The rate of in-hospital seizures after mechanical thrombectomy has increased over time, according to study results published in Neurology Open Access.

Mechanical thrombectomy is a cornerstone therapy for acute ischemic stroke caused by large vessel occlusion (LVO), particularly after its endorsement by the American Heart Association/American Stroke Association in 2015. Patients undergoing mechanical thrombectomy typically present with severe LVO strokes involving extensive vascular territories and frequent cortical involvement. These are both established risk factors for seizures.

Researchers analyzed data from the National Inpatient Sample from 2016 to 2022 to evaluate in-hospital seizures among adults hospitalized with ischemic stroke who underwent mechanical thrombectomy. The analysis included 632,485 patients.

Overall, 1.88% of patients (n=11,903) had a seizure diagnosis recorded during the index hospitalization. The rate of seizures increased from 1.60% in 2016 to 2.34% in 2022. Rates of both status epilepticus and nonstatus seizures increased during the study period, from 0.079% to 0.206% and from 1.52% to 2.13%, respectively.

Several independent risk factors identified in this study are common and potentially modifiable early in the stroke course, highlighting opportunities for targeted metabolic and medical optimization.

Patients with status epilepticus had longer hospital stays than patients with nonstatus seizures and those without seizures (mean, 17.32 vs 7.86 vs 5.03 days, respectively; P <.001). They also had higher mean hospital charges ($371,485.72 vs $164,213.88 vs $119,561.20, respectively; P <.001) and in-hospital mortality (25% vs 6.7% vs 4.6%, respectively; P <.001).

In multivariable analyses of vascular territory and thrombectomy location, seizure risk was associated with intracranial artery thrombectomy (odds ratio [OR], 1.39; P =.016), left internal carotid artery thrombectomy (OR, 1.39; P =.014), right internal carotid artery thrombectomy (OR, 1.35; P =.026), right vertebral artery thrombectomy (OR, 2.46; P =.003), and left vertebral artery thrombectomy (OR, 2.06; P =.016). Among patients with status epilepticus, only left vertebral artery thrombectomy remained independently associated with risk (OR, 5.65; P =.002). Right anterior cerebral artery stroke was also associated with increased seizure risk (OR, 2.40; P =.002).

Comorbidities independently associated with seizure risk included the following:

  • Psychoses (OR, 2.88; P <.001);
  • Depression (OR, 1.65; P <.001);
  • Lymphoma (OR, 1.80; P =.044); 
  • Fluid and electrolyte disorders (OR, 1.43; P <.001);
  • Alcohol abuse (OR, 1.40; P =.001);
  • Chronic pulmonary disease (OR, 1.30; P <.001); and,
  • Complicated diabetes (OR, 1.15; P =.030)

Obesity was associated with lower seizure risk (OR, 0.84; P =.011). Among patients with status epilepticus, significant associations included fluid and electrolyte disorders (OR, 2.20; P <.001), uncomplicated hypertension (OR, 1.97; P =.013), complicated diabetes (OR, 1.65; P =.016), coagulopathy (OR, 1.63; P =.038), and brain herniation (OR, 2.18; P =.002).

Study limitations include the lack of detailed procedural and stroke-severity data and the inability to determine whether seizures were procedure-related. Also, seizure diagnoses were based on in-hospital coding, preventing assessment of seizure timing or postdischarge recurrence.

The study authors concluded, “Several independent risk factors identified in this study are common and potentially modifiable early in the stroke course, highlighting opportunities for targeted metabolic and medical optimization.”