Letter to the editor. Lack of evidence for a causal relationship between hypoxic-ischemic encephalopathy and subdural hemorrhage in fetal life, infancy,and early childhood

The legal challenges to the diagnosis of shaken baby syndrome or how to counter 12 common fake news

BACKGROUND

The shaken baby syndrome (SBS) is a common cause of severe traumatic lesions in infants. Although well established for almost five decades, SBS and its diagnosis are becoming more and more aggressively challenged in courts. These challenges feed on the scientific debate and controversies regarding the pathophysiology and the differential diagnoses, scientific uncertainty being readily exploited by specialized barristers.

MATERIAL AND METHODS

In the present review, we analyze the most common challenges to the concept of SBS and its diagnosis, as well as the scientific evidence available to counter these challenges, the differential diagnoses, and how SBS can be diagnosed with confidence.

RESULTS

We found that the pathophysiology of SBS is well documented, with stereotyped descriptions by perpetrators, in good correlation with experimental studies and computer models. SBS is a well-defined clinico-pathological entity with a characteristic constellation of lesions; with a rigorous evaluation protocol, its diagnosis can be made rapidly and with excellent accuracy beyond a reasonable doubt.

CONCLUSION

It is important that medical experts master an extensive knowledge regarding the pathophysiology of the lesions of SBS, in particular infantile subdural hematomas, as well as other CSF-related conditions. This emphasizes the role that pediatric neurosurgeons should play in the clinical and medicolegal management of these patients.

Intracranial hemorrhage in term neonates

BACKGROUND

Intracranial hemorrhage (ICH) is an uncommon but important cause of morbidity and mortality in term neonates; currently, ICH is more frequently diagnosed because of improved neuroimaging techniques.

PURPOSE

The study aims to evaluate the clinical characteristics and neuroimaging data (pattern, size, distribution) of neonatal ICH.

METHODS

We reviewed MRI data from July 2004 to June 2015 for 42 term neonates with ICH who were less than 1 month old. We recorded clinical data and manifestations, mode of delivery, Apgar score at 1 and 5 min, associated hypoxic insult, birth trauma, neurological symptoms, EEG results, extent and site of hemorrhage, neurosurgical intervention, and developmental outcomes. The clinical outcome was determined for 27 neonates. Risk factors were assessed in relation to ICH.

RESULTS

A total of 42 neonates who presented with ICH underwent MR imaging 2 to 22 days postnatally (mean age 9.3 days). The majority of clinical symptoms were present in patients within the first 24 h of life (n = 31), but symptoms appeared until day 10 postnatally (mean 4.9 days, n = 11). Seizure or seizure-like activity was the most common presenting symptom (17/42, 40.5%), with apnea seen in another seven infants (7/42, 16.7%). The majority of infants had a normal prenatal course. Two patients had antenatally detected hydrocephalus. Ten had infratentorial hemorrhage, and two had supratentorial hemorrhage. A total of 30 infants had a combination of infratentorial and supratentorial hemorrhage. Subdural hemorrhage (SDH) was the most common type of hemorrhage (40/42, 95.2%), followed by nine cases of parenchymal hemorrhage, seven of subarachnoid hemorrhage, three of germinal matrix hemorrhage (GMH), and one of epidural hemorrhage (EDH). A total of 16 infants had two or more types of hemorrhage. SDH was identified along the tentorium (n = 38) as well as over the cerebellar hemispheres (n = 39), along the interhemispheric fissure (n = 10), and over the occipital (n = 13) or parietooccipital (n = 11) lobes. Intraparenchymal hemorrhage involved either the frontal (n = 4), parietal (n = 3), or cerebellar (n = 2) lobes. Traumatic delivery was suspected in 20 patients (47.6%), and perinatal asphyxia was present in 21 patients (50.0%). A low Apgar score at 5 min and a history of perinatal asphyxia were the factors that most predicted poor clinical outcomes (n = 12/27). Logistic regression analysis revealed that a history of perinatal asphyxia resulted in poor outcomes. No patients died. One infant required burr hole drainage of a right parietal EDH, one infant needed a subcutaneous reservoir, and three infants required a ventriculoperitoneal shunt for obstructive hydrocephalus.

CONCLUSION

SDH was the most common type of ICH in term infants. Combined supratentorial and infratentorial hemorrhage was more common than isolated infratentorial hemorrhage in these infants. A total of 44.4% of patients had poor outcomes, with perinatal asphyxia the most common statistically significant cause.

Increased number of fetal nucleated red blood cells in the placentas of term or near-term stillborn and neonates correlates with the presence of diffuse intradural hemorrhage in the perinatal period

Release of nucleated red blood cells (nRBCs) into the peripheral blood occurs in stillbirths/neonates with a probable hypoxic mode of death and antenatal stress. We correlated the number of nRBCs in the placenta with the occurrence of intradural (IDH) and subdural hemorrhage (SDH) and the potential link with fetal hypoxia. Two groups of 22 cases each of nonmacerated term or near-term (≥36 weeks of gestational age) stillborn or newborns dying in the 1st day of life were studied. One group had IDH (with or without SDH) and the other did not have IDH or SDH. In each case, the number of nRBCs was determined in 10 consecutive placental fields at ×40. Data were analyzed with Fisher exact test, receiver operating characteristic (ROC) curve analysis, and logistic regression. There was a significant association between the diffuse IDH and increased number of nRBCs (Fisher exact test P  =  0.0165). An ROC curve analysis showed that the cut-off number of nRBCs with the highest accuracy was 2.15 nRBCs/high-power field, with 79% sensitivity and 67% specificity. The presence of diffuse IDH was associated with SDH (Fisher exact test, P  =  0.002). The absence of hypoxic brain change was associated with the absence of diffuse IDH (odds ratio 0.308; P  =  0.039). We established a significant correlation between the release of nRBCs into the placental circulation and the occurrence of diffuse IDH and between diffuse IDH and the presence of SDH.

Evidence of occurrence of intradural and subdural hemorrhage in the perinatal and neonatal period in the context of hypoxic Ischemic encephalopathy: an observational study from two referral institutions in the United Kingdom

The occurrence of subdural hemorrhage (SDH) on the convexities of the cerebral hemispheres is not an unusual finding in the setting of intrauterine, perinatal, or neonatal deaths, the hemorrhage usually presenting either as a thin film over the occipital poles or as a small infratentorial bleed. Working in 2 referral centers with over 30,000 deliveries per year, we routinely examine the dura macroscopically and histologically in nonmacerated fetuses over 24 weeks in gestation and in neonates. This paper describes our experience of intradural hemorrhage (IDH) and SDH associated with hypoxia. Our series comprises 25 fetuses and 30 neonates with obvious macroscopic intradural hemorrhage and hypoxia of varying degrees of severity diagnosed by systematic examination of the brain. Fetal gestational age ranged from 26-41/40 weeks (all no more than 24 hours from intrauterine death), while the 30 neonates lived for between 1 hour and 19 days. Simultaneously with IDH, frank SDH was seen in 2 of 3 of all cases (16 fetuses and 20 neonates). Intradural hemorrhage was more prominent in the posterior falx and tentorium, most likely because of the existence of 2 venous plexus at these sites. Our findings demonstrate that SDH and cerebral hypoxia are common associations of IDH and that SDH (often seen as a thin film ofhemorrhage) almost always occurs in association with diffuse falcine IDH. Diffuse IDH with SDH are more frequently associated with severe or moderate hypoxic ischemic encephalopathy (HIE), while mild or early HIE is more common with focal IDH without SDH.

The neuropathology of infant subdural haemorrhage

Subdural haemorrhage (SDH) in the infant has a different pattern from that seen in the older child and adult. It is usually a widespread, bilateral, thin film, unlike the thick, space-occupying and often unilateral clot seen in older children and adults after trauma. Whether both arise by the same mechanism is unknown, but it seems unlikely. Most SDH is said to be due to trauma but in infants there are other, atraumatic causes. Birth is also important; recent MRI studies show an incidence of almost 50% in asymptomatic neonates. Traumatic SDH is said to result from rupture of bridging veins but new insights into the anatomy of infant dura suggest a dural origin for thin film subdural bleeding in young babies. Acute SDH usually rapidly resolves, but sometimes develops into a chronic fluid collection. Healing of SDH is by formation of a granulating membrane which may confer vulnerability to rebleeding, either spontaneously or after an otherwise innocuous event. SDH has a particular significance as one of the features of the triad (together with retinal haemorrhage and encephalopathy) associated with non-accidental injury. As the possibility of non-accidental injury is often first raised by a radiologic report of subdural bleeding, it becomes critically important in the interpretation of the scan appearances to understand the unique physiology and anatomy of the infant dura.