Traumatic acute epidural hematoma caused by injury of the diploic channels

Acute epidural hemorrhage following burr-hole irrigation for chronic subdural hematoma: A possible association with the diploic veins

A 50-year-old man presented with headache and left hemiparesis. No noticeable preceding head trauma was observed. Computed tomography (CT) scans revealed a compressive chronic subdural hematoma (CSDH). The patient underwent burr-hole irrigation, during which he was considerably restless. In addition, extensive avulsion was found in the parietal dura mater posterior to the burr hole. CT performed immediately after the surgery revealed the emergence of a thick epidural hematoma (EDH) located posterior to the burr-hole. During emergency craniotomy for the EDH, there was no identifiable injury to the dura mater or the meningeal vessels. However, a review of the CT scans confirmed well-developed diploic spaces just above the center of the EDH, with connecting channels between the diploic spaces and extracranial sites. Based on these observations, we assumed that the diploic vein might have caused the EDH. Diploic veins can cause AEDH after burr hole irrigation for CSDH. Appropriate intraoperative sedation and protective irrigation maneuvers can reduce the risk of such AEDH.

Decompressive craniectomy surgery in a dog with intracranial extradural hematoma following blunt force trauma

A young miniature poodle was presented following blunt force trauma to the head. The dog initially responded well to medical management before developing clinical signs associated with increased intracranial pressure 48 h post-injury that became refractory to hyperosmolar therapy. A computed tomography scan obtained 76 h post-injury showed a short, oblique, non-displaced, complete fissure in the right temporal bone and a second short, oblique, non-displaced, complete fissure in the ventral aspect of the temporal bone. A biconvex, moderately hyperattenuating, space-occupying temporoparietal lesion was visualized immediately adjacent to the area of the temporal fractures. These findings were consistent with a diagnosis of intracranial extradural hematoma. Decompressive craniectomy successfully evacuated the extradural hematoma to alleviate increased intracranial pressure. The dog's neurologic function recovered quickly postoperatively. At follow-up physical examinations at 14 and 437 d, excellent return to function was noted. Key clinical message: This report describes the diagnosis and surgical management of an intracranial extradural hematoma in a dog with increased intracranial pressure refractory to medical management. Furthermore, this report describes the diagnostic imaging findings used to diagnose this particular form of primary brain injury.

Infantile acute subdural hemorrhage probably caused by injury to the diploic channels

A 6-month-old, previously healthy boy hit the right frontal region of his head against the corner of a plastic toy box. At presentation, a small area with scalp discoloration was noted in the right frontal region. Head computed tomography at the level of discoloration revealed an intracranial hematoma, 5 mm in maximal thickness, below the coronal suture. In addition, there were bony bridges connecting the frontal and parietal bones. Furthermore, a linear crack was found in the diploe of the frontal bone in contact with the coronal suture. Cerebral MRI confirmed linear hyperintensity between the inner tables. We assumed that a kind of ping-pong ball fracture was caused by the head blow, centering on the coronal suture, resulting in rupture of contacting diploic channels and tear of the dura mater, and forming a subdural hematoma. Acute subdural hemorrhage may be caused by an insignificant blow to the coronal suture in infantile patients with underdeveloped cranial bones and sutures, accompanied by subtle external findings.

Calvarial diploic venous channels: delineation with maximal intensity projection technique

PURPOSE

To date, very few studies have explored the three-dimensional architecture of calvarial diploic venous channels (CDVCs). This study aimed to characterize the three-dimensional architecture of CDVCs using maximum intensity projection (MIP) images based on contrast-enhanced magnetic resonance imaging (MRI).

METHODS

A total of 77 patients with intact calvarial hemispheres and underlying dura mater and dural sinuses underwent contrast-enhanced MRI. Among them, we extracted the data of 49 with at least a part of the major CDVC pathways identified on the MIP images for analysis.

RESULTS

On serial contrast-enhanced MRI images, the CDVCs were commonly detected as curvilinear structures with inhomogeneous diameters and tributaries, while the MIP images delineated the three-dimensional architecture of the developed CDVC pathways. More than such CDVC pathway was entirely delineated on the right in 67.3% and on the left in 71.4%, most frequently in the frontal and temporal regions, with their connecting sites to the sphenoparietal and superior sagittal sinuses. The morphology, distribution, and course of the identified CDVCs were highly variable. In 55.1%, the CDVCs formed fenestrations that were variable in size, shape, and number.

CONCLUSIONS

The developed CDVC pathways may be characterized by morphological variability and fenestrations. Thin-sliced, contrast-enhanced MRI is useful to depict diploic veins, while MIP images allow for better appreciation of the entire course of the developed CDVC pathways. Traumatic and intraoperative disconnection between the dura mater overlying the dural sinuses and the adjacent inner table of the skull can cause epidural venous bleeding.