MRI-Based Brain Volume Scoring in Cerebral Malaria Is Externally Valid and Applicable to Lower-Resolution Images

BACKGROUND AND PURPOSE

Children with cerebral malaria have an elevated risk of mortality and neurologic morbidity. Both mortality and morbidity are associated with initially increased brain volume on MR imaging, as graded by the Brain Volume Score, a subjective ordinal rating scale created specifically for brain MRIs in children with cerebral malaria. For the Brain Volume Score to be more widely clinically useful, we aimed to determine its independent reproducibility and whether it can be applicable to lower-resolution MRIs.

MATERIALS AND METHODS

To assess the independent reproducibility of the Brain Volume Score, radiologists not associated with the initial study were trained to score MRIs from a new cohort of patients with cerebral malaria. These scores were then compared with survival and neurologic outcomes. To assess the applicability to lower-resolution MRI, we assigned Brain Volume Scores to brain MRIs degraded to simulate a very-low-field (64 mT) portable scanner and compared these with the original scores assigned to the original nondegraded MRIs.

RESULTS

Brain Volume Scores on the new cohort of patients with cerebral malaria were highly associated with outcomes (OR for mortality = 16, P < .001). Scoring of the simulated degraded images remained consistent with the Brain Volume Scores assigned to the original higher-quality (0.35 T) images (intraclass coefficients > 0.86).

CONCLUSIONS

Our findings demonstrate that the Brain Volume Score is externally valid in reproducibly predicting outcomes and can be reliably assigned to lower-resolution images.

DON in pediatric cerebral malaria, a phase I/IIA dose-escalation safety study: study protocol for a clinical trial

BACKGROUND

Despite treatment with highly effective antimalarial drugs, malaria annually claims the lives of over half a million children under 5-years of age in sub-Saharan Africa. Cerebral malaria (CM), defined as Plasmodium falciparum infection with coma, is the severe malaria syndrome with the highest mortality. Studies in the CM mouse model suggest that a T cell-mediated response underlies CM pathology, opening a new target for therapy in humans. This trial aims to establish the preliminary safety of one such novel therapy, the glutamine antagonist 6-diazo-5-oxo-L-norleucine (DON).

METHODS

In this phase I/IIa dose-escalation clinical trial, a single dose of intravenous (IV) DON is administered to three participants groups-healthy adults and adults with uncomplicated malaria, then pediatric participants with CM-to primarily assess safety. The secondary objective of this trial is to assess pharmacokinetics of DON over a range of doses. The open-label adult portion of the trial enrolls 40 healthy adults concurrently with 40 adults with uncomplicated malaria. Cohorts of 10 participants receive a single IV dose of DON with doses escalating between cohorts from 0.1 mg/kg, 1.0 mg/kg, 5.0 mg/kg, to 10 mg/kg. Following subsequent safety review, a randomized, double-blind, and placebo-controlled pediatric study enrolls 72 participants aged 6 months to 14 years with CM. The pediatric portion of the study minimally spans three malaria seasons including a planned interim analysis after 50% of pediatric enrollments. The first half of pediatric participants receive DON 0.1 mg/kg, 1.0 mg/kg, or placebo. Dosing for the second half of pediatric participants is informed by the safety and preliminary efficacy results of those previously enrolled. The pediatric portion of the study has an exploratory outcome evaluating the preliminary efficacy of DON. Efficacy is assessed by diagnostics predictive of CM outcome: electroencephalography (EEG), magnetic resonance imaging (MRI), and transcranial doppler (TCD), measured before and after DON administration. All participants with malaria receive standard of care antimalarials in accordance with local guidelines, regardless of study drug dose group.

DISCUSSION

This preliminary safety and efficacy study evaluates DON, a candidate adjunctive therapy for pediatric CM. If results support DON preliminary safety and efficacy, follow-up phase II and III clinical trials will be indicated.

TRIAL REGISTRATION

This trial was registered on ClinicalTrials.gov on 28 July 2022 (NCT05478720).

Post hospital admission blood lactate measurements are associated with mortality but not neurologic morbidity in children with cerebral malaria

BACKGROUND

In children with cerebral malaria (CM) admission blood lactate has previously guided intravenous fluid therapy and been validated as a prognostic biomarker associated with death. The usefulness of post-admission measurements of blood lactate in children with CM is less clear. The strength of association between blood lactate and neurological sequelae in CM survivors, as well as the optimal duration of post-admission measurements of blood lactate to identify children at higher risk of adverse outcomes is unknown.

METHODS

A retrospective cohort study of 1674 Malawian children with CM hospitalized from 2000 to 2018 who had blood lactate measurements every 6 h for the first 24 h after admission was performed. The strength of association between admission lactate or values measured at any time point in the first 24 h post-admission and outcomes (mortality and neurological morbidity in survivors) was estimated. The duration of time after admission that lactate remained a valid prognostic biomarker was assessed.

RESULTS

When lactate is analysed as a continuous variable, children with CM who have higher values at admission have a 1.05-fold higher odds (95% CI 0.99-1.11) of death compared to those with lower lactate values. Children with higher blood lactate at 6 h have 1.16-fold higher odds (95% CI 1.09-1.23) of death, compared to those with lower values. If lactate levels are dichotomized into hyperlactataemic (lactate > 5.0 mmol/L) or not, the strength of association between admission lactate and mortality increases (OR = 2.49, 95% CI 1.47-4.22). Blood lactate levels obtained after 18 h post-admission are not associated with outcomes. Similarly, the change in lactate concentrations through time during the first 24 h of hospital admission is not associated with outcomes. Blood lactate during hospitalization is not associated with adverse neurologic outcomes in CM survivors.

CONCLUSIONS

In children with CM, blood lactate is associated with death but not neurologic morbidity in survivors. To comprehensively estimate prognosis, blood lactate in children with CM should be assessed at admission and for 18 h afterwards.

Cerebral Metabolic Crisis in Pediatric Cerebral Malaria

Cerebral metabolic energy crisis (CMEC), often defined as a cerebrospinal fluid (CSF) lactate: pyruvate ratio (LPR) >40, occurs in various diseases and is associated with poor neurologic outcomes. Cerebral malaria (CM) causes significant mortality and neurodisability in children worldwide. Multiple factors that could lead to CMEC are plausible in these patients, but its frequency has not been explored. Fifty-three children with CM were enrolled and underwent analysis of CSF lactate and pyruvate levels. All 53 patients met criteria for a CMEC (median CSF LPR of 72.9 [interquartile range [IQR]: 58.5-93.3]). Half of children met criteria for an ischemic CMEC (median LPR of 85 [IQR: 73-184]) and half met criteria for a nonischemic CMEC (median LPR of 60 [IQR: 54-79]. Children also underwent transcranial doppler ultrasound investigation. Cerebral blood flow velocities were more likely to meet diagnostic criteria for low flow (<2 standard deviation from normal) or vasospasm in children with an ischemic CMEC (73%) than in children with a nonischemic CMEC (20%, p  = 0.04). Children with an ischemic CMEC had poorer outcomes (pediatric cerebral performance category of 3-6) than those with a nonischemic CMEC (46 vs. 22%, p  = 0.03). CMEC was ubiquitous in this patient population and the processes underlying the two subtypes (ischemic and nonischemic) may represent targets for future adjunctive therapies.

Loss to Hospital Follow-Up in Pediatric Cerebral Malaria Survivors: A Case-Control Study

Children surviving central nervous system (CNS) infections are at high risk of neurological, behavioral, and cognitive sequalae. Early identification, characterization, and treatment of these sequelae may improve child and family health. In Africa, it is unclear if there are demographic or clinical factors that increase the risk of post-hospital loss to follow-up in children with CNS infections. If these factors exist, targeted educational efforts to increase rates of post-hospital retention could be focused on families at highest risk. We performed a case-control study of Malawian children with cerebral malaria, a locally common CNS infection, previously admitted to a specialized research unit in Blantyre, Malawi. Routine survivor post-hospital follow-up was scheduled for 1 month, 6 months, and 12 months. We compared demographic and clinical characteristics between 84 children who missed one or more of these post-hospital visits with 120 children who attended all visits. There were no statistically significant differences in demographic or clinical characteristics between children whose families returned for all follow-up visits and those who did not. Specifically, when comparing these groups, we found no differences in age (P = 00.646), sex (P = 0.789), duration of hospitalization (P = 0.903), distance from home to hospital (P = 0.355), type or severity of neurological sequelae (P = 0.837), guardian literacy (P = 0.057), or number of discharge medications (P = 0.464). No factors assessed in this study were associated with higher risk of loss to follow-up in Malawian child survivors of CNS infections. During hospitalization, educational efforts to increase post-hospital retention should focus on all families.

Admission Clinical and EEG Features Associated With Mortality and Long-term Neurologic and Cognitive Outcomes in Pediatric Cerebral Malaria

BACKGROUND AND OBJECTIVES

For children with cerebral malaria, mortality is high, and in survivors, long-term neurologic and cognitive dysfunctions are common. While specific clinical factors are associated with death or long-term neurocognitive morbidity in cerebral malaria, the association of EEG features with these outcomes, particularly neurocognitive outcomes, is less well characterized.

METHODS

In this prospective cohort study of 149 children age 6 months to 12 years who survived cerebral malaria in Kampala, Uganda, we evaluated whether depth of coma, number of clinical seizures, or EEG features during hospitalization were associated with mortality during hospitalization, short-term and long-term neurologic deficits, or long-term cognitive outcomes (overall cognition, attention, memory) over the 2-year follow-up.

RESULTS

Higher Blantyre or Glasgow Coma Scores (BCS and GCS, respectively), higher background voltage, and presence of normal reactivity on EEG were each associated with lower mortality. Among clinical and EEG features, the presence of >4 seizures on admission had the best combination of negative and positive predictive values for neurologic deficits in follow-up. In multivariable modeling of cognitive outcomes, the number of seizures and specific EEG features showed independent association with better outcomes. In children younger than 5 years throughout the study, seizure number and presence of vertex sharp waves were independently associated with better posthospitalization cognitive performance, faster dominant frequency with better attention, and higher average background voltage and faster dominant background frequency with better associative memory. In children younger than 5 years at CM episode but 5 years or older at cognitive testing, seizure number, background dominant frequency, and the presence of vertex sharp waves were each associated with changes in cognition, seizure number and variability with attention, and seizure number with working memory.

DISCUSSION

In children with cerebral malaria, seizure number is strongly associated with the risk of long-term neurologic deficits, while seizure number and specific EEG features (average background voltage, dominant rhythm frequency, presence of vertex sharp waves, presence of variability) are independently associated with cognitive outcomes. Future studies should evaluate the predictive value of these findings.

Automated analysis of low-field brain MRI in cerebral malaria

A central challenge of medical imaging studies is to extract biomarkers that characterize disease pathology or outcomes. Modern automated approaches have found tremendous success in high-resolution, high-quality magnetic resonance images. These methods, however, may not translate to low-resolution images acquired on magnetic resonance imaging (MRI) scanners with lower magnetic field strength. In low-resource settings where low-field scanners are more common and there is a shortage of radiologists to manually interpret MRI scans, it is critical to develop automated methods that can augment or replace manual interpretation, while accommodating reduced image quality. We present a fully automated framework for translating radiological diagnostic criteria into image-based biomarkers, inspired by a project in which children with cerebral malaria (CM) were imaged using low-field 0.35 Tesla MRI. We integrate multiatlas label fusion, which leverages high-resolution images from another sample as prior spatial information, with parametric Gaussian hidden Markov models based on image intensities, to create a robust method for determining ventricular cerebrospinal fluid volume. We also propose normalized image intensity and texture measurements to determine the loss of gray-to-white matter tissue differentiation and sulcal effacement. These integrated biomarkers have excellent classification performance for determining severe brain swelling due to CM.

Capacity Building in Pediatric Critical Care-Global Health Research and Education: The Blantyre Experience

Pediatric critical care medicine (PCCM), as it is practiced in high-income countries, is focused on specialized medical care for the most vulnerable pediatric patient populations. However, best practices for provision of that care globally are lacking. Thus, PCCM research and education programming can potentially fill significant knowledge gaps by facilitating the development of evidence-based clinical guidelines that reduce child mortality on a global scale. Malaria remains a leading cause of pediatric mortality worldwide. The Blantyre Malaria Project (BMP) is a research and clinical care collaborative that has focused on reducing the public health burden of pediatric cerebral malaria in Malawi since 1986. In 2017, the requirements of a new research study led to the creation of PCCM services in Blantyre, creating the opportunity to establish a PCCM-Global Health Research Fellowship by BMP in collaboration with the University of Maryland School of Medicine. In this perspective piece, we reflect on the evolution of the PCCM-Global Health research fellowship. Although the specifics of this fellowship are out of the scope of this perspective, we discuss the context allowing for the development of this program and explore some early lessons learned to consider for future capacity-building efforts in the future of PCCM-Global Health research.

Temporal Trends of Blood Glucose in Children with Cerebral Malaria

Hypoglycemia, defined as a blood glucose < 2.2 mmol/L, is associated with death in pediatric cerebral malaria (CM). The optimal duration of glucose monitoring in CM is unknown. We collected data from 1,674 hospitalized Malawian children with CM to evaluate the association between hypoglycemia and death or neurologic disability in survivors. We assessed the optimal duration of routine periodic measurements of blood glucose. Children with hypoglycemia at admission had a 2.87-fold higher odds (95% CI: 1.35-6.09) of death and, if they survived, a 3.21-fold greater odds (95% CI: 1.51-6.86) of sequelae at hospital discharge. If hypoglycemia was detected at 6 hours but not at admission, there was a 7.27-fold higher odds of death (95% CI: 1.85-8.56). The presence of newly developed hypoglycemia after admission was not independently associated with neurological sequelae in CM survivors. Among all new episodes of blood sugar below a treatment threshold of 3.0 mmol/L, 94.7% occurred within 24 hours of admission. In those with blood sugar below 3.0 mmol/L in the first 24 hours, low blood sugar persisted or recurred for up to 42 hours. Hypoglycemia at admission or 6 hours afterward is strongly associated with mortality in CM. Children with CM should have 24 hours of post-admission blood glucose measurements. If a blood glucose less than the treatment threshold of 3.0 mmol/L is not detected, routine assessments may cease. Children who have blood sugar values below the treatment threshold detected within the first 24 hours should continue to have periodic glucose measurements for 48 hours post-admission.

Implementation of a Low-Field Portable MRI Scanner in a Resource-Constrained Environment: Our Experience in Malawi

Low-field, portable MR imaging may expedite patient management in the setting of critical illness. We successfully implemented low-field MR imaging at the Queen Elizabeth Central Hospital in Malawi; a low-resource setting. We present our experience of low-field, portable MR imaging start-up and use in Malawi; the first of its kind in Sub-Saharan Africa, together with complementary troubleshooting mechanisms that may be used especially in similar resource-constrained contexts.

Using EEG in Resource-Limited Areas: Comparing Qualitative and Quantitative Interpretation Methods in Cerebral Malaria

BACKGROUND

Our goal was to compare the strength of association and predictive ability of qualitative and quantitative electroencephalographic (EEG) factors with the outcomes of death and neurological disability in pediatric cerebral malaria (CM).

METHODS

We enrolled children with a clinical diagnosis of CM admitted to Queen Elizabeth Central Hospital (Blantyre, Malawi) between 2012 and 2017. A routine-length EEG was performed within four hours of admission. EEG data were independently interpreted using qualitative and quantitative methods by trained pediatric neurophysiologists. EEG interpreters were unaware of patient discharge outcome.

RESULTS

EEG tracings from 194 patients were reviewed. Multivariate modeling revealed several qualitative and quantitative EEG variables that were independently associated with outcomes. Quantitative methods modeled on mortality had better goodness of fit than qualitative ones. When modeled on neurological morbidity in survivors, goodness of fit was better for qualitative methods. When the probabilities of an adverse outcome were calculated using multivariate regression coefficients, only the model of quantitative EEG variables regressed on the neurological sequelae outcome showed clear separation between outcome groups.

CONCLUSIONS

Multiple qualitative and quantitative EEG factors are associated with outcomes in pediatric CM. It may be possible to use quantitative EEG factors to create automated methods of study interpretation that have similar predictive abilities for outcomes as human-based interpreters, a rare resource in many malaria-endemic areas. Our results provide a proof-of-concept starting point for the development of quantitative EEG interpretation and prediction methodologies useful in resource-limited settings.

Post-Malaria Anemia Is Rare in Malawian Children with Cerebral Malaria

Artesunate therapy for severe malaria syndromes has been associated with post-treatment hemolysis and anemia. We defined post-malaria anemia as any decrease in hematocrit between the index hospitalization for severe malaria and 1 month after. We determined the incidence and severity of post-malaria anemia in Malawian children surviving cerebral malaria (CM) by analyzing hospital and follow-up data from a long-standing study of CM pathogenesis. Children enrolled before 2014 and treated with quinine (N = 258) were compared with those admitted in 2014 and after, and treated with artesunate (N = 235). The last hematocrit value obtained during hospitalization was compared with the 1-month post-hospitalization hematocrit value. The overall rate of a post-hospitalization decrease in hematocrit in children surviving CM was 5.3% (11 of 235 or 4.7% for quinine, 15 of 258 or 5.8% for artesunate; odds ratio, 3.23 [0.88, 18.38]); no patients with a decrease in hematocrit were symptomatic, and none required transfusion after hospitalization. Of the 26 children who had a decrease in hematocrit 1 month after hospitalization, 23.1% had evidence of a new malaria infection. When children treated with quinine and artesunate were combined, a higher hematocrit level on admission, lower quantitative histidine-rich protein level, and splenomegaly were associated independently with post-malaria anemia. In African survivors of CM, post-malaria anemia is rare, mild, and unassociated with the anti-malarial treatment received.

Central Nervous System Virus Infection in African Children with Cerebral Malaria

We aimed to identify the contribution of central nervous system (CNS) viral coinfection to illness in African children with retinopathy-negative or retinopathy-positive cerebral malaria (CM). We collected cerebrospinal fluid (CSF) from 272 children with retinopathy-negative or retinopathy-positive CM and selected CSF from 111 of these children (38 retinopathy positive, 71 retinopathy negative, 2 retinopathy unknown) for analysis by metagenomic next-generation sequencing. We found CSF viral coinfections in 7/38 (18.4%) retinopathy-positive children and in 18/71 (25.4%) retinopathy-negative children. Excluding HIV-1, human herpesviruses (HHV) represented 61% of viruses identified. Excluding HIV-1, CNS viral coinfection was equally likely in children who were retinopathy positive and retinopathy negative (P = 0.1431). Neither mortality nor neurological morbidity was associated with the presence of virus (odds ratio [OR] = 0.276, 95% CI: 0.056-1.363). Retinopathy-negative children with a higher temperature, lower white blood cell count, or being dehydrated were more likely to have viral coinfection. Level of consciousness at admission was not associated with CNS viral coinfection in retinopathy-negative children. Viral CNS coinfection is unlikely to contribute to coma in children with CM. The herpesviruses other than herpes simplex virus may represent incidental bystanders in CM, reactivating during acute malaria infection.

Outcomes measures in children after acute central nervous system infections and malaria

PURPOSE OF REVIEW

Acute central nervous system (CNS) infections in children result in significant mortality and neurologic morbidity worldwide. This article summarizes the recent pediatric literature published on outcomes measures used after acute infectious meningitis, encephalitis, and cerebral malaria, and highlights ongoing research efforts to standardize outcomes measurements. Search terms were geared toward functional, cognitive, behavioral, and other outcome assessments.

RECENT FINDINGS

Recent data suggest that, depending on microbiological cause, there are differences in currently used outcome measures following acute CNS infections. Outcomes assessments include a variety of formal psychological tests (structured interviews and neuropsychological tests of cognitive and motor functioning) and dichotomized or ordinal scales. Standardization of outcome measures, however, is lacking. Global efforts to standardize outcomes that encompass both the child and family are ongoing.

SUMMARY

Centers worldwide can track and measure a variety of cognitive, behavioral, and functional outcomes after acute CNS infections. Standardized documentation and coding of clinically important outcomes is needed. Further research to evaluate effective practices using acute adjunctive and rehabilitation therapies will be aided by outcome measure standardization.

Admission EEG findings in diverse paediatric cerebral malaria populations predict outcomes

BACKGROUND

Electroencephalography at hospital presentation may offer important insights regarding prognosis that can inform understanding of cerebral malaria (CM) pathophysiology and potentially guide patient selection and risk stratification for future clinical trials. Electroencephalogram (EEG) findings in children with CM in Uganda and Malawi were compared and associations between admission EEG findings and outcome across this diverse population were assessed. Demographic, clinical and admission EEG data from Ugandan and Malawian children admitted from 2009 to 2012 with CM were gathered, and survivors assessed for neurological abnormalities at discharge.

RESULTS

281 children were enrolled (Uganda n = 122, Malawi n = 159). The Malawian population was comprised only of retinopathy positive children (versus 72.5% retinopathy positive in Uganda) and were older (4.2 versus 3.7 years; p = 0.046), had a higher HIV prevalence (9.0 versus 2.8%; p = 0.042), and worse hyperlactataemia (7.4 versus 5.2 mmol/L; p < 0.001) on admission compared to the Ugandan children. EEG findings differed between the two groups in terms of average voltage and frequencies, reactivity, asymmetry, and the presence/absence of sleep architecture. In univariate analyses pooling EEG and outcomes data for both sites, higher average and maximum voltages, faster dominant frequencies, and retained reactivity were associated with survival (all p < 0.05). Focal slowing was associated with death (OR 2.93; 95% CI 1.77-7.30) and a lower average voltage was associated with neurological morbidity in survivors (p = 0.0032).

CONCLUSIONS

Despite substantial demographic and clinical heterogeneity between subjects in Malawi and Uganda as well as different EEG readers at each site, EEG findings on admission predicted mortality and morbidity. For CM clinical trials aimed at decreasing mortality or morbidity, EEG may be valuable for risk stratification and/or subject selection.

Evidence from a natural experiment that malaria parasitemia is pathogenic in retinopathy-negative cerebral malaria

Cerebral malaria (CM) can be classified as retinopathy-positive or retinopathy-negative, based on the presence or absence of characteristic retinal features. While malaria parasites are considered central to the pathogenesis of retinopathy-positive CM, their contribution to retinopathy-negative CM is largely unknown. One theory is that malaria parasites are innocent bystanders in retinopathy-negative CM and the etiology of the coma is entirely non-malarial. Because hospitals in malaria-endemic areas often lack diagnostic facilities to identify non-malarial causes of coma, it has not been possible to evaluate the contribution of malaria infection to retinopathy-negative CM. To overcome this barrier, we studied a natural experiment involving genetically inherited traits, and find evidence that malaria parasitemia does contribute to the pathogenesis of retinopathy-negative CM. A lower bound for the fraction of retinopathy-negative CM that would be prevented if malaria parasitemia were to be eliminated is estimated to be 0.93 (95% confidence interval: 0.68, 1).

DOI:http://dx.doi.org/10.7554/eLife.23699.001

Malaria is a life-threatening disease caused by a parasite that is transferred between people by infected mosquitoes. Most infected individuals suffer flu-like symptoms, but in rare cases malaria can affect the brain, resulting in brain damage, coma or death.

The World Health Organization defines a person as suffering from cerebral malaria if the person is in a coma, has malaria parasites in his or her blood, and has no known alternative cause of the coma. Patients suffering from cerebral malaria are categorized based on whether they have damage to the back of the eyes known as retinopathy. It had previously been found that children who died of “retinopathy-positive” cerebral malaria (i.e. those who had retinopathy) had malaria parasites stuck in small vessels in their brains, which likely caused the coma. By contrast, children who died of “retinopathy-negative” cerebral malaria lacked this parasitic condition, and often also had other infections that can cause a coma, such as meningitis or sepsis.

Because hospitals in many of the areas most affected by malaria often lack the ability to identify what – other than malaria – caused a coma, it was not clear whether malaria parasites influence how retinopathy-negative cerebral malaria develops.

People with certain genetic variants – such as those that underlie sickle cell disease – are protected against the symptoms of malaria infections, and so these variants should also protect against cerebral malaria cases caused by the parasites. Small et al. therefore looked through data that had been collected over several years from people who had been admitted to a hospital in Malawi for cerebral malaria. This revealed that the genetically inherited sickle cell trait is highly protective against retinopathy-negative (as well as retinopathy-positive) cerebral malaria. Therefore, malaria parasites do play a role in a substantial proportion of cases of retinopathy-negative cerebral malaria.

Although Small et al. provide evidence that malaria parasites play a role in retinopathy-negative cerebral malaria, they may not be the only cause of the coma. In the future, the absence of retinopathy could be used as a sign to look for additional factors that contribute to the coma. Currently, all cerebral malaria patients are treated in the same way. Understanding how malaria parasites interact with other illnesses to produce a coma could lead to the development of targeted treatment plans for retinopathy-negative patients.

DOI:http://dx.doi.org/10.7554/eLife.23699.002

Safety of lumbar puncture in comatose children with clinical features of cerebral malaria

Objective:

We assessed the independent association of lumbar puncture (LP) and death in Malawian children admitted to the hospital with the clinical features of cerebral malaria (CM).

Methods:

This was a retrospective cohort study in Malawian children with clinical features of CM. Allocation to LP was nonrandom and was associated with severity of illness. Propensity score–based analyses were used to adjust for this bias and assess the independent association between LP and mortality.

Results:

Data were available for 1,075 children: 866 (80.6%) underwent LP and 209 (19.4%) did not. Unadjusted mortality rates were lower in children who underwent LP (15.3% vs 26.7% in the no-LP group) but differences in covariates between the 2 groups suggested bias in LP allocation. After propensity score matching, all covariates were balanced. Propensity score–based analyses showed no change in mortality rate associated with LP: by inverse probability weighting, the average risk reduction was 2.0% at 12 hours (95% confidence interval −1.5% to 5.5%, p = 0.27) and 1.7% during hospital admission (95% confidence interval −4.5% to 7.9%, p = 0.60). Undergoing LP did not change the risk of mortality in subanalyses of children with severe brain swelling on MRI or in those with papilledema.

Conclusion:

In comatose children with suspected CM who were clinically stable, we found no evidence that LP increases mortality, even in children with objective signs of raised intracranial pressure.

Prevalence of depression in Parkinson's disease patients in Ethiopia

BACKGROUND

Parkinson's disease (PD) is associated with cognitive and psychiatric disturbances including depression, anxiety, psychotic symptoms and sleep disturbances. These psychiatric manifestations have a negative impact on disease course and the medical management of PD patients. Major depression has a greater negative impact on patients' quality of life than abnormal motor function, and is associated with faster cognitive decline and progression of motor deficits. Thus, the objective of this study was to determine the prevalence and pattern of depression in PD outpatients in Ethiopia. We determined the age range in which depression in PD patients is most common, the most common symptoms of depression, and the epidemiologic confounders associated with depression in PD patients.

METHODS

We conducted a cross-sectional point prevalence study of all PD patients attending the follow-up clinics of the departments of neurology at Black Lion Teaching and Zewuditu Memorial Hospitals in Addis Ababa, Ethiopia, from May 2013 to August 2013. We collected information using a structured questionnaire which assessed demographic information, clinical history, and neurologic function.

RESULT

Of the 101 patients surveyed, the prevalence of depression was 58/101(57.4%). Of these patients, 1 of 58(1.7%) was on antidepressant medications. These low proportions likely indicate a low index of suspicion and under treatment of depression in PD outpatients.

CONCLUSION

In Ethiopian PD outpatients, depression is under recognized and undertreated. We recommend routine use of screening tools. In those who screen positive for depression, treatment is warranted. Further studies are needed to confirm these findings, and to increase our understanding of specific signs and symptoms of depression in the context of PD.

Brain MRI of children with retinopathy-negative cerebral malaria

Our goals were to understand the brain magnetic resonance imaging (MRI) findings in children with retinopathy-negative cerebral malaria (CM) and investigate whether any findings on acute MRI were associated with adverse outcomes. We performed MRI scans on children admitted to the hospital in Blantyre, Malawi with clinically defined CM. Two hundred and seventeen children were imaged during the study period; 44 patients were malarial retinopathy-negative; and 173 patients were retinopathy-positive. We compared MRI findings in children with retinopathy-negative and retinopathy-positive CM. In children who were retinopathy-negative, we identified MRI variables that were associated with death and adverse neurologic outcomes. On multivariate analysis, cortical diffusion weighted imaging (DWI) abnormality and increased brain volume were strongly associated with neurologic morbidity in survivors. Investigations to explore the underlying pathophysiologic processes responsible for these MRI changes are warranted.

The interaction of malnutrition and neurologic disability in Africa

Malnutrition and neurodisability are both major public health problems in Africa. This review highlights key areas where they interact. This happens throughout life and starts with maternal malnutrition affecting fetal neurodevelopment with both immediate (eg, folate deficiency causing neural tube defects) and lifelong implications (eg, impaired cognitive function). Maternal malnutrition can also increase the risk of perinatal problems, including birth asphyxia, a major cause of neurologic damage and cerebral palsy. Macronutrient malnutrition can both cause and be caused by neurodisability. Mechanisms include decreased food intake, increased nutrient losses, and increased nutrient requirement. Specific micronutrient deficiencies can also lead to neurodisability, for example, blindness (vitamin A), intractable epilepsy (vitamin B6), and cognitive impairment (iodine and iron). Toxin ingestion (eg, from poorly processed cassava) can cause neurodisability including a peripheral polyneuropathy and a spastic paraparesis. We conclude that there is an urgent need for nutrition and disability programs to work more closely together.

Cerebral malaria

Malaria, the most significant parasitic disease of man, kills approximately one million people per year. Half of these deaths occur in those with cerebral malaria (CM). The World Health Organization (WHO) defines CM as an otherwise unexplained coma in a patient with malarial parasitemia. Worldwide, CM occurs primarily in African children and Asian adults, with the vast majority (greater than 90%) of cases occurring in children 5 years old or younger in sub-Saharan Africa. The pathophysiology of the disease is complex and involves infected erythrocyte sequestration, cerebral inflammation, and breakdown of the blood-brain barrier. A recently characterized malarial retinopathy is visual evidence of Plasmodium falciparum's pathophysiological processes occurring in the affected patient. Treatment consists of supportive care and antimalarial administration. Thus far, adjuvant therapies have not been shown to improve mortality rates or neurological outcomes in children with CM. For those who survive CM, residual neurological abnormalities are common. Epilepsy, cognitive impairment, behavioral disorders, and gross neurological deficits which include motor, sensory, and language impairments are frequent sequelae. Primary prevention strategies, including bed nets, vaccine development, and chemoprophylaxis, are in varied states of development and implementation. Continuing efforts to find successful primary prevention options and strategies to decrease neurological sequelae are needed.

Pediatric cerebral malaria: a scourge of Africa

Cerebral malaria, defined as an otherwise unexplained coma in a patient with Plasmodium falciparum parasitemia, affects up to 1 million people per year, the vast majority of them being children living in sub-Saharan Africa. Despite optimal treatment, this condition kills 15% of those affected and leaves 30% of survivors with neurologic sequelae. The clinical diagnosis is hampered by its poor specificity, but the presence or absence of a malarial retinopathy in cerebral malaria has proven to be important in the differentiation of underlying coma etiology. Both antimalarials and intense supportive care are necessary for optimal treatment. As of yet, clinical trials of adjunctive therapies have not improved the high rates of mortality and morbidity. Survivors are at high risk of neurologic sequelae including epilepsy, neurodisabilities and cognitive–behavioral problems. The neuroanatomic and functional bases of these sequelae are being elucidated. Although adjunctive therapy trials continue, the best hope for African children may lie in disease prevention. Strategies include bednets, chemoprophylaxis and vaccine development.

Seasonal differences in retinopathy-negative versus retinopathy-positive cerebral malaria

Children with traditionally defined cerebral malaria (CM) can be subcategorized by the presence or absence of malaria retinopathy. We retrospectively reviewed the seasonal pattern of retinopathy status in patients admitted with CM in Blantyre, Malawi from 1997 to 2010. The proportion of children with CM who were retinopathy-positive was significantly greater during the peak seasonal rains when the community incidence of uncomplicated malaria is higher. This finding supports the hypothesis that retinopathy-negative and retinopathy-positive CM categories have different underlying etiologies.

Neurologic outcomes in retinopathy-negative cerebral malaria survivors

OBJECTIVES

Patients surviving retinopathy-positive cerebral malaria (CM) are at high risk for the development of epilepsy, developmental disabilities, and behavioral abnormalities. We aimed to establish whether retinopathy-negative CM is also a risk factor for these outcomes.

METHODS

Between 2005 and 2007, survivors of CM and concurrently hospitalized controls in Blantyre, Malawi, were followed to assess the development of neurologic abnormalities. At discharge and every 3 months thereafter, incident cases of epilepsy and developmental disabilities were ascertained using screening questionnaires and confirmatory neurologic examinations. Incident cases of epilepsy and developmental disabilities were compared in retinopathy-negative CM survivors to controls and retinopathy-positive CM survivors.

RESULTS

Thirty-five retinopathy-negative CM survivors were enrolled. Their neurologic outcomes were compared to 132 retinopathy-positive CM survivors and 272 controls. Compared to survivors of retinopathy-positive CM, children without malaria retinopathy have an equal odds of adverse neurologic outcome (odds ratio [OR] = 1.0, 95% confidence interval [CI] 0.4-2.2). Eleven of 35 survivors of retinopathy-negative CM had at least 1 adverse neurologic outcome compared to 2 of 272 controls (OR 61.9, 95% CI 13.0-295.5). In retinopathy-negative CM survivors, a Blantyre Coma Scale score ≤ 1 on admission was associated with an adverse outcome.

CONCLUSIONS

Compared with controls, children surviving either retinopathy-negative or -positive CM are at similar high risk for adverse neurologic outcomes. Studies to evaluate preventive and therapeutic strategies in children with both retinopathy-negative and -positive CM are needed to improve mortality, morbidity, or both.

Severe pernicious anaemia in an 8-year-old African girl

An 8-year-old girl presented with severe muscular weakness, peripheral neuropathy, ataxia, fever and macrocytic anaemia. Clinically, vitamin B(12) (cobalamin) deficiency was considered. Despite the lack of pre-treatment laboratory confirmation of the diagnosis, a therapeutic trial of hydroxocobalamin injections was begun. After several days, a partial clinical response was seen. Within 5 months all symptoms had resolved. After treatment was initiated, laboratory analysis of pre-treatment blood samples confirmed the presence of vitamin B(12) deficiency. Auto-antibodies to intrinsic factor and parietal cells, pathognomonic for pernicious anaemia, were confirmed. Vitamin B(12) deficiency owing to dietary deficiency is not uncommon in children in developing countries. Although nutritional deficiency might have played a role in our patient, this case illustrates that the neurological manifestations of pernicious anaemia can present at a young age in African populations.

Melphalan-induced toxicity in nude mice following pretreatment with buthionine sulfoximine

Melphalan-induced toxicity in nude mice following pretreatment with a regimen of L-buthionine sulfoximine (BSO), previously shown to enhance the activity of this alkylating agent against rhabdomyosarcoma and glioma xenografts, was examined. Mice were pretreated with i.p. BSO (2.5 mmol/kg x 7 doses at 12-h intervals plus concomitant availability of a 20-mM solution in the drinking water) or vehicle prior to a single i.p. injection of melphalan (35.65 mg/m2). As compared with control animals who received no BSO pretreatment, mice pretreated with BSO lost weight prior to therapy with melphalan (6.9% weight loss vs 0.3% weight gain; P less than 0.005) and showed a greater mean nadir weight loss after melphalan (3.8% vs. 2.1%; P = 0.049). Treatment with melphalan was associated with histologic evidence of reversible gastrointestinal toxicity, reversible myelosuppression, and histologic evidence of acute renal tubular necrosis, with no differences being observed between mice that had been pretreated with BSO and those that had been pretreated with vehicle. No evidence of cardiac, hepatic, or skeletal muscle toxicity was found in melphalan-treated animals. These results suggest that treatment of nude mice with melphalan following BSO-mediated depletion of glutathione does not result in enhanced organ toxicity despite an increase in the antineoplastic activity of this alkylating agent.