In the fast lane: Receptor trafficking during status epilepticus

Status epilepticus: Is there a Stage 1 plus?

In status epilepticus (SE), "time is brain." Currently, first-line therapy consists of benzodiazepines (BDZs) and SE is classified by the response to treatment; stage 2 or established SE is defined as "BDZ-resistant SE." Nonetheless, this classification does not always work, especially in the case of prolonged convulsive SE, where many molecular changes occur and γ-aminobutyric acid signaling becomes excitatory. Under these circumstances, BDZ therapy might not be optimal, and might be possibly detrimental, if given alone; as the duration of SE increases, so too does BDZ resistance. Murine models of SE showed how these cases might benefit more from synergistic combined therapy from the start. The definition of Stage 1 plus is suggested, as a stage requiring combined therapy from the start, which includes prolonged SE with seizure activity going on for >10 min, the time that marks the disruption of receptor homeostasis, with increased internalization. This specific stage might require a synergistic approach from the start, with a combination of first- and second-line treatment.

Staged treatment response in status epilepticus: Lessons from the SENSE registry

OBJECTIVES

Although in epilepsy patients the likelihood of becoming seizure-free decreases substantially with each unsuccessful treatment, to our knowledge this has been poorly investigated in status epilepticus (SE). We aimed to evaluate the proportion of SE cessation and functional outcome after successive treatment steps.

METHODS

We conducted a post hoc analysis of a prospective, observational, multicenter cohort (Sustained Effort Network for treatment of Status Epilepticus [SENSE]), in which 1049 incident adult SE episodes were prospectively recorded at nine European centers. We analyzed 996 SE episodes without coma induction before the third treatment step. Rates of SE cessation, mortality (in ongoing SE or after SE control), and favorable functional outcome (assessed with modified Rankin scale) were evaluated after each step.

RESULTS

SE was treated successfully in 838 patients (84.1%), 147 (14.8%) had a fatal outcome (36% of them died while still in SE), and 11 patients were transferred to palliative care while still in SE. Patients were treated with a median of three treatment steps (range 1-13), with 540 (54.2%) receiving more than two steps (refractory SE [RSE]) and 95 (9.5%) more than five steps. SE was controlled after the first two steps in 45%, with an additional 21% treated after the third, and 14% after the fourth step. Likelihood of SE cessation (p < 0.001), survival (p = 0.003), and reaching good functional outcome (p < 0.001) decreased significantly between the first two treatment lines and the third, especially in patients not experiencing generalized convulsive SE, but remained relatively stable afterwards.

SIGNIFICANCE

The significant worsening of SE prognosis after the second step clinically supports the concept of RSE. However, and differing from findings in human epilepsy, RSE remains treatable in about one third of patients, even after several failed treatment steps. Clinical judgment remains essential to determine the aggressiveness and duration of SE treatment, and to avoid premature treatment cessation in patients with SE.