Low-field magnetic resonance image enhancement via stochastic image quality transfer.

Low-field (<1T) magnetic resonance imaging (MRI) scanners remain in widespread use in low- and middle-income countries (LMICs) and are commonly used for some applications in higher income countries e.g. for small child patients with obesity, claustrophobia, implants, or tattoos. However, low-field MR images commonly have lower resolution and poorer contrast than images from high field (1.5T, 3T, and above). Here, we present Image Quality Transfer (IQT) to enhance low-field structural MRI by estimating from a low-field image the image we would have obtained from the same subject at high field. Our approach uses (i) a stochastic low-field image simulator as the forward model to capture uncertainty and variation in the contrast of low-field images corresponding to a particular high-field image, and (ii) an anisotropic U-Net variant specifically designed for the IQT inverse problem. We evaluate the proposed algorithm both in simulation and using multi-contrast (T1-weighted, T2-weighted, and fluid attenuated inversion recovery (FLAIR)) clinical low-field MRI data from an LMIC hospital. We show the efficacy of IQT in improving contrast and resolution of low-field MR images. We demonstrate that IQT-enhanced images have potential for enhancing visualisation of anatomical structures and pathological lesions of clinical relevance from the perspective of radiologists. IQT is proved to have capability of boosting the diagnostic value of low-field MRI, especially in low-resource settings.

Assessment of Adverse Events Following COVID-19 Vaccination: A Cross-sectional Study in Ibadan, Nigeria.

Background: Vaccination has been described as the most critical tool to end the COVID-19 pandemic and to save lives and livelihoods. This study aimed to evaluate the spectrum of adverse events following immunization with the COVID-19 AstraZeneca/Oxford vaccine in Ibadan, southwestern Nigeria. Methodology: A cross-sectional study. Adults aged ≥ 18 years who had received the Astra-Zeneca/Oxford COVID-19 vaccine at selected COVID-19 vaccination centres across three Local Government Areas in Ibadan, SW Nigeria were interviewed by means of a structured questionnaire to determine the spectrum of adverse events following immunisation (AEFI). Results: We enrolled 369 adults; 179 males and 190 females, with a mean of age of 37.8 ±12.0 years. Three hundred and thirty-two (90.0%) of the subjects experienced one or more AEFI. Of the total AEFIs reported, the most frequent were headache 225 (21.1%), fatigue/tiredness 186 (17.4%), pain at the injection site 99 (9.3%) and myalgia 97(9.1%). Nine in ten (96.4%) of these AEFIs occurred within 48 hours post-vaccination. Higher severity of adverse events score (p=0.049) and multiple AEFIs (p=0.01) were associated with the first dose of the vaccine. There were severe AEFI in 1.2 % (95% CI: 0.3-.9.0%) of the respondents. Presumed or confirmed COVID 19 infection before vaccination increased the odds of AEFI (OR 7.0, 95% CI: 1.8-27.8). Conclusion: Our study showed a high frequency of AEFI among recipients of the Astra Zenecca/Oxford vaccine in Ibadan. Majority of the AEFIs are mild and self-limiting. Previous infection with COVID-19 appears to increase the risk of AEFI.

Oxidative stress indices in ASD children in Sub-Sahara Africa.

BACKGROUND: The pathogenesis of autism spectrum disorder (ASD) remains a medical challenge even in the developed world. Although genetics and epigenetic factors have been variously indicted as major causes of the disorder, development of oxidative stress especially in the formative years of children has equally gained prominence as an etiological basis of the disorder. Oxidative stress is characterized by the production of excessive amounts of free radicals, decreased levels of antioxidants with the attendant imbalance in oxidant/antioxidant ratio. This study was designed to determine the levels of essential metals [magnesium (Mg), zinc (Zn), and copper (Cu)] and toxic metal, lead (Pb), and generation of oxidative stress by their abnormal interaction. METHOD: Twenty-five children clinically diagnosed for ASD according to DSM-IV-TR and 25 neuro-typical (NT) children (controls), (aged 5.96 ± 1.40 years and 6.18 ± 2.59 years respectively) were recruited for this study. Essential and toxic metals were analyzed using induction-coupled plasma-mass spectrometry (ICP-MS); oxidative stress markers [malondialdehyde (MDA), total plasma peroxidase (TPP), and total antioxidant capacity (TAC)] were determined using appropriate biochemical methods. Oxidative stress index (OSI) was calculated. RESULTS: The levels of TPP and TAC were significantly reduced while MDA was higher in ASD compared to NT. Although OSI was higher in ASD, the difference was not significant. Pb (lead) concentration was significantly increased while Mg, Zn, and Cu levels were reduced significantly in ASD compared to NT. A significant negative correlation between Mg and OSI (r = - 0.438; p = 0.029) was observed in NT. CONCLUSION: Reduction in Zn and Mg levels with a concurrent increase in Pb in children with ASD in this study may be the basis of inadequate TAC manifesting as increased MDA and reduced TPP levels. The attendant imbalance in oxidant/antioxidant ratio may result in abnormality in neuronal transduction leading to the abnormal cognitive and speech functions characteristic of ASD.

Epidemiology of Stroke in Sickle Cell Disease.

Sickle cell disease is the most common cause of stroke in childhood, both ischaemic and haemorrhagic, and it also affects adults with the condition. Without any screening or preventative treatment, the incidence appears to fall within the range 0.5 to 0.9 per 100 patient years of observation. Newborn screening with Penicillin prophylaxis and vaccination leading to reduced bacterial infection may have reduced the incidence, alongside increasing hydroxyurea prescription. Transcranial Doppler screening and prophylactic chronic transfusion for at least an initial year has reduced the incidence of stroke by up to 10-fold in children with time averaged mean of the maximum velocity >200 cm/s. Hydroxyurea also appears to reduce the incidence of first stroke to a similar extent in the same group but the optimal dose remains controversial. The prevention of haemorrhagic stroke at all ages and ischaemic stroke in adults has not yet received the same degree of attention. Although there are fewer studies, silent cerebral infarction on magnetic resonance imaging (MRI), and other neurological conditions, including headache, epilepsy and cognitive dysfunction, are also more prevalent in sickle cell disease compared with age matched controls. Clinical, neuropsychological and quantitative MRI screening may prove useful for understanding epidemiology and aetiology.

Transcranial Doppler screening in Nigerian children with sickle cell disease: A 10-year longitudinal study on the SPPIBA cohort.

BACKGROUND: Primary stroke prevention programmes for children with sickle cell disease (SCD) have been shown to be feasible interventions in resource-poor countries. Different hydroxyurea (HU) regimens have been utilised in ameliorating the severity of SCD. OBJECTIVE: To determine the long-term outcomes of the stroke prevention programme for children with SCD in Ibadan (SPPIBA), Nigeria. METHODS: A longitudinal study of 396 children with haemoglobin SS disease who had been on the stroke prevention programme for a minimum period of 5 years. All enrollees had nonimaging TCD performed at baseline and thereafter 3-monthly or annually. Children with TCD velocities ≥170 cm/s were treated with HU by dose-escalation regimen. RESULTS: The mean age at first TCD examination was 102 ± 46.7 months and the period of follow-up ranged from 5 to 10 years (mean = 7.2 ± 1.7). Time to significant decline in TCD velocities ranged from 5 to 35 months, (median = 10.0 months). The minimum dose of HU required to achieve significant decline in TCD velocities ranged from 15 to 31 mg/kg/day, mean 23.7 (±3.9). HU dose escalation beyond 20 mg/kg/day was required to attain significant reductions in the time-averaged mean of maximal velocities (TAMMV) in 69.1% of the cases. Two stroke events occurred giving a stroke incidence of 0.08 per 100 patient-years. CONCLUSION: The majority of Nigerian children with SCD and elevated TCD velocities achieved significant decline in TAMMV within the first year of HU therapy but on higher doses of HU. It might be important to individualise HU doses for optimal outcomes in primary stroke prevention.

Data-driven malaria prevalence prediction in large densely populated urban holoendemic sub-Saharan West Africa.

Over 200 million malaria cases globally lead to half-million deaths annually. The development of malaria prevalence prediction systems to support malaria care pathways has been hindered by lack of data, a tendency towards universal "monolithic" models (one-size-fits-all-regions) and a focus on long lead time predictions. Current systems do not provide short-term local predictions at an accuracy suitable for deployment in clinical practice. Here we show a data-driven approach that reliably produces one-month-ahead prevalence prediction within a densely populated all-year-round malaria metropolis of over 3.5 million inhabitants situated in Nigeria which has one of the largest global burdens of P. falciparum malaria. We estimate one-month-ahead prevalence in a unique 22-years prospective regional dataset of > 9 × 104 participants attending our healthcare services. Our system agrees with both magnitude and direction of the prediction on validation data achieving MAE ≤ 6 × 10-2, MSE ≤ 7 × 10-3, PCC (median 0.63, IQR 0.3) and with more than 80% of estimates within a (+ 0.1 to - 0.05) error-tolerance range which is clinically relevant for decision-support in our holoendemic setting. Our data-driven approach could facilitate healthcare systems to harness their own data to support local malaria care pathways.

Pediatric Hearing Thresholds Post-bacterial Meningitis.

Introduction: Disabling hearing loss as a sequela of bacterial meningitis results from damage to the auditory system. This study was designed to ascertain the hearing thresholds in survivors of bacterial meningitis and the risk factors of hearing loss in childhood bacterial meningitis. Methodology: One hundred and two children admitted and treated for bacterial meningitis were recruited prospectively along with 102 age- and sex-matched controls who had auditory evaluation using otoacoustic emission and auditory brain stem response tests 48 h prior to hospital discharge. This was also repeated at the follow-up clinic at 1 month after hospital discharge, irrespective of the initial hearing assessment results. Result: There were 57 (55.9%) males and 45 (44.1%) females among the cases (mean age, 5.34 ± 4.40 years) and 55 (53.9%) males and 47 (46.1%) females among the controls (mean age, 5.31 ± 3.15 years). The prevalence of hearing loss was 30.4% among the cases, while it was 6.9% among the controls. The risk factors of hearing impairment in this study were the presence of anemia, leukocytosis, and hypoglycorrhachia. Conclusion: Hearing impairment with varying degrees of severity is a frequent complication of bacterial meningitis in children.

Non-Dose-Dependent Changes in Liver Enzyme Levels of Children With Epilepsy on Treatment With Sodium Valproate.

BACKGROUND: Sodium valproate (VPA) is considered as the drug of choice for the treatment of generalized epilepsy in children. Sodium Valproate may be hepatotoxic. AIM: To assess the level of derangement of liver enzymes in children with epilepsy on treatment with sodium valproate. METHODS: A cohort study. One hundred fifty-three children, comprising 51 with epilepsy on treatment with VPA (group I), 51 with epilepsy on treatment with other antiepileptic drugs (AEDs) but not VPA (group II), and 51 with nonconvulsive disorders (group III) had liver function tests performed for them. Data were analyzed by SPSS version 23.0. RESULTS: There were 85 males and 68 females, aged 6 months to 14 years (median = 7.0 years). There was no significant difference in the mean plasma levels of alanine transaminase (ALT), alkaline phosphatase, and gamma glutamyl transferase across the three groups of children. The mean aspartate transaminase level was significantly higher in children in group III. There was a statistically significant negative correlation between the duration of AED therapy and the mean serum level of AST (r = -0.266, P = 0.016). The serum ALT level showed a statistically significant positive correlation with the duration of AED therapy (r = 0.268, P = 0.015). CONCLUSION: Sodium valproate monotherapy does not appear to be associated with significant hepatotoxicity in children in our cohort.

Depleted circulatory complement-lysis inhibitor (CLI) in childhood cerebral malaria returns to normal with convalescence.

BACKGROUND: Cerebral malaria (CM), is a life-threatening childhood malaria syndrome with high mortality. CM is associated with impaired consciousness and neurological damage. It is not fully understood, as yet, why some children develop CM. Presented here is an observation from longitudinal studies on CM in a paediatric cohort of children from a large, densely-populated and malaria holoendemic, sub-Saharan, West African metropolis. METHODS: Plasma samples were collected from a cohort of children with CM, severe malarial anaemia (SMA), uncomplicated malaria (UM), non-malaria positive healthy community controls (CC), and coma and anemic patients without malaria, as disease controls (DC). Proteomic two-dimensional difference gel electrophoresis (2D-DIGE) and mass spectrometry were used in a discovery cohort to identify plasma proteins that might be discriminatory among these clinical groups. The circulatory levels of identified proteins of interest were quantified by ELISA in a prospective validation cohort. RESULTS: The proteome analysis revealed differential abundance of circulatory complement-lysis inhibitor (CLI), also known as Clusterin (CLU). CLI circulatory level was low at hospital admission in all children presenting with CM and recovered to normal level during convalescence (p < 0.0001). At acute onset, circulatory level of CLI in the CM group significantly discriminates CM from the UM, SMA, DC and CC groups. CONCLUSIONS: The CLI circulatory level is low in all patients in the CM group at admission, but recovers through convalescence. The level of CLI at acute onset may be a specific discriminatory marker of CM. This work suggests that CLI may play a role in the pathophysiology of CM and may be useful in the diagnosis and follow-up of children presenting with CM.

Expert-level automated malaria diagnosis on routine blood films with deep neural networks.

Over 200 million malaria cases globally lead to half a million deaths annually. Accurate malaria diagnosis remains a challenge. Automated imaging processing approaches to analyze Thick Blood Films (TBF) could provide scalable solutions, for urban healthcare providers in the holoendemic malaria sub-Saharan region. Although several approaches have been attempted to identify malaria parasites in TBF, none have achieved negative and positive predictive performance suitable for clinical use in the west sub-Saharan region. While malaria parasite object detection remains an intermediary step in achieving automatic patient diagnosis, training state-of-the-art deep-learning object detectors requires the human-expert labor-intensive process of labeling a large dataset of digitized TBF. To overcome these challenges and to achieve a clinically usable system, we show a novel approach. It leverages routine clinical-microscopy labels from our quality-controlled malaria clinics, to train a Deep Malaria Convolutional Neural Network classifier (DeepMCNN) for automated malaria diagnosis. Our system also provides total Malaria Parasite (MP) and White Blood Cell (WBC) counts allowing parasitemia estimation in MP/µL, as recommended by the WHO. Prospective validation of the DeepMCNN achieves sensitivity/specificity of 0.92/0.90 against expert-level malaria diagnosis. Our approach PPV/NPV performance is of 0.92/0.90, which is clinically usable in our holoendemic settings in the densely populated metropolis of Ibadan. It is located within the most populous African country (Nigeria) and with one of the largest burdens of Plasmodium falciparum malaria. Our openly available method is of importance for strategies aimed to scale malaria diagnosis in urban regions where daily assessment of thousands of specimens is required.

Annual stroke incidence in Nigerian children with sickle cell disease and elevated TCD velocities treated with hydroxyurea.

BACKGROUND: Elevated transcranial Doppler (TCD) velocities accurately predict stroke risk in children with sickle cell disease (SCD). Chronic blood transfusion, the gold standard for primary stroke prevention, is faced with numerous challenges in Africa. Hydroxyurea (HU) has been shown to reduce elevated TCD velocities in children with SCD. AIM: To determine the effectiveness of HU in reducing the risk of primary stroke in a cohort of Nigerian children with SCD and elevated velocities treated with HU. METHODS: Children with SCD and TCD velocities ≥170 cm/sec treated with HU were prospectively followed with 3-monthly TCD and neurological evaluations for ≥12 months to determine the incidence of primary stroke. RESULTS: One hundred and four children, 53 males, and 51 females were enrolled into the study. Their ages ranged from 2 to 16 years with a mean of 6 years. At first TCD examination, velocities ranged from 173 to 260 cm/sec with conditional and abnormal risk velocities in 60 (57.7%) and 44 (42.3%) children, respectively. Follow up ranged from 1 to 8 years with a mean of 3.6 years. Mean TCD velocities showed a significant decline from 198.2 (standard deviation [SD] = 15.6) cm/sec to 169.3 (SD = 21.4) cm/sec (P < 0.001). One stroke event occurred in the cohort, giving a stroke incidence of 0.27/100 person years. CONCLUSION: HU significantly reduces TCD velocities in Nigerian children with SCD and elevated TCD velocities, with a corresponding reduction in the incidence of primary stroke. HU may represent a potential alternative for primary stroke prevention in low and middle income countries where the burden of SCD resides.

Positive and inverse correlation of blood lead level with erythrocyte acetylcholinesterase and intelligence quotient in children: implications for neurotoxicity.

Blood lead level (BLL) is insufficiently sensitive for early detection of Lead-induced neurotoxicity (LIN). This study determined the possible role of the combination of BLL, intelligent quotient (IQ) and erythrocyte acetylcholinesterase (AChE) activity in the early detection of LIN in Children. Apparently healthy children (n=309) from eight public primary schools in Ibadan, Nigeria were recruited and classified into: children with Elevated BLL (EBLL) and children with Acceptable BLL (control) based on CDC cut-off for childhood lead exposure. Neurological indices (speech, memory, cranial nerves and cerebellar functions), IQ, BLL and erythrocyte AChE activity were assessed using standard methods, Standard Progressive Matrices, AAS and HPLC respectively. Statistical analysis involved Student's t-test, Pearson's correlation and multivariate regression. p<0.05 was considered significant. There were 169 (54.7%) children with EBLL while there were 140 (45.3%) control children. Both groups exhibited normal speech, memory, cranial nerves and cerebellar functions. However, IQ was lower in EBLL children (85.9±11.6) compared with control (91.5±14.0) while BLL and AChE activity were higher in EBLL children (0.4±0.1 µmol/l; 117.5±25.5 µkat/l) compared with control (0.2±0.0 µmol/l; 59.4±10.2 µkat/l). BLL showed inverse correlation with IQ (r=-0.134, p=0.019) but positive correlation with AChE (r=0.978, p≤0.001). 16.2% of the observed variation in BLL could be accounted for by AChE using the equation; [BLL=-0.007+0.003 AChE] p<0.05. Elevated blood lead level is prevalent among the school children and appears to have adverse effect on their IQ. Erythrocyte AChE could be a promising marker for early recognition of significant environmental lead exposure and lead-induced neurotoxicity in children.

Low plasma haptoglobin is a risk factor for life-threatening childhood severe malarial anemia and not an exclusive consequence of hemolysis.

Severe Malarial Anemia (SMA), a life-threatening childhood Plasmodium falciparum malaria syndrome requiring urgent blood transfusion, exhibits inflammatory and hemolytic pathology. Differentiating between hypo-haptoglobinemia due to hemolysis or that of genetic origin is key to understand SMA pathogenesis. We hypothesized that while malaria-induced hypo-haptoglobinemia should reverse at recovery, that of genetic etiology should not. We carried-out a case-control study of children living under hyper-endemic holoendemic malaria burden in the sub-Saharan metropolis of Ibadan, Nigeria. We show that hypo-haptoglobinemia is a risk factor for childhood SMA and not solely due to intravascular hemolysis from underlying schizogony. In children presenting with SMA, hypo-haptoglobinemia remains through convalescence to recovery suggesting a genetic cause. We identified a haptoglobin gene variant, rs12162087 (g.-1203G > A, frequency = 0.67), to be associated with plasma haptoglobin levels (p = 8.5 × 10-6). The Homo-Var:(AA) is associated with high plasma haptoglobin while the reference Homo-Ref:(GG) is associated with hypo-haptoglobinemia (p = 2.3 × 10-6). The variant is associated with SMA, with the most support for a risk effect for Homo-Ref genotype. Our insights on regulatory haptoglobin genotypes and hypo-haptoglobinemia suggest that haptoglobin screening could be part of risk-assessment algorithms to prevent rapid disease progression towards SMA in regions with no-access to urgent blood transfusion where SMA accounts for high childhood mortality rates.

Epilepsy in transition from child care to adult service: a missing link in sub-Saharan Africa.

Epilepsy is a common chronic neurological disease which predominantly affects children and young adults. The disease is highly stigmatised and transition from child care to adult services is not routine in many low- and middle-income countries. Where a treatment system follows routines which cannot be sustained in such countries because of specialised manpower challenges, it becomes imperative that appropriate care models be sought for patients whose seizures fail to remit in childhood. In teaching hospitals, well-organised, multidisciplinary meetings and a planned transfer between paediatric and adult neurologists will be feasible. However, an alternative model is advocated at the community level where the majority of the patients reside which involves task shifting to general practitioners and community healthcare workers. The latter can organise home visits to ensure management compliance. This will ensure better seizure outcomes and a good quality of life for epileptic patients.

Seizure-related injuries in children and adolescents with epilepsy.

BACKGROUND: Children with epilepsy are reported to be at a greater risk of injuries compared with their peers who do not have epilepsy. OBJECTIVES: We set out to determine the frequency and pattern of seizure-related injuries in children with epilepsy seen at the University College Hospital (UCH), Ibadan, Nigeria. METHODS: Consecutive cases of epilepsy seen at the pediatric neurology clinic of the UCH, Ibadan over a period of 6months were evaluated for injuries in the preceding 12months using a structured questionnaire. These were compared with age- and sex-matched controls. RESULTS: A total of 125 children with epilepsy and 125 age- and sex-matched controls were studied. Injuries occurred more frequently in children with epilepsy than in their peers (p=0.01, OR 1.935, 95% CI 1.142-3.280). Epilepsy was generalized in 80 (64.0%), and localization-related in 45 (36.0%). Idiopathic epilepsy accounted for 74 (59.2%), and the remaining 51 (40.8%) had remote symptomatic epilepsy. Fifty-seven (45.6%) children had suffered seizure-related injuries with multiple injuries in 31 (24.8%). The most frequent were skin/soft tissue lacerations (26.4%), injuries to the tongue and soft tissues of the mouth (19.2%), minor head injuries (15.2%), and dental injuries with tooth loss (8.0%). There was a statistically significant association between seizure frequency and seizure-related injuries (p=0.002). Children on polytherapy had a significantly higher frequency of seizure-related injuries (p<0.001). CONCLUSION: Epilepsy is a major risk factor for injuries in childhood. High seizure frequency increases the risk of multiple injuries in children with epilepsy.

Hydroxyurea lowers transcranial Doppler flow velocities in children with sickle cell anaemia in a Nigerian cohort.

BACKGROUND: Sickle cell anaemia (SCA) is the leading genetic disorder in Nigeria. Elevated velocities ≥170 cm/sec occur in about a third of Nigerian children with SCA. Chronic blood transfusion for stroke prevention is faced with a myriad of challenges in our practice. OBJECTIVES: To evaluate the effectiveness of hydroxyurea (HU) in reducing flow velocities in a cohort of Nigerian children with SCA and elevated velocities treated with HU. METHODS: An observational study was carried out on a cohort of Nigerian children with SCA and elevated velocities identified on routine transcranial Doppler (TCD) screening. HU was recommended in those with TCD velocities ≥ 170cm/sec as stipulated in our hospital protocol. Outcomes were compared after ≥12 months of observation. RESULTS: Fifty children with elevated TCD velocities were studied; 31 consented to HU therapy and 19 declined. Children on HU showed a statistically significant decline in mean velocities from 199.7 [17.1] cm/sec to 165.8 [20.7] cm/sec (P < 0.001) with a significant increase in mean packed cell volume from 21.1 [3.4] to 25.0 [2.8]%. Children without treatment had a significant rise in mean velocities from 190.2 [10.8] cm/sec to 199.7 [14.9] cm/sec (P = 0.003). Children with conditional risk velocities on HU were less likely to convert to abnormal risk (P < 0.001). Two stroke events occurred, one in each group. No adverse effects of HU were recorded in the cohort. CONCLUSION: HU appears to significantly reduce TCD velocities in Nigerian children with SCA and elevated velocities ≥170 cm/sec with beneficial effect on the haematological profile. HU may provide an effective approach to primary stroke prevention, particularly in Africa.

A Review of e-Health Interventions for Maternal and Child Health in Sub-Sahara Africa.

To review e-health interventions for maternal and child health (MCH) and to explore their influence on MCH practices in sub-Sahara Africa (SSA). Keyword searches were used to retrieve articles from four databases and the websites of organisations involved in e-health projects for MCH in SSA. A total of 18relevant articles were retrieved using inclusion and exclusion criteria. The researchers reveal the prevalence of the application of mobile phones for MCH care and the influence of the use of information and communication technology (ICT) for delivering MCH information and services to target populations. There is a need to move the application of ICT for MCH care from pilot initiatives to interventions involving all stakeholders on a sub-regional scale. These interventions should also adopt an integrated approach that takes care of the information needs at every stage along the continuum of care. It is anticipated that the study would be useful in the evolution and implementation of future ICT-based programmes for MCH in the region.

Transcranial Doppler ultrasonography in children with sickle cell anemia: Clinical and laboratory correlates for elevated blood flow velocities.

BACKGROUND: Transcranial Doppler (TCD) sonography of major cerebral arteries is now recommended for routine screening for stroke risk in children with sickle cell disease (SCD). METHODS: We performed TCD studies on children with sickle cell anemia (SCA) seen at the pediatric hematology clinic over a period of 2 years. TCD scans were repeated yearly in children with normal flow velocities and every 3 months in children with elevated velocities. Findings were correlated with clinical variables, hematologic indices, and arterial oxygen saturation. Predictors of elevated velocities were identified by multiple linear regressions. RESULTS: We enrolled 237 children and performed a total of 526 TCD examinations. Highest time-averaged maximum flow velocities were ≥170 cm/s in 72 (30.3%) cases and ≥200 cm/s in 20 (8.4%). Young age, low hematocrit, low hemoglobin, and arterial oxygen desaturation <95% showed significant correlations with presence of increased cerebral flow velocities. CONCLUSIONS: Low hematocrit, low hemoglobin concentration, young age, and low arterial oxygen desaturation predicted elevated cerebral blood flow velocities and, invariably, increased stroke risk, in children with SCA. Children who exhibit these features should be given high priority for TCD examination in the setting of limited resources.

Prevalence of transcranial Doppler abnormalities in Nigerian children with sickle cell disease.

Transcranial Doppler (TCD) ultrasonography helps to identify children with sickle cell disease (SCD) who are at an increased risk of stroke,making primary stroke prevention a reality. A cross-sectional study of145 Nigerian children aged ≥3 years with SCD was carried out to describe the pattern of cerebral blood flow (CBF) abnormalities. The mean time-averaged mean velocity (TAMV) was 152 ±27.0 cm/sec and122 ±22.0 cm/sec in Hb SS and Hb S1C group, respectively. Abnormal velocities were recorded in six (4.7%) of the Hb SS patients and none of the Hb S1C while conditional risk (CR) velocities were recorded in 19.7% of Hb SS (low conditional 11.0%, high conditional 8.7%) and low conditional in 5.6% of Hb S1C cases. Cerebral flow velocities showed a negative correlation with age and hematocrit. Compared with African-American children, Nigerian children with Hb SS disease have a considerably higher prevalence of CR velocities.

Cranial magnetic resonance imaging findings in kwashiorkor.

Protein energy malnutrition (PEM) is an important public health problem in the developing countries, although it is becoming uncommon in South West Nigeria. Cerebral changes have been associated with severe PEM. This study evaluated the neurological changes using Magnetic Resonance Imaging (MRI) in Ibadan south west Nigeria. The 5 children evaluated had a median age of 16 months and all the children had brain changes compatible with cerebral atrophy. In addition two of the children had periventricular white matter changes, while one these two had mega cisterna magna in addition. Though this study did not re-evaluate the brains of these children after nutritional rehabilitation, it is possible that changes are reversible as demonstrated in earlier studies.