Concordance between the interictal focal EEG pattern and MRI lesions as a predictor of a favorable surgical outcome in patients with epileptic spasms: a Chinese study.

OBJECTIVE

The aim of this study was to evaluate the electro-clinical features, etiology, treatment, and postsurgical seizure outcomes in patients with intractable epileptic spasms (ESs).

METHODS

The authors retrospectively studied the medical records of all patients who had presented with medically intractable ESs and had undergone surgery in the period between October 2009 and August 2015. The interictal electroencephalography (EEG) pattern, MRI studies, magnetoencephalography findings, and postsurgical seizure outcomes were compared.

RESULTS

Twenty-six patients, 12 boys and 14 girls (age range 3-22 years), were eligible for study inclusion. Of these 26 patients, 84.6% (22) presented with multiple seizure types including partial seizures (PSs) independent of the ESs (30.8%); ESs followed by tonic seizures (30.8%); myoclonic seizures (19.2%); tonic seizures (19.2%); ESs followed by PSs (19.2%); focal seizures with secondary generalization (15.4%); atypical absence (11.5%); PSs followed by ESs (7.7%); and myoclonic followed by tonic seizures (7.7%). Seventeen patients underwent multilobar resection and 9 underwent unilobar resection. At the last follow-up (mean 36.6 months), 42.3% of patients were seizure free (outcome classification [OC] 1), 23.1% had > 50% reduction in seizure frequency (OC2-OC4), and 34.6% had < 50% reduction in seizure frequency or no improvement (OC5 and OC6). Predictors of favorable outcomes included an interictal focal EEG pattern and concordance between interictal EEG and MRI-demonstrated lesions (p = 0.001 and 0.004, respectively).

CONCLUSIONS

A favorable surgical outcome is achievable in a highly select group of patients with ESs secondary to structural lesions. Interictal EEG can help in identifying patients with the potential for favorable resective outcomes.