Similar cortical morphometry trajectories from 5 to 9 years in children with perinatal HIV who started treatment before age 2 years and uninfected controls.

BACKGROUND: Life-long early ART (started before age 2 years), often with periods of treatment interruption, is now the standard of care in pediatric HIV infection. Although cross-sectional studies have investigated HIV-related differences in cortical morphology in the setting of early ART and ART interruption, the long-term impact on cortical developmental trajectories is unclear. This study compares the longitudinal trajectories of cortical thickness and folding (gyrification) from age 5 to 9 years in a subset of children perinatally infected with HIV (CPHIV) from the Children with HIV Early antiRetroviral therapy (CHER) trial to age-matched children without HIV infection. METHODS: 75 CHER participants in follow-up care at FAMCRU (Family Centre for Research with Ubuntu), as well as 66 age-matched controls, received magnetic resonance imaging (MRI) on a 3 T Siemens Allegra at ages 5, 7 and/or 9 years. MR images were processed, and cortical surfaces reconstructed using the FreeSurfer longitudinal processing stream. Vertex-wise linear mixed effects (LME) analyses were performed across the whole brain to compare the means and linear rates of change of cortical thickness and gyrification from 5 to 9 years between CPHIV and controls, as well as to examine effects of ART interruption. RESULTS: Children without HIV demonstrated generalized cortical thinning from 5 to 9 years, with the rate of thinning varying by region, as well as regional age-related gyrification increases. Overall, the means and developmental trajectories of cortical thickness and gyrification were similar in CPHIV. However, at an uncorrected p < 0.005, 6 regions were identified where the cortex of CPHIV was thicker than in uninfected children, namely bilateral insula, left supramarginal, lateral orbitofrontal and superior temporal, and right medial superior frontal regions. Planned ART interruption did not affect development of cortical morphometry. CONCLUSIONS: Although our results suggest that normal development of cortical morphometry between the ages of 5 and 9 years is preserved in CPHIV who started ART early, these findings require further confirmation with longitudinal follow-up through the vulnerable adolescent period.

South African Children: A Matched Cohort Study of Neurodevelopmental Impairment in Survivors of Invasive Group B Streptococcus Disease Aged 5 to 8 Years.

BACKGROUND: Invasive group B Streptococcus (iGBS) sepsis and meningitis are important causes of child mortality, but studies on neurodevelopmental impairment (NDI) after iGBS are limited. Using Griffiths Mental Development Scales-Extended Revised (GMDS-ER), we described NDI in iGBS survivors and non-iGBS children from South Africa, as part of a 5-country study. METHODS: We identified children aged 5-8 years with a history of iGBS and children with no history of iGBS between October 2019 and January 2021. Children were matched on sex, and birth data (month, year) (matched cohort study). Moderate or Severe NDI was the primary outcome as a composite of GMDS-ER motor, GMDS-ER cognition, hearing, and vision. Secondary outcomes included mild NDI, any emotional-behavioral problems, and GMDS-ER developmental quotients (DQ) calculated by dividing the age equivalent GMDS-ER score by the chronological age. RESULTS: In total, 160 children (iGBS survivors, 43; non-iGBS, 117) were assessed. Among iGBS survivors 13 (30.2%) had meningitis, and 30 (69.8%) had sepsis. Six (13.9%) iGBS survivors, and 5 (4.3%) non-iGBS children had moderate or severe NDI. Children who survived iGBS were 5.56 (95% confidence interval [CI]: 1.07-28.93; P = .041) times more likely to have moderate or severe NDI at 5-8 years than non-iGBS children. Compared to the non-iGBS children, iGBS meningitis survivors had a significantly lower global median DQ (P < .05), as well as a lower median DQ for the language GMDS-ER subscale and performance GMDS-ER subscale (P < .05). CONCLUSIONS: Children surviving iGBS, particularly meningitis, are more likely to have NDI at 5-8 years compared to non-iGBS children. Further research is required to improve detection and care for at-risk newborns.

Multimodal magnetic resonance neuroimaging measures characteristic of early cART-treated pediatric HIV: A feature selection approach.

Children with perinatally acquired HIV (CPHIV) have poor cognitive outcomes despite early combination antiretroviral therapy (cART). While CPHIV-related brain alterations can be investigated separately using proton magnetic resonance spectroscopy (1 H-MRS), structural magnetic resonance imaging (sMRI), diffusion tensor imaging (DTI), and functional MRI (fMRI), a set of multimodal MRI measures characteristic of children on cART has not been previously identified. We used the embedded feature selection of a logistic elastic-net (EN) regularization to select neuroimaging measures that distinguish CPHIV from controls and measured their classification performance via the area under the receiver operating characteristic curve (AUC) using repeated cross validation. We also wished to establish whether combining MRI modalities improved the models. In single modality analysis, sMRI volumes performed best followed by DTI, whereas individual EN models on spectroscopic, gyrification, and cortical thickness measures showed no class discrimination capability. Adding DTI and 1 H-MRS in basal measures to sMRI volumes produced the highest classification performance validation accuracy = 85 % AUC = 0.80 . The best multimodal MRI set consisted of 22 DTI and sMRI volume features, which included reduced volumes of the bilateral globus pallidus and amygdala, as well as increased mean diffusivity (MD) and radial diffusivity (RD) in the right corticospinal tract in cART-treated CPHIV. Consistent with previous studies of CPHIV, select subcortical volumes obtained from sMRI provide reasonable discrimination between CPHIV and controls. This may give insight into neuroimaging measures that are relevant in understanding the effects of HIV on the brain, thereby providing a starting point for evaluating their link with cognitive performance in CPHIV.

Multivariate approach for longitudinal analysis of brain metabolite levels from ages 5-11 years in children with perinatal HIV infection.

Treatment guidelines recommend that children with perinatal HIV infection (PHIV) initiate antiretroviral therapy (ART) early in life and remain on it lifelong. As part of a longitudinal study examining the long-term consequences of PHIV and early ART on the developing brain, 89 PHIV children and a control group of 85 HIV uninfected children (HIV-) received neuroimaging at ages 5, 7, 9 and 11 years, including single voxel magnetic resonance spectroscopy (MRS) in three brain regions, namely the basal ganglia (BG), midfrontal gray matter (MFGM) and peritrigonal white matter (PWM). We analysed age-related changes in absolute metabolite concentrations using a multivariate approach traditionally applied to ecological data, the Correlated Response Model (CRM) and compared these to results obtained from a multilevel mixed effect modelling (MMEM) approach. Both approaches produce similar outcomes in relation to HIV status and age effects on longitudinal trajectories. Both methods found similar age-related increases in both PHIV and HIV- children in almost all metabolites across regions. We found significantly elevated GPC+PCh across regions (95% CI=[0.033; 0.105] in BG; 95% CI=[0.021; 0.099] in PWM; 95% CI=[0.059; 0.137] in MFGM) and elevated mI in MFGM (95% CI=[0.131; 0.407]) among children living with PHIV compared to HIV- children; additionally the CRM model also indicated elevated mI in BG (95% CI=[0.008; 0.248]). These findings suggest persistent inflammation across the brain in young children living with HIV despite early ART initiation.

African Multi-Site 2-Year Neuropsychological Study of School-Age Children Perinatally Infected, Exposed, and Unexposed to Human Immunodeficiency Virus.

BACKGROUND: Children living with human immunodeficiency virus (HIV) are at neuropsychological risk for cognitive and motor dysfunction. However, few prospective, multi-site studies have evaluated neuropsychological outcomes longitudinally among perinatally infected African children who received early antiretroviral treatment (ART). METHODS: We enrolled 611 children aged 5 to 11 years at 6 sites (South Africa [3], Zimbabwe, Malawi, Uganda). Of these, there were 246 children living with HIV (HIV+) who were initiated on ART before 3 years of age in a prior clinical trial comparing nevirapine to lopinavir/ritonavir (International Maternal Pediatric Adolescent Acquired Immunodeficiency Syndrome Clinical Trials [IMPAACT] P1060); 183 age-matched, exposed but uninfected (HEU) children; and 182 unexposed and uninfected (HUU) children. They were compared across 3 assessment time points (Weeks 0, 48, and 96) on cognitive ability (Kaufman Assessment Battery for Children, second edition [KABC-II]), attention/impulsivity (Tests of Variables of Attention [TOVA]), motor proficiency (Bruininks-Oseretsky Test, second edition [BOT-2]), and on the Behavior Rating Inventory of Executive Function (BRIEF). The cohorts were compared using linear mixed models, adjusting for site, child's age and sex, and selected personal/family control variables. RESULTS: The HIV+ cohort performed significantly worse than the HEU and HUU cohorts for all KABC-II, TOVA, and BOT-2 performance outcomes across all 3 time points (P values < .001). The HUU and HEU cohorts were comparable. For the KABC-II planning/reasoning subtests, the HIV+ children showed less improvement over time than the HUU and HEU groups. The groups did not differ significantly on the BRIEF. CONCLUSIONS: Despite initiation of ART in early childhood and good viral suppression at the time of enrollment, the HIV+ group had poorer neuropsychological performance over time, with the gap progressively worsening in planning/reasoning. This can be debilitating for self-management in adolescence.

Association between caregiver depression symptoms and child executive functioning. Results from an observational study carried out in four sub-Saharan countries.

Depressive symptoms among HIV-positive (HIV+) women may negatively impact their health and possibly that of their young children through risk of compromised caregiving. We evaluated how depression symptoms in predominantly (97%) female caregivers relate to neurodevelopmental outcomes in their HIV affected children. Data come from the IMPAACT P1104s Study, an observational cohort across six sites in four countries: Zimbabwe, South Africa, Uganda and Malawi. Participants (n = 611) were 5-11-year-old children with HIV (HIV), HIV exposed uninfected (HEU), or HIV unexposed uninfected (HUU). Primary caregivers were assessed for depression with the Hopkins Symptom Checklist (HSCL) and children with Behavior Rating Inventory for Executive Function (BRIEF) parent-report, Kauffman Assessment Battery for Children II (KABC), Bruininks-Oseretsky Test of Motor Proficiency 2nd Ed. (BOT-2), Test of Variables of Attention (TOVA), Multiple Indicators Cluster Survey, Child Disability and Development scales (MICS-4). Caregivers with higher depression scores (>1.75 mean HSCL score) reported more executive function problems in their children, regardless of HIV status. All executive function scores were significantly (p < 0.001) associated with depressive symptomatology at baseline and across time. Caregiver depressive symptomatology was not associated with other assessed neurocognitive outcomes. These results highlight the potential impact of caregiver depression on child behavioral outcomes.

Recovery of HIV encephalopathy in perinatally infected children on antiretroviral therapy.

AIM: To describe the trajectory of clinical signs in children who developed human immunodeficiency virus encephalopathy (HIVE) after starting early antiretroviral therapy (ART). METHOD: This was a retrospective case-cohort description of HIVE among Cape Town participants from the Children with HIV Early AntiRetroviral treatment (CHER) trial. Criteria for HIVE diagnosis were at least two of: (1) acquired central motor deficit, (2) impaired brain growth, and (3) failure to attain or loss of developmental milestones in the absence of an alternative aetiology. RESULTS: Of 133 surviving participants who initiated ART at a median age of 9 weeks and who were followed until a median age of 6 years, 20 (12%) developed HIVE at a median age 31 months (interquartile range 19-37). In these, the first neurological deterioration was noticed at a median age of 19 months, when 16 were on ART and nine had undetectable HIV viral load for a median of 12 months. Signs of upper motor neurons were present in 18, of whom 12 resolved and four had persistent spastic diplegia; 19 had motor delay, of whom 14 resolved; 12 had language delay, of whom 11 resolved; and 16 had impaired brain growth, of whom only five recovered. For the 16 participants already on ART at HIVE diagnosis, regimens were not altered in response to diagnosis. INTERPRETATION: HIVE may occur despite early ART initiation and virological suppression and then resolve on unchanged ART, most likely as intrathecal inflammation subsides. WHAT THIS PAPER ADDS: Despite suppressive antiretroviral therapy, children can develop human immunodeficiency virus encephalopathy, The most common manifestations are motor deficits and impaired brain growth. Most experience improvement, with many resolving without additional intervention.

Diffusion tensor imaging point to ongoing functional impairment in HIV-infected children at age 5, undetectable using standard neurodevelopmental assessments.

BACKGROUND: Perinatal HIV infection negatively impacts cognitive functioning of children, main domains affected are working memory, processing speed and executive function. Early ART, even when interrupted, improves neurodevelopmental outcomes. Diffusion tension imaging (DTI) is a sensitive tool assessing white matter damage. We hypothesised that white matter measures in regions showing HIV-related alterations will be associated with lower neurodevelopmental scores in specific domains related to the functionality of the affected tracts. METHODS: DTI was performed on children in a neurodevelopmental sub study from the Children with HIV Early Antiretroviral (CHER) trial. Voxel-based group comparisons to determine regions where fractional anisotropy and mean diffusion differed between HIV+ and uninfected children were done. Locations of clusters showing group differences were identified using the Harvard-Oxford cortical and subcortical and John Hopkins University WM tractography atlases provided in FSL. This is a second review of DTI data in this cohort, which was reported in a previous study. Neurodevelopmental assessments including GMDS and Beery-Buktenica tests were performed and correlated with DTI parameters in abnormal white matter. RESULTS: 38 HIV+ children (14 male, mean age 64.7 months) and 11 controls (4 male, mean age 67.7 months) were imaged. Two clusters with lower fractional anisotropy and 7 clusters with increased mean diffusion were identified in the HIV+ group. The only neurodevelopmental domain with a trend of difference between the HIV+ children and controls (p = 0.08), was Personal Social Quotient which correlated to improved myelination of the forceps minor in the control group. As a combined group there was a negative correlation between visual perception and radial diffusion in the right superior longitudinal fasciculus and left inferior longitudinal fasciculus, which may be related to the fact that these tracts, forming part of the visual perception pathway, are at a crucial state of development at age 5. CONCLUSION: Even directed neurodevelopmental tests will underestimate the degree of microstructural white matter damage detected by DTI. The visual perception deficit detected in the entire study population should be further examined in a larger study.

Neurodevelopmental outcome of HIV-exposed but uninfected infants in the Mother and Infants Health Study, Cape Town, South Africa.

OBJECTIVES: To compare neurodevelopmental outcomes of HIV-exposed uninfected (HEU) and HIV-unexposed uninfected (HUU) infants in a peri-urban South African population. HEU infants living in Africa face unique biological and environmental risks, but uncertainty remains regarding their neurodevelopmental outcome. This is partly due to lack of well-matched HUU comparison groups needed to adjust for confounding factors. METHODS: This was a prospective cohort study of infants enrolled at birth from a low-risk midwife obstetric facility. At 12 months of age, HEU and HUU infant growth and neurodevelopmental outcomes were compared. Growth was evaluated as WHO weight-for-age, length-for-age, weight-for-length and head-circumference-for-age Z-scores. Neurodevelopmental outcomes were evaluated using the Bayley scales of Infant Development III (BSID) and Alarm Distress Baby Scale (ADBB). RESULTS: Fifty-eight HEU and 38 HUU infants were evaluated at 11-14 months of age. Performance on the BSID did not differ in any of the domains between HEU and HUU infants. The cognitive, language and motor scores were within the average range (US standardised norms). Seven (12%) HEU and 1 (2.6%) HUU infant showed social withdrawal on the ADBB (P = 0.10), while 15 (26%) HEU and 4 (11%) HUU infants showed decreased vocalisation (P = 0.06). There were no growth differences. Three HEU and one HUU infant had minor neurological signs, while eight HEU and two HUU infants had macrocephaly. CONCLUSIONS: Although findings on the early neurodevelopmental outcome of HEU infants are reassuring, minor differences in vocalisation and on neurological examination indicate a need for reassessment at a later age.

Favourable outcome in a child with symptomatic diagnosis of Glutaric aciduria type 1 despite vertical HIV infection and minor head trauma.

The first case of Glutaric aciduria Type 1(GA1) in an African child was reported in 2001. GA1 has a prevalence of 1:5000 in black South Africans. Although early diagnosis is essential for a favourable outcome, newborn screening is not routine in South Africa where an estimated 320,000 children have HIV infection. Neurodevelopmental delay and encephalopathy are complications of both HIV and GA1. In such a setting it is important to recognise that HIV and GA1 can occur simultaneously. We present an HIV-infected South African male child of Xhosa descent with macrocephaly who commenced combination antiretroviral therapy (ART) at 8 weeks of age in a clinical trial which included a neurodevelopmental sub-study. He developed short-lived focal seizures at 16 months after minor head trauma. Neurological examination was normal. Neuroimaging showed temporal lobe atrophy, subtle hyperintense signal change in the globus pallidus, and focal haemosiderosis in the right Sylvian fissure region. As findings were not in keeping with HIV encephalopathy, a urine metabolic screen was undertaken which suggested GA1. Genetic testing confirmed Arg293Trp mutation. He began L-carnitine and a low protein diet as a restricted diet was not practicable. At 21 months he developed pulmonary tuberculosis, requiring 6 months treatment. He did not develop any neurologic motor symptoms. Serial neurodevelopmental and neuropsychological test scores until 9 years were similar to healthy neighbourhood controls, except for mild language delay at 3½ years. Detection of GA1, probably facilitated through participation in a clinical trial, was pivotal for a favourable outcome. The concomitant use of ART and anti-tuberculous therapy in a child with GA1 appears safe.

Altered brain morphometry in 7-year old HIV-infected children on early ART.

Even with the increased roll out of combination antiretroviral therapy (cART), paediatric HIV infection is associated with neurodevelopmental delays and neurocognitive deficits that may be accompanied by alterations in brain structure. Few neuroimaging studies have been done in children initiating ART before 2 years of age, and even fewer in children within the critical stage of brain development between 5 and 11 years. We hypothesized that early ART would limit HIV-related brain morphometric deficits at age 7. Study participants were 7-year old HIV-infected (HIV+) children from the Children with HIV Early Antiretroviral Therapy (CHER) trial whose viral loads were supressed at a young age, and age-matched uninfected controls. We used structural magnetic resonance imaging (MRI) and FreeSurfer ( http://www.freesurfer.net/ ) software to investigate effects of HIV and age at ART initiation on cortical thickness, gyrification and regional brain volumes. HIV+ children showed reduced gyrification compared to controls in bilateral medial parietal regions, as well as reduced volumes of the right putamen, left hippocampus, and global white and gray matter and thicker cortex in small lateral occipital region. Earlier ART initiation was associated with lower gyrification and thicker cortex in medial frontal regions. Although early ART appears to preserve cortical thickness and volumes of certain brain structures, HIV infection is nevertheless associated with reduced gyrification in the parietal cortex, and lower putamen and hippocampus volumes. Our results indicate that in early childhood gyrification is more sensitive than cortical thickness to timing of ART initiation. Future work will clarify the implications of these morphometric effects for neuropsychological function.

HIV encephalopathy with bilateral lower limb spasticity: gross motor function and antiretroviral therapy.

AIM: To describe gross motor function in children with bilateral lower limb (BLL) spasticity due to human immunodeficiency virus encephalopathy (HIVE), and to investigate the association between age, CD4 percentage, and viral load at initiation of antiretroviral therapy (ART) and current gross motor function. METHOD: Thirty ambulant children with HIVE and BLL spasticity were recruited. Clinical parameters, including ART, were obtained from medical records. Gross motor function was assessed using the 88-item Gross Motor Function Measure (GMFM-88). RESULTS: The participant group was comprised of 14 males and 16 females (median age 8y; interquartile range [IQR] 7-11y). ART was initiated at a median age of 7 months (IQR 5-11mo) with a median CD4 percentage of 4.7% (IQR 2.3-8.0) and viral load of log10 6.0 (IQR 5.6-6.4). The median total GMFM-88 score was 89% (IQR 78-94%), with a wide range of scores in the 'Standing' domain (26-97%) and 'Walking, Running, and Jumping' domain (8-99%). No associations were detected between age at initiation of ART, CD4 percentage, or viral load and total GMFM-88 score. INTERPRETATION: Limitations in gross motor function in children with HIVE and BLL spasticity range from mild to severe. ART initiation factors were not able to predict functional status in this sample.

HIV encephalopathy with bilateral lower limb spasticity: upper limb motor function and level of activity and participation.

AIM: To describe upper limb motor function and level of activity and participation in children with HIV encephalopathy (HIVE) and bilateral lower limb (BLL) spasticity. METHOD: Thirty ambulant children with HIVE and BLL spasticity and 20 typically developing children, between 5 years and 12 years, were recruited. Upper limb motor function was assessed using the Purdue Pegboard and level of activity and participation using the Computer-Adapted Pediatric Evaluation of Disabilities Inventory (PEDI-CAT). RESULTS: The HIVE group comprised 14 males and 16 females (mean age [SD] 8y 8mo [2y 2mo], Gross Motor Function Classification System (GMFCS) level I [n=10], II [n=11], and III [n=9]) and the typically developing group comprised 11 males and 9 females (mean age 8y 8mo [2y 3mo]). The HIVE group had lower scores than the typically developing group for all pegboard tasks and three of the four PEDI-CAT domains (p≤0.001). However, individual outcome scores varied substantially within each GMFCS level. INTERPRETATION: Children with HIVE and BLL spasticity may have significantly poorer upper limb motor performance and lower levels of activity and participation than typically developing children. These findings suggest that an assessment of upper limb motor function should form part of optimal care for this population.

Assessing the performance of different DTI motion correction strategies in the presence of EPI distortion correction.

Diffusion tensor imaging (DTI) is susceptible to several artifacts due to eddy currents, echo planar imaging (EPI) distortion and subject motion. While several techniques correct for individual distortion effects, no optimal combination of DTI acquisition and processing has been determined. Here, the effects of several motion correction techniques are investigated while also correcting for EPI distortion: prospective correction, using navigation; retrospective correction, using two different popular packages (FSL and TORTOISE); and the combination of both methods. Data from a pediatric group that exhibited incidental motion in varying degrees are analyzed. Comparisons are carried while implementing eddy current and EPI distortion correction. DTI parameter distributions, white matter (WM) maps and probabilistic tractography are examined. The importance of prospective correction during data acquisition is demonstrated. In contrast to some previous studies, results also show that the inclusion of retrospective processing also improved ellipsoid fits and both the sensitivity and specificity of group tractographic results, even for navigated data. Matches with anatomical WM maps are highest throughout the brain for data that have been both navigated and processed using TORTOISE. The inclusion of both prospective and retrospective motion correction with EPI distortion correction is important for DTI analysis, particularly when studying subject populations that are prone to motion. Hum Brain Mapp 37:4405-4424, 2016. © 2016 Wiley Periodicals, Inc.

Early Antiretroviral Therapy in South African Children Reduces HIV-1-Infected Cells and Cell-Associated HIV-1 RNA in Blood Mononuclear Cells.

We measured cell-associated human immunodeficiency virus (HIV)-1 DNA (CAD) and RNA (CAR) and plasma HIV-1 RNA in blood samples from 20 children in the Children with HIV Early Antiretroviral (CHER) cohort after 7-8 years of suppressive combination antiretroviral therapy (cART). Children who initiated cART early (<2 months; n = 12) had lower HIV-1 CAD (median, 48 vs 216; P < .01) and CAR (median, 5 vs 436; P < .01) per million peripheral blood mononuclear cells than children who started later (≥ 2 months; n = 8). Plasma HIV-1 RNA levels were not significantly lower in early-treated children (0.5 vs 1.2 copies/mL; P = .16). Early treatment at <2 months of age reduces the number of HIV-infected cells and HIV CAR.

Motion artifact reduction in pediatric diffusion tensor imaging using fast prospective correction.

PURPOSE: To evaluate the patterns of head motion in scans of young children and to examine the influence of corrective techniques, both qualitatively and quantitatively. We investigate changes that both retrospective (with and without diffusion table reorientation) and prospective (implemented with a short navigator sequence) motion correction induce in the resulting diffusion tensor measures. MATERIALS AND METHODS: Eighteen pediatric subjects (aged 5-6 years) were scanned using 1) a twice-refocused, 2D diffusion pulse sequence, 2) a prospectively motion-corrected, navigated diffusion sequence with reacquisition of a maximum of five corrupted diffusion volumes, and 3) a T1 -weighted structural image. Mean fractional anisotropy (FA) values in white and gray matter regions, as well as tractography in the brainstem and projection fibers, were evaluated to assess differences arising from retrospective (via FLIRT in FSL) and prospective motion correction. In addition to human scans, a stationary phantom was also used for further evaluation. RESULTS: In several white and gray matter regions retrospective correction led to significantly (P < 0.05) reduced FA means and altered distributions compared to the navigated sequence. Spurious tractographic changes in the retrospectively corrected data were also observed in subject data, as well as in phantom and simulated data. CONCLUSION: Due to the heterogeneity of brain structures and the comparatively low resolution (∼2 mm) of diffusion data using 2D single shot sequencing, retrospective motion correction is susceptible to distortion from partial voluming. These changes often negatively bias diffusion tensor imaging parameters. Prospective motion correction was shown to produce smaller changes.

Hearing assessment data in HIV-infected and uninfected children of Cape Town, South Africa.

Researchers are showing that the rate of hearing loss in children with perinatal HIV infection (PHIV) is higher than in HIV-unexposed, uninfected children. These data, however, have been collected mostly in the USA; extensive hearing data from low- and middle-income countries are lacking. The purpose of this study was to collect audiometric data in PHIV and HIV-uninfected children living in Cape Town, South Africa. Questionnaire data along with distortion product otoacoustic emissions (DPOAEs) and pure-tone testing were completed. Hearing loss was determined using the pure-tone thresholds defined as a pure-tone average (PTA) of 500, 1000, 2000, and 4000 Hz of >15 dB HL in the poorer ear. All data were compared between PHIV and HIV-uninfected children. Sixty-one (37 PHIV and 24 HIV-uninfected) children had hearing data. HIV status was not significantly associated with DPOAEs. The rate of conductive hearing loss was 11.5%; five PHIV and two HIV-uninfected children. The rate of any hearing loss was higher in PHIV children, but this difference was not statistically significant. PHIV children had a significantly higher mean PTA in the poorer ear than HIV-uninfected children. Conductive type of hearing loss was more common than sensorineural hearing loss. The underlying cause of hearing loss in the present study therefore remains unclear. Future research should include an examination of auditory neural function in an effort to determine the possible reason for differences in hearing.

Corpus callosum thickness on mid-sagittal MRI as a marker of brain volume: a pilot study in children with HIV-related brain disease and controls.

BACKGROUND: Corpus callosum thickness measurement on mid-sagittal MRI may be a surrogate marker of brain volume. This is important for evaluation of diseases causing brain volume gain or loss, such as HIV-related brain disease and HIV encephalopathy. OBJECTIVE: To determine if thickness of the corpus callosum on mid-sagittal MRI is a surrogate marker of brain volume in children with HIV-related brain disease and in controls without HIV. MATERIALS AND METHODS: A retrospective MRI analysis in children (<5 years old) with HIV-related brain disease and controls used a custom-developed semi-automated tool, which divided the midline corpus callosum and measured its thickness in multiple locations. Brain volume was determined using volumetric analysis. Overall corpus callosum thickness and thickness of segments of the corpus callosum were correlated with overall and segmented (grey and white matter) brain volume. RESULTS: Forty-four children (33 HIV-infected patients and 11 controls) were included. Significant correlations included overall corpus callosum (mean) and total brain volume (P = 0.05); prefrontal corpus callosum maximum with white matter volume (P = 0.02); premotor corpus callosum mean with total brain volume (P = 0.04) and white matter volume (P = 0.02), premotor corpus callosum maximum with white matter volume (P = 0.02) and sensory corpus callosum mean with total brain volume (P = 0.02). CONCLUSION: Corpus callosum thickness correlates with brain volume both in HIV-infected patients and controls.

Quality of 186 child brain spectra using motion and B0 shim navigated single voxel spectroscopy.

PURPOSE: To evaluate B0 shim and motion navigated single voxel spectroscopy in children. Assess the repeatability of metabolite concentrations in three regions: medial frontal grey matter, peritrigonal white matter, and basal ganglia. Determine the extent of intra- and interacquisition movement in this population. METHODS: Linewidth and signal to noise ratio were calculated to assess spectral quality of 186 spectra at 3 Tesla. Repeatability was assessed on 31 repeat scans. Navigator images were used to assess localization errors, while navigator motion and shim logs were used to demonstrate the efficacy of correction needed during the scans. RESULTS: Average linewidths ± standard deviations of N-acetyl aspartate are 3.8 ± 0.6 Hz, 4.4 ± 0.5 Hz, and 4.7 ± 0.8 Hz in each region, respectively. Scan-to-scan measurement variance in metabolite concentrations closely resembled the expected variance. A total of 73% and 32% of children moved before and during the acquisition, causing a voxel shift of more than 10% of the voxel volume, 1.5 mm. The predominant movement directions were sliding out of the coil and nodding (up-down rotation). First-order B0 corrections were significant (>10 µT/m) in 18 % of acquisitions. CONCLUSION: Prospective motion and B0 correction provides high quality repeatable spectra. The study found that most children moved between acquisitions and a substantial number moved during acquisitions.