A Glioma Presenting as a Posterior Circulation Stroke

Initial computed tomography (CT) revealed an area of hypodensity in the left occipital lobe in the distribution of the posterior cerebral artery (Figure 1). Besides the hemianopsia, the neurological examination was unremarkable. During his first 24 h within hospital, he experienced a generalized tonic-clonic seizure and subsequent magnetic resonance imaging (MRI) showed a confluent hyperintensity in the left temporo-occipital region with a small area of restricted diffusion and no enhancement (Figure 1). The typical presentation of glioblastoma is a rapidly progressive neurological deficit, but acute presentations due to seizures or hemorrhage are well known.2 Ischemic strokes associated with glioblastoma are rare, but infiltration or compression of arterial walls, leptomeningeal involvement, and a procoagulant state have been described as possible precipitant factors.3 De novo glioblastomas have also been reported in the area previously affected by a stroke, possibly due to loss of blood–brain barrier integrity, immune surveillance or changes in the lesion microenvironment.4 Gliomas mimicking ischemic stroke have been reported in the literature, with glioblastomas and high-grade gliomas being the most common.5-7 Seizures are one of the most frequent presenting symptoms in glioblastoma, occurring in up to 40% of cases, but seizures also account for approximately 20% of all suspected strokes and are the most common stroke mimic.2,8 The occipital lobe is the least frequent lobar localization for gliomas, although it is also a highly epileptogenic area.9,10 Diagnostic certainty is essential in order to expedite tissue diagnosis and treatment.