Authors: Camilo Andrés Romero Hernández, Nathaly Cerón Blanco, Jonathan Suárez Rubiano, Nicolás Soto Moreno.
Stroke represents one of the main causes of mortality in the world, being estimated as the clinical condition with the highest number of associated deaths only behind ischemic heart disease [1]. Of which approximately 80% of stroke are of ischemic origin [2]. One third of these events may correspond to proximal occlusions of the intracranial arteries of the anterior or posterior circulation. Basilar artery occlusion (BAO) represents approximately 1% of ischemic strokes and 5% of all occlusions of large cerebral vessels [3]. BAO is a catastrophic event, 70% of patients have a fatal outcome or severe disability [3].
Recent studies have shown that endovascular treatment of BAO is safe, with a greater probability of reperfusion and leads to better outcomes than medical treatment [4,5]. Successful endovascular management of BAO depends in part on the promptness of intervention. However, early identification of BAO can sometimes be difficult. Simple cranial computed tomography (CT), which is the recommended image for the initial evaluation of patients with suspected stroke, has a low sensitivity for detecting posterior fossa ischemic signs compared to brain MRI [6]. Additionally, the clinical presentation of BAO is challenging and difficult to interpret, taking into account the large territory that the basilar irrigates, which gives rise to a variety of symptoms and signs, as well as sharing some similar clinical characteristics with stroke of the anterior system [7].
In proximal occlusions of the intracranial arteries, it is sometimes possible to detect the hyperdense artery sign on simple skull CT. The sign consists of a hyperdense image corresponding to the course of an artery. Intravascular hyperdensity may appear before ischemic parenchymal changes and in this context represents acute thrombus formation. The hyperdense appearance is determined by the increase in hematocrit and the relative decrease in plasma within the thrombus [8]. The hyperdense sign has been more frequently described in proximal occlusions of the middle cerebral artery and has been associated with a greater probability of a stroke of cardioembolic origin. The hyperdense sign in BAO has been less frequently described and its association with the mechanism of ischemia and patient prognosis has not been established [9].
Two cases of the hyperdense sign on simple skull CT due to BAO are presented below.