Transcranial Doppler Assessment Research Articles

Prospective single-center study on the reliability of ipsilateral cerebral oximetry using near-infrared spectroscopy as a predictor for selective shunting during carotid endarterectomy.

Many techniques are available for the intraoperative assessment of brain perfusion during carotid endarterectomy, such as carotid stump pressure, near-infrared spectroscopy, somatosensory evoked potentials, transcranial Doppler, electroencephalography, and clinical assessment. The decision for selective carotid shunt insertion is dependent on clinical deterioration or the detection of cerebral hypoperfusion after cross-clamping of the internal carotid artery. Monitoring cerebral oximetry using near-infrared spectroscopy is a noninvasive technique for cerebral oxygen saturation measurement, reflecting changes in cerebral blood flow during carotid endarterectomy. The aim of this study was to evaluate the reliability of near-infrared spectroscopy as a predictor of selective shunting during carotid endarterectomy. In total, 47 conventional carotid endarterectomy surgeries were performed at our hospital between March 2016 and December 2021. All surgeries were performed under a regional cervical block supplemented with local infiltration anesthesia. All patients were monitored by cerebral oximetry using bilateral near-infrared spectroscopy probes and clinical assessment through communication with the patient (numerical, visual, and verbal) to indicate a selective shunt. Near-infrared spectroscopy values were recorded before and after internal carotid cross-clamping and after declamping. Any decrease in ipsilateral cerebral oximetry-near-infrared spectroscopy values equal to or more than 20% from the pre-clamping baseline reading associated with deterioration in neurological status (hemiparesis, aphasia, or deterioration in level of consciousness) after internal carotid artery cross-clamping was considered an indication for intraluminal carotid shunting. After internal carotid artery cross-clamping, 5 of 47 patients (10.6%) developed a significant drop in cerebral oxygen saturation associated with obvious clinical assessment deterioration in verbal communication and weakness in contralateral arm power. A Pruitt-Inahara carotid shunt was subsequently inserted, and 42 patients remained stable throughout surgery. The average decline in ipsilateral near-infrared spectroscopy values was 23.8% in patients with clinical deterioration. The average decline was 8.6% in patients who remained stable. Monitoring ipsilateral cerebral oximetry using near-infrared spectroscopy is an easy and reliable method for indicating selective shunting during carotid endarterectomy. A 20% decrease in ipsilateral brain tissue oximetry after internal carotid artery cross-clamping provides a reliable cut-off value for selective intraluminal carotid shunting during carotid endarterectomy.

New evidence for fractional pressure ratio prediction by pulsatility index from transcranial Doppler in patients with symptomatic cerebrovascular stenosis disease.

The pulsatility index (PI) derived from transcranial Doppler (TCD) assessment may represent the cerebral resistance and altered cerebral blood flow. The purpose of this study was to assess the performance of the TCD PI in correlation with wire-based fractional pressure ratio (FPR). This study included 33 patients with symptomatic atherosclerotic lesions of the extracranial and intracranial large arteries, specifically the internal carotid artery, middle cerebral artery (MCA), vertebral artery (VA) V4 segment, and basilar artery (BA), all of which exhibited luminal stenosis ranging from 50% to 70%. TCD was performed prior to angiography in order to determine the flow distal to the lesion. We performed cerebrovascular angiography with a pressure wire to measure the FPR of vessels with stenotic lesions. Bland-Altman analysis and ordinal least square (OLS) linear regression were used to quantify the correlation between PI and FPR. A total of 42 TCD data points were analyzed. At the TCD locations distal to the lesions, the correlation coefficients were no less than 0.90%, with almost all P values <0.001, which indicated very strong positive correlations; the exception to this was the distal TCD for MCA segment lesions (r=0.897; P=0.015) and VA V4 segment (r=0.964; P=0.036). The Bland-Altman plot demonstrated a small difference (0.003) between the distal TCD PI and the FPR, with an acceptable 95% confidence interval [95% confidence interval (CI): 0.06-0.12]. The PI obtained through TCD assessment distal to the stenotic lesion exhibited a correlation with the FPR computed using pressure wire measurements.

Cerebrovascular CO2 reactivity and dynamic cerebral autoregulation through the eighth decade of life and their implications for cognitive decline

Aging is accompanied by a decrease in cerebral blood flow (CBF), especially in the presence of preclinical cognitive decline. The role of cerebrovascular physiology including regulatory mechanisms of CBF in processes underlying aging and subclinical cognitive decline is, however, not fully understood. We explored changes in cerebrovascular CO2 reactivity and dynamic cerebral autoregulation (dCA) through the eighth decade of life, and their relation with early cognitive decline. After 10.9 years, twenty-eight (age, 80.0 ± 3.5 years; 46% female) out of forty-eight healthy older adults who had participated in a previous study (age at baseline, 70 ± 4 years; 42% female), underwent repeated transcranial Doppler assessments. Linear mixed-model analyses revealed small reductions in cerebrovascular CO2 reactivity with aging (−0.37%/mmHg, P = 0.041), whereas dCA was modestly enhanced (gain: −0.009 cm/s/mmHg, P = 0.038; phase: +8.9 degrees, P = 0.004). These changes were more pronounced in participants who had developed subjective memory complaints at follow-up. Our observations confirm that dCA is not impaired in aging, despite lower cerebral perfusion and cerebrovascular reactivity. Altogether, this unique longitudinal study highlights the involvement of cerebrovascular health in preclinical cognitive decline, which is of clinical relevance in the development of dementia management strategies.

Transcranial Doppler Screening of Children with Sickle Cell Disease for a Large, Multinational Interventional Study: Experience from the Phase 3 HOPE-Kids 2 Trial Investigating the Effect of Voxelotor Treatment on Transcranial Doppler Flow Velocity

Introduction: Transcranial Doppler (TCD) ultrasound is an effective screening tool for identifying children with sickle cell disease (SCD) who are at high risk of stroke. Implementing TCD screening, along with appropriate therapies, for the purpose of primary stroke prevention in resource-constrained settings remains challenging. HOPE-KIDS 2 (NCT04218084) is an ongoing, phase 3, multicenter, double-blind, placebo-controlled trial of voxelotor in children with SCD and elevated arterial cerebral blood flow (measured by time-averaged maximum of the mean velocity [TAMMV]). Our aim is to describe the findings from successful implementation of a standardized TCD screening protocol that was conducted in a multinational setting. Methods: The purpose of HOPE-KIDS 2 is to evaluate the effect of voxelotor treatment on reducing the risk of stroke in participants aged 2 to &amp;lt;15 years with SCD who have conditional TAMMV (170 to &amp;lt;200 cm/s) at baseline. Children aged 2 to &amp;lt;15 years with SCD (HbSS/HbSβ 0) were screened after local sonographers were trained and certified on standardized TCD examination protocol, using the same model of Multi-Dop T digital machine (Compumedics DWL, Germany). TCD assessments were sent for central quality review and interpretation by 2 independent reviewers. STOP criteria were used to classify stroke risk: normal, &amp;lt;170 cm/s; conditional, 170 to &amp;lt;200 cm/s; or abnormal, ≥200 cm/s. Patient baseline characteristics, including clinical measurements of markers of anemia and hemolysis, were measured during study screening. The reasons for patient screen failure were summarized. Results: Between Nov 2020 and Feb 2023, 708 participants consented at 29 sites in Nigeria (n=250; 5 sites), Kenya (n=241; 4 sites), Egypt (n=145; 4 sites), Ghana (n=28; 2 sites), the US (n=17; 8 sites), Italy (n=9; 3 sites), Oman (n=9; 1 site), Saudi Arabia (n=8; 1 site), and the UK (n=1; 1 site). Of these patients, 92.1% (652/708) completed TCD screening examinations (mean [SD] age 7.6 [3.24] years; range 2.0-14.0 years; 50.8% male; 23.0% receiving hydroxyurea). Of the patients who completed TCD screening, the mean (SD) TAMMV was 163.0 (31.26) cm/s, and 47.1% (307/652) had conditional TCD at baseline (29.0% low conditional, 18.1% high conditional). The main reason for screen failure was index TAMMV outside of conditional range (abnormal, n=39 [6.0%]; normal, n=306 [46.9%]). Elevated TAMMV on screening TCD was more common in younger children (2 to ≤8 years vs &amp;gt;8 to &amp;lt;15 years); patients aged 2-8 years comprised 66.8% and 82.1% of the conditional and abnormal TCD categories, respectively. There were 39 assessments that required adjudication, but only 9 were deemed unreadable. Of all patients screened, 36.2% (236/652) fulfilled eligibility criteria for randomization; the characteristics at screening of these patients are summarized (Table). The mean (SD) Hb level and TAMMV at screening for randomly assigned patients was 7.7 (1.06) g/dL and 182.7 (7.53) cm/s, respectively. Conclusions: Clinical sites for the HOPE-KIDS 2 study successfully implemented a standardized, local TCD screening protocol supported by central quality review. For a large interventional trial aimed at reducing the risk of stroke in children with SCD, African and Middle Eastern sites presented relatively few limitations with respect to participant screening.

TCD assessment in fulminant hepatic failure: Improvements in cerebral autoregulation after liver transplantation

Introduction and ObjectivesAcute liver failure, also known as fulminant hepatic failure (FHF), includes a spectrum of clinical entities characterized by acute liver injury, severe hepatocellular dysfunction and hepatic encephalopathy. The objective of this study was to assess cerebral autoregulation (CA) in 25 patients (19 female) with FHF and to follow up with seventeen of these patients before and after liver transplantation. Patients and MethodsThe mean age was 33.8 years (range 14–56, SD 13.1 years). Cerebral hemodynamics was assessed by transcranial Doppler (TCD) bilateral recordings of cerebral blood velocity (CBv) in the middle cerebral arteries (MCA). ResultsCA was assessed based on the static CA index (SCAI), reflecting the effects of a 20–30 mmHg increase in mean arterial blood pressure on CBv induced with norepinephrine infusion. SCAI was estimated at four time points: pretransplant and on the 1st, 2nd and 3rd posttransplant days, showing a significant difference between pre- and posttransplant SCAI (p = 0.005). SCAI peaked on the third posttransplant day (p = 0.006). Categorical analysis of SCAI showed that for most patients, CA was reestablished on the second day posttransplant (SCAI > 0.6). ConclusionsThese results suggest that CA impairment pretransplant and on the 1st day posttransplant was re-established at 48–72 h after transplantation. These findings can help to improve the management of this patient group during these specific phases, thereby avoiding neurological complications, such as brain swelling and intracranial hypertension.

Perioperative cerebral perfusion in aortic arch surgery: a potential link with neurological outcome.

The aim of this study was to examine whether perioperative changes in cerebral blood flow (CBF) relate to postoperative neurological deficits in patients undergoing aortic arch surgery involving antegrade selective cerebral perfusion (ASCP). We retrospectively analysed data from patients who underwent aortic arch surgery involving ASCP and perioperative transcranial Doppler assessments. Linear mixed-model analyses were performed to examine perioperative changes in mean bilateral blood velocity in the middle cerebral arteries, reflecting changes in CBF, and their relation with neurological deficits, i.e. ischaemic stroke and/or delirium. Logistic regression analyses were performed to explore possible risk factors for postoperative neurological deficits. In our study population (N = 102), intraoperative blood velocities were lower compared to preoperative levels, and lowest during ASCP. Thirty-six (35%) patients with postoperative neurological deficits (ischaemic stroke, n = 9; delirium, n = 25; both, n = 2) had lower blood velocity during ASCP compared to patients without (25.4 vs 37.0 cm/s; P = 0.002). Logistic regression analyses revealed lower blood velocity during ASCP as an independent risk factor for postoperative neurological deficits (odds ratio = 0.959; 95% confidence interval: 0.923, 0.997; P = 0.037). Lower intraoperative CBF during ASCP seems independently related to postoperative neurological deficits in patients undergoing aortic arch surgery. Because CBF is a modifiable factor during ASCP, our observation has significant potential to improve clinical management and prevent neurological deficits.

A novel computational fluid dynamic method and validation for assessing distal cerebrovascular microcirculatory resistance

Background and objectiveThe non-invasive assessment of microcirculatory resistance could improve the treatment of cerebrovascular stenosis. This study aimed to validate a novel computational strategy for determining the reference value of microcirculatory resistance in patients with cerebrovascular stenosis. MethodsWe reconstructed a patient-specific 3-dimensional model of the extracranial-intracranial arteries. A computational strategy incorporating patient-specific pressure-wire measurements was developed to estimate the blood flow rate and microcirculatory resistance. Throughout the computational fluid dynamics (CFD) simulation, the boundary conditions were adjusted according to the developed algorithm. Pearson correlation and Bland-Altman analyses were used to quantify the correlation and agreement between CFD calculations and transcranial Doppler (TCD) assessment. ResultsA strong correlation was found between the CFD-based and invasive distal pressure measurements (P<0.0001). Meanwhile, the CFD and TCD-based flow measurements were highly correlated (r = 0.853; P = 0.001). Furthermore, there was a correlation between the mean velocity measured by CFD and the mean velocity measured by TCD (r = 0.777; P<0.001). Good agreement was observed between the mass flow by CFD simulation and volumetric flow by TCD (P = 0.0266, mean difference: -0.7814 mmHg, limits of agreement, -4.0905 - 2.5276). However, the mean velocities from CFD simulation were in less agreement with those from the TCD assessment (P = 0.3992, mean difference, -0.0485; limits of agreement, -0.6141 - 0.5170). Results of the CFD simulation indicate that the flow resistance varies greatly between individuals. ConclusionsThe computational strategy of incorporating patient-specific pressure-wire measurements may serve as an effective approach to evaluate the actual reference values of microcirculatory resistance. In addition, an individualized assessment of non-invasive flow resistance is necessary for the accurate determination of non-invasive cerebrovascular pressure.

Intolerance to occlusion during carotid artery stenting with proximal protection: causes, mechanisms, treatment and prevention.

Periprocedural cerebral microembolization is the most important complication of carotid artery stenting. Among several variables that play a role to reduce this risk, brain protection (proximal vs. distal) plays a pivot role. Data are accumulating in favor of a better performance of proximal vs. distal especially in symptomatic patients and high-risk carotid plaques. A prerequisite for the technique to be safe and effective is the presence of a valid intracranial collateral circulation to compensate for the target vessel hemisphere avoiding patient intolerance. This complication may occur either soon after the common carotid balloon occlusion or slowly developing during the procedure peaking at the stent post-dilation step. While Willis' circle anatomic variants are the most frequent cause of acute intolerance, a mix of anatomic, hemodynamic and patient cerebral condition play a role for the late developing form. Prevention is the best treatment of intolerance through a pre- and procedural imaging with different techniques (CT angiography, NMR angiography, transcranial Doppler assessment, digital subtraction angiography and back pressure monitoring).

Transcranial Doppler assessment of patients with cerebral small vessel disease

BackgroundCerebral small vessel disease (SVD) is associated with acute events such as lacunar and hemorrhagic strokes, or chronic events such as cognitive deficit in the form of subcortical dementia, mood deficit in the form of late onset depression, sphincteric affection, and gait apraxia. Under conditions of moderate blood flow deficit, the inability of sclerotic vessels to dilate due to impairment of the cerebral autoregulation, renders the periventricular white matter seriously ischemic. Therefore, it is important to detect the implications of cerebral large artery disease on the severity of SVD, and the ability of transcranial duplex (TCD) to evaluate it in people at risk.MethodsFifty lacunar stroke patients were recruited, and evaluated using MRI brain to assess SVD score, carotid duplex and TCD to assess extracranial and intracranial stenoses, respectively.ResultsBoth intracranial and extracranial stenoses showed significant relation to the severity of cerebral SVD. Moreover, there were significant relation between intracranial stenosis and presence of lacuna and EPVS.ConclusionCerebral large artery disease contributes to the pathogenesis and severity of cerebral SVD. Therefore, TCD may be a useful tool for the prediction of occurrence of cerebral SVD in high-risk individuals, especially hypertensives.

817 Robotic Semi-Automated Transcranial Doppler Assessment of Cerebrovascular Autoregulation in Post Concussional Syndrome: Methodological Considerations

Abstract Introduction Post-concussive syndrome (PCS) refers to a constellation of physical, cognitive, and emotional symptoms after traumatic brain injury (TBI). Despite its incidence, the underlying mechanisms are unclear. We hypothesised that impaired cerebral autoregulation (CA) is a contributor. Method A prospective, observational study was integrated into outpatient clinics at a tertiary neurosurgical centre. Data points included: demographics, symptoms (Post-Concussion Symptom Scale [PCSS]), neuropsychological assessment (Cambridge Neuropsychological Test Automated-Battery [CANTAB]) and cerebrovascular metrics (Mxa co-efficient and the transient hyperaemic-response ratio [THRR]) - via transcranial Doppler (TCD), plethysmography and bespoke software (ICM+). Results 12 participants were recruited with 2 excluded after unsuccessful cerebrovascular TCD insonation. 10 participants (5 TBI patients, 5 healthy controls) were included in the analysis (median age 26.5, male:female 7:3). Median PCSS scores were 6/126 (TBI subgroup). Median CANTAB percentiles were 78 (healthy controls) and 25 (TBI). Mxa was calculated for 90% and THRR for 50% of participants. Median study time was 127.5 minutes and feedback (n = 6) highlighted the perceived acceptability of the study. Conclusions This pilot study has demonstrated a feasible and reproducible assessment of PCS and CA metrics (non-invasively) in a real-world setting. By scaling this methodology, we hope to test whether CA changes are correlated with symptomatic PCS in patients post-TBI.

Case Studies in Neuroscience: Transcranial Doppler assessment of increased cerebral blood flow during iterative seizures

This case study aimed at monitoring ictal vasodilation in a clinical setting in order to confirm the experimental data on enhanced cerebral perfusion during epileptic seizures. Clinical observation of a patient presenting relapsing seizures in the intensive care unit. Transcranial Doppler (TCD) was used to monitor both blood velocities and the arterial caliber in the B-flow mode as a proxy of blood flow of the middle cerebral artery (MCA). A 35-year-old woman experienced partial epileptic seizures lasting 1 min that recurred every 5 min. Seizures were monitored with continuous EEG and TCD. During the seizure, the MCA caliber increased while velocities remained stable, which doubled the MCA blood flow. Immediately after the seizure, the artery caliber returned to its initial value, and the velocities increased by one third of the initial value. After intensification of antiepileptic treatment, clinical seizures ceased andTCD findings returned to normal MCA caliber and velocities. Auto-immune encephalitis was identified by brain biopsy and the patient recovered with corticosteroids treatment. This is the first description of ictal vasodilatation assessed by TCD. Our current understanding holds that cerebral blood flow increases during a seizure, but our report demonstrates thatarterial dilation preceded the acceleration of velocities. This case study confirms in a clinical setting the impact of seizures on cerebral blood flow.

The Use of Near-Infrared Spectroscopy and/or Transcranial Doppler as Non-Invasive Markers of Cerebral Perfusion in Adult Sepsis Patients With Delirium: A Systematic Review.

Background:Several studies have previously reported the presence of altered cerebral perfusion during sepsis. However, the role of non-invasive neuromonitoring, and the impact of altered cerebral perfusion, in sepsis patients with delirium remains unclear.Methods:We performed a systematic review of studies that used near-infrared spectroscopy (NIRS) and/or transcranial Doppler (TCD) to assess adults (≥18 years) with sepsis and delirium. From study inception to July 28, 2020, we searched the following databases: Ovid MedLine, Embase, Cochrane Library, and Web of Science.Results:Of 1546 articles identified, 10 met our inclusion criteria. Although NIRS-derived regional cerebral oxygenation was consistently lower, this difference was only statistically significant in one study. TCD-derived cerebral blood flow velocity was inconsistent across studies. Importantly, both impaired cerebral autoregulation during sepsis and increased cerebrovascular resistance were associated with delirium during sepsis. However, the heterogeneity in NIRS and TCD devices, duration of recording (from 10 seconds to 72 hours), and delirium assessment methods (e.g., electronic medical records, confusion assessment method for the intensive care unit), precluded meta-analysis.Conclusion:The available literature demonstrates that cerebral perfusion disturbances may be associated with delirium in sepsis. However, future investigations will require consistent definitions of delirium, delirium assessment training, harmonized NIRS and TCD assessments (e.g., consistent measurement site and length of recording), as well as the quantification of secondary and tertiary variables (i.e., Cox, Mxa, MAPOPT), in order to fully assess the relationship between cerebral perfusion and delirium in patients with sepsis.

Association between transcranial Doppler vasospasm and functional outcome after subarachnoid hemorrhage.

AIM OF THE STUDY:This study aimed to investigate the association between transcranial Doppler (TCD) vasospasm and patient outcome and to assess the predictive factors for developing TCD vasospasm after subarachnoid hemorrhage (SAH).MATERIALS AND METHODS:This retrospective observational study included adult patients with nontraumatic SAH. Patient characteristics and TCD values were recorded retrospectively from patient records. Data on maxTCD (maximal TCD value recorded on any side between day 1 and day 14) as well as Δ TCD (maximal difference between mean velocity measured on days 1–3 and days 4–14 on any side) were calculated. The modified Rankin Score was recorded from electronic patient notes at discharge and 3, 6, and 12 months after ictus. The effect of TCD vasospasm, maxTCD, and Δ TCD on the clinical outcome was investigated. Potential predictive factors for developing TCD vasospasm were assessed. The association between the same factors and maxTCD and Δ TCD were explored.RESULTS:One hundred and thirty-eight patients were included in the study. Higher age was associated with a lower risk of developing TCD vasospasm (odds ratio: 0.952, 95% confidence interval: 0.924–0.982, P = 0.002). Fisher grade was a predictor of developing TCD vasospasm (P = 0.05). Age was negatively correlated with maxTCD (R = −0.47, P = 0.01). There was no statistically significant difference in patient outcome at hospital discharge and at 3, 6, and 12 months between patients with and without TCD vasospasm. Higher maxTCD and Δ TCD were associated with a worse clinical outcome at 3 months after SAH ictus.CONCLUSIONS:The clinical benefit of routine TCD assessments in SAH patients remains uncertain.

Robotic Semi-Automated Transcranial Doppler Assessment of Cerebrovascular Autoregulation in Post-Concussion Syndrome: Methodological Considerations.

Post-concussion syndrome (PCS) refers to a constellation of physical, cognitive, and emotional symptoms after traumatic brain injury (TBI). Despite its incidence and impact, the underlying mechanisms of PCS are unclear. We hypothesized that impaired cerebral autoregulation (CA) is a contributor. In this article, we present our protocol for non-invasively assessing CA in patients with TBI and PCS in a real-world clinical setting. A prospective, observational study was integrated into outpatient clinics at a tertiary neurosurgical center. Data points included: demographics, symptom profile (Post-Concussion Symptom Scale [PCSS]) and neuropsychological assessment (Cambridge Neuropsychological Test Automated-Battery [CANTAB]). Cerebrovascular metrics (nMxa co-efficient and the transient hyperaemic-response ratio [THRR]) were collected using transcranial Doppler (TCD), finger plethysmography, and bespoke software (ICM+). Twelve participants were initially recruited but 2 were excluded after unsuccessful insonation of the middle cerebral artery (MCA); 10 participants (5 patients with TBI, 5 healthy controls) were included in the analysis (median age 26.5 years, male to female ratio: 7:3). Median PCSS scores were 6/126 for the TBI patient sub-groups. Median CANTAB percentiles were 78 (healthy controls) and 25 (TBI). nMxa was calculated for 90% of included patients, whereas THRR was calculated for 50%. Median study time was 127.5 min and feedback (n = 6) highlighted the perceived acceptability of the study. This pilot study has demonstrated a reproducible assessment of PCS and CA metrics (non-invasively) in a real-world setting. This protocol is feasible and is acceptable to participants. By scaling this methodology, we hope to test whether CA changes are correlated with symptomatic PCS in patients post-TBI.

Watching the Brain: an Overview of Neuromonitoring Systems and Their Utility in the Emergency Department

This review describes strategies for the emergency department setting that help facilitate monitoring of patients with acute neurological injuries. Multiple invasive and non-invasive modalities are available for the emergency physician to utilize as adjuncts to the physical examination and imaging of patients with neurological injuries. The value of these modalities lies in detection of subtle changes that signal early neurological decompensation. This article focuses on the most common devices along with their adoption and implementation into the practice of emergency medicine. The field of non-invasive neuromonitoring techniques is rapidly flourishing with an emphasis on portability and reproducibility, enhancing adoption into the practice of emergency medicine. Devices such as the extra-ventricular drain have proven to be of both diagnostic and therapeutic benefit, allowing for both global ICP monitoring and CSF sampling. However, as emergency physicians become more facile in the use of ultrasound, procedures such as optic nerve sheath diameter evaluation and transcranial Doppler assessments add to the availability of bedside neuromonitoring. It is important to note that many of these devices still require further validation. The field of neuromonitoring encompasses invasive and non-invasive techniques. While useful, they require further validation to establish standardized protocols that would allow for consistent and reliable implementation in the emergency department.

Factors associated with abnormal cerebral blood flow in Egyptian children with sickle cell disease

Background: Transcranial Doppler (TCD) is a well-established tool for cerebrovascular assessment. Estimating the flow velocity across the intracranial arteries helps to identify children with sickle cell anaemia who are at risk for stroke. Objective: Our aim is to correlate TCD findings with clinical condition in children with sickle cell disease (SCD) to determine the value of TCD assessment as a predictive tool for stroke in SCD and to identify any association of TCD findings with disease severity, transfusion therapy and treatment administered. Methods: Eighty-five paediatric SCD patients aged from 3 years to 18 years of both genders who were followed up at the Hematology Clinic of New Children’s Hospital at Cairo University were included in this cross-sectional observational study. All our participants underwent routine laboratory investigations and TCD assessments. Results: Oof the 85 patients, two patients (2.3%) died before completing the TCD study and eventually 83 patients were included in the analysis. Seventeen (20.5%) patients had abnormal TCD findings, seven (8.4%) patients showed high-risk findings and 10 (12.1%) patients had conditional flow pattern. Logistic linear regression analysis confirmed that annual frequency of blood transfusion and hydroxyurea (HU) dose were associated with a decreased risk of abnormal TCD findings. Conclusion: The current study demonstrates that our TCD data reproduce the findings of other studies and that it is very likely the results from large trials are applicable for Egyptian children. The annual frequency of blood transfusion and HU dose were associated with a decreased frequency of abnormal TCD findings.

Transcranial Doppler and magnetic resonance angiography assessment of intracranial stenosis: An analysis of screening modalities.

BACKGROUND:Time-of-flight (TOF) magnetic resonance angiography (MRA) of the head and transcranial Doppler (TCD) are used to diagnose intracranial stenosis, an important cause of ischemic stroke. We aimed to compare TCD findings with TOF-MRA results in a population of patients with symptoms of cerebrovascular disease in whom both tests were done within a short intervening period of each other.METHODS:This is a retrospective, single-center study. Among adult patients referred for symptoms of cerebrovascular disease in both outpatient and inpatient settings, those who received a TCD with adequate insonation of all intracranial arteries and underwent MRA within 3 months intervals of TCD were included in this study. We evaluated the agreement between the results of these two modalities, and also assessed sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of TCD through receiver-operating characteristic (ROC) curve analysis, while MRA considered as a comparator.RESULTS:Among eighty included patients, 720 arteries were examined. An overall significant agreement of 96.5% was observed between TCD and MRA (Kappa = 0.377, P < 0.001). Compared to MRA, TCD had sensitivity of 42.1%, specificity of 99.6%, PPV of 72.7%, and NPV of 98.4% (ROC area: 0.708 [0.594–0.822]). TCD is specifically accurate in evaluating middle cerebral artery (MCA) (ROC area = 0.83).CONCLUSIONS:The high NPV of TCD in our study indicates the utility of TCD as a diagnostic test to exclude the presence of intracranial stenosis. This study supports TCD as a convenient, safe, and reproducible imaging modality applicable in the screening of intracranial stenosis, especially to evaluate MCA.

Role of Transcranial Doppler Assessment of Cerebral Blood Flow in Neonatal Sepsis

Neonatal sepsis is one of the leading causes of morbidity and mortality among term and preterm infants worldwide.assessment of the changes in cerebral blood flow velocity [CBFV] in cases of the neonatal sepsis.This study including 100 infants. 60neonates are diagnosed with neonatal sepsis [Sepsis group].while the other 40 neonates with no signs of neonatal sepsis [Control group]. Trans-cranial Doppler [TCD] was carried out for assessment of blood flow velocity in the anterior [ACA] and middle cerebral arteries [MCA] Peak systolic velocity [PSV], end diastolic velocity [EDV], and resistive index [RI] were measured.RI and PI were significantly decreased, with mean RI 0.56in MCA & Median RI in ACA 0.59 & Median PI 0.98; 0.98 in MCA & ACA respectively in the case group, while with a mean RI 0.75 in MCA & Median RI 0.72 in ACA respectively & Median PI1.35; 1.27 in MCA & ACA respectively .Whereas the Peak systolic velocity was increased with a mean of 69.07 in MCA & Median of 66.4 in ACA respectively in case group & mean of 50.22; in MCA & Median of 44.0 in ACA in control group with p value <0.001 in MCA & ACA respectively. neonatal sepsis causes increase in Peak systolic velocity & decrease in the Resistive & Pulsatility index thus causing increase in the cerebral blood flow, which in turn showed increased incidence in Intraventricular hemorrhage .

Role of Transcranial Doppler Assessment of Cerebral Blood Flow in Neonatal Sepsis

Role of Transcranial Doppler Assessment of Cerebral Blood Flow in Neonatal Sepsis

Transcranial Doppler and Hematoma Expansion in Acute Spontaneous Primary Intracerebral Hemorrhage.

Context:The data on the role of Transcranial Doppler (TCD) in the management of acute primary intracerebral hemorrhage (ICH) is meager.Aims:To study TCD variables associated with hematoma expansion in acute primary ICH.Settings and Design:The study was carried out in the neurosciences department of Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh from July 2010 to September 2011 employing a prospective, double blinded non randomized study design.Materials and Methods:Acute ICH patients within 24 h of symptom onset were recruited. Baseline neuroimaging study (Computerized tomography, CT scan of brain) was performed to assess the pure hematoma volume by AXBXC/2 method. Baseline TCD parameters were obtained from both the middle cerebral arteries (MCAs; affected and unaffected hemisphere): Peak Systolic velocity, End Diastolic velocity, Mean Flow velocity, Resistance Index, and Pulsatility Index. Follow up (24 h) assessment of hematoma volume and TCD were carried out. Each of the TCD variables were compared in hematoma expansion (>33% increase in hematoma volume on the follow-up CT) and non-expansion group.Statistical analysis:On univariate analysis, the Student's t-test and contingency tables with the X2 test were used. A forward stepwise multivariate logistic regression analysis with hematoma expansion at 24 h as the dependent variable and ROC analysis was carried out, using SPSS software version 16 (Chicago, IL). P value < 0.05 was considered significant.Results:Twenty-five patients completed the study. Ten patients (40%) had hematoma expansion. Multivariate analysis revealed unaffected hemisphere MCA Pulsatility Index ratio [unaffected hemisphere MCA Follow up Pulsatility Index/baseline Pulsatility Index] of > 1.055 as the lone correlate of hematoma expansion (sensitivity of 90% and specificity of 60%).Conclusion:Frequent assessment with TCD could aid in prediction of hematoma expansion by measuring unaffected hemisphere Pulsatility Index ratios.