A 72-year-old female with a past history of a right frontoparietal stroke and residual left hemiparesis presented to the ER with a one-day history of headache and confusion. One month previously she had been diagnosed with a deep venous thrombosis in her leg and had been started on lovenox and Coumadin. There was no reported history of antecedent trauma. Physical exam, other than the residual deficits from her previous infarct, was noncontributory. Laboratory values were within normal limits given patient's current anticoagulation status. A noncontrast head CT was subsequently performed and demonstrated an area of extra-axial hyperdensity marginating the clivus and extending from the most inferiorly visualized aspect of the anterior foramen magnum cephalad towards the left and right cerebellopontine angle cisterns (Figures 1,2). A spontaneous retroclival subdural hematoma was suspected. Less likely considerations included an extra-axial hypercellular mass such as meningioma, lymphoma or plasmacytoma.
Axial noncontrast CT image through the posterior fossa demonstrates an area of extra-axial hyperdensity compatible with hemorrhage in the retroclival region effacing the pontomedullary subarachnoid space. Remote left cerebellar infarct incidentally observed.
Axial noncontrast CT at the level of the foramen magnum demonstrates mild compression of the cervicomedullary junction by the extra-axial hematoma.
Appl Radiol. 2017;46(3) © 2017 Anderson Publishing, Ltd.