Deep medullary vein engorgement and superficial medullary vein engorgement: two patterns of perinatal venous stroke

Imaging of Hemorrhagic Stroke in Children

Hemorrhagic stroke (HS) is an important cause of neurologic morbidity and mortality in children and is more common than ischemic stroke between the ages of 1 and 14 years, a notable contradistinction relative to adult stroke epidemiology. Rapid neuroimaging is of the utmost importance in making the diagnosis of HS, identifying a likely etiology, and directing acute care. Computed tomography and MR imaging with flow-sensitive MR imaging and other noninvasive vascular imaging studies play a primary role in the initial diagnostic evaluation. Catheter-directed digital subtraction angiography is critical for definitive diagnosis and treatment planning.

Widespread haemorrhages in infants post-shunting (WHIPS): clinical features, risk factors and neuroimaging characteristics of a rare and under-recognised phenomenon

PURPOSE

Infants undergoing CSF shunting procedures face a rare complication which we propose to rename "Widespread Haemorrhages in Infants Post-Shunting" (WHIPS) to better capture this unique phenomenon specific to infants undergoing CSF diversion. Our objective is to analyse the risk factors for WHIPS development and provide a detailed neuroradiological description of these haemorrhages.

MATERIALS AND METHODS

A radiology information system (RIS) was searched using the search terms "shunt" and/or "catheter" and/or "drain" and/or "ventriculoperitoneal" and/or "VP" between September 2008 to January 2021 for patients < 12 months of age. Clinical data was compiled for each patient meeting the inclusion criteria. Included cases were reviewed by three radiologists for the presence of WHIPS with calculation of the bifrontal ratio and documenting haemorrhage number, morphology, location and lobar distribution.

RESULTS

51 patients met inclusion criteria, 8 WHIPS patients and 43 controls. There was a statistically significant correlation between a larger post-op head circumference and WHIPS (p = 0.04). WHIPS was associated with post-haemorrhagic hydrocephalus and post-infectious hydrocephalus (p = 0.009). WHIPS were identified in the cortico-subcortical regions, periventricular white matter, and deep white matter. Haemorrhages were either punctate, ovoid or confluent. Haemorrhages ranged from single to innumerable.

CONCLUSIONS

WHIPS represent a rare and under-recognised complication of CSF shunting unique to the infantile population. We postulate deep and superficial medullary venous haemorrhage as an underlying mechanism related to disordered intracranial hydrodynamics which are exacerbated in the infantile population due to underdeveloped arachnoid granulations and a compliant skull.

Cerebral venous thrombosis and deep medullary vein thrombosis: Padua experience over the last two decades

BACKGROUND

Cerebral venous thrombosis (CVT) is a cerebrovascular disorder that accounts for 20% of perinatal strokes. CVT incidence ranges from 0.67 to 1.12 per 100,000 newborns, while the incidence of "deep medullary vein thrombosis" (DMVT), a subtype of CVT, cannot be accurately estimated. This study aims to analyze the case history of CVT in the neonatal period, with a specific focus on DMVT.

MATERIALS AND METHODS

Newborns diagnosed with CVT, with or without DMVT, between January 2002 and April 2023, were collected using the Italian Registry of Infantile Thrombosis (RITI). Cerebral MRIs were reviewed by an expert neuroradiologist following a standardized protocol.

RESULTS

Forty-two newborns with CVT were identified, of which 27/42 (64%) had CVT, and the remaining 15/42 (36%) had DMVT (isolated DMVT in 9/15). Symptom onset occurred in the first week of life (median 8 days, IQR 4-14) with a male prevalence of 59%. The most common risk factors for CVT were complicated delivery (38%), prematurity (40%), congenital heart diseases (48%), and infections (40%). Seizures were the predominant presenting symptom in 52% of all cases. Hemorrhagic infarction was higher in cases with isolated DMVT (77%) compared to patients with CVT without DMVT (p = 0.013). Antithrombotic treatment was initiated in 36% of patients. Neurological impairment was observed in 48% of cases at discharge, while 18 out of 31 infants (58%) presented one or more neurological deficits at long term follow up.     Conclusion: DMVT occurs in over a third of neonates with CVT. Multicentric studies are essential to establish standardized protocols for therapy, neuroimaging, and follow-up in these patients.

Incidence and clinical analysis of asymptomatic intracranial hemorrhage in neonates with cerebral hypoxic-ischaemic risk based on multisequence MR images

The incidence and clinical distribution of intracranial haemorrhage (ICH) in neonates at risk of cerebral hypoxia-ischaemia have not been reported in specific studies. Based on conventional magnetic resonance imaging (MRI) versus susceptibility weighted imaging (SWI), this study aimed to analyse the occurrence of asymptomatic ICH in newborns with or without risk of cerebral hypoxia-ischaemia and to accumulate objective data for clinical evaluations of high-risk neonates and corresponding response strategies. 317 newborns were included. MRI revealed that the overall incidence of ICH was 59.31%. The most common subtype was intracranial extracerebral haemorrhage (ICECH) which included subarachnoid haemorrhage (SAH) and subdural haemorrhage (SDH). ICECH accounted for 92.02% of ICH. The positive detection rate of ICECH by SWI was significantly higher than that by T1WI. The incidence of total ICH, ICECH and SAH was greater among children who were delivered vaginally than among those who underwent caesarean delivery. Asymptomatic neonatal ICH may be a common complication of the neonatal birth process, and SWI may improve the detection rate. Transvaginal delivery and a weight greater than 2500 g were associated with a high incidence of ICECH in neonates. The impact of neonatal cerebral hypoxia-ischaemia risk factors on the occurrence of asymptomatic ICH may be negligible.

Neuroimaging of Neonatal Stroke: Venous Focus

Perinatal venous infarcts are underrecognized clinically and at imaging. Neonates may be susceptible to venous infarcts because of hypercoagulable state, compressibility of the dural sinuses and superficial veins due to patent sutures, immature cerebral venous drainage pathways, and drastic physiologic changes of the brain circulation in the perinatal period. About 43% of cases of pediatric cerebral sinovenous thrombosis occur in the neonatal period. Venous infarcts can be recognized by ischemia or hemorrhage that does not respect an arterial territory. Knowledge of venous drainage pathways and territories can help radiologists recognize characteristic venous infarct patterns. Intraventricular hemorrhage in a term neonate with thalamocaudate hemorrhage should raise concern for internal cerebral vein thrombosis. A striato-hippocampal pattern of hemorrhage indicates basal vein of Rosenthal thrombosis. Choroid plexus hemorrhage may be due to obstruction of choroidal veins that drain the internal cerebral vein or basal vein of Rosenthal. Fan-shaped deep medullary venous congestion or thrombosis is due to impaired venous drainage into the subependymal veins, most commonly caused by germinal matrix hemorrhage in the premature infant and impeded flow in the deep venous system in the term infant. Subpial hemorrhage, an underrecognized hemorrhage stroke type, is often observed in the superficial temporal region, and its cause is probably multifactorial. The treatment of cerebral sinovenous thrombosis is anticoagulation, which should be considered even in the presence of intracranial hemorrhage. ©RSNA, 2024 Test Your Knowledge questions in the supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Perinatal hypoxic-ischemic brain injury: What's behind the "ribbon effect"?

Ribbon effect describes a perceived macroscopic color reversal of the gray and white matter, characterized by a pale cortex and diffusely dusky underlying white matter. This finding is thought to be unique to the perinatal period and indicative of hypoxic-ischemic injury. However, the clinical and microscopic correlates of this macroscopic finding have not been clearly defined. A 21-year retrospective study of autopsies was performed. Ribbon effect was seen in 190 subjects, ages 20 weeks gestation to 9.5 months adjusted age. Clinical associations and radiographic findings were similar in ribbon effect cases and controls. A variety of histologic findings were observed including acute neuronal injury, diffuse white matter gliosis, and white matter necrosis. Only white matter vascular congestion was significantly correlated to the macroscopic severity of ribbon effect; the severity of white matter injury and acute neuronal injury were not significantly correlated to ribbon effect. While hypoxic-ischemic changes were present in nearly all cases of ribbon effect, the location, severity, and chronicity of these changes varied considerably, and similar findings were observed in controls. The presence of ribbon effect therefore does not predict microscopic findings apart from vascular congestion, highlighting the importance of microscopic examination in perinatal brain autopsies.

Deep Medullary Vein Thrombosis in Newborns: A Systematic Literature Review

BACKGROUND

Deep medullary vein (DMV) thrombosis is a rare cause of brain damage in both preterm and full-term neonates. In this study, we aimed to collect data on clinical and radiological presentation, treatment, and outcome of neonatal DMV thrombosis.

METHODS

Systematic literature review on neonatal DMV thrombosis was carried out in PubMed, ClinicalTrial.gov, Scopus, and Web of Science up to December 2022.

RESULTS

Seventy-five published cases of DMV thrombosis were identified and analysed (preterm newborns were 46%). Neonatal distress, respiratory resuscitation, or need for inotropes were present in 34/75 (45%) of patients. Signs and symptoms at presentation included seizures (38/75, 48%), apnoea (27/75, 36%), lethargy or irritability (26/75, 35%). At magnetic resonance imaging (MRI), fan-shaped linear T2 hypointense lesions were documented in all cases. All had ischaemic injuries, most often involving the frontal (62/74, 84%) and parietal lobes (56/74, 76%). Signs of haemorrhagic infarction were present in 53/54 (98%). Antithrombotic treatment was not mentioned in any of the studies included. Although mortality was low (2/75, 2.6%), a large proportion of patients developed neurological sequelae (intellectual disability in 19/51 [37%] and epilepsy in 9/51 [18%] cases).

CONCLUSIONS

DMV thrombosis is rarely identified in the literature, even if it is possibly under-recognized or under-reported. Presentation in neonatal age is with seizures and non-specific systemic signs/symptoms that often cause diagnostic delay, despite the pathognomonic MRI picture. The high rate of morbidity, which determines significant social and health costs, requires further in-depth studies aimed at earlier diagnosis and evidence-based prevention and therapeutic strategies.

Deep cerebral venous abnormalities in premature babies with GMH-IVH: a single-centre retrospective study

PURPOSE

Germinal matrix haemorrhage/intraventricular haemorrhage (GMH-IVH) is a multifactorial injury with both anatomic and haemodynamic involvement. Normal variants in preterm deep cerebral venous anatomy associated with GMH-IVH have been previously described using MRI susceptibility weighted imaging (SWI). The aims of this study were to use SWI to compare the deep venous systems of a cohort of preterm neonates with various grades of GMH-IVH to a group of age-matched controls without GMH-IVH and to present novel retrospective SWI imaging findings.

METHODS

A neuroradiologist retrospectively evaluated 3T MRI SWI and phase imaging of 56 preterm neonates with GMH-IVH (14 of each grade) and 27 controls without GMH-IVH, scoring the venous irregularities according to three variables: decreased venous patency, increased lumen susceptibility and the presence of collaterals. Eight different venous locations, including indicated bilateral components, were evaluated: straight sinus, vein of galen, internal cerebral, direct lateral, thalamostriate, atrial and the anterior septal veins. Variables were analysed for statistical significance. Inter-rater reliability was determined via subset evaluation by a second paediatric radiologist.

RESULTS

Deep venous abnormalities were significantly more common in patients with GMH-IVH, with Wilcoxon Rank Sum Test demonstrating significant increase with GMH-IVH for total decreased venous patency (W=0, p<0.0001), increased lumen susceptibility and collateral formation. Venous abnormalities were also positively correlated with an increase in GMH-IVH grade from I to IV (patency, ρ=0.782, p<0.01) (increased lumen susceptibility, ρ=0.739, p<0.01) (collaterals, ρ=0.649, p<0.01), not just GMH-IVH alone.

CONCLUSION

Deep venous abnormalities are significantly correlated with GMH-IVH alone and an increase in GMH-IVH grade. Further study is needed to determine cause and effect.

Subpial hemorrhages in neonates: imaging features, clinical factors and outcomes

Neonatal subpial hemorrhage is a poorly understood type of intracranial hemorrhage. Herein, we reported on 34 neonates with subpial hemorrhages, focusing on the imaging features, clinical factors, and outcomes of this type of intracranial hemorrhage. This retrospective case series enrolled 34 neonates with subpial hemorrhages. We analyzed their magnetic resonance (MR) images, clinical manifestations, and prognoses. We categorized, for the first time, the MR images of patients with subpial hemorrhages into three imaging patterns; moreover, on the basis of a yin-yang sign, we added a sandwich sign, attaining an MR image feature that was easier to understand. MR Patterns A and B both have good prognoses, and most patients had normal clinical outcomes. Subpial hemorrhage in neonates may be diagnosed via imaging patterns. Recognizing this pattern of hemorrhage may help gain a better understanding of the associated risk factors.

Imaging the Cerebral Veins in Pediatric Patients: Beyond Dural Venous Sinus Thrombosis

The range of intracranial venous anomalies in children differs from that in adults. As a commonly encountered highly morbid disease, sinovenous thrombosis has been discussed extensively in the literature, and the associated imaging considerations are similar in pediatric and adult patients. The authors shift the focus to less frequently discussed cerebral venous diseases in pediatric patients. First, the practical embryology pertinent to malformations, syndromes, and variants such as vein of Galen aneurysmal malformation, Sturge-Weber syndrome, and developmental venous anomalies are discussed. Second, anatomic considerations that are applicable to neuroimaging in pediatric patients with cerebral venous anomalies are reviewed. In the discussion of anatomy, special attention is given to the medullary venous system that serves the cerebral white matter, superficial cortical veins (tributaries of the dural venous sinuses), and bridging veins, which carry blood from the superficial cortical veins through the potential subdural space into the dural venous sinuses. Third, the selection of imaging modalities (US, CT and CT venography, and MRI) is addressed, and various MR venographic pulse sequences (time-of-flight, phase-contrast, and contrast-enhanced sequences) are compared. Finally, a broad variety of congenital and acquired superficial and deep venous diseases in children are reviewed, with emphasis on less frequently discussed entities involving the medullary (eg, deep medullary venous engorgement and thrombosis, periventricular hemorrhagic venous infarction due to germinal matrix hemorrhage), cortical (eg, cortical venous thrombosis), and bridging (eg, acute and chronic manifestations of injury in abusive head trauma) veins, as well as the deep veins and dural venous sinuses (eg, varix). © RSNA, 2023 Quiz questions for this article are available through the Online Learning Center. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

A radiomics-based study of deep medullary veins in infants: Evaluation of neonatal brain injury with hypoxic-ischemic encephalopathy via susceptibility-weighted imaging

Objective

The deep medullary veins (DMVs) can be evaluated using susceptibility-weighted imaging (SWI). This study aimed to apply radiomic analysis of the DMVs to evaluate brain injury in neonatal patients with hypoxic-ischemic encephalopathy (HIE) using SWI.

Methods

This study included brain magnetic resonance imaging of 190 infants with HIE and 89 controls. All neonates were born at full-term (37+ weeks gestation). To include the DMVs in the regions of interest, manual drawings were performed. A Rad-score was constructed using least absolute shrinkage and selection operator (LASSO) regression to identify the optimal radiomic features. Nomograms were constructed by combining the Rad-score with a clinically independent factor. Receiver operating characteristic curve analysis was applied to evaluate the performance of the different models. Clinical utility was evaluated using a decision curve analysis.

Results

The combined nomogram model incorporating the Rad-score and clinical independent predictors, was better in predicting HIE (in the training cohort, the area under the curve was 0.97, and in the validation cohort, it was 0.95) and the neurologic outcomes after hypoxic-ischemic (in the training cohort, the area under the curve was 0.91, and in the validation cohort, it was 0.88).

Conclusion

Based on radiomic signatures and clinical indicators, we developed a combined nomogram model for evaluating neonatal brain injury associated with perinatal asphyxia.

Subpial Hemorrhage : A Distinctive Neonatal Stroke Pattern

BACKGROUND AND PURPOSE

Subpial hemorrhage is a rare form of neonatal stroke, still poorly understood. The aim of this study was to characterize a cohort of term and preterm neonates with subpial hemorrhages and contribute to a better knowledge of this condition.

MATERIAL AND METHODS

Clinical records and magnetic resonance (MR) imaging data of all neonates with subpial hemorrhage followed at a pediatric hospital between 2010 and 2020 were retrospectively reviewed.

RESULTS

A total of 10 patients were included in the analysis, 40% of whom were term neonates. Operative vaginal delivery was registered in 30%. Temporal was the most common location of subpial hemorrhage (70%), and all patients displayed underlying brain infarction. A characteristic yin-yang pattern was present in 90% of the study cohort, and ingurgitation of medullary veins on susceptibility weighted imaging in 80%. Cerebellar microbleeds were observed in 60% of neonates, both term and preterm. When available, MR angiography and venography were unremarkable. Patients' clinical outcome was variable, with early prematurity not associated to worse outcomes.

CONCLUSION

Subpial hemorrhage has a distinctive MR pattern, with underlying parenchymal venous infarction, and can occur in term and preterm neonates. This study results suggest an association between subpial hemorrhage and cerebellar microbleeds but further studies are required to confirm it and better understand the pathophysiology of subpial hemorrhage.

Anatomy of Intracranial Veins

The cerebral venous system is complex and sophisticated and serves various major functions toward maintaining brain homeostasis. Cerebral veins contain about 70% of cerebral blood volume, have thin walls, are valveless, and cross seamlessly white matter, ependymal, cisternal, arachnoid, and dural boundaries to eventually drain cerebral blood either into dural sinuses or deep cerebral veins. Although numerous variations in the cerebral venous anatomic arrangement may be encountered, the overall configuration is relatively predictable and landmarks relatively well defined. A reasonable understanding of cerebral vascular embryology is helpful to appreciate normal anatomy and variations that have clinical relevance. Increasing interest in transvascular therapy, particularly transvenous endovascular intervention provides justification for practitioners in the neurosciences to acquire at least a basic understanding of the cerebral venous system.

Cerebral Venous Sinus Thrombosis in Preterm Infants

BACKGROUND:

Neonatal cerebral venous sinus thrombosis (CVST) can lead to brain injury and neurodevelopmental impairments. Previous studies of neonatal CVST have focused on term infants, and studies of preterm infants are lacking. In this study, we examined the clinical and radiological features, treatment and outcome of CVST in preterm infants.

METHODS:

This was a retrospective, consecutive cohort study of preterm infants (gestational age <37 weeks) with radiologically confirmed CVST. All magnetic resonance imaging/MRV and CT/CTV scans were re-reviewed to study thrombus characteristics and pattern of brain injury. Outcome was assessed by the validated pediatric stroke outcome measure at the most recent clinic visit.

RESULTS:

Twenty-six preterm infants with CVST were studied. Of these, 65% were moderate-late preterm (32–37 weeks), 27% very preterm (28–32 weeks), and 8% extreme preterm (<28 weeks). Most (73%) were symptomatic at presentation with seizures or abnormal exam. Transverse (85%) and superior sagittal (42%) sinuses were common sites of thrombosis. Parenchymal brain injury was predominantly periventricular (35%) and deep white matter (31%) in location. Intraventricular hemorrhage occurred in 46%. Most infants (69%) were treated with anticoagulation. No treated infant (including eleven with pretreatment hemorrhage) had new or worsening post-treatment hemorrhage. Outcomes ranged from no deficits (50%), mild-moderate (25%), and severe (25%) impairment.

CONCLUSIONS:

In our sample of preterm infants with CVST, more than one-quarter were asymptomatic. White matter brain lesions predominated and one-half had neurological deficits at follow-up. Anticoagulation of preterm CVST in this small cohort appeared to be safe. Larger studies of preterm CVST are needed.

Medullary vein architecture modulates the white matter BOLD cerebrovascular reactivity signal response to CO2: Observations from high-resolution T2* weighted imaging at 7T

Brain stress testing using blood oxygenation level-dependent (BOLD) MRI to evaluate changes in cerebrovascular reactivity (CVR) is of growing interest for evaluating white matter integrity. However, even under healthy conditions, the white matter BOLD-CVR response differs notably from that observed in the gray matter. In addition to actual arterial vascular control, the venous draining topology may influence the WM-CVR response leading to signal delays and dispersions. These types of alterations in hemodynamic parameters are sometimes linked with pathology, but may also arise from differences in normal venous architecture. In this work, high-resolution T2*weighted anatomical images combined with BOLD imaging during a hypercapnic breathing protocol were acquired using a 7 tesla MRI system. Hemodynamic parameters including base CVR, hemodynamic lag, lag-corrected CVR, response onset and signal dispersion, and finally ΔCVR (corrected CVR minus base CVR) were calculated in 8 subjects. Parameter maps were spatially normalized and correlated against an MNI-registered white matter medullary vein atlas. Moderate correlations (Pearson's rho) were observed between medullary vessel frequency (MVF) and ΔCVR (0.52; 0.58 for total WM), MVF and hemodynamic lag (0.42; 0.54 for total WM), MVF and signal dispersion (0.44; 0.53 for total WM), and finally MVF and signal onset (0.43; 0.52 for total WM). Results indicate that, when assessed in the context of the WM venous architecture, changes in the response shape may only be partially reflective of the actual vascular reactivity response occurring further upstream by control vessels. This finding may have implications when attributing diseases mechanisms and/or progression to presumed impaired WM BOLD-CVR.

Research advances in neonatal cerebral sinovenous thrombosis

Neonatal cerebral sinovenous thrombosis (CSVT) is a cerebrovascular disease with a seriously underestimated incidence rate. Due to a lack of specific clinical manifestations and the low sensitivity of conventional imaging examinations, it has long been considered a rare disease in neonates. In recent years, the development of magnetic resonance technology has improved the diagnostic rate of CSVT. This article reviews the research advances in intracranial venous anatomy of neonates and clinical manifestations, imaging features, treatment, and prognosis of CSVT and deep venous thrombosis, in order to improve the understanding and to make correct diagnosis and treatment of neonatal CSVT.