Search

Objective The objective of this study was to characterize the independent risk factors for seizures in critically ill patients monitored with continuous EEG (cEEG). Methods We retrospectively investigated variables associated with cEEG seizures, first in the entire cohort of 156 patients and, subsequently, in the subgroup without seizures in the first 30 minutes of monitoring. Results Seizures were observed in 19.2% of recordings, and in 50% of these, seizures occurred in the first 30 minutes. In the entire cohort, epilepsy, acute seizures prior to cEEG, interictal epileptiform discharges (IEDs), lateralized periodic discharges (LPDs), and brief potentially ictal rhythmic discharges (BIRDs) were associated with a higher incidence of cEEG seizures, whereas coma, intravenous anaesthetic drugs, and generalized periodic discharges (GPDs) were associated with a lower incidence of seizures. On multivariate analysis, this association was maintained for acute seizures before cEEG (OR: 5.92) and IEDs (OR: 6.81). Excluding patients with seizures at the beginning of monitoring, acute seizures before cEEG, IEDs, LPDs, and BIRDs were associated with an increased risk of seizures. The presence of IEDs or LPDs in the first 30 minutes was associated with a 4.14-fold greater chance of seizures on cEEG. On multivariate analysis, acute seizures prior to recording (OR 7.29) and LPDs (OR: 5.38) remained associated with seizures on cEEG. Due to the sample size, BIRDs were not included in multivariate models. Significance Acute seizures prior to monitoring, IEDs, LPDs and BIRDs are important risk factors for cEEG seizures in critically ill patients.

We conducted a retrospective study in order to investigate the clinical significance of temporopolar grey/white matter abnormalities (GWMA) in patients with temporal lobe epilepsy (TLE) and unilateral hippocampal sclerosis (HS) with a long post-surgical follow-up.The study comprised 122 consecutive patients with medically refractory TLE and unilateral HS who underwent epilepsy surgery and had a minimum postoperative follow-up of 5 years. Patients were divided into two groups, based on findings of pre-surgical MRI: group 1 with GWMA and 2 with normal signal and grey/white matter definition in temporal pole. Demographic and clinical data were reviewed and compared between groups.GWMA were found in 52.5% of patients, always ipsilateral to HS. Compared with group 2, group 1 patients had earlier epilepsy onset (mean, 9.3 vs 14.4 years, P=0.001), a higher occurrence of first seizure ≤2 years of age (25.8% vs 10.5%, P=0.036; OR=2.96 [95% CI=1.07-8.19]), and greater prevalence of left HS (76.6% vs 43.1%, P0.001; OR=4.31 [95% CI=1.98-9.38]). No differences were found in gender, presence or type of initial precipitating injury, history of secondary generalized seizures, duration of epilepsy, seizure frequency before surgery, neuropsychological evaluation and presence or lateralization of pre-surgical interictal epileptiform discharges. Postoperative follow-up varied from 5 to 11.5 years (mean 7.4) and was similar in both groups (P=0.155). The proportion of patients classified as seizure-free (Engel class I) at last follow-up in groups 1 and 2 were 73.4% and 69%, respectively (P=0.689). Similarly, the percentages of seizure-free patients with no antiepileptic drugs at last evaluation were not different between groups (P=0.817). In logistic regression analysis, left HS (P=0.001; OR=4.166 [95% CI=1.86-9.34]) and age at epilepsy onset ≤2 years (P=0.047; OR=3.885 [95% CI=1.86-17.50]) were independently associated with risk of having GWMA.GWMA are frequent findings in patients with TLE and HS, and may help lateralize the epileptogenic zone. Our data support the hypothesis that GWMA are caused by seizure-related insults during the critical period of cerebral myelination. GWMA did not influence the postoperative seizure outcome of patients with TLE and HS, even after an extended duration of post-surgical follow-up.

Epileptic spasms were defined by the International League Against Epilepsy Task Force on Classification and Terminology in 2001 as a specific seizure type. Epileptic spasms without hypsarrhythmia have been described in some series of patients, occurring either in infancy or childhood. More prolonged epileptic spasms without hypsarrhythmia were previously defined as a different seizure type, and referred to as "tonic spasm seizures". Here, we present a 5-year-old boy who started having epileptic spasms without hypsarrhythmia at 8 months of age, effectively treated with oxcarbazepine. With the withdrawal of medication, epileptic spasms returned. Video-EEG monitoring revealed high-voltage slow waves superimposed by low-voltage fast activity, followed by an electrodecremental phase and a burst of asymmetric fast activity, time-locked to clinical tonic spasm seizures. Brain MRI showed left temporal atrophy with temporal pole grey/white matter junction blurring and ictal PET-CT showed left basal frontal hypermetabolism. Seizures were refractory to several AEDs and vigabatrin was introduced with seizure cessation. Despite efforts to classify epileptic spasms, these are still considered as part of the group of unknown seizure types. In some cases, a focal origin has been suggested, leading to the term "periodic spasms" and "focal spasms". In this case, epileptic spasms without hypsarrhythmia, associated with tonic spasms, may be a variant of focal spasms and might be considered as an epileptic syndrome. [Published with video sequence].