA was similar to healthy volunteers (gain: 1.24 [0.94-1.49] vs. 1.22 [1.06-1.34] cm mm Hg-1 s-1, p = 0.97; phase: 0.33 [0.15-0.56] vs. 0.69 [0.50-0.77] rad, p = 0.09). Neurocognitive testing showed a perioperative decline in the Letter Digit Coding Score (p = 0.04), while weaker dCA was associated with a lower Stroop Color Word Test (rho = - 0.90; p = 0.01). Discussion and Conclusion We found no changes in dCA 6 hours after CPB. However, based on the data at hand, it cannot be ruled out that changes in dCA predispose to POCD, which calls for larger studies that assess the potential impact of dCA in the early postoperative period on POCD.

Head Position Change Is Not Associated with Acute Changes in Bilateral Cerebral Oxygenation in Stable Preterm Infants during the First 3 Days of Life.

Several recent intraventricular hemorrhage prevention bundles include midline head positioning to prevent potential disturbances in cerebral hemodynamics. We aimed to study the impact of head position change on regional cerebral saturations (SctO2) in preterm infants (< 30 weeks gestational age) during the first 3 days of life. Bilateral SctO2 was measured by near-infrared spectroscopy. The infant's head was turned sequentially to each side from midline (baseline) in 30-minute intervals while keeping the body supine. Bilateral SctO2 before and after each position change were compared using paired t-test. In relatively stable preterm infants (gestational age 26.5 ± 1.7 weeks, birth weight 930 ± 220 g; n = 20), bilateral SctO2 remained within normal range (71.1-75.3%) when the head was turned from midline position to either side. Stable preterm infants tolerated brief changes in head position from midline without significant alternation in bilateral SctO2; the impact on critically ill infants needs further evaluation.

EHMTI-0323. Pediatric aspects of venous headache. The indicators of cerebral venous outflow for diagnostics and treatment of children

Disturbances of cerebral venous hemodynamics define development of child headache. However directed by the diagnosis and subsequent treatment these disturbances are not considered. The absence of diagnostics algorithm and norms of cerebral venous blood flow limits the possibility of timely therapy at children.

Cerebral venous hemodynamic disturbances in children with different types of headache. The role of transcranial ultrasonography methods

Results All children with headaches were separated according the clinical and ultrasound findings: migraine, tension type of headache, headache with increase or reduction of arterial pressure, headache caused by cerebral venous dysfunction. 30% of them had cerebral anomalies (of craniovertebral junction and deep brain veins). The children complained of headaches (100%) and also vegetative dysfunction (80%), nasal bleeding (60%), vomiting (40%), dizziness and noise in ears (35%). Venous outflow in the cavernous sinus, straight sinus, great cerebral vein of Galen have been registered by TCD, TCCD. Cerebral venous hemodynamic disturbances (“markers”) revealed in all groups children: migraine – 35 %, tension type of headache – 40 %, headache with increase or reduction of arterial pressure – from 25 % to 55 %. Thus a venous outflow is stimulated and makes influence on intracranial venous circulation. The estimation of cerebral venous hemodynamic disturbances in literature is described mainly in adults, but they are of great importance in clinical manifestations, especially in children. Diagnosis of such disturbances in children is not detected in time, though they often turn out to be one of the main evidence of cerebrovascular pathology. The complex research of cerebral venous hemodynamics presents new possibilities for revealing disturbances of cerebral venous blood circulation. The conservative treatment which has been performed under ultrasonographic control (TCD, TCCD) in children with disturbances of cerebral hemodynamics, led to objective improvement in 85% of children.

Posttraumatic Refractory Intracranial Hypertension and Brain Herniation Syndrome: Cerebral Hemodynamic Assessment before Decompressive Craniectomy

Background. The pathophysiology of traumatic brain swelling remains little understood. An improved understanding of intracranial circulatory process related to brain herniation may have treatment implications. Objective. To investigate the cerebral hemodynamic changes associated with brain herniation syndrome due to traumatic brain swelling. Methods. Nineteen head-injured patients with evidence of refractory intracranial hypertension and transtentorial herniation were prospectively studied. Cerebral hemodynamic assessment by transcranial Doppler (TCD) ultrasonography was performed prior to decompressive craniectomy. Patients and their cerebral hemispheres were classified according to TCD-hemodynamic patterns, and the data correlated with neurological status, midline shift on CT scan, and Glasgow outcome scale scores at 6 months after injury. Results. A wide variety of cerebral hemodynamic findings were observed. Ten patients (52.7%) presented with cerebral oligoemia, 3 patients (15.8%) with cerebral hyperemia, and 6 patients with nonspecific circulatory pattern. Circulatory disturbances were more frequently found in the side of maximal cerebral swelling than in the opposite side. Pulsatility index (PI) values suggested that ICP varied from acceptable to considerably high; patients with increased PI, indicating higher microvascular resistance. No correlation was found between cerebral hemodynamic findings and outcome. Conclusions. There is a marked heterogeneity of cerebral hemodynamic disturbances among patients with brain herniation syndrome.

Фактори ризику ішемічного інсульту

The article contains data on modern methods of ischemic stroke diagnosis. Instrumental tests and their diagnostic yield in determining the pathogenetic mechanism of stroke especially in patients with atrial fibrillation have been analysed. Holter monitoring of electrocardiography and blood pressure has specific significance in patients with rhythm disorders in acute period of ischemic stroke for determining pathogenesis of dysrhythmias and disturbances of central and cerebral hemodynamics.

Initiation of resuscitation with high tidal volumes causes cerebral hemodynamic disturbance, brain inflammation and injury in preterm lambs.

AimsPreterm infants can be inadvertently exposed to high tidal volumes (VT) in the delivery room, causing lung inflammation and injury, but little is known about their effects on the brain. The aim of this study was to compare an initial 15 min of high VT resuscitation strategy to a less injurious resuscitation strategy on cerebral haemodynamics, inflammation and injury.MethodsPreterm lambs at 126 d gestation were surgically instrumented prior to receiving resuscitation with either: 1) High VT targeting 10–12 mL/kg for the first 15 min (n = 6) or 2) a protective resuscitation strategy (Prot VT), consisting of prophylactic surfactant, a 20 s sustained inflation and a lower initial VT (7 mL/kg; n = 6). Both groups were subsequently ventilated with a VT 7 mL/kg. Blood gases, arterial pressures and carotid blood flows were recorded. Cerebral blood volume and oxygenation were assessed using near infrared spectroscopy. The brain was collected for biochemical and histologic assessment of inflammation, injury, vascular extravasation, hemorrhage and oxidative injury. Unventilated controls (UVC; n = 6) were used for comparison.ResultsHigh VT lambs had worse oxygenation and required greater ventilatory support than Prot VT lambs. High VT resulted in cerebral haemodynamic instability during the initial 15 min, adverse cerebral tissue oxygenation index and cerebral vasoparalysis. While both resuscitation strategies increased lung and brain inflammation and oxidative stress, High VT resuscitation significantly amplified the effect (p = 0.014 and p<0.001). Vascular extravasation was evident in the brains of 60% of High VT lambs, but not in UVC or Prot VT lambs.ConclusionHigh VT resulted in greater cerebral haemodynamic instability, increased brain inflammation, oxidative stress and vascular extravasation than a Prot VT strategy. The initiation of resuscitation targeting Prot VT may reduce the severity of brain injury in preterm neonates.

Possibilities of transcranial color-coded sonography in pathology of deep brain veins in children

A study in children with headaches associated mainly with venous hemodynamic disturbances has been performed. The role of cerebral venous disturbances has been defined in children with structural cerebral abnormalities: craniovertebral junction anomalies (Chiari abnormalities I) and hypoplasia of cerebral venous sinuses. Disturbances of cerebral hemodynamics revealed by ultrasonic methods determine the management of patients with different cerebral venous abnormalities.

Inflammation in utero exacerbates ventilation-induced brain injury in preterm lambs

Cerebral blood flow disturbance is a major contributor to brain injury in the preterm infant. The initiation of ventilation may be a critical time for cerebral hemodynamic disturbance leading to brain injury in preterm infants, particularly if they are exposed to inflammation in utero. We aimed to determine whether exposure to inflammation in utero alters cardiopulmonary hemodynamics, resulting in cerebral hemodynamic disturbance and related brain injury during the initiation of ventilation. Furthermore, we aimed to determine whether inflammation in utero alters the cerebral hemodynamic response to challenge induced by high mean airway pressures. Pregnant ewes received intra-amniotic lipopolysaccharide (LPS) or saline either 2 or 4-days before preterm delivery (at 128 ± 1 days of gestation). Lambs were surgically instrumented for assessment of pulmonary and cerebral hemodynamics before delivery and positive pressure ventilation. After 30 min, lambs were challenged hemodynamically by incrementing and decrementing positive end-expiratory pressure. Blood gases, arterial pressures, and blood flows were recorded. The brain was collected for biochemical and histological assessment of inflammation, brain damage, vascular extravasation, hemorrhage, and oxidative injury. Carotid arterial pressure was higher and carotid blood flow was more variable in 2-day LPS lambs than in controls during the initial 15 min of ventilation. All lambs responded similarly to the hemodynamic challenge. Both 2- and 4-day LPS lambs had increased brain interleukin (IL)-1β, IL-6, and IL-8 mRNA expression; increased number of inflammatory cells in the white matter; increased incidence and severity of brain damage; and vascular extravasation relative to controls. Microvascular hemorrhage was increased in 2-day LPS lambs compared with controls. Cerebral oxidative injury was not different between groups. Antenatal inflammation causes adverse cerebral hemodynamics and increases the incidence and severity of brain injury in ventilated preterm lambs.