The impact of changes in gadolinium-enhancement on disease progression in children with neurofibromatosis type 1-associated optic pathway glioma: a retrospective analysis.

PURPOSE: There has been limited investigation of imaging features associated with visual acuity (VA) decline and initiation of treatment for patients with neurofibromatosis type 1 (NF1) and optic pathway glioma (OPG). METHODS: To evaluate the association of increased gadolinium enhancement with decline in VA, initiation of chemotherapy, and tumor growth, we performed a retrospective cohort study of children diagnosed with NF1-OPG between January 2006 to June 2016. Two cohorts were defined: a new diagnosis and a longitudinal cohort. Outcomes were examined at 1 and 2 years from initial diagnosis, and 1 and 2 years from initial increase in enhancement in the longitudinal cohort. RESULTS: Eighty patients were eligible; all 80 contributed to the new diagnosis cohort and 73 to the longitudinal cohort. Fifty-six patients (70%) demonstrated enhancing NF1-OPG at diagnosis. 39% of patients in the new diagnosis cohort and 45% of those in the longitudinal cohort developed increased enhancement during the study period. There was no significant association between increases in enhancement and VA decline in the newly diagnosed or longitudinal cohorts, as well as with initiation of treatment in the longitudinal cohort. Although there was an association of enhancement increase with treatment in the new diagnosis cohort, this association was not maintained when stratified by concurrent change in tumor size. CONCLUSION: Increased gadolinium-enhancement independent of a concurrent increase in tumor size on MRI should not be used as a marker of NF1-OPG progression and does not appear to be associated with visual decline or initiation of chemotherapy.

Amyotrophic lateral sclerosis phenotypes significantly differ in terms of magnetic susceptibility properties of the precentral cortex.

OBJECTIVES: The aim of our study was to investigate whether the magnetic susceptibility varies according to the amyotrophic lateral sclerosis (ALS) phenotypes based on the predominance of upper motor neuron (UMN)/lower motor neuron (LMN) impairment. METHODS: We retrospectively collected imaging and clinical data of 47 ALS patients (12 with UMN predominance (UMN-ALS), 16 with LMN predominance (LMN-ALS), and 19 with no clinically defined predominance (Np-ALS)). We further enrolled 23 healthy controls (HC) and 15 ALS mimics (ALS-Mim). These participants underwent brain 3-T magnetic resonance imaging (3-T MRI) with T1-weighted and gradient-echo multi-echo sequences. Automatic segmentation and quantitative susceptibility mapping (QSM) were performed. The skewness of the susceptibility values in the precentral cortex (SuscSKEW) was automatically computed, compared among the groups, and correlated to the clinical variables. RESULTS: The Kruskal-Wallis test showed significant differences in terms of SuscSKEW among groups (χ2(3) = 24.2, p < 0.001), and pairwise tests showed that SuscSKEW was higher in UMN-ALS compared to those in LMN-ALS (p < 0.001), HC (p < 0.001), Np-ALS (p = 0.012), and ALS-Mim (p < 0.001). SuscSKEW was highly correlated with the Penn UMN score (Spearman's rho 0.612, p < 0.001). CONCLUSION: This study demonstrates that the clinical ALS phenotypes based on UMN/LMN sign predominance significantly differ in terms of magnetic susceptibility properties of the precentral cortex. Combined MRI-histopathology investigations are strongly encouraged to confirm whether this evidence is due to iron overload in UMN-ALS, unlike in LMN-ALS. KEY POINTS: • Magnetic susceptibility in the precentral cortex reflects the prevalence of UMN/LMN impairment in the clinical ALS phenotypes. • The degree of UMN/LMN impairment might be well described by the automatically derived measure of SuscSKEW in the precentral cortex. • Increased SuscSKEW in the precentral cortex is more relevant in UMN-ALS patients compared to those in Np-ALS and LMN-ALS patients.

Regional impairment of cortical and deep gray matter perfusion in preterm neonates with low-grade germinal matrix-intraventricular hemorrhage: an ASL study.

PURPOSE: The long-term impact of low-grade germinal matrix-intraventricular hemorrhage (GMH-IVH) on brain perfusion has not been fully investigated. We aimed to compare cortical and deep gray matter (GM) cerebral blood flow (CBF) obtained with pseudo-continuous arterial spin labeling (pCASL), among preterm neonates with and without low-grade GMH-IVH and full-term controls. METHODS: 3T-pCASL examinations of 9 healthy full-term neonates (mean gestational age 38.5 weeks, range 38-39) and 28 preterm neonates studied at term-equivalent age were analyzed. Eighteen preterm neonates presented normal brain MRI (mean gestational age 30.50 weeks, range 29-31) and 10 low-grade GMH-IVH according to Volpe's grading system (mean gestational age 32 weeks, range 28-34). A ROI-based mean CBF quantification was performed in 5 cortical (frontal, parietal, temporal, insula, occipital), and 4 subcortical GM regions (caudate, putamen, pallidum, thalamus) for each cerebral hemisphere. CBF differences were explored using a nonparametric analysis of covariance. RESULTS: Low-grade GMH-IVH hemispheres showed consistently lower CBF in all GM regions when compared with healthy preterm neonates, after controlling the confounding effect of gestational age, postmenstrual age, and birth weight P < .001, η2 = .394. No significant differences were observed between neonates with low-grade GMH and full-term controls. Healthy preterm neonates showed significantly higher CBF than full-term controls in parietal (P = .032), temporal (P = .016), and occipital cortex (P = .024), and at level of thalamus (P = .023) and caudate nucleus (P = .014). CONCLUSION: Low-grade GMH-IVH is associated with lower CBF in posterior cortical and subcortical gray matter regions in preterm neonates, suggesting regional vulnerability of these developing brain structures.

Enterovirus and parechovirus meningoencephalitis in infants: A ten-year prospective observational study in a neonatal intensive care unit.

BACKGROUND: Non-polio enteroviruses (EV) and human parechoviruses (HPeV) are known etiological agents of meningoencephalitis in neonates. However, reports of neuroradiological findings and neurodevelopmental outcomes in this population are scarce. OBJECTIVES: to describe clinical characteristics, neuroradiological findings and, in a subset of patients, neurodevelopmental outcomes in a cohort of infants with EV or HPeV meningoencephalitis within 60 days of life. STUDY DESIGN: clinical/laboratory data, neuroradiological findings (cranial ultrasound, cUS, brain magnetic resonance imaging, MRI), and neurodevelopmental outcomes assessed by Ages and Stages Questionnaires - third edition were prospectively collected. RESULTS: overall, 32 infants with EV (21, 67.8 %) or HPeV (11, 28.2 %) meningoencephalitis were enrolled. Infants with HPeV (73 %: type 3 HPeV) presented more frequently with seizures (18.2 % vs. 0, p value=0.03), lymphopenia (1120 vs. 2170 cells/mm3, p = 0.02), focal anomalies at electroencephalography (EEG) (63.6 vs. 23.8 %, p = 0.03), and pathological findings at MRI (72.7 % vs. 15.8 %, p value=0.004) compared to those affected by EV. cUS was not significantly altered in any of the enrolled infants. All infants with EV meningoencephalitis evaluated at 12-24 months and at 30-48 months were normal. Two out of the 7 infants with HPeV meningoencephalitis showed some concerns in gross motor (1/7, 14.3 %) or in problem solving (1/7, 14.3 %) function at 30-48 months of age. CONCLUSIONS: In our cohort, neonates infected by HPeV had more severe clinical manifestations, more alterations at brain MRI, and some signs of long-term neurodevelopmental delay. Our data highlight the heterogeneity of manifestations in infants with EV or HPeV meningoencephalitis, and the need for long-term follow-up of those infected by HPeV in the neonatal period.

Ischaemic Stroke of the "Hand-Knob" Area Due to Paradoxical Cerebral Air Embolism after Central Venous Catheterization-A Doubly Rare Occurrence: A Case Report and an Overview of Pathophysiology, Diagnosis, and Treatment.

Central venous catheters (CVCs) are increasingly used across specialties for invasive haemodynamic monitoring and for the delivery of fluids, medications, and nutritional support. Cerebral air embolism (CAE) is a rare but potentially fatal complication associated with the insertion, maintenance, and removal of CVCs. It can occur through different mechanisms, including the direct retrograde ascension of air into the cerebral veins and paradoxical embolism due to a right-to-left intracardiac or intrapulmonary shunt. The "hand-knob" area is the cortical region within the primary motor cortex that contains the representation of the hand. It is located in the superior precentral gyrus and is the site of less than 1% of all ischaemic strokes. We report here the case of a patient who experienced an ischaemic stroke of the right "hand-knob" area, due to paradoxical CAE through a previously undiagnosed patent foramen ovale (PFO), after the insertion of a catheter in the right internal jugular vein. We also provide an overview of the pathophysiology, diagnosis, and treatment of CAE. Suspecting CAE in the case of an acute neurological event occurring in close temporal relationship with central venous catheterization is paramount to allow the early recognition and treatment of this uncommon form of iatrogenic stroke.