Discussion

This study presents a descriptive analysis of postmortem findings observed in infants under one year of age with homicidal blunt head trauma examined at a large metropolitan medical examiner’s office. The aim was not to define diagnostic injury patterns or to infer mechanisms of injury, but to document the distribution and frequency of intracranial, ocular, spinal, and extracranial findings encountered in this case series and to discuss technical considerations relevant to their postmortem assessment.

Intracranial injuries were common in this cohort, consistent with prior forensic and clinical reports describing infant head trauma [24, 25]. The present findings are limited to anatomical distribution and histopathological observations and do not address mechanism, timing, or force thresholds. Skull fractures were present in 46.2% of cases, a prevalence comparable to that reported in other case series of AHT [26–28]. Brain injuries are commonly associated with progressive deterioration of consciousness due to increased intracranial pressure, which may clinically manifest as bulging of the fontanelles [29]. The relatively low frequency of epidural hemorrhage (EDH) observed in this series (12.8%) is consistent with the literature, as in young children the dura is more firmly adherent to the inner table of the skull, the middle meningeal artery is not yet fully embedded within a bony groove, and the calvarial bones are more pliable, all of which reduce the likelihood of meningeal vessel laceration following blunt impact [30]. In contrast, acute subdural hemorrhage (SDH) and subarachnoid hemorrhage (SAH) were frequently identified (both 89.7%). In infants, SDH often presents as a thin film and has been attributed, in prior biomechanical and autopsy studies, to rupture of bridging veins associated with rotational acceleration–deceleration forces [31–33].

Diffuse axonal injury was identified in a subset of cases. The absence of routine immunohistochemical staining during the study period represents a methodological limitation and may have contributed to underrecognition [34, 35].

Cervical spinal cord injury was identified in 41.1% of cases. These injuries, primarily EDH, underscore the vulnerability of the pediatric cervical spine, attributed to anatomical features such as ligamentous laxity and relatively large head size [36–38].

The absence of vertebral fractures is consistent with existing studies indicating that spinal injuries in infants are typically hemorrhagic or ligamentous rather than osseous in nature [39].

The co-occurrence of injuries, such as SDH, retinal hemorrhages, and rib fractures, is a combination of injuries reported in prior forensic series and concerning for inflicted trauma [12]. Published data report extremely low fatality rates from short-distance falls, which rarely produce diffuse intracranial or retinal hemorrhages [40–42].

Ocular findings are commonly reported in pediatric head trauma. In this study, retinal hemorrhages (87.2%) and optic nerve sheath hemorrhages (84.6%) were frequently observed, consistent with findings described in prior forensic and clinical literature [43–45]. Several mechanisms have been proposed to account for these findings, including acute increases in intracranial pressure, vitreoretinal traction, and rupture of the central retinal vein [46].

Retinal hemorrhages, particularly when bilateral or multilayered, have been reported less frequently in accidental trauma and more often in cases involving severe head injury. Prior biomechanical and clinical studies have proposed angular acceleration deceleration forces, including shaking or impact, as possible contributors to these findings, although they are not pathognomonic. Consensus statements and professional guidelines have noted that minor falls or routine activities are generally not associated with the extent or patterns of retinal hemorrhage described in severe infant head trauma [47]. Although uncommon, retinal hemorrhages related to cardiopulmonary resuscitation cannot be excluded a priori and, when present, are typically few, intraretinal, and confined to the posterior pole [48]. When available, premortem ophthalmologic examination records should be reviewed to complement postmortem findings [49].

The interpretation of ocular findings should be considered within the broader context of associated injuries. Prior work has suggested that the number and combination of findings, including intracranial lesions with retinal hemorrhages or skeletal injuries, may contribute to assessment of severe head trauma [50]. In the present series, multiple injury types were frequently observed within the same individuals, underscoring the need for a comprehensive and integrated postmortem evaluation.

Accordingly, pediatric forensic autopsy in infants requires particular care due to anatomical fragility and the wide differential diagnosis among natural, accidental, and violent causes of death. Pre autopsy imaging represents an essential component of the evaluation, with standardized radiological protocols recommended in suspected abusive head trauma cases [17, 51, 52]. When available, computed tomography and magnetic resonance imaging provide the greatest diagnostic yield, while conventional radiographic skeletal surveys remain essential for the detection of skeletal trauma.

A thorough external examination is mandatory. All skin lesions, including bruises, abrasions, burns, and bite marks, should be carefully documented and photographed, with particular attention to findings that are unusual or inconsistent with accidental trauma, especially in non-ambulatory infants [53].

Standard autopsy in infants includes a Y shaped incision with complete examination of the scalp, skull, and brain. Key findings include subgaleal hemorrhage, cranial sutures diastasis, fontanelle tension, and intracranial and retinal hemorrhages [54].

Given the importance of accurately documenting intraocular hemorrhage in cases of suspected infant and young child head trauma, removal of the eyes with a portion of each optic nerve and submission for ophthalmopathologic examination is recommended. The eyes and optic nerves can be easily removed with a posterior approach from the intracranial cavity to preserve ocular structures [17–19]. A layered anterior neck dissection is recommended to assess hemorrhage around the hyoid bone and adjacent soft tissues, and the thoracoabdominal examination should document costal fractures and visceral injuries.

In selected cases, deeper dissection of subcutaneous tissues and musculature may reveal occult hemorrhage. Cerebrospinal fluid collection may be performed for ancillary studies with caution to avoid anatomic disruption [17–19]. Vitreous humor should not be collected in cases of obvious head trauma, as the eyes require removal for ophthalmopathologic evaluation.

While standard and selective ancillary procedures may identify additional injuries, certain anatomical regions, particularly the cervical spine and associated nerve roots, may remain incompletely assessed without targeted dissection. In this context, prior research has reported an association between suspected neck hyperflexion–extension and unilateral or bilateral hemorrhages involving the cervical spinal nerve roots, most consistently at levels C3–C5, whereas such findings were uncommon in cases without suspected neck injury [55]. The authors proposed that injury to these nerve roots, which innervate the diaphragm, could contribute to respiratory compromise and secondary hypoxic–ischemic encephalopathy, offering an alternative hypothesis for some intracranial findings traditionally attributed to primary intracranial trauma. Importantly, their study emphasized that such cervical nerve root injuries are not detectable with routine autopsy techniques and require targeted dissection and histologic examination of the cervical spine and associated soft tissues.

In the present series, cervical spinal cord and meningeal hemorrhages were identified in a substantial proportion of cases, supporting the value of careful cervical spine examination in pediatric head trauma. Cervical spinal cord involvement was observed in 41.1% of cases, with extradural and subdural hemorrhages being the most frequent lesions. The frequency and anatomical distribution of cervical spinal cord and meningeal hemorrhages observed in this series highlight the potential for clinically and forensically relevant findings in regions that may be incompletely assessed with routine autopsy techniques. In particular, hemorrhagic changes involving the cervical spinal cord, nerve roots, and adjacent soft tissues may be subtle, anatomically complex, and easily overlooked when examination is limited or fragmented.

Despite increasing recognition of spinal cord involvement in abusive head trauma, examination of the cervical spine remains non standardized in many forensic protocols. Conventional autopsy techniques often involve separate removal of the brain and spinal cord, which may limit evaluation of the cervicomedullary region. To address these limitations, several extended dissection techniques have been described, including immersion methods for preservation of fragile brain tissue, posterior approaches allowing continuous removal of the brain and spinal cord, and en bloc cervical spine techniques that preserve anatomical relationships among the spinal cord, nerve roots, ganglia, and surrounding soft tissues [56–63]. While these approaches may enhance visualization of deep cervical structures, they are technically demanding and their applicability depends on available resources and expertise, particularly in infant autopsies.

For this reason, the authors of this study propose a slight revision of the method described by Ali et al. [63], employing a primarily posterior approach to the cervical spine rather than the anterior approach originally described. This alternative technique provides broader anatomical exposure and facilitates preservation of relevant structures for documentation. The dissection technique for en bloc removal of the cervical spine and spinal cord following the posterior approach involves the following steps:

Preparation: With the body placed supine, a complete autopsy is performed, including removal of the thoracic and abdominal organs, skull opening and brain removal to expose the anterior, middle, and posterior cranial fossae, and the layered anterior neck dissection. The distal portions of carotid arteries are delicately detached from the surrounding neck tissues and moved away from the spine.Occipital Bone Section: From the intracranial cavity, the periforamen magnum region of the occipital bone is sawed using an oscillating saw to create a square or rectangular cut around the foramen magnum (Fig. 3). Suggested dissection landmarks include: a superior border at the level of the sella turcica, an inferior border approximately 2 cm from the posterior margin of the foramen magnum, and lateral borders approximately 1–2 cm from the lateral margins of the foramen. The cut should be deep enough to allow for the visualization of the external soft tissues of the skull base and posterior neck.Change of body position: The body is placed in the prone position, with a support block positioned beneath the chest to allow the cervical region to become naturally hyperflexed (Fig. 4).Posterior dissection: A posterior body dissection is performed to expose the soft tissues and spine, extending superiorly to visualize the base of the skull and the foramen magnum (Fig. 5a, b). If hemorrhage of the subcutaneous tissues or skeletal muscles is observed, a layered posterior skin dissection should be conducted.Cervical Spine Isolation: If the periforamen magnum segment has been sawed correctly, the operator should be able to identify a discontinuity between the proximal portion of the cervical spine and the base of the skull (Fig. 6).

Fig. 3: Cranial base showing the periforamen magnum region. Approximate landmarks are shown on the left, and the final result after dissection with an oscillating blade is shown on the right

Fig. 4: Hyperflexion of the neck

Fig. 5: (a) Dissection landmarks for the posterior body dissection. (b) Posterior body skin and soft tissues dissection

Fig. 6: Area of tissues discontinuation between the proximal aspect of the cervical spine and the skull base (black arrow and dotted square)

The residual soft tissue bands are cleared using a sharp scalpel. The soft tissues surrounding the cervical spine are then dissected, and a transverse incision is made between C7 and T1 to isolate the cervical region (Fig. 7).

Fig. 7: Dissection landmarks for the isolation and removal of cervical spine block

Using an oscillating saw, longitudinal cuts are made through the first bilateral ribs along the paravertebral regions, approximately 2 cm distal to the costovertebral junction. This facilitates the safe preservation of the nerve root ganglia. Once the remaining regional soft tissues are cleared, the cervical spine, including the spinal cord and associated nerve root ganglia, can be removed en bloc.

6.Retaining the cervical spine block. The extracted cervical spine segment (Fig. 8a-c) is then fixed in formaldehyde, decalcified, serially sectioned, and examined both grossly and microscopically.

Fig. 8: Cervical block. (a) Lateral view; (b) superior view; (c) inferior view

Forensic pathologists should be aware that this method can be resource-intensive and is best reserved for suspected trauma or homicide cases rather than routine autopsies [62]. This technique necessitates adjustments in the histology laboratory, including the implementation of new protocols and the use of specialized equipment to accommodate the processing and staining of larger tissue blocks. Nevertheless, once mastered, the technique enables rapid and efficient evisceration of the entire cervical spine block and is applicable to pediatric subjects of any age.

Finally, ancillary studies, such as postmortem toxicology, microbiology (including blood and tissue cultures, and viral studies – to be collected at the beginning of the internal examination to avoid contaminations), and carbon monoxide testing, are also essential in suspected child abuse cases, even when the cause of death appears to be obvious trauma. These investigations help rule out natural disease processes, identify coexisting conditions (e.g., infections or metabolic disorders), detect substances that may increase the child’s vulnerability, and exclude alternative explanations for clinical or autopsy findings.