The role of perfusion CT in identifying stroke mimics in the emergency room: a case of status epilepticus presenting with perfusion CT alterations

The differentiation between stroke and seizure can be a clinically arduous task for both emergency medicine physicians and neurologists [1,2]. Patients with diseases that mimic stroke account for one-fifth of patients with brain attacks [1]. Imaging may therefore be critical in making a diagnosis in the acute setting. Seizure is one condition that can mimic a stroke. Commonly, patients with Todd's paralysis or those with nonconvulsive status epilepticus can be clinically indistinct from those with acute stroke. Further complicating the clinical scenario, seizure may also be a presenting sign of stroke [3]. Recently the time frame for standard treatment of acute stroke with IV tissue plasminogen activator was expanded from 3 h to 4.5 h from ictus onset [4]. Although this extension of time is supported by the American Heart Association, it is not FDA approved and comes with a different set of relative contraindications. Intravenous thrombolytics are not without the risk of complications, including intracranial hemorrhage [5]. Non-contrast CT (NCCT) of the head is the current gold standard in excluding intracranial hemorrhage prior to administration of intravenous thrombolysis. However, NCCT has a limited role in differentiating those patients with stroke from those with seizure. Although current guidelines advocate only NCCT as the imaging modality of choice in the initial evaluation of acute stroke, this case illustrates the importance of CT perfusion studies in the radiographic evaluation of brain attack patients in order to avoid misdiagnosis and inadvertent treatment of non-stroke patients with thrombolytic therapy. Furthermore, whereas hypoperfusion related to strokes has been widely investigated by CT-perfusion imaging [6,7], this case demonstrates the hyperperfusion state often seen on perfusion CT in emergency room patients with epilepsy. We describe an interesting case of a patient presenting to the Shands Hospital at the University of Florida emergency room