Pathology of retinal hemorrhage in abusive head trauma

New Insights into the Diagnosis and Age Determination of Retinal Hemorrhages from Abusive Head Trauma: A Systematic Review

(1) Background: Head trauma represents the first cause of death in abused children, but diagnostic knowledge is still limited. The characteristic findings of abusive head trauma (AHT) are retinal hemorrhages (RH) and additional ocular findings, including optic nerve hemorrhages (ONH). However, etiological diagnosis must be cautious. (2) Methods: The Preferred Reporting Items for Systematic Review (PRISMA) standards were employed, and the research focus was the current gold standard in the diagnosis and timing of abusive RH. (3) Results: Sixteen articles were included for qualitative synthesis. The importance of an early instrumental ophthalmological assessment emerged in subjects with a high suspicion of AHT, with attention to the localization, laterality, and morphology of the findings. Sometimes it is possible to observe the fundus even in deceased subjects, but the current techniques of choice consist of Magnetic Resonance Imaging and Computed Tomography, also useful for the timing of the lesion, the autopsy, and the histological investigation, especially if performed with the use of immunohistochemical reactants against erythrocytes, leukocytes, and ischemic nerve cells. (4) Conclusions: The present review has made it possible to build an operational framework for the diagnosis and timing of cases of abusive retinal damage, but further research in the field is needed.

The Eyes Have It: How Critical are Ophthalmic Findings to the Diagnosis of Pediatric Abusive Head Trauma?

Pediatric abusive head trauma (AHT), still colloquially known as shaken baby syndrome, is a leading cause of morbidity and mortality among infants. Controversy has grown surrounding this diagnosis, and the specificity of the clinical findings-subdural hemorrhage, cerebral edema, and retinal hemorrhages-has been challenged. A literature search of peer reviewed publications on PubMed pertaining to the history, clinical, and pathologic features of AHT was conducted using the terms "shaken baby syndrome," "non-accidental trauma," "abusive head trauma," "inflicted traumatic brain injury," "shaken impact syndrome," and "whiplash shaken infant syndrome." Focus was placed on articles discussing ophthalmic findings in AHT. Retinal hemorrhages-particularly those that are too numerous to count, occurring in all layers of the retina (preretinal, intraretinal, subretinal), covering the peripheral pole and extending to the ora serrata, and accompanied by retinoschisis and other ocular/periocular hemorrhages-are highly suggestive of AHT, particularly in the absence of otherwise explained massive accidental trauma. Although the diagnosis has grown in controversy in recent years, AHT has well-documented clinical and pathologic findings across a large number of studies.

Novel in vivo depiction of optic nerves hemorrhages in child abuse: a 3D-SWI pilot study

Purpose

Until now, the diagnosis of optic nerves hemorrhages in abusive head trauma (AHT) has been obtained only in the postmortem setting. The aim of the IRB-approved study was to assess the presence of optic nerves hemorrhages in AHT patients using 3D-SWI.

Methods

Thirteen children with a final confirmed multidisciplinary diagnosis of AHT underwent coronal and axial 3D-SWI imaging of the orbits. The presence of optic nerve sheath (ONS) hemorrhages was defined by thickening and marked 3D-SWI hypointensity of the ONS, resulting in mass effect upon the CSF space. Optic nerve (ON) hemorrhages were defined by areas of susceptibility artifacts in the ON parenchyma. Superficial siderosis was defined by susceptibility artifact coating the ON. Furthermore, data about post-traumatic deformity of the ONS at the head of the optic nerve were collected.

Results

The average age of the population was 7.9 ± 5.9 months old. The average GCS was 11.8 ± 4.5. The male to female ratio was 7:6. ONS hemorrhages were identified in 69.2% of cases. Superficial siderosis and ON hemorrhages were identified in 38.5 and 76.9% of cases, respectively. 3D-SWI also depicted traumatic deformity of the ONS at the level of the optic nerve head in 10 cases (76.9%). No statistical correlations were identified between RetCam findings and 3D-SWI findings or GCS and ON hemorrhages.

Conclusion

This research shows that dedicated MRI with volumetric SWI of the orbits can depict hemorrhages in the ON, ONS, and ONS injury, in AHT victims.

PATHOLOGY OF PERIMACULAR FOLDS DUE TO VITREORETINAL TRACTION IN ABUSIVE HEAD TRAUMA

PURPOSE

To demonstrate vitreoretinal traction as a mechanism for perimacular folds in abusive head trauma.

METHODS

We performed gross and histopathologic examination of eyes of children with suspected abusive head trauma and identified those with typical perimacular folds. Information was collected regarding the incident that led to the child's death and systemic manifestations noted at autopsy. Eyes were prepared in a fashion that allowed for demonstration of the vitreoretinal interface.

RESULTS

Ten eyes of five patients (2-13 months) were examined. All patients had systemic manifestations of abusive trauma including intracranial injury. All cases provided evidence of vitreoretinal traction producing perimacular folds. Condensed vitreous was seen attached to the apices of the retinal folds, and the detached internal limiting membrane comprising the inner surfaces of the schisis cavity. Four cases showed severe bilateral multilayered symmetric retinal hemorrhages extending to the ora serrata. All cases showed optic nerve sheath subdural hemorrhage and subarachnoid hemorrhage. Orbital hemorrhage was unilateral in two cases and bilateral in three cases. Four cases showed orbital fat hemorrhage. One case showed extraocular muscle sheath and cranial nerve sheath hemorrhage. Two cases showed juxtapapillary intrascleral hemorrhage.

CONCLUSION

Vitreoretinal traction is the likely mechanism of perimacular folds in abusive head trauma.

Photographic assessment of retinal hemorrhages in infant head injury: the Childhood Hemorrhagic Retinopathy Study

BACKGROUND

Retinal hemorrhages (RH) in babies in the absence of severe trauma or a medical cause have been strongly associated with abusive head trauma (AHT). We examined the pattern of RH in accidental head injury and AHT objectively using widefield retinal imaging.

METHODS

A total of 118 infants and children 1-36 months of age admitted with head injuries at two centers were included in this prospective, consecutive, comparative cohort study. Dilated fundus examination was performed with indirect ophthalmoscopy and widefield imaging. Designation of AHT was made using predetermined criteria independent of retinal findings. Retinal images were graded by two independent observers.

RESULTS

There were 21 cases of AHT. RH were present in 14 cases (66%); macular retinoschisis or retinal folds, in 8 (38%). There were 86 cases of accidental head injuries, with RH present in 2 (2%); there were none with retinal folds or retinoschisis. In cases of head injury with intracranial hemorrhage, the positive likelihood ratio of AHT with RH was 5.7 (95% CI, 2.6-12.00) and negative likelihood ratio was 0.26 (95% CI, 0.11-0.62). A severe, panretinal pattern with multilayered hemorrhages was the most specific for AHT.

CONCLUSIONS

Our imaging study confirmed that RH in infants with head injury have a high positive likelihood ratio for AHT. A severe hemorrhagic retinopathy, particularly in association with perimacular folds or macular retinoschisis, has the highest positive predictive value for AHT.

The optic nerve sheath hemorrhage is a non-specific finding in cases of suspected child abuse

In young infants, the triad consisting of acute encephalopathy, retinal hemorrhages, and a subdural hematoma is a nonspecific finding. It has traumatic and non-traumatic etiologies. The triad may be found among a vast spectrum of natural diseases. Optic nerve sheath hemorrhage in infants is typically detected at autopsy. It is a nonspecific finding that can be found in traumatic and non-traumatic etiologies. Neither the triad nor the ONSH are pathognomonic for an abusive head injury. Opposite to the triad, the spectrum of non-traumatic etiologies of ONSH is limited. In infants ONSH rarely occurs in spontaneous subarachnoidal hemorrhage or in infectious conditions. Our results show that the clinical significance of the optic nerve sheath hemorrhage in the forensic work-up of fatal cases of alleged abusive head injury is its limited differential diagnosis. Only after careful differential diagnosis ONSH may contribute to the diagnosis of AHT. However, the main limitation of our study is the sampling bias, as the eyes are usually removed when abusive head trauma is suspected.

Shaken Baby Syndrome: a review

Shaken Baby Syndrome occurs in infants as a result of the brain pushing against the skull due to severe acceleration-deceleration forces. Symptoms of Shaken Baby Syndrome include subdural, subarachnoid, and retinal hemorrhages. MRI and ocular examinations are used to determine the extent of mental and visual damage and β-amyloid precursor protein immunohistochemical staining is used to detect axonal injuries. Surgeries such as Subdural hemorrhage (SDH) evacuation surgery and the Burr hole craniotomy are used to treat Shaken Baby Syndrome; however, the prognosis is poor in many cases. Because of the severity of Shaken Baby Syndrome and its traumatic and sometimes fatal effects, it is important to educate new parents, nurses, and doctors on the syndrome in order to prevent incidents.

Mechanics of the brain: perspectives, challenges, and opportunities

The human brain is the continuous subject of extensive investigation aimed at understanding its behavior and function. Despite a clear evidence that mechanical factors play an important role in regulating brain activity, current research efforts focus mainly on the biochemical or electrophysiological activity of the brain. Here, we show that classical mechanical concepts including deformations, stretch, strain, strain rate, pressure, and stress play a crucial role in modulating both brain form and brain function. This opinion piece synthesizes expertise in applied mathematics, solid and fluid mechanics, biomechanics, experimentation, material sciences, neuropathology, and neurosurgery to address today’s open questions at the forefront of neuromechanics. We critically review the current literature and discuss challenges related to neurodevelopment, cerebral edema, lissencephaly, polymicrogyria, hydrocephaly, craniectomy, spinal cord injury, tumor growth, traumatic brain injury, and shaken baby syndrome. The multi-disciplinary analysis of these various phenomena and pathologies presents new opportunities and suggests that mechanical modeling is a central tool to bridge the scales by synthesizing information from the molecular via the cellular and tissue all the way to the organ level.

Experimental analyses of the retinal and subretinal haemorrhages accompanied by shaken baby syndrome/abusive head trauma using a dummy doll

INTRODUCTION

We explored several modes of violent shaking using a dummy doll with an eyeball model to reproduce abusive events that lead to retinal haemorrhages (RH) seen in shaken baby syndrome or abusive head trauma (SBS/AHT).

MATERIALS AND METHODS

A dummy doll equipped with an eyeball model was prepared. The eyeball model was filled with a model of vitreous body, i.e. agar gel or water, and was with a pressure sensor to measure normal stress.

RESULTS

The modes of shaking were classified into three patterns, i.e. fast shaking with the fore arms, fast shaking with the whole arms and synchronized shaking with the whole arms. The frequency of the cyclic acceleration-deceleration history experienced by the head of the dummy doll was 5.0, 4.0 and 2.2 Hz, respectively, with the maximum acceleration of 20, 20 and 60 m/s(2), respectively. We considered the last of these three modes of shaking as possibly corresponding to the worst case of violent shaking. This mode of shaking could be instructed to volunteers who acted as imitate perpetrators, and resulted in both increased peak intensities of the acceleration experienced by the head of the dummy doll and increased stresses on the retina at the posterior pole of the eyeball model.

DISCUSSION

The time integral of the stress through a single cycle of shaking was 107 Pa·s, much larger than that of a single event of fall, which resulted in 60-73 Pa·s. Taking into account that abusive shaking is likely to include multiple cycles, the time integral of the stress due to abusive shaking can be even larger. This clear difference may explain why RH in SBS/AHT is frequent, while RH in accidental falls is rare.

Hearing loss in the shaken baby syndrome

OBJECTIVES

To evaluate hearing in children diagnosed with shaken baby syndrome.

METHODS

A retrospective study conducted in a pediatric tertiary care center between 2006 and 2012. Children diagnosed with shaken baby syndrome were included for hearing evaluation by conventional audiometry, distortion product otoacoustic emissions and auditory brainstem responses.

RESULTS

Twenty-eight children were included (22 boys and 6 girls). The mean age of children at presentation was 8 months (range 1-26 months) and the mean delay before audiometric evaluation was 30 months (range 1-87 months). One child was diagnosed as having a moderate sensorineural hearing loss. The tympanic membrane mobility was normal (type A) for both ears in 22 children, one child had a reduced tympanic mobility in one ear, two children had a negative pressure, one child had a functional trans-tympanic tube and test was not performed in 2 patients.

CONCLUSION

This is the first study reporting hearing loss as a possible result of shaken baby syndrome. However, further studies with larger number of children would be preferable. We recommend hearing evaluation for these children to rule out hearing loss.

History of an abusive head trauma including a lucid interval and a retinal hemorrhage is most likely false

A lucid interval (LI) is the period of time between regaining consciousness after a short period of unconsciousness, resulting from a head injury and deteriorating after the onset of neurologic signs and symptoms caused by that injury. The incentive for this study was the case of a father who left his 14-week-old infant with the nanny in whose custody the infant had collapsed. The nanny denied involvement in the injury, and the father became a suspect. Of 47 abusive head trauma (AHT) cases, 8 were found to have an LI in the past. The history of the cases were thoroughly analyzed and compared with evidence in the literature. An LI is not compatible with an inertial brain injury. Shaking has either an immediate effect or no effect, which means that an LI occurs only in pure impact or blunt injuries. When "shaking lesions" are found including a retinal hemorrhage while the history mentions an LI, the story most likely is false, regardless of whether the perpetrator confesses. The finding of an LI may change the assessment of an AHT case. Lucid interval is a valuable variable in the diagnostic accuracy of an AHT.

Reliability of grading retinal hemorrhages in abusive head trauma

PURPOSE

To study the intra- and inter-observer reliability of pediatric ophthalmologists in grading retinal hemorrhages in abusive head trauma.

METHODS

Pediatric ophthalmologists attending the 2009 annual meeting of the American Association for Pediatric Ophthalmology and Strabismus participated in an onsite survey. The participants were required to compare a collection of fundus photographs of patients with abusive head trauma to two standardized photographs, A and B. Participants graded photographs as normal (no retinal hemorrhages), better than A but not normal, same as A, between A and B, same as B, or worse than B. The survey was divided into four parts: part 1 consisted of 20 photographs to be graded; part 2 was a questionnaire about participant's professional experience; part 3 consisted of 20 photographs to be graded (including 15 graded in part 1 but reordered); and part 4 asked about the criteria used to grade the photographs.

RESULTS

Of the 95 participants, 92 (97%) were licensed physicians with a mean of 14 years in practice. The intra-rater reliability was found to be high, with overall average of 85% pre- and post-agreement on the common pictures. Kendall's coefficient of concordance was used as the statistical measure of inter-rater reliability and had a high value (0.82).

CONCLUSIONS

Pediatric ophthalmologists showed high intra- and inter-observer reliability in grading retinal hemorrhages in abusive head trauma.

Incidence of retinal hemorrhages in abusive head trauma

PURPOSE

To evaluate whether a relationship exists between the presence of retinal hemorrhages and confessions and/or identified perpetrators in cases of abusive head trauma.

METHODS

A retrospective chart review was conducted of all abusive head trauma cases. All cases that met criteria for abusive head trauma were placed into one of three categories: perpetrator confessed (category A), perpetrator identified without confession (category B), and no perpetrator identified (category C).

RESULTS

Forty-eight cases met the criteria for abusive head trauma, with 18, 16, and 14 cases in categories A, B, and C, respectively. Retinal hemorrhages were identified in 16 of 18 (88%) cases in category A, 12 of 16 (75%) in category B, and 6 of 14 (43%) in category C. A statistically significant difference regarding the presence of retinal hemorrhages was seen for perpetrator identified (28 of 34 or 82%) compared to no perpetrator identified (6 of 14 or 43%) (P = .034). The difference in retinal hemorrhages was correlated to the higher incidence of acute presentation in the perpetrator identified group (31 of 34 or 91%) compared to that in the perpetrator not identified group (9 of 14 or 64%) (P = .023).

CONCLUSION

The incidence of retinal hemorrhages in abusive head trauma for identified perpetrators, regardless of a confession, is similar. However, there is a statistically significant decrease in the incidence of retinal hemorrhages in abusive head trauma when comparing identified perpetrators to non-identified perpetrators. This decreased incidence of retinal hemorrhages was statistically correlated to a lower incidence of acute presentation in victims of abusive head trauma without an identified perpetrator.[J Pediatr Ophthalmol Strabismus 2013;50(3):169-172.].