Do cerebral blood flow velocities change in iron deficiency anemia?

Transcranial doppler velocities in a large healthy population of African children

Background and purpose

Transcranial doppler ultrasound (TCD) is a tool that diagnoses and monitors pathophysiological changes to the cerebrovasculature. As cerebral blood flow velocities (CBFVs) increase throughout childhood, interpretation of TCD examinations in pediatrics requires comparison to age matched normative data. Large cohorts of healthy children have not been examined to develop these reference values in any population. There is a complete absence of normative values in African children where, due to lack of alternate neuroimaging techniques, utilization of TCD is rapidly emerging.

Materials and methods

A prospective study of 710 healthy African children 3 months-15 years was performed. Demographics, vital signs, and hemoglobin values were recorded. Participants underwent a complete, non-imaging TCD examination. Systolic (Vs), diastolic (Vd), and mean (Vm) flow velocities and pulsatility index (PI) were calculated by the instrument for each measurement.

Results

Vs, Vd, and Vm increased through early childhood in all vessels, with the highest CBFVs identified in children 5-5.9 years. There were few significant gender differences in CBFVs in any vessels in any age group. No correlations between blood pressure or hemoglobin and CBFVs were identified. Children in the youngest age groups had CBFVs similar to those previously published, whereas nearly every vessel in children ≥3 years had significantly lower Vs, Vd, and Vm.

Conclusions

For the first time, reference TCD values for African children are established. Utilization of these CBFVs in the interpretation of TCD examinations in this population will improve the overall accuracy of TCD as a clinical tool on the continent.

Influence of COVID-19 and employees’ response to deviations on employee enactment

Developing countries’ economies are in shambles as a result of the coronavirus. Developing countries like Bangladesh began opening its business sector in May 2020 in order to preserve the economy. To mitigate the effect of coronavirus, the government has implemented “new normal” guidelines for businesses. The primary goals of this research are to determine how the COVID-19 pandemic has influenced employee performance and to determine the workers’ perspectives regarding the changes that have been made to their everyday lives. To complete this research, employee performance was assessed using the employee response to change (ERC) method. Employees from many sectors have been studied. For this research, 300 people from various sectors were surveyed online at random. The study was quantitative as well as exploratory. It was based solely on original data. The research used a non-probability sampling approach to collect data. The survey questionnaire was sent to those who replied via Google Forms. Results and visual representations are found using SPSS software and Microsoft Excel. COVID-19 and the reaction to employee changes have a considerable detrimental influence on employee performance, according to all of the study’s findings. The employee’s focus, communication, and attention to work are all adversely affected by these “new normal” alterations

Cerebral hemodynamic changes to transcranial Doppler sonography in celiac disease: A pilot study

Background

Sonographic mesenteric pattern in celiac disease (CD) suggests a hyperdynamic circulation. Despite the well-known CD-related neurological involvement, no study has systematically explored the cerebral hemodynamics to transcranial Doppler sonography.

Materials and methods

Montreal Cognitive Assessment (MoCA) and 17-item Hamilton Depression Rating Scale (HDRS) were assessed in 15 newly diagnosed subjects with CD and 15 age-, sex-, and education-matched healthy controls. Cerebral blood flow (CBF) velocities and indices of resistivity (RI) and pulsatility (PI) from the middle cerebral artery (MCA), bilaterally, and the basilar artery (BA) were recorded. We also assessed cerebral vasomotor reactivity (CVR) through the breath-holding test (BHT).

Results

Worse scores of MoCA and HDRS were found in patients compared to controls. Although patients showed higher values of CBF velocity from MCA bilaterally compared to controls, both at rest and after BHT, no comparison reached a statistical significance, whereas after BHT both RI and PI from BA were significantly higher in patients. A significant negative correlation between both indices from BA and MoCA score were also noted.

Conclusion

These treatment-naïve CD patients may show some subtle CVR changes in posterior circulation, thus possibly expanding the spectrum of pathomechanisms underlying neuroceliac disease and in particular gluten ataxia. Subclinical identification of cerebrovascular pathology in CD may help adequate prevention and early management of neurological involvement.

Iron deficiency anemia and thrombosis risk in children-revisiting an old hypothesis

Iron deficiency anemia has a high prevalence in children and has repeatedly been implicated as a risk factor for arterial and venous thrombosis. As an effective therapy for iron deficiency anemia is available, understanding the association between this form of anemia and the potentially severe thrombosis phenotype is of major clinical interest. Recent findings shed light on pathophysiology of hypercoagulability resulting from iron-restricted erythropoiesis. Specifically, an animal model of induced iron deficiency allowed identifying multiple mechanisms, by which iron deficiency anemia results in increased thrombus formation and thrombus progression both in arterial and venous thrombosis. These findings complement and support conclusions derived from clinical data. The purpose of this mini review is to summarize current evidence on the association of iron deficiency anemia and thrombosis. We want to increase the awareness of iron deficiency as a risk factor for thrombosis in the pediatric population. We discuss how novel pathophysiological concepts can be translated into the clinical settings and suggest clinical studies on prevention and treatment strategies in high-risk patient groups.

Cerebral Blood Flow Velocity is Not Associated with Serum Hemoglobin in Children with Malaria-Associated Anemia

BACKGROUND AND PURPOSE

Hemoglobin (Hbg) is often thought to impact cerebral blood flow velocity (CBFV). This study was performed to investigate the relationship between Hbg value and CBFV in African children with malaria.

METHODS

In this prospective, observational study, children aged 3 months to 18 years with malaria and a normal Blantyre coma score underwent a single transcranial Doppler ultrasound (TCD) examination with a concurrent Hbg check.

RESULTS

One hundred fifty-six children with a mean age of 43 months were enrolled. Thirty-three children (21%) had severe anemia (Hbg <5g/dL), 46 (29%) had moderate anemia (Hbg 5-6.9 g/dL), 63 children (41%) had mild anemia (7-9.9 g/dL), and 14 children (9%) had no anemia (Hbg >10 g/dL) at the time of TCD examination. Mean averaged CBFV in the middle cerebral artery (MCA) for the cohort was 99% of predicted based on normative values standardized for age. There was no significant correlation between Hbg levels and measured CBFV in the MCA (r = -.09; 95% CI, -.24-.07; P = .29).

CONCLUSION

In a large sample of African children with malaria, Hbg did not correlate with CBFVs as measured by TCD. Future work that includes baseline TCD measurements and Hbg values as well as other physiological parameters known to influence CBFVs is necessary to confirm these findings.

Investigation of causes of sex-related differences in ocular blood flow in healthy eyes determined by laser speckle flowgraphy

Sex-related differences are present in the systemic and ocular blood flow. However, the cause of the sex-related differences has not been determined. We investigated the ocular blood flow, represented by the mean blur rate (MBR), on the optic nerve head (ONH) determined by laser speckle flowgraphy in 138 males (63.9 ± 8.9 years) and 194 females (63.5 ± 9.4 years). The correlations between the MBR on the ONH and the clinical data were determined. The overall ONH-MBR was significantly higher in females than males (P < 0.001). In addition, the levels of the hemoglobin and hematocrit were significantly lower in females than in males (P < 0.001). The ONH-MBR was negatively and significantly correlated with the levels of the hemoglobin and hematocrit (both, P < 0.001). Multiple regression analyses showed that the sex (β = 0.248, P < 0.001) was an independent factor correlated with the ONH-MBR when the clinical examination data were not included in the analyses. However, when the clinical examination data were included, the hemoglobin level (β = −0.295, P < 0.001) was an independent factor that contributed to the ONH-MBR but the sex was not. We conclude that the sex-related differences in the hemoglobin level and the negative correlation between hemoglobin and the ONH-MBR are the causes of the sex-related differences in the ONH-MBR.

Alterations in cerebral oxygen metabolism after traumatic brain injury in children

Traumatic brain injury (TBI) is the most common cause of acquired disability in children. Metabolic defects, and in particular mitochondrial dysfunction, are important contributors to brain injury after TBI. Studies of metabolic dysfunction are limited, but magnetic resonance methods suitable for use in children are overcoming this limitation. We performed noninvasive measurements of cerebral blood flow and oxygen metabolic index (OMI) to assess metabolic dysfunction in children with severe TBI. Cerebral blood flow is variable after TBI but hypoperfusion and low OMI are predominant, supporting metabolic dysfunction. This finding is consistent with preclinical and adult clinical studies of brain metabolism and mitochondrial dysfunction after TBI.