Intrauterine Zika virus infection: review of the current findings with emphasis in the prenatal and postnatal brain imaging diagnostic methods.

Zika virus (ZIKV) is a widespread flavivirus transmitted to humans through the bite of Aedes mosquitoes. The number of ZIKV cases increased significantly between 2015 and 2016, and Brazil was the first to report autochthonous transmission of infection. The main neurological disorder related to ZIKV infection is microcephaly. Fetal magnetic resonance imaging (MRI) is the gold standard examination for the analysis of fetal brain infection, followed by obstetric ultrasonography. Cerebral atrophy, intracranial calcifications, ventriculomegaly, cerebellar, and brain gyrus abnormalities are some of the most common findings. Postnatal MRI shows high sensitivity and specificity. Corpus callosum abnormalities, cerebellar hypoplasia, and choroid plexus dilation can be also observed. We present a review of congenital ZIKV infection with emphasis on pre and postnatal brain findings using ultrasonography, MRI, computed tomography, and three-dimensional reconstruction models.

The Neurobiology of Zika Virus: New Models, New Challenges.

The Zika virus (ZIKV) attracted attention due to one striking characteristic: the ability to cross the placental barrier and infect the fetus, possibly causing severe neurodevelopmental disruptions included in the Congenital Zika Syndrome (CZS). Few years after the epidemic, the CZS incidence has begun to decline. However, how ZIKV causes a diversity of outcomes is far from being understood. This is probably driven by a chain of complex events that relies on the interaction between ZIKV and environmental and physiological variables. In this review, we address open questions that might lead to an ill-defined diagnosis of CZS. This inaccuracy underestimates a large spectrum of apparent normocephalic cases that remain underdiagnosed, comprising several subtle brain abnormalities frequently masked by a normal head circumference. Therefore, new models using neuroimaging and artificial intelligence are needed to improve our understanding of the neurobiology of ZIKV and its true impact in neurodevelopment.

A Possible Association Between Zika Virus Infection and CDK5RAP2 Mutation.

INTRODUCTION: Flaviviridae family belongs to the Spondweni serocomplex, which is mainly transmitted by vectors from the Aedes genus. Zika virus (ZIKV) is part of this genus. It was initially reported in Brazil in December 2014 as an unknown acute generalized exanthematous disease and was subsequently identified as ZIKV infection. ZIKV became widespread all over Brazil and was linked with potential cases of microcephaly. CASE REPORT: We report a case of a 28-year-old Colombian woman, who came to the Obstetric Department with an assumed conglomerate of fetal abnormalities detected via ultrasonography, which was performed at 29.5 weeks of gestation. The patient presented with multiple abnormalities, which range from a suggested Arnold-Chiari malformation, compromising the lateral and third ventricles, liver calcifications, bilateral pyelocalic dilatations, other brain anomalies, and microcephaly. At 12 weeks of gestation, the vertical transmission of ZIKV was suspected. At 38.6 weeks of gestation, the newborn was delivered, with the weight in the 10th percentile (3,180 g), height in the 10th percentile (48 cm), and cephalic circumference under the 2nd percentile (31 cm). Due to the physical findings, brain magnetic resonance imaging (MRI) was performed, revealing a small and deviated brain stem, narrowing of the posterior fossa, a giant posterior fossa cyst with ventricular dilatation, a severe cortical and white matter thinning, cerebellar vermis with hypoplasia, and superior and lateral displacement of the cerebellum. In addition, hydrocephalus was displayed by the axial sequence, and the cerebral cortex was also compromised with lissencephaly. Schizencephaly was found with left frontal open-lip, and no intracranial calcifications were found. Two novel heterozygous nonsense mutations were identified using whole-exome sequencing, and both are located in exon 8 under the affection of ZIKV congenital syndrome (CZS) that produced a premature stop codon resulting in the truncation of the cyclin-dependent kinase 5 regulatory subunit-associated protein 2 (CDK5RAP2) protein. CONCLUSION: We used molecular and microbiological assessments to report the initial case of vertically transmitted ZIKV infection with congenital syndrome associated with a neurological syndrome, where a mutation in the CDK5RAP2 gene was also identified. The CDK5RAP2 gene encodes a pericentriolar protein that intervenes in microtubule nucleation and centriole attachment. Diallelic mutation has previously been associated with primary microcephaly.

Gray Matter Volume in Elderly adults With ADHD: Associations of Symptoms and Comorbidities With Brain Structures.

Objective: To investigate total and selected region-of-interest-based gray matter volume (GMV) in older adults with ADHD. Method: Twenty-five elderly (≥65 years old) patients with ADHD and 34 healthy controls underwent 1.5-T magnetic resonance imaging (MRI). We used voxel-based morphometry to compare GMV between groups and performed a correlation analysis with ADHD symptoms and comorbidities. Results: Findings revealed a smaller total GMV in males with ADHD and a smaller GMV in the right medial frontal orbital area extending toward the medial frontal superior, the frontal superior, and the subgenual anterior cingulate cortex (ACC) besides correlations between inattentiveness and ACC (bilaterally) and left cerebellum, hyperactivity/impulsivity and the left frontal inferior orbital, depression and caudate (bilaterally), and the right inferior parietal lobule. Conclusion: Neural correlates in regions related to attention, executive control, and affective processing suggest that impairments in frontostriatal and frontoparietal-cerebellar areas observed in adults with ADHD persist into old age.

First report case with negative genetic study (array CGH, exome sequencing) in patients with vertical transmission of Zika virus infection and associated brain abnormalities.

INTRODUCTION: Zika virus (ZIKV) is a little-known emerging mosquito-borne flavivirus. The perinatal ZIKV infection was associated with birth defects during the Brazilian outbreak. There was an increased risk of intrauterine transmission of the virus and a marked increase in the number of newborns with microcephaly. We report on two such cases. CASE REPORT: The first case was a 25-year-old pregnant woman from Colombia who became acutely ill with general symptoms during the tenth week of gestation, followed by severe generalized itching and maculopapular rash for approximately five days. This case was reported during the epidemic stage of the ZIKV infection in Colombia. At 23.3 gestational weeks, ultrasonography showed abnormal intracranial anatomy with cerebral ventriculomegaly, microcephaly, and parenchymal calcification. Given the grave prognosis, the patient elected to terminate the pregnancy at 25 gestational weeks. The second case was a 24-year-old pregnant woman who became acutely ill during the 17th week of gestation, which corresponded with the ZIKV epidemic in Colombia. At 30.5 gestational weeks, ultrasonography showed isolated fetal cerebral ventriculomegaly. We detected ZIKV in the amniotic fluid; however, the virus was not detected in the urine or serum of the mother or fetus. Tests for dengue virus, chikungunya virus, Toxoplasma gondii, rubella virus, cytomegalovirus, herpes simplex virus, HIV, hepatitis B and C, and parvovirus B19 were all negative. Different samples obtained from the placenta, amniotic liquid, and cerebrospinal fluid were positive for viral isolation of ZIKV RNA using TaqMan RT-PCR. Additionally, the parents and fetuses were tested for genetic diseases using whole exome sequencing and array CGH to rule out possible genetic syndromes that produce these congenital abnormalities. CONCLUSION: These were the first cases in Colombia to show early vertical transmission of ZIKV and the first cases associated with congenital cerebral abnormalities in which molecular, infectious, and genomic tests were performed.

Congenital brain abnormalities during a Zika virus epidemic in Salvador, Brazil, April 2015 to July 2016.

BackgroundNorth-eastern Brazil was the region most affected by the outbreak of congenital Zika syndrome that followed the 2015 Zika virus (ZIKV) epidemics, with thousands of suspected microcephaly cases reported to the health authorities, mostly between late 2015 and early 2016. Aim: To describe clinical and epidemiological aspects of the outbreak of congenital brain abnormalities (CBAs) and to evaluate the accuracy of different head circumference screening criteria in predicting CBAs.MethodBetween April 2015 and July 2016, the Centers for Information and Epidemiologic Surveillance of Salvador, Brazil investigated the reported cases suspected of microcephaly and, based on intracranial imaging studies, confirmed or excluded a diagnosis of CBA. Sensitivity, specificity and positive and negative predictive values of different head circumference screening criteria in predicting CBAs were calculated.ResultsOf the 365 investigated cases, 166 (45.5%) had confirmed CBAs. The most common findings were intracranial calcifications and ventriculomegaly in 143 (86.1%) and 111 (66.9%) of the 166 CBA cases, respectively. Prevalence of CBAs peaked in December 2015 (2.24 cases/100 live births). Cases of CBAs were significantly more likely to have been born preterm and to mothers who had clinical manifestations of arboviral infection during pregnancy. None of the head circumference screening criteria performed optimally in predicting CBAs.ConclusionThis study highlights the magnitude of neurological consequences of the ZIKV epidemic and the limitations of head circumference in accurately identifying children with CBA. Gestational symptoms compatible with ZIKV infection should be combined with imaging studies for efficient detection of suspect CBAs during ZIKV epidemics.

Amplitude-Integrated Electroencephalography for Early Recognition of Brain Injury in Neonates with Critical Congenital Heart Disease.

OBJECTIVE: To study perioperative amplitude-integrated electroencephalography (aEEG) as an early marker for new brain injury in neonates requiring cardiac surgery for critical congenital heart disease (CHD). STUDY DESIGN: This retrospective observational cohort study investigated 76 neonates with critical CHD who underwent neonatal surgery. Perioperative aEEG recordings were evaluated for background pattern (BGP), sleep-wake cycling (SWC), and ictal discharges. Spontaneous activity transient (SAT) rate, inter-SAT interval (ISI), and percentage of time with an amplitude <5 µV were calculated. Routinely obtained preoperative and postoperative magnetic resonance imaging of the brain were reviewed for brain injury (moderate-severe white matter injury, stroke, intraparenchymal hemorrhage, or cerebral sinovenous thrombosis). RESULTS: Preoperatively, none of the neonates showed an abnormal BGP (burst suppression or worse) or ictal discharges. Postoperatively, abnormal BGP was seen in 18 neonates (24%; 95% CI, 14%-33%) and ictal discharges was seen in 13 neonates (17%; 95% CI, 8%-26%). Abnormal BGP and ictal discharges were more frequent in neonates with new postoperative brain injury (P = .08 and .01, respectively). Abnormal brain activity (ie, abnormal BGP or ictal discharges) was the single risk factor associated with new postoperative brain injury in multivariable logistic regression analysis (OR, 4.0; 95% CI, 1.3-12.3; P = .02). Postoperative SAT rate, ISI, or time <5 µV were not associated with new brain injury. CONCLUSION: Abnormal brain activity is an early, bedside marker of new brain injury in neonates undergoing cardiac surgery. Not only ictal discharges, but also abnormal BGP, should be considered a clear sign of underlying brain pathology.

Neuroimaging findings associated with congenital Zika virus syndrome: case series at the time of first epidemic outbreak in Pernambuco State, Brazil.

PURPOSE: This study aimed to describe the prenatal and postnatal neuroimaging and clinical findings in a clinical series following congenital Zika virus syndrome during the first epidemic Zika virus (ZIKV) outbreak in the State of Pernambuco, Brazil. METHODS: We (the authors) conducted a retrospective study of a prospectively collected case series of fetuses and neonates with microcephaly born to mothers with presumed/confirmed congenital ZIKV syndrome. Prenatal ultrasound findings were reviewed to identify potential central nervous system (CNS) abnormalities. Neonates underwent postnatal neuroimaging follow up by computed tomography (CT)-scan or magnetic resonance (MR) imaging. RESULTS: The prenatal and postnatal outcomes of eight fetuses/neonates born to mothers with presumed/confirmed congenital ZIKV syndrome were examined. The mean gestational age at ultrasound was 31.3 weeks. Severe microcephaly was identified in seven fetuses (87.5%), while ventriculomegaly and brain calcifications were detected in all fetuses. The mean gestational age at delivery and head circumference were 38 weeks and 30.2 cm, respectively. All cases of microcephaly but one was confirmed postnatally. Brain CT scans or MRIs were performed in seven newborns, and all had periventricular and/or parenchymal calcifications, symmetrical or asymmetrical ventriculomegaly, pachygyria, and reduced sulcation and gyration. MR imaging aided the detection of one undetected case of corpus callosum dysgenesis and was essential in documenting reduced mantel of the cerebral cortex and reduced gyration and sulcation, especially involving the parietal lobe. In addition, MR imaging was also able to display irregular interfaces with the subcortical white matter, a finding consistent with polymicrogyria, more frequently seen at the level of the frontal lobe and atrophic and thinned pons. CONCLUSION: Severe microcephaly and CNS abnormalities may be associated with congenital ZIKV syndrome.

Ultrasonographic observations of the fetal brain in the first 100 pregnant women with Zika virus infection in Trinidad and Tobago.

OBJECTIVE: To evaluate the fetal brain in pregnant women infected with Zika virus in a limited-resource setting. METHODS: In an observational study in Trinidad and Tobago, 100 pregnant women infected with Zika virus who were referred for fetal medicine services provided by a single clinician were enrolled from March 31 to September 2, 2016. Two-dimensional ultrasonography was undertaken. RESULTS: The women were aged 17-41 years (mean 27.5 ± 5.7). Six cases of fetal brain abnormalities consistent with Zika infection were detected before 26 gestational weeks. The gestational period at infection and time of presentation ranged, respectively, from 7+3 to 16+0  weeks and from 23+2 to 25+5  weeks. In all cases, centiles of the biparietal diameter and head circumference decreased progressively over time to below the third centile. The skull contour appeared irregular, owing to collapse or overlap of the fetal skull bones. In four cases, brain anomalies were not obvious on the transabdominal scan but were diagnosed on the transvaginal scan. In a further two cases, brain abnormalities presented after 26 weeks of gestation. CONCLUSION: Overall, 8.0% of women infected with Zika virus had fetuses with brain abnormalities suggestive of Zika congenital syndrome. Six cases were detected before 26 weeks and two cases after 26 weeks.

Brain MRI and magnetic resonance spectroscopy findings in patients with hyperargininemia.

BACKGROUND AND PURPOSE: Hyperargininemia (HA) is a rare autosomal recessive metabolic disorder and the neuroimaging features of this disease have seldom been reported. Hyperammonemic encephalopathy is uncommon in HA, and the clinical presentation of HA is distinct from other urea cycle disorders. This paper describes the brain MRI findings and a magnetic resonance spectroscopy (MRS) study of a series of Brazilian HA patients. METHODS: Brain MR images were obtained in eight male and two female patients with the classic HA phenotype. Six patients were evaluated twice. Single-voxel (1)H-MRS was also performed in six of the patients. RESULTS: Only 1 patient, with less severe neurological symptoms, had normal MRI images. A variable degree of cerebral atrophy was noted in the other patients, and 3 patients also presented mild symptoms of cerebellar atrophy. MRS indicated no metabolic abnormalities in any patient. CONCLUSIONS: We present the MRI and MRS findings of a large series of HA patients. Variable degrees of brain atrophy and mild cerebellar atrophy were observed, and these findings were not specific. No metabolic abnormality was observed using MRS in this series of patients.

Displasia septo-optica. Evaluación clínica, endocrinológica y neuro-radiológica. Seguimiento de 46 pacientes pediátricos / Septo-optic dysplasia. Clinical, endocrinological, and neuroradiological evaluation. Follow-up of 46 pediatric patients

La displasia septo-óptica (DSO) es una condición rara y altamente heterogénea, definida por la combinación de hipoplasia del nervio óptico (HNO), malformaciones cerebrales de la línea media, tales como aplasia/hipoplasia de septum pellucidum y cuerpo calloso, e insuficiencia hipotálamo-hipofisaria de grado variable. Se realizó un trabajo que tuvo como objetivo caracterizar la población de pacientes con diagnóstico de DSO seguidos en nuestro Hospital durante 7 años. Se incluyeron 46 pacientes (18 mujeres) que fueron divididos en 2 grupos, según tuviesen o no insuficiencia hipotálamo-hipofisaria (IHH). El 58.7% (n=27) presentó IHH de algún tipo, mientras que el 41.3% (n=19) no la presentó. En aquellos 19 pacientes con IHH se diagnosticaron deficiencia de GH y TSH (85.1%) y de ACTH (48.1%). La longitud corporal (mediana) del grupo con IHH fue más baja (p = 0,01) que la del grupo sin IHH, a pesar de que la edad fue menor a 2 años en todos los casos. Los pacientes fueron seguidos 1,3-8,3 años. Se observaron incidencias similares de agenesia del cuerpo calloso, del septum pellucidum, y ventriculomegalia, pero las alteraciones del desarrollo cortical se observaron con mayor frecuencia en los pacientes sin IHH. La ictericia neonatal, convulsiones y/o hipoglucemia, y micropene en neonatos y lactantes con DSO se presentaron en el subgrupo con IHH. El 58,7% de los pacientes con DSO presentaron algún grado de insuficiencia hipotálamo-hipofisaria. En la mayoría de los casos el diagnóstico de IHH no se realizó en el momento de aparición de los síntomas, sino más tardíamente en su seguimiento. En el 45% de los pacientes se evaluaron alteraciones radiológicas del SNC, específicamente en la región hipofisaria. Una fracción importante de las deficiencias de TSH/T4 (36,4%), GH (50%) y ACTH (23%) aparecieron mas tardíamente en el curso de la evolución. En 10 niños con déficit de hormona de crecimiento (2 tests farmacológicos sin respuesta) se realizó el tratamiento sustitutivo con rhGH (durante un periodo de 4±3 años), observándose una mejoría promedio de + 1,5 SDS en la talla de estos pacientes. En conclusión, la hipoplasia neonatal de nervios ópticos, asociada o no a ictericia e hipoglucemia, debe ser un signo de alarma para el diagnóstico de DSO, con riesgo de insuficiencia suprarrenal, shock y muerte, y puede requerir, por lo tanto, urgente tratamiento. Las deficiencias pueden aparecer en el curso de la evolución, a pesar del carácter congénito de la anomalía. Finalmente, se deben sustituir las deficiencias hormonales y tener presente que el tratamiento con rhGH puede mejorar la talla final en estos pacientes (AU)

Septo-optic dysplasia (SOD) is a rare and highly heterogeneous condition consisting of a combination of optic nerve hypoplasia (ONH), midline brain abnormalities, such as aplasia/hypoplasia of the septum pellucidum (ASP) and corpus callosum; and variable degree of hypoyalamo-pituitary insufficiency. The aim of this study was to characterize a population of SOD patients diagnosed and followed at the Garrahan Pediatric Hospital, from 1989 to 2006. We included 46 patients (18 females), that were divided into two groups according to the presence or absence of hypothalamic-pituitary insufficiency (IHH). Fifty nine% of SOD patients presented with IHH. GH and TSH deficiencies were diagnosed in 85.1% of IHH patients, while ACTH deficiency was found in 48.1%. Height (median) for the IHH group was shorter (p = 0,01) than for the group without IHH. Patients were followed for 1.3-8.3 years. Similar incidence of corpus callosum and/or septum pellucidum agenesis and ventriculomegaly were found in the two groups, but we observed more association with cortical developmental disorders in patients without IHH. In newborns, the association of ophthalmologic disorders and jaundice, seizures and/or hypoglycemia and micropene should frequently lead to the diagnosis of SOD and IHH. While 58,7% of DSO patients presented with hypothalamic-pituitary deficiency, only 45% of them showed sellar radiological abnormalities. Although SOD is a congenital disease, hormonal deficiencies may appear during follow-up. In 10 children with SOD and GH deficiency, rhGh treatment (for 4±3 years) improved height in 1.5 SDSs. In conclusion: in newborns with nerve optic hypoplasia, associated or not with jaundice, seizures and hypoglycaemia, the diagnosis of SOD and IHH should be considered. Treatment could be an emergency need because of risk of adrenal insufficiency and hypoglycemia (AU)

Neuromyelitis optica: brain abnormalities in a Brazilian cohort

Neuromyelitis optica (NMO) is a demyelinating disease consisting of relapsing-remitting optic neuritis and myelitis with a more severe course than Multiple Sclerosis. Recently, it has been shown that almost 50 percent of patients with NMO can have brain magnetic resonance imaging (MRI) abnormalities. We report on six Brazilian patients with NMO, fulfilling the 1999 Wingerchuck criteria for this disease, with abnormal brain MRI and discuss their clinical and radiological features.

Neuromielite óptica (NMO) é doença desmielinizante, remitente-recorrente, com acometimento predominante dos nervos ópticos e medula espinal e uma evolução mais grave comparada à esclerose múltipla. Estudos recentes demonstraram que até 50 por cento dos pacientes com NMO podem apresentar lesões encefálicas à ressonância magnética (RM). Relatamos seis pacientes brasileiros com NMO, que satisfazem os critérios diagnósticos de Wingerchuck (1999) para NMO, com alterações encefálicas em RM de encéfalo e discutimos seus dados clínicos e de imagem.