To analyze seizure-like motor phenomena immediately occurring after concussion (concussive convulsions).Methods
Twenty-five videos of concussive convulsions were obtained from YouTube as a result of numerous sports-related search terms. The videos were analyzed by four independent observers, documenting observations of the casualty, the head injury, motor symptoms of the concussive convulsions, the postictal period, and the outcome.Results
Immediate responses included the fencing response, bear hug position, and bilateral leg extension. Fencing response was the most common. The side of the hit (p = 0.039) and the head turning (p = 0.0002) was ipsilateral to the extended arm. There was a tendency that if the blow had only a vertical component, the bear hug position appeared more frequently (p = 0.12). The motor symptom that appeared with latency of 6 ± 3 s was clonus, sometimes superimposed with tonic motor phenomena. Clonus was focal, focally evolving bilateral or bilateral, with a duration of 27 ± 19 s (5–72 s). Where lateralization of clonus could be determined, the side of clonus and the side of hit were contralateral (p = 0.039).Significance
Concussive convulsions consist of two phases. The short-latency first phase encompasses motor phenomena resembling neonatal reflexes and may be of brainstem origin. The long-latency second phase consists of clonus. We hypothesize that the motor symptoms of the long-latency phase are attributed to cortical structures; however, they are probably not epileptic in origin but rather a result of a transient cortical neuronal disturbance induced by mechanical forces.
This study attempted to validate the effects of neonatal estradiol in ameliorating the spasms in the prenatally betamethasone-primed N-methyl-d-aspartate (NMDA) model of infantile spasms in rats as shown previously in a mouse Arx gene knock-in expansion model of infantile spasms.Methods
Neonatal rats prenatally exposed to betamethasone (on day 15 of pregnancy) were treated with subcutaneous 40 ng/g estradiol benzoate (EB) between postnatal days (P)3–P10 or P0–P5. A synthetic estrogen analogue, diethylstilbestrol, was used between P0 and P5 (2 μg per rat, s.c.). On P12, P13, and P15, the rats were subjected to NMDA-triggered spasms, and latency to onset and number of spasms were evaluated. Rats with EB on P3–P10 were tested after spasms in the open field, novel object recognition, and elevated plus maze to determine effects of treatment on behavior. Additional rats with P3–P10 or P0–P5 EB were investigated for γ-aminobutyric acid (GABA)ergic neurons (glutamate decarboxylase [GAD]67 expression) in the neocortex. As a positive control, a group of rats received either subcutaneous adrenocorticotropic hormone (ACTH) (2 × 0.3 mg/kg on P12 and 3 × 0.3 mg/kg on P13 and P14) or vehicle after the first episode of spasms on P12.Results
Neither EB treatment nor diethylstilbestrol consistently affected expression of spasms in this model, although we found a significant increase in GAD67-immunopositive cells in the neocortex after P3–P10 and P0–P5 EB treatment, consistent with a study in mice. Behavioral tests showed increase in lateralization in male rats treated with P3–P10 EB, a behavioral trait usually associated with female sex. Diethylstilbestrol treatment in male rats resulted in arrested pubertal descent of testes. ACTH had robust effects in suppressing spasms.Significance
Treatment of infantile spasms (IS) using neonatal EB may be justified in those cases of IS that present with detectable deficits in GABAergic neurons. In other types of IS, the efficacy of neonatal EB and its analogues is not supported.
Long-term socioeconomic consequences and health care costs of childhood and adolescent-onset epilepsy
To estimate long-term socioeconomic consequences and health care costs of epilepsy with onset in childhood and adolescence.Methods
A historical prospective cohort study of Danish individuals with epilepsy, age up to 20 years at time of diagnosis between January 1981 and December 2012. Information about marital status, parenthood, educational level, employment status, income, use of the health care system, and cost of medicine was obtained from nationwide administrative and health registers.Results
We identified 12,756 and 28,319 people with diagnosed with epilepsy, ages 0–5 and 6–20 years at onset, respectively. Using follow-up data for a maximum of 30 years, 1,394 of those ages 0–5 years at onset were compared with 2,897 controls persons without epilepsy, and 10,195 of those ages 6–20 years at onset were compared with 20,678 controls without epilepsy. Compared with people without the epilepsy, those with epilepsy tended to have a lower level of education, to be less likely to be married, to be more likely to live alone, and to have higher divorce and unemployment rates, lower employment rates, and people with epilepsy were more likely to receive disability pension and social security. Income was lower from employment, which in part was compensated by social security, sick pay, disability pension and unemployment benefit, sick pay (public-funded), disability pension, and other public transfers. Predicted health care costs 30 years after epilepsy onset were significantly higher among persons with epilepsy onset at 0–5 and 6–20 years, including costs for outpatient and inpatient services (hospital services), emergency room use, primary health care sector (general practice), and use of medication.Significance
The long-term negative effects on all aspects of health care and social domains, including marital status, parental socioeconomic status, educational level, employment status, and use of welfare benefits compared with controls without epilepsy calls for increased awareness on childhood- and adolescent-onset epilepsy.
Based on data from the EURAP observational International registry of antiepileptic drugs (AEDs) and pregnancy, we assessed changes in seizure control and subsequent AED changes in women who underwent attempts to withdraw valproic acid (VPA) during the first trimester of pregnancy. Applying Bayesian statistics, we compared seizure control in pregnancies where VPA was withdrawn (withdrawal group, n = 93), switched to another AED (switch group, n = 38), or maintained (maintained-therapy group, n = 1,588) during the first trimester. The probability of primarily or secondarily generalized tonic–clonic seizures (GTCS) was lower in the maintained-therapy group compared with the other two groups, both in the first trimester and for the entire duration of pregnancy. GTCS were twice as common during pregnancy in the withdrawal (33%) and switch groups (29%) compared with the maintained-treatment group (16%). Limitations in the data and study design do not allow to establish a cause–effect relationship between treatment changes and seizure outcome, but these observations provide a signal that withdrawal of, or switch from, VPA during the first trimester could lead to loss of seizure control, and highlight the need for a specifically designed prospective observational study.
There is scant evidence to guide the management of infantile spasms after successful response to initial therapies. There is significant risk of relapse, largely because effective pharmacologic treatments cannot be continued long term because of concern for significant adverse events. Zonisamide (ZNS) and topiramate (TPM) are commonly used to prevent relapse, and the purpose of this study was to specifically evaluate the efficacy of ZNS and TPM as agents for secondary prevention of infantile spasms.Methods
Patients with video–electroencephalography (EEG) confirmed resolution of infantile spasms were retrospectively identified. Relevant clinical data were systematically collected, including lead time from onset of spasms to successful treatment response, etiology of infantile spasms, number of treatment failures prior to response, timing of relapse, and detailed exposure data for ZNS and TPM.Results
We identified 106 patients with response to hormonal therapy (n = 58), vigabatrin (n = 25), or surgery (n = 23). To prevent relapse of infantile spasms, 37 patients received ZNS, 34 received TPM, 3 received both ZNS and TPM, and 38 patients received neither ZNS nor TPM. There were 44 relapses, occurring a median of 6.9 (3.2–10.8) months after initial response. Time to relapse was not affected by treatment with ZNS or TPM. Relapse was less likely among patients who were older (hazard ratio 0.97 [per month], p = 0.036) and those who responded to surgical resection (hazard ratio = 0.28, p = 0.017). Of note, we identified a relatively refractory cohort with multiple treatment failures and long lead time to initial response.Significance
In this refractory cohort, neither ZNS nor TPM was successful in preventing relapse of infantile spasms, despite relatively high dosages. At this time, aside from surgical resection in eligible candidates, there is no known treatment that is efficacious in the prevention of relapse of infantile spasms.
The aim of our study was to investigate the neuronal networks underlying background oscillations of epileptic encephalopathy with continuous spikes and waves during slow sleep (CSWS).Methods
Sleep electroencephalography (EEG) studies before and after the treatment were investigated in 15 patients with CSWS. To investigate functional and effective connectivity within the network generating the delta activity in the background sleep EEG, the methods of dynamic imaging of coherent sources (DICS) and renormalized partial directed coherence (RPDC) were applied.Results
Independent of etiology and severity of epilepsy, background EEG pattern in patients with CSWS before treatment is associated with the complex network of coherent sources in medial prefrontal cortex, somatosensory association cortex/posterior cingulate cortex, medial prefrontal cortex, middle temporal gyrus/parahippocampal gyrus/insular cortex, thalamus, and cerebellum. The analysis of information flow within this network revealed that the medial parietal cortex, the precuneus, and the thalamus act as central hubs, driving the information flow to other areas, especially to the temporal and frontal cortex. The described CSWS-specific pattern was no longer observed in patients with normalized sleep EEG. In addition, frequency of spiking showed a strong linear correlations with absolute source power, source coherence strength, and source RPDC strength at both time points: (1) Spike and wave index (SWI) versus absolute source power at EEG1 (r = 0.56; p = 0.008) and at EEG2 (r = 0.45; p = 0.009); (2) SWI versus source coherence strength at EEG1 (r = 0.71; p = 0.005) and at EEG2 (r = 0.52; p = 0.006); and (3) SWI versus source RPDC strength at EEG1 (r = 0.65; p = 0.003) and at EEG2 (r = 0.47; p = 0.009).Significance
The leading role of the precuneus and thalamus in the hierarchical organization of the network underlying the background EEG points toward the significance of fluctuations of vigilance in the generation of CSWS. This hierarchical network organization appears to be specific for CSWS as it is resolved after successful treatment.
5-Hydroxytryptophan, a precursor for serotonin synthesis, reduces seizure-induced respiratory arrest
The DBA/1 mouse is a relevant animal model of sudden unexpected death in epilepsy (SUDEP), as it exhibits seizure-induced respiratory arrest (S-IRA) evoked by acoustic stimulation, followed by cardiac arrhythmia and death. Defects in serotonergic neurotransmission may contribute to S-IRA. The tryptophan hydroxylase-2 (TPH2) enzyme converts L-tryptophan to 5-hydroxytryptophan (5-HTP), a precursor for central nervous system (CNS) serotonin (5-HT) synthesis; and DBA/1 mice have a polymorphism that decreases TPH2 activity. We, therefore, hypothesized that supplementation with 5-HTP may bypass TPH2 and suppress S-IRA in DBA/1 mice.Methods
TPH2 expression was examined by Western blot in the brainstem of DBA/1 and C57BL/6J mice both with and without acoustic stimulation. Changes in breathing and cardiac electrical activity in DBA/1 and C57BL/6J mice that incurred sudden death during generalized seizures evoked by pentylenetetrazole (PTZ) were studied by plethysmography and electrocardiography. The effect of 5-HTP administration on seizure-induced mortality evoked by acoustic stimulation or by PTZ was investigated in DBA/1 mice.Results
Repetitive acoustic stimulation resulted in reduced TPH2 protein in the brainstem of DBA/1 mice as compared with C57BL/6J mice. S-IRA evoked by acoustic stimulation in DBA/1 mice was significantly reduced by 5-HTP. Following S-IRA, cardiac electrical activity could be detected for minutes before terminal asystole and death in both DBA/1 and C57BL/6J mice after PTZ treatment. The incidence of S-IRA by PTZ administration was greater in DBA/1 than in C57BL/6J mice, and administration of 5-HTP also significantly reduced S-IRA by PTZ in DBA/1 mice.Significance
Our data suggest that S-IRA is the primary event leading to death incurred in most DBA/1 and some C57BL/6J mice during PTZ-evoked seizures. Suppression of S-IRA by 5-HTP suggests that 5-HT transmission contributes to the pathophysiology of S-IRA, and that 5-HTP, an over-the-counter supplement available for human consumption, may be clinically useful in preventing SUDEP.
Leucine-rich glioma inactived-1 (LGI1) antibodies are associated with limbic encephalitis and distinctive seizure types, which are typically immunotherapy-responsive. Although nonspecific electroencephalography (EEG) abnormalities are commonly seen, specific EEG characteristics are not currently understood to be useful for suspecting the clinical diagnosis. Based on initial observations in two patients, we analyzed the clinical features and EEG recordings in a larger series of patients (n = 9) and describe a novel ictal pattern that can suggest the diagnosis of LGI1-antibody–mediated encephalitis, even in the absence of typical clinical features. As expected, psychiatric and cognitive symptoms were common, as were tonic seizures associated with EEG electrodecremental events (often with the so-called faciobrachial dystonic semiology). Remarkably, in five patients, a near absence of interictal epileptiform discharges contrasted with frequent subclinical temporal lobe seizures, at times triggered by hyperventilation. This latter EEG pattern may facilitate early diagnosis of this serious but potentially treatable condition.
Atrophy of the pedunculopontine nucleus region in patients with sleep-predominant seizures: A voxel-based morphometry study
Non–rapid eye movement (NREM) sleep increases interictal epileptiform discharges and frequency of seizures, whereas REM sleep suppresses them. The pedunculopontine nucleus (PPN), one of the REM sleep–modulating structures, is postulated to have a potent antiepileptogenic role. We asked if patients with sleep-predominant seizures (SPS) show volume changes in the region of the PPN compared to those with seizures occurring during awake state only (nSPS). The volume of the PPN region was assessed in patients with SPS, those with nSPS, and healthy volunteers, through voxel-based morphometry and automated, nonbiased region of interest (ROI) analysis of T1 magnetic resonance (MR) images. The volume of PPN region was statistically smaller in patients with SPS (n = 33) than in those with nSPS (n = 40) and healthy controls (n = 30) after controlling for covariates. These results suggest that a structural change in the PPN may be associated with sleep-predominant timing of seizure occurrence. Our findings might help understand the intervening pathomechanism that lies between the human sleep–wake cycle and epilepsy.
Seizure-onset zone localization by statistical parametric mapping in visually normal 18F-FDG PET studies
Neuroimaging is crucial in the presurgical evaluation of patients with medically refractory epilepsy. To improve the moderate sensitivity of [18F]fluorodeoxyglucose–positron emission tomography (18F-FDG-PET), our aim was to evaluate the usefulness of statistical parametric mapping (SPM) to localize the seizure-onset zone (SOZ) in PET studies deemed normal by visual assessment.Methods
Fifty-five patients with medically refractory epilepsy whose 18F-FDG-PET was visually evaluated as normal were retrospectively included. Twenty of these patients had undergone surgical intervention. PET images were analyzed by SPM8 using a corrected p-value of p < 0.05 and three uncorrected p-values of p < 0.0001, p < 0.001, and p < 0.005, matched with minimum cluster sizes of k > 0, k > 20, k > 100, and k > 200, respectively. The SPM-identified potential seizure zone (SZ) was compared to the SOZ, which was determined by consensus during patient management meetings in the epilepsy unit, taking into account presurgical tests. Studies in which the SPM-identified potential SZ was concordant with the SOZ were considered “correctly localizing.”Results
The SPM threshold combination with the least restrictive p-value and greatest minimum cluster size achieved the highest rate of correctly localizing studies. When p < 0.005/k > 200 was used, 40% (22/55) of studies were correctly localizing, and the concordance obtained in the surgically intervened subgroup was substantial (к = 0.607, 95% confidence interval [CI] 0.258–0.957), which was comparable to the concordance obtained by magnetic resonance imaging (MRI) (к = 0.783, 95% CI 0.509–1.000).Significance
SPM offers improved SOZ localization in 18F-FDG-PET studies that are negative on visual assessment. For this purpose, statistical parametric maps could be thresholded with liberal p-values and restrictive cluster sizes.