Magnetic Resonance Imaging after Seizures in Patients with an Ischemic Stroke

Impact of Seizure Recurrence on 1-Year Functional Outcome and Mortality in Patients With Poststroke Epilepsy

BACKGROUND AND OBJECTIVES

The functional outcome and mortality of post-stroke epilepsy (PSE) patients have not been assessed in a prospective study. Previous reports have suggested that PSE patients may suffer from prolonged functional deterioration following a seizure. In the current study, we prospectively investigated the functional outcome and mortality of PSE patients and analyzed the impact of seizure recurrence on the outcomes.

METHODS

This is part of the Prognosis of Post-Stroke Epilepsy (PROPOSE) study, a multicenter, prospective observational cohort study, where 392 PSE patients (at least one unprovoked seizure more than 7 days after the onset of the last symptomatic stroke) were followed for at least 1 year at eight hospitals in Japan. The current study included only PSE patients with a first-ever seizure and assessed their functional decline and mortality at 1 year. Functional decline was defined as an increase in modified Rankin Scale (mRS) score at 1 year compared to baseline, excluding death. The associations between seizure recurrence and the outcomes were analyzed statistically.

RESULTS

A total of 211 patients (median age of 75 years; median mRS score of 3) were identified. At 1 year, 50 patients (23.7%) experienced seizure recurrence. Regarding outcomes, 25 patients (11.8%) demonstrated functional decline, and 20 (9.5%) had died. Most patients died of pneumonia or cardiac disease (seven patients each), and no known causes of death were directly related to recurrent seizures. Seizure recurrence was significantly associated with functional decline (odds ratio 2.96 [95% CI 1.25-7.03], P=0.01), even after adjusting for potential confounders (adjusted odds ratio 3.26 [95% CI 1.27-8.36], P=0.01), but not with mortality (odds ratio 0.79 [95% CI 0.18-2.61], P=0.79). Moreover, there was a significant trend where patients with more recurrent seizures were more likely to have functional decline (8.7%, 20.6%, and 28.6% in none, 1, and 2 or more recurrent seizures, respectively; P=0.006).

DISCUSSION

One-year functional outcome and mortality of PSE patients were poor. Seizure recurrence was significantly associated with functional outcome, but not with mortality. Further studies are needed to ascertain whether early and adequate anti-seizure treatment can prevent the functional deterioration of PSE patients.

Prognosis of poststroke epilepsy

This narrative review describes the literature on the impact of poststroke epilepsy (PSE) on stroke rehabilitation, quality of life (QoL), and mortality. Since severe stroke is a risk factor for PSE, it is not surprising that many studies report associations between PSE and poor functional outcome after stroke. However, some studies also report associations between PSE and outcome with multivariate analysis with adjustment for stroke severity, indicating that PSE may hamper rehabilitation. The mechanisms of such an effect remain unknown, and more studies are needed. Although the literature is heterogeneous, evidence is accumulating that PSE increases the risk of death. The majority of deaths are attributed to vascular disease, highlighting the importance of treating vascular risk in patients with PSE. Patients with PSE report poor QoL, especially if seizure freedom is not achieved. It is, therefore, worrying that although PSE is often considered easy to treat, many patients fail to achieve seizure freedom. Neurologists treating PSE should pursue seizure freedom in the same manner as all patients. With improved survival after stroke and raised ambitions in rehabilitation after stroke, the impact of PSE on life after stroke is a matter of growing importance. Future studies are needed on interventions that reduce the risk of vascular events in PSE. Qualitative studies describing obstacles experienced by patients with PSE are also currently lacking in the literature. This article is part of the Special Issue "Seizures & Stroke".

Seizures and epilepsy in patients with a posterior circulation infarct

Seizures occur mainly in patients with cortical infarcts in the anterior circulation. Those related to a posterior circulation infarct (POCI) are considered rare. This study investigated the characteristics of patients with seizures related to a POCI. A total of 180 consecutive patients admitted with a POCI had a 2- to 7-year follow-up; 24 of them (13.6%) developed seizures. Vascular risk factors, etiology and extension of the infarct, degree of neurologic impairment, and outcome were compared in the patients with and without seizures. Complex partial type seizure was the most common presentation. Stroke characteristics were largely the same in the patients with and without seizures. History of a previous stroke was noted in 62.5% of the seizure group and in 17.9% of the nonseizure group (P < .001). Clinical outcome was worse in the seizure group (P = .004). The relative incidence of seizures in patients with a POCI was not lower than that in the overall stroke population. The high incidence of recurrent stroke is the main risk factor for seizures in patients with a POCI. The seizures themselves are responsible for the increased dependence rate.

Chronic obstructive pulmonary disease as a risk factor for stroke-related seizures

Chronic obstructive pulmonary disease (COPD) is a risk factor for cardiovascular disorders and different types of stroke. The present retrospective study investigates whether COPD is also a risk factor for the development of seizures in stroke patients. The study population consisted of 237 patients with stroke-related seizures. The control population was composed of 939 patients, admitted for a stroke between 2002 and 2004 and who did not develop epileptic spells on a follow up of 2 years. The stroke type and aetiology, and the vascular risk factors, including COPD, were compared. The seizure patients were older (P = 0.009) and had more arterial hypertension (P = 0.046) and cardiac-embolic strokes (P = 0.045) than the control group. On logistic regression only partial anterior circulation syndrome/infarct (PACS/I) and COPD (P < 0.001) emerged as independent risk factors for the development of seizures in stroke patients. The occurrence of seizures was not related to the severity of the COPD or to its type of treatment. The present study confirms that seizures occur most frequently in patients with a PACS/I. Although we were unable to demonstrate why COPD is a risk factor for seizures in stroke patients, its frequent associated nocturnal oxygen desaturation seems to be the most plausible explanation. Further prospective are needed to assess the role of COPD as a possible independent risk factor for stroke-related seizures.