European Journal of Cardiovascular Medicine

In posterior fossa, traumatic conditions are less frequent, and extradural hematoma is the most frequently encountered traumatic pathology. Traumatic posterior fossa extradural hematomas (PFEDHs) represent a rare clinical entity. It has been reported that PFEDH constitutes only 4–7% of all extradural hematomas.^[1,2] This rare condition can present with rapid clinical deterioration by quickly increasing in size and causing brain stem compression. Therefore, timely diagnosis of PFEDH is very important for good outcomes^.[3] Obtaining cranial computed tomography (CT) for detecting PFEDH that has not caused any clinical findings yet, is especially of vital importance.

This study was conducted at Department of Neurosurgery, Gajra Raja Medical College, Gwalior, Madhya Pradesh, India  from a period of July 2021 to June 2023 of 23 cases of PFEDHs A retrospective analysis of records was conducted, encompassing an examination of clinical presentations, admission Glasgow Coma Scale (GCS) scores, injury mechanisms, radiological findings, the presence of other intracranial traumatic lesions, interventions undertaken, and postoperative outcomes. In all cases, postoperative scans were obtained within 2–4 hours of surgery. The assessment of outcomes was based on the Glasgow Outcome Score (GOS) at the point of discharge and during a follow-up period of 6 months.

Over a 2-year period, a total of 23 cases of posterior fossa extradural hematoma (PFEDH) were identified. The mean age of the patients was 25 years, with a notable presence of female individuals. Road traffic accidents were the predominant mode of injury, while falls from height and assault constituted the remaining cases. The most frequent clinical presentation was headache, universally observed in conscious patients, localized primarily to the occipital or suboccipital region—consistent with the site of the primary impact. Vomiting and altered sensorium were also common symptoms, observed in 12 and 8 cases, respectively.

All patients underwent noncontrast CT (NCCT) brain scans with 5 mm axial cuts of the posterior fossa, revealing PFEDH in every case. In the majority, the hematoma was unilateral (20 cases), while in three cases, it was on either side of the midline. Notably, hydrocephalus reappeared in two cases on postoperative days 7 and 11, both associated with intraventricular hemorrhage identified in the admission CT. Cerebrospinal fluid diversion via ventriculoperitoneal shunt was performed in these instances.

Out of the 23 cases, 17 underwent surgical intervention, and 6 were initially planned for nonsurgical management. However, three of the latter group transitioned to surgical intervention between day 2 and day 4 post-trauma due to unsuccessful nonsurgical management. Incision and craniotomy procedures were tailored based on the site and size of the extradural hemorrhage. Detailed results are presented in accompanying tables.

Extradural hematoma occurs in approximately 1% of individuals presenting with head trauma. Posterior fossa extradural hematomas (PFEDHs) are even rarer, constituting only 0.1–0.3% of all traumatic cranial conditions. While most cases of PFEDH are associated with skull fractures, it is noteworthy that extradural hematomas can also arise without a fracture. In children, who have more flexible bones, there is a relatively higher likelihood of developing extradural hematomas without associated fractures.

The typical mechanism of extradural hematoma formation involves the separation of the periosteal dura mater from the calvarium, followed by the rupture of vessels located in between after a traumatic event. This vascular rupture leads to a swift enlargement of the hematoma. However, when venous structures are implicated, the clinical manifestations may present in a delayed and chronic manner. Understanding these mechanisms is crucial for the accurate diagnosis and timely intervention in extradural hematomas, contributing to improved patient outcomes.

Unlike supratentorial EDHs where the source of bleeding is usually the middle meningeal artery in temporoparietal EDHs and the anterior ethmoidal artery in frontal EDHs^,[4] PFEDHs have a venous origin in 85% of the cases and develop as a result of injury to the transverse or sigmoid sinuses secondary to occipital bone fracture^.[5] The typical narrative associated with an extradural hematoma, particularly in the context of temporal extradural hematomas (EDHs), involves a brief period of unconsciousness following trauma. This is succeeded by a "lucid interval," which can extend for hours. Subsequently, altered sensorium emerges, marking the onset of a potentially life-threatening neurological condition. Surgical intervention is the standard approach for treating epidural hematomas, except for cases involving very small hematomas that may be monitored through follow-up assessments^..[6] Given that the majority of posterior fossa extradural hematomas (PFEDHs) are of venous origin and exhibit slow expansion, the development of clinical symptoms is gradual. Early diagnosis becomes crucial, and imaging methods play a vital role in achieving this. Currently, non-contrast computed tomography (NCCT) scans are the preferred imaging modality for brain trauma. An acute extradural hematoma is visualized as a biconvex hyperdense mass situated between the duramater and the skull bone on NCCT. Rapid blood accumulation can result in the appearance of hypodense areas within the lesion, known as the "Swirl sign," indicating a high probability of active bleeding from a vessel.

On magnetic resonance (MR) imaging, an acute extradural hematoma appears as a localized extra-axial collection between the dura and the inner table of the skull bone. A distinctive feature on MR imaging is the visualization of the dura as a line with very low signal between the hematoma and the brain parenchyma, which is pathognomonic for extradural hematoma. While distinguishing small extradural hematomas that haven't formed a biconvex shape due to their small volume may be challenging, the demonstration of the dura between the parenchyma and the hematoma remains diagnostic on MR imaging.

Furthermore, MR imaging proves to be more sensitive in detecting associated parenchymal conditions or dural venous sinus thrombosis that may be linked to PFEDH, providing a comprehensive assessment beyond the hematoma itself.

^[4,7] Considering the challenges associated with obtaining MR imaging in unstable trauma patients, the primary and frequently employed method for initial imaging remains non-contrast computed tomography (NCCT). In our study involving 23 patients with traumatic posterior fossa extradural hematomas (PFEDHs), 15 patients presented with an occipital bone fracture. Additional conditions included subarachnoid hemorrhage, fractures of the occipital and temporal bones, supratentorial subdural hematoma, cerebral edema, cerebellar parenchymal pathology, and supratentorial parenchymal hematoma.

Upon excluding patients with only occipital fractures, in line with existing literature, the most commonly encountered traumatic pathology in the posterior fossa was extradural hematoma. Consistent with previous reports, it has been noted in the literature that PFEDHs are most frequently observed in the first decade of life. The predominance of occipital fractures in our study aligns with the importance of recognizing these fractures as potential indicators of PFEDHs, emphasizing the continued significance of NCCT as the primary diagnostic tool in trauma cases^.[8,9] our study, we observed 8 pediatric cases, with 15 individuals falling within their first decade of life. The utilization of cranial CT examination emerged as a valuable and effective imaging method. Its short acquisition time proved advantageous, enabling the identification of occipital fractures—an association prevalent in the majority of posterior fossa extradural hematomas (PFEDHs). Cranial CT not only facilitated the definition of hematoma size and mass effects but also allowed visualization of potential supratentorial conditions. Notably, in the literature, approximately half of PFEDH cases have been reported to be associated with such supratentorial conditions. The swift and informative nature of cranial CT establishes its role as a practical diagnostic tool for a comprehensive assessment of PFEDHs and their potential concomitant pathologies.^[10,11]

Posterior fossa extradural hematomas (PFEDHs) are uncommon but can have potentially rapid and fatal consequences. The expansion of the hematoma can lead to critical issues such as compression of the brainstem, tonsillar herniation, and obstructive hydrocephalus within the confined space of the posterior cranial fossa. Early diagnosis and urgent evacuation are crucial for achieving favorable outcomes. PFEDHs are often linked with occipital bone fractures and may present additional injuries, such as supratentorial or infratentorial subdural hematoma, intraparenchymal hematoma, or intraventricular hemorrhage. The management of associated intracranial injuries should be undertaken emergently based on the clinical scenario. Despite optimal care, the presence of these associated injuries can contribute to worse outcomes, with the severity of these additional injuries playing a significant role in determining the overall prognosis.