Temporal Lobe Epilepsy after Refractory Status Epilepticus: An Illustrative Case and Review of the Literature

New onset refractory status epilepticus (NORSE) is a relatively newly defined disease entity, where otherwise healthy individuals develop unrelenting seizures that do not respond to conventional anticonvulsant therapy and may require months of therapy with anesthetic drugs. We have described a case of NORSE who subsequently developed mesial temporal lobe sclerosis (MTS) and recurrent temporal lobe seizures. We discuss the possible pathophysiological mechanisms by which refractory seizures may contribute to the development of temporal lobe epilepsy (TLE). 1. Introduction Temporal lobe pathology is associated with critical illness via a variety of mechanisms. Cardiac arrhythmias and asystole are known to complicate temporal lobe seizures [1]. Severe infections of the nervous system, such as herpes simplex virus infection, can cause hemorrhagic destruction of the temporal lobe and subsequent cerebral edema and herniation. The temporal tips and mesial temporal lobe structures are also commonly affected in traumatic brain injury, often resulting in memory impairment, posttraumatic epilepsy, and other deficits [2–4]. The hippocampus is the most vulnerable structure in cases of hypoxic-ischemic insults, as with transient cardiac arrest, with profound memory deficit as a frequent outcome [5]. Perhaps one of the most common reasons that an intensivist (or neurointensivist) may come to care for patients with ultimate temporal lobe dysfunction is with seizures, particularly status epilepticus. Status epilepticus has often been associated with temporal lobe epilepsy as being a complication of, or a cause of, temporal lobe pathology. Although there have been many studies which have evaluated the clinical outcome of patients with status epilepticus (and refractory status epilepticus) in the intensive care setting [6–11], there is relatively little data regarding temporal lobe epilepsy as a sequela of prolonged seizure activity outside of febrile status epilepticus [10–13]. More importantly, the exact mechanisms relating an episode of status epilepticus with subsequent temporal lobe epilepsy remain largely unclear. In this report, we provide a case illustration of a previously well patient who subsequently developed multifocal epilepsy following new-onset refractory status epilepticus (NORSE) syndrome of unclear etiology [14]. The epilepsy syndrome was characterized by independent bilateral temporal lobe epilepsy (TLE), plus multifocal interictal epileptic spikes that were also maximal in the temporal regions. We use this case to illustrate that refractory status