Bridging veins and autopsy findings in abusive head trauma

Macroscopic and histological examination of human bridging veins

In infantile abusive head injury (AHT), subdural haemorrhage (SDH) is commonly held to result from traumatic damage to bridging veins traversing from the surface of the brain to the dura and dural venous sinuses. However, there are limited published radiological or autopsy demonstrations of ruptured bridging veins and several authors also assert that bridging veins are too large to rupture due to the forces associated with AHT. There have been several studies on the size, locations and numbers of adult bridging veins and there is one small study of infant bridging veins. However, there are no microscopic studies of infant bridging veins and only a select few ultrastructural investigations of adult bridging veins. Hitherto, it has been assumed that bridging veins from infants and younger children will display the same anatomical characteristics as those in adulthood. At 19 neonatal, infant and young child post-mortem examinations, we macroscopically examined and sampled bridging veins for microscopy. We compared the histology of those samples with bridging veins from an older child and two adults. We demonstrate that adult bridging veins are usually surrounded by supportive meningeal tissue that appears to be lacking or minimally present around the bridging veins of younger children. Neonatal, infant and young children's veins had a free 'bridging' section. Neonatal and infant bridging veins had smaller diameter ranges and thinner walls (some only 5-7 µm) than those seen in older children and adults. Bridging vein walls contained both fine strands of elastic fibers and a more pronounced elastic lamina. The presence of an elastic lamina occurred more frequently in the older age groups These anatomical differences between the veins of adults and young children may help to explain apparent increased vulnerability of neonatal/infant bridging veins to the forces associated with a shaking-type traumatic event.

Neovascularization in Outer Membrane of Chronic Subdural Hematoma : A Rationale for Middle Meningeal Artery Embolization

OBJECTIVE

Chronic subdural hematomas (cSDHs) are generally known to result from traumatic tears of bridging veins. However, the causes of repeat spontaneous cSDHs are still unclear. We investigated the changes in vasculature in the human dura mater and outer membrane (OM) of cSDHs to elucidate the cause of their spontaneous repetition.

METHODS

The dura mater was obtained from a normal control participant and a patient with repeat spontaneous cSDHs. The pathological samples from the patient included the dura mater and OM tightly adhered to the inner dura. The samples were analyzed with a particular focus on blood and lymphatic vessels by immunohistochemistry, 3-dimensional imaging using a transparent tissue clearing technique, and electron microscopy.

RESULTS

The dural border cell (DBC) layer of the dura mater and OM were histologically indistinguishable. There were 5.9 times more blood vessels per unit volume of tissue in the DBC layer and OM in the patient than in the normal control. The DBC layer and OM contained pathological sinusoidal capillaries not observed in the normal tissue; these capillaries were connected to the middle meningeal arteries via penetrating arteries. In addition, marked lymphangiogenesis in the periosteal and meningeal layers was observed in the patient with cSDHs.

CONCLUSION

Neovascularization in the OM seemed to originate from the DBC layer; this is a potential cause of repeat spontaneous cSDHs. Embolization of the meningeal arteries to interrupt the blood supply to pathological capillaries via penetrating arteries may be an effective treatment option.

Imaging of Abusive Head Trauma in Children

In this article, we describe relevant anatomy, mechanisms of injury, and imaging findings of abusive head trauma (AHT). We also briefly address certain mimics of AHT, controversies, pearls, and pitfalls. Concepts of injury, its evolution, and complex nature of certain cases are highlighted with the help of case vignettes.

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.

Abusive head injuries in infants: from founders to denialism and beyond

INTRODUCTION

Abusive head injuries is a major cause of severe morbidity and the main cause of mortality by head trauma in infants.

MATERIAL AND METHODS

Based on published data and their own clinical and medicolegal practice, the authors review briefly the historical roots and emergence of the concept of abusive head injuries (AHI), until the present scientific understanding of shaken baby syndrome (SBS) and Silverman syndrome. They then discuss the present epidemic of denialism and how this challenge to science should be seen as a stimulus to increase research and improve the accuracy of diagnosis and medical practice.

RESULTS

The denial of SBS is especially damaging because it undermines the possibilities of prevention and reparation for victims. The authors expand on AHI being part of a wider context of domestic violence and the prevention of child abuse being part of a broad and long-term endeavor to defend civilization values.

CONCLUSIONS

Prevention of AHI is a major challenge for the future. In the fields of science and prevention of child abuse, the input of pediatric neurosurgeons should not be underestimated.

Non-accidental head injury of infants: legal implications for the pediatric neurosurgeon

BACKGROUND

Though the neurosurgeon's role in non-accidental head injury (NAHT) is the prompt recognition and care of the inflicted injuries, he/she should be aware of the possible legal implications related to this particular neurosurgical condition.

MATERIAL AND METHODS

Based on published data and their own clinical and medico-legal practice, the authors review the role of the neurosurgeon in NHAT.

RESULTS

Besides the contribution that can be given by the neurosurgeon to a correct differential diagnosis, he/she is likely to be involved in the interpretations of the pathological findings in the case where the judge may request for a medical opinion concerning etiology, circumstances, severity, and consequences. As a member of a multidisciplinary team, usually the neurosurgeon is only requested for information regarding the lesions he was called to recognize and treat. Nevertheless, such information may have a pivotal part in the evaluation process. Consequently, the neurosurgeon should be able to reach a correct differential diagnosis of NAHT among all the events that may share similar clinical and anatomo-pathological characteristics and be aware of the ongoing scientific controversies related to the diagnosis and pathophysiology.

CONCLUSIONS

In practical terms, the pediatric neurosurgeon is called to individuate and record all the precise details of the condition to be eventually offered to the judge in case of controversy. Whereas the diagnosis of NAHT should be evoked at the initial phase in order not to leave the child unprotected, all possible alternative hypotheses should be ruled out "beyond reasonable doubt" for the court. The medical file should be maintained in the record carefully and be accessible even after a long time.

Is bridging vein rupture/thrombosis associated with subdural hematoma at birth?

BACKGROUND

The combination of bridging vein rupture/thrombosis and subdural hematoma in infants has recently gained attention as highly suggestive of abusive head trauma. While subdural hematomas are frequently observed at birth, there are no previous studies of bridging vein rupture/thrombosis prevalence in that context.

OBJECTIVE

To evaluate the prevalence of bridging vein rupture/thrombosis in newborns with and without subdural hematoma.

MATERIALS AND METHODS

This bicentric retrospective study (2012-2019) looked at all brain MRIs performed in neonates. We noted delivery method, demographic data and intracranial injuries and analyzed any clots at the vertex as potential markers of bridging vein rupture/thrombosis.

RESULTS

We analyzed 412 MRIs in 412 neonates. Age was (mean ± standard deviation [SD]) 5.4±2.2 days and 312 (76%) infants were full term (38.3±2.9 weeks from last menstrual period). The delivery method was vaginal birth for 42% (n=174), cesarean section for 43% (n=179), and unknown for 14% (n=59). Subdural hematoma was present in 281 MRIs (68.0%, [95% confidence interval = 63.3-72.5]). Six MRIs showed at least one clot at the vertex, assumed to be possible bridging vein rupture/thrombosis (1.5%, [0.5-3.1%]). Only one MRI showed more than two clots at the vertex, in a context of maternal infection. There was no significant difference in terms of gestational age at birth, delivery method or the presence of subdural hematoma or parenchymal injuries between those 6 infants and the 406 others.

CONCLUSION

Bridging vein rupture/thrombosis at birth is very rare and unlikely to be related to subdural hematoma.

Answer to Lynøe: Interesting data about confessions and abusive head trauma, but suboptimal analysis

The authors of the cited paper respond to the critics formulated by a Swedish leading expert regarding methodology shortcomings of our study "Confessed versus denied inflicted head injuries in infants: similarities and differences." They admit some methodological limitations but maintain their conclusions that the diagnosis was correct in the confession and denial groups and that the denial was more difficult in the more severe cases.

Chronic subdural hemorrhage predisposes to development of cerebral venous thrombosis and associated retinal hemorrhages and subdural rebleeds in infants

For infants presenting with subdural hemorrhage, retinal hemorrhage, and neurological decline the "consensus" opinion is that this constellation represents child abuse and that cerebral venous sinus thrombosis and cortical vein thrombosis is a false mimic. This article contends that this conclusion is false for a subset of infants with no evidence of spinal, external head, or body injury and is the result of a poor radiologic evidence base and misinterpreted data. Underdiagnosis of thrombosis is the result of rapid clot dissolution and radiologic under recognition. A pre-existing/chronic subdural hemorrhage predisposes to development of venous sinus thrombosis/cortical vein thrombosis, triggered by minor trauma or an acute life-threatening event such as dysphagic choking, variably leading to retinal and subdural hemorrhages and neurologic decline. These conclusions are based on analysis of the neuroradiologic imaging findings in 11 infants, all featuring undiagnosed cortical vein or venous sinus thrombosis. Subtle neuroradiologic signs of and the mechanisms of thrombosis are discussed. Subarachnoid hemorrhage from leaking thrombosed cortical veins may be confused with acute subdural hemorrhage and probably contributes to the development of retinal hemorrhage ala Terson's syndrome. Chronic subdural hemorrhage rebleeding from minor trauma likely occurs more readily than bleeding from traumatic bridging vein rupture. Radiologists must meet the challenge of stringent evaluation of neuro imaging studies; any infant with a pre-existing subdural hemorrhage presenting with neurologic decline must be assumed to have venous sinus or cortical vein thrombosis until proven otherwise.

History and current progress of chronic subdural hematoma

Chronic subdural hematoma (CSDH) is characterized by an encapsulated collection of old blood. Although CSDH has become the most frequent pathologic entity in daily neurosurgical practice, there are some unresolved research questions. In particular, the causes and recurrent risk factors of CSDH remain as an object of debate. The split of the dural border layer forms a few tiers of dural border cells over the arachnoid layer. Tissue plasminogen activator plays an important role as a key factor of defective coagulation. Historically, CSDH has often been treated via burr hole craniostomy using a closed drainage system. Several different operative strategies and peri-operative strategies such as the addition of burr holes, addition of cavity irrigation, position of drain, or postural position, have been described previously. Although the direction of the drainage tube, residual air, low intensity of T1-weighted images on MRI, and niveau formation have been reported as risk factors for recurrence, antiplatelet or anticoagulant drug use has not yet been verified as a risk factor. Recently, pharmaceutical strategies, including atorvastatin, significantly improved the neurological function in CSDH patients. Many case series, without randomization, have been reported; and given its promising result, several randomized clinical trials using pharmaceutical as well as operative and perioperative strategies were initiated to obtain sufficient data. In contrast, relatively fewer basic studies have achieved clinical applications in CSDH, although it is one of the most common clinical entities. Further scientific basic research may be essential for achieving a novel treatment strategy for CSDH.

Thrombosis is not a marker of bridging vein rupture in infants with alleged abusive head trauma

Aim

Thrombosis of bridging veins has been suggested to be a marker of bridging vein rupture, and thus AHT, in infants with subdural haematoma.

Methods

This is a non‐systematic review based on Pubmed search, secondary reference tracking and authors’ own article collections.

Results

Radiological studies asserting that imaging signs of cortical vein thrombosis were indicative of traumatic bridging vein rupture were unreliable as they lacked pathological verification of either thrombosis or rupture, and paid little regard to medical conditions other than trauma. Autopsy attempts at confirmation of ruptured bridging veins as the origin of SDH were fraught with difficulty. Moreover, microscopic anatomy demonstrated alternative non‐traumatic sources of a clot in or around bridging veins. Objective pathological observations did not support the hypothesis that a radiological finding of bridging vein thrombosis was the result of traumatic rupture by AHT. No biomechanical models have produced reliable and reproducible data to demonstrate that shaking alone can be a cause of bridging vein rupture.

Conclusion

There is no conclusive evidence supporting the hypothesis that diagnostic imaging showing thrombosed bridging veins in infants correlates with bridging vein rupture. Hence, there is no literature support for the use of thrombosis as a marker for AHT.

Venous injury in pediatric abusive head trauma: a pictorial review

Abusive head trauma (AHT) is the leading cause of fatal head injuries in children younger than 2 years. An intracranial pathology can exist even in the setting of a normal physical exam. A delay in the diagnosis of AHT can have serious life-threatening consequences for the child and increases the potential the child will be abused again. In this article, we review the traumatic subdural hematoma as well as various morpho-structural patterns of shearing injuries and thrombosis of intracranial bridging veins. This work serves as a summary of patterns of imaging features of intracranial venous injury in AHT, as described in the literature, to facilitate familiarity and early detection of abusive head trauma in the pediatric population. Essentially, in AHT there is a traumatic injury to the bridging vein with either partial or complete tear. This can secondarily result in thrombosis at the terminal end of the bridging vein with blood clots adjacent to the bridging vein.

Venous injury in pediatric abusive head trauma: a pictorial review

Abusive head trauma (AHT) is the leading cause of fatal head injuries in children younger than 2 years. An intracranial pathology can exist even in the setting of a normal physical exam. A delay in the diagnosis of AHT can have serious life-threatening consequences for the child and increases the potential the child will be abused again. In this article, we review the traumatic subdural hematoma as well as various morpho-structural patterns of shearing injuries and thrombosis of intracranial bridging veins. This work serves as a summary of patterns of imaging features of intracranial venous injury in AHT, as described in the literature, to facilitate familiarity and early detection of abusive head trauma in the pediatric population. Essentially, in AHT there is a traumatic injury to the bridging vein with either partial or complete tear. This can secondarily result in thrombosis at the terminal end of the bridging vein with blood clots adjacent to the bridging vein.

Pediatric Abusive Head Trauma: A Systematic Review

Abusive head trauma (AHT) represents a commonly misdiagnosed condition. In fact, there is no pathognomonic sign that allows the diagnosis in children. Therefore, it is such an important medico-legal challenge to evaluate reliable diagnostic tools. The aim of this review is to evaluate the current scientific evidence to assess what the best practice is in order to diagnose AHT. We have focused particularly on evaluating the importance of circumstantial evidence, clinical history, the use of postmortem radiological examinations (such as CT and MRI), and the performance of the autopsy. After autopsy, histological examination of the eye and brain play an important role, with attention paid to correlation with symptoms found in vivo.

[Bridging vein injuries in shaken baby syndrome : Forensic-radiological meta-analysis with special focus on the tadpole sign]

Shaken baby syndrome is a common variant of the abusive head trauma in infants and toddlers and is still subject of intensive research. In recent years, a number of radiological studies on the diagnostic and forensic relevance of injured bridging veins were conducted using different imaging modalities. The present article will give an overview on the current state of research in this field and will discuss the forensic implications. The meta-analysis of the seven currently existing studies revealed that injuries of the bridging veins and bridging vein thromboses, respectively, frequently appear as rounded, enlarged, and/or tubular structures. The "tadpole sign" may serve as a valuable tool for the identification of these formations. Especially, T2*/SWI (susceptibility-weighted imaging) sequences allow for good detectability of these lesions and should always be generated when abusive head trauma is suspected. In conclusion, it can be recommended that the presence of radiologically detectable bridging vein injuries should give reason to search for other manifestations of physical child abuse.

Cortical and bridging veins of the upper cerebral convexity: a magnetic resonance imaging study

PURPOSE

There is no study exploring the cortical veins (CVs) and connecting bridging veins (BVs) with neuroimaging modalities. The present study aimed to characterize these veins of the upper cerebral convexity.

METHODS

A total of 89 patients with intact cerebral hemispheres and covering meninges underwent thin-sliced, contrast magnetic resonance imaging (MRI). In addition, three injected specimens were dissected in this study.

RESULTS

In cadaver dissection, the BVs were observed to course in the arachnoid sheaths, suspended from the dura mater. The medial parts of the BVs, located near the superior sagittal sinus (SSS)-BV junction site, were occasionally exposed subdurally. The CVs were formed by venous channels arising from the cerebral gyri and those emerging from the sulci. On MRI, the CVs and connecting BVs were identified in the medial and latera convexity areas and medial surface of the cerebrum. These veins were highly variable in number, thickness, length, course, and distribution. In the medial convexity area, the CVs arising from the gyri were identified in 58% of patients, while they were found only in 11% of patients in the lateral convexity area.

CONCLUSION

In the medial convexity area, involving the parasagittal region, the CVs connect more densely with the BVs that may predispose to injury during neurosurgical procedures. Mechanical impact exerted the area, diameter of the veins in the craniocaudal direction, and number of venous afferences may affect the SSS-BV junctional region in an indirect manner and lead to the development of acute subdural hematoma.

Dural Venous Channels: Hidden in Plain Sight-Reassessment of an Under-Recognized Entity

BACKGROUND AND PURPOSE

Tentorial sinus venous channels within the tentorium cerebelli connecting various cerebellar and supratentorial veins, as well as the basal vein, to adjacent venous sinuses are a well-recognized entity. Also well-known are "dural lakes" at the vertex. However, the presence of similar channels in the supratentorial dura, serving as recipients of the Labbe, superficial temporal, and lateral and medial parieto-occipital veins, among others, appears to be underappreciated. Also under-recognized is the possible role of these channels in the angioarchitecture of certain high-grade dural fistulas.

MATERIALS AND METHODS

A retrospective review of 100 consecutive angiographic studies was performed following identification of index cases to gather data on the angiographic and cross-sectional appearance, location, length, and other features. A review of 100 consecutive dural fistulas was also performed to identify those not directly involving a venous sinus.

RESULTS

Supratentorial dural venous channels were found in 26% of angiograms. They have the same appearance as those in the tentorium cerebelli, a flattened, ovalized morphology owing to their course between 2 layers of the dura, in contradistinction to a rounded cross-section of cortical and bridging veins. They are best appreciated on angiography and volumetric postcontrast T1-weighted images. Ten dural fistulas not directly involving a venous sinus were identified, 6 tentorium cerebelli and 4 supratentorial.

CONCLUSIONS

Supratentorial dural venous channels are an under-recognized entity. They may play a role in the angioarchitecture of dural arteriovenous fistulas that appear to drain directly into a cortical vein. We propose "dural venous channel" as a unifying name for these structures.

MRI Findings in Pediatric Abusive Head Trauma: A Review

Trauma is the most common cause of death and significant morbidity in childhood; abusive head trauma (AHT) is a prominent cause of significant morbidity and mortality in children younger than 2 years old. Correctly diagnosing AHT is challenging both clinically and radiologically. The primary diagnostic challenges are that the abused children are usually too young to provide an adequate history, perpetrators are unlikely to provide truthful account of trauma, and clinicians may be biased in their assessment of potentially abused children. The main radiological challenge is that there is no single imaging finding that is independently specific for or diagnostic of AHT. The radiological evaluation should be based on the multiplicity and severity of findings and an inconsistency with the provided mechanism of trauma. While the most common neuroimaging finding in AHT is subdural hemorrhage, other less well-known magnetic resonance imaging (MRI) findings such as the "lollipop sign" or "tadpole sign," parenchymal or cortical lacerations, subpial hemorrhage, cranio-cervical junction injuries including retroclival hematomas, as well as diffuse hypoxic brain injury have been identified and described in the recent literature. While AHT is ultimately a clinical diagnosis combining history, exam, and neuroimaging, familiarity with the typical as well as the less-well known MRI findings will improve recognition of AHT by radiologists.

Parasagittal vertex clots on head CT in infants with subdural hemorrhage as a predictor for abusive head trauma

BACKGROUND

Abusive head trauma (AHT) is the most common cause of subdural hemorrhage (SDH) in infants younger than 12 months old. Clot formation in the parasagittal vertex seen on imaging has been associated with SDH due to AHT. There have been very few studies regarding these findings; to our knowledge, no studies including controls have been performed.

OBJECTIVE

To describe parasagittal vertex clots on head computed tomography (CT) in infants with SDH and AHT compared to patients with SDH and accidental trauma, and to evaluate for parasagittal vertex clots in the absence of SDH in the setting of known accidental head trauma.

MATERIALS AND METHODS

All infants younger than 12 months old with SDH present on CT scan were retrospectively identified from 2004 to 2014. Blinded, independent review of all CT scans for clot formation at the parasagittal vertex was performed by a pediatric neuroradiologist.

RESULTS

Ninety-nine patients were eligible for analysis. Mean age was 4 months. Fifty-seven (57.6%) were male. Fifty-five (55.6%) patients were identified as having AHT and 22 (22.2%) had accidental trauma. Forty-five (81.2%) patients with AHT had parasagittal vertex clots present on CT scan compared to 8 (36.4%) patients with accidental trauma. Compared to patients without parasagittal vertex clots, those with parasagittal vertex clots were more likely to have AHT (66.2% vs. 32.3%, P=0.001), no known mechanism of injury (69.1% vs. 32.3%, P=0.015), retinal hemorrhage (75% vs. 35.5%, P=0.002) and hypoxic-ischemic changes (25% vs. 0%, P=0.002). Patients with parasagittal vertex clots have eight times the odds of AHT compared to patients without parasagittal vertex clots. Age-matched control patients who underwent head CT scan due to a history of accidental head injury without SDH were identified (n=87); no patient in the control group had parasagittal vertex clots.

CONCLUSION

The finding of parasagittal vertex clots on CT scans should raise suspicion for abuse and prompt further investigation, especially in the setting of no known, uncertain or inconsistent mechanism of injury.

The profile of blunt traumatic infratentorial cranial bleed types

Infratentorial traumatic intracranial bleeds (ICBs) are rare and the distribution of subtypes is unknown. To characterize this distribution the National Trauma Data Bank (NTDB) 2014 was queried for adults with single type infratentorial ICB, n = 1,821: subdural hemorrhage (SDH), subarachnoid hemorrhage (SAH), epidural hemorrhage (EDH), and intraparenchymal hemorrhage (IPH). Comparisons were made between the groups with statistical significance determined using chi squared and t-tests. SDH occurred in 29% of patients, mostly in elderly on anti-coagulants (13%) after a fall (77%), 42% of them underwent craniotomy, their mortality was the lowest (4%). SAH was the most common (56%) occurring mostly from traffic related injuries (27%). Furthermore, 9% of them had a severe head injury Glasgow Coma Scale ≤8 (GCS), but had the lowest Injury Severity Score (ISS, median 8) as well as a short hospital length of stay, 5.1 ± 6.2 days. These patients were most likely to be discharged to home (64%). They had the lowest mortality (4%). EDH was the least common ICB (5%), occurred in younger patients (median age 49 years), and it had the highest percentage of associated injuries (13%). EDH patients presented with the poorest neurological status (26% GCS ≤8, ISS median 25) and were operated on more than any other ICB type (55%). EDH was the highest mortality (9%) ICB type and had a low discharge to home rate (58%). IPH was uncommon (10%). Infratentorial bleeds types have different clinical courses, and outcomes. Understanding these differences can be useful in managing these patients.

Endoscopic Lavage of Extensive Chronic Subdural Hematoma in an Infant After Abusive Head Trauma: Adaptation of a Technique From Ventricular Neuroendoscopy

Subdural fluid collections are frequently encountered in young children after non-accidental injury. In a subset of patients, these collections progress in size and ultimately require permanent drainage, which is commonly achieved with subdural-peritoneal shunts. However, excessive protein and cellular contents in the fluid are potential risk factors for shunt failure. Here, we describe the adaptation of an endoscopic lavage technique established for ventricular endoscopy with the aim of improving fluid condition prior to shunting. We present a case of subdural fluid collections secondary to non-accidental injury, where permanent shunting was required but could not be performed due to excessive protein and cellular levels in the subdural fluid despite conventional burr hole drainage. A two-month-old male infant presented with a bulging and tense fontanel, a reduced level of consciousness, bradycardia, and significant macrocephaly. Computed tomography (CT) demonstrated massive bilateral, low attenuation subdural fluid collections, reaching a diameter of 4.5 cm. Emergency burr hole washout and insertion of subdural drains was performed. Despite prolonged drainage over 10 days, the protein level remained at 544 mg/dl and the mean erythrocyte count at 6,493/µl. Continuous drainage was required to avoid clinical deterioration due to raised intracranial pressure; however, the fluid condition was still considered incompatible with permanent subdural-peritoneal shunting. We, therefore, performed an endoscopic subdural lavage with a careful evacuation of residual blood deposits. No complications were encountered. Postoperatively, mean protein level was 292 mg/dl and mean erythrocyte count was 101/µl. Endoscopic lavage could be safely performed in a case of extensive subdural low attenuation fluid collections, where conventional burr hole drainage failed to improve protein and cellular contents as a prerequisite for successful permanent shunting. We conclude that adaptation of this technique can be helpful in selected cases as an alternative procedure.

A systematic autopsy survey of human infant bridging veins

In the first years of life, subdural haemorrhage (SDH) within the cranial cavity can occur through accidental and non-accidental mechanisms as well as from birth-related injury. This type of bleeding is the most common finding in victims of abusive head trauma (AHT). Historically, the most frequent cause of SDHs in infancy is suggested to be traumatic damage to bridging veins traversing from the brain to the dural membrane. However, several alternative hypotheses have been suggested for the cause and origin of subdural bleeding. It has also been suggested by some that bridging veins are too large to rupture through the forces associated with AHT. To date, there have been no systematic anatomical studies on infant bridging veins. During 43 neonatal, infant and young child post-mortem examinations, we have mapped the locations and numbers of bridging veins onto a 3D model of the surface of a representative infant brain. We have also recorded the in situ diameter of 79 bridging veins from two neonatal, one infant and two young children at post-mortem examination. Large numbers of veins, both distant from and directly entering the dural venous sinuses, were discovered travelling between the brain and dural membrane, with the mean number of veins per brain being 54.1 and the largest number recorded as 94. The mean diameter of the bridging veins was 0.93 mm, with measurements ranging from 0.05 to 3.07 mm. These data demonstrate that some veins are extremely small and subjectively, and they appear to be delicate. Characterisation of infant bridging veins will contribute to the current understanding of potential vascular sources of subdural bleeding and could also be used to further develop computational models of infant head injury.

Anatomical and Physiological Differences between Children and Adults Relevant to Traumatic Brain Injury and the Implications for Clinical Assessment and Care

General and central nervous system anatomy and physiology in children is different to that of adults and this is relevant to traumatic brain injury (TBI) and spinal cord injury. The controversies and uncertainties in adult neurotrauma are magnified by these differences, the lack of normative data for children, the scarcity of pediatric studies, and inappropriate generalization from adult studies. Cerebral metabolism develops rapidly in the early years, driven by cortical development, synaptogenesis, and rapid myelination, followed by equally dramatic changes in baseline and stimulated cerebral blood flow. Therefore, adult values for cerebral hemodynamics do not apply to children, and children cannot be easily approached as a homogenous group, especially given the marked changes between birth and age 8. Their cranial and spinal anatomy undergoes many changes, from the presence and disappearance of the fontanels, the presence and closure of cranial sutures, the thickness and pliability of the cranium, anatomy of the vertebra, and the maturity of the cervical ligaments and muscles. Moreover, their systemic anatomy changes over time. The head is relatively large in young children, the airway is easily compromised, the chest is poorly protected, the abdominal organs are large. Physiology changes—blood volume is small by comparison, hypothermia develops easily, intracranial pressure (ICP) is lower, and blood pressure normograms are considerably different at different ages, with potentially important implications for cerebral perfusion pressure (CPP) thresholds. Mechanisms and pathologies also differ—diffuse injuries are common in accidental injury, and growing fractures, non-accidental injury and spinal cord injury without radiographic abnormality are unique to the pediatric population. Despite these clear differences and the vulnerability of children, the amount of pediatric-specific data in TBI is surprisingly weak. There are no robust guidelines for even basics aspects of care in children, such as ICP and CPP management. This is particularly alarming given that TBI is a leading cause of death in children. To address this, there is an urgent need for pediatric-specific clinical research. If this goal is to be achieved, any clinician or researcher interested in pediatric neurotrauma must be familiar with its unique pathophysiological characteristics.