Clinical pathways of epileptic seizures and status epilepticus: results from a survey in Italy

Modafinil exerts anticonvulsive effects against lithium-pilocarpine-induced status epilepticus in rats: A role for tumor necrosis factor-α and nitric oxide signaling

BACKGROUND

Status epilepticus (SE) is a continuous episode of seizures which leads to hippocampal neurodegeneration, severe systemic inflammation, and extreme damage to the brain. Modafinil, a psychostimulant and wake-promoting agent, has exerted neuroprotective and anti-inflammatory effects in previous preclinical studies. The aim of this study was to assess effects of modafinil on the lithium-pilocarpine-induced SE rat model and to explore possible involvement of tumor necrosis factor-α (TNF-α) and nitric oxide (NO) pathways in this regard.

METHODS

Status epilepticus was provoked by injection of lithium chloride (127 mg/kg, intraperitoneally [i.p]) and pilocarpine (60 mg/kg, i.p.) in rats. Animals received different modafinil doses (50, 75, 100, and 150 mg/kg, i.p.) and SE scores were documented over 3 hours of duration. Moreover, the role of the nitrergic pathway in the effects of modafinil was evaluated by injection of the non-selective NO synthase (NOS) inhibitor L-N^G-Nitro arginine methyl ester (L-NAME, 10 mg/kg, i.p.), the selective neuronal NOS inhibitor 7-nitroindazole (30 mg/kg, i.p.), and the selective inducible NOS inhibitor aminoguanidine (100 mg/kg, i.p.) 15 min before saline/vehicle or modafinil. The ELISA method was used to quantify TNF-α and NO metabolite levels in the isolated hippocampus.

RESULTS

Modafinil at 100 mg/kg significantly decreased SE scores (P < 0.01). Pre-treatment with L-NAME, 7-nitroindazole, and aminoguanidine significantly reversed the anticonvulsive effects of modafinil. Status epilepticus-induced animals showed significantly higher NO metabolite and TNF-α levels in their hippocampal tissues, an effect that was reversed by modafinil (100 mg/kg, i.p.) treatment. Administration of NOS inhibitors resulted in excessive NO level reduction but an escalation of TNF-α level in modafinil-treated SE-animals.

CONCLUSION

Our study revealed anticonvulsive effects of modafinil in the lithium-pilocarpine-induced SE rat model via possible involvement of TNF-α and nitrergic pathways.

Status epilepticus: review on diagnosis, monitoring and treatment

Status epilepticus (SE) is a frequent neurological emergency associated with high morbidity and mortality. According to the new ILAE 2015 definition, SE results either from the failure of the mechanisms responsible for seizure termination or initiation, leading to abnormally prolonged seizures. The definition has different time points for convulsive, focal and absence SE. Time is brain. There are changes in synaptic receptors leading to a more proconvulsant state and increased risk of brain lesion and sequelae with long duration. Management of SE must include three pillars: stop seizures, stabilize patients to avoid secondary lesions and treat underlying causes. Convulsive SE is defined after 5 minutes and is a major emergency. Benzodiazepines are the initial treatment, and should be given fast and an adequate dose. Phenytoin/fosphenytoin, levetiracetam and valproic acid are evidence choices for second line treatment. If SE persists, anesthetic drugs are probably the best option for third line treatment, despite lack of evidence. Midazolam is usually the best initial choice and barbiturates should be considered for refractory cases. Nonconvulsive status epilepticus has a similar initial approach, with benzodiazepines and second line intravenous (IV) agents, but after that, aggressiveness should be balanced considering risk of lesion due to seizures and medical complications caused by aggressive treatment. Usually, the best approach is the use of sequential IV antiepileptic drugs (oral/tube are options if IV options are not available). EEG monitoring is crucial for diagnosis of nonconvulsive SE, after initial control of convulsive SE and treatment control. Institutional protocols are advised to improve care.

The Potential Therapeutic Role of the HMGB1-TLR Pathway in Epilepsy

Epilepsy is one of the most common serious neurological disorders, affecting over 70 million people worldwide. For the treatment of epilepsy, antiepileptic drugs (AEDs) and surgeries are widely used. However, drug resistance and adverse effects indicate the need to develop targeted AEDs based on further exploration of the epileptogenic mechanism. Currently, many efforts have been made to elucidate the neuroinflammation theory in epileptogenesis, which may show potential in the treatment of epilepsy. In this respect, an important target protein, high mobility group box 1 (HMGB1), has received increased attention and has been developed rapidly. HMGB1 is expressed in various eukaryotic cells and localized in the cell nucleus. When HMGB1 is released by injuries or diseases, it participates in inflammation. Recent studies suggest that HMGB1 via Toll-like receptor (TLR) pathways can trigger inflammatory responses and play an important role in epilepsy. In addition, studies of HMGB1 have shown its potential in the treatment of epilepsy. Herein, the authors analyzed the experimental and clinical evidence of the HMGB1-TLR pathway in epilepsy to summarize the theory of epileptogenesis and provide insights into antiepileptic therapy in this novel field.

An online, interactive, screen-based simulator for learning basic EEG interpretation

OBJECTIVE

Develop and pilot test a simulator that presents ten commonly encountered representative clinical contexts for trainees to learn basic electroencephalogram (EEG) interpretation skills.

METHODS

We created an interactive web-based training simulator that allows self-paced, asynchronous learning and assessment of basic EEG interpretation skills. The simulator uses the information retrieval process via a free-response text box to enhance learning. Ten scenarios were created that present dynamic (scrolling) EEG tracings resembling the clinical setting, followed by questions with free-text answers. The answer was checked against an accepted word/phrase list. The simulator has been used by 76 trainees in total. We report pilot study results from the University of Florida's neurology residents (N = 24). Total percent correct for each scenario and average percent correct for all scenarios were calculated and correlated with most recent In-training Examination (ITE) and United States Medical License Examination (USMLE) scores.

RESULTS

Neurology residents' mean percent correct scenario scores ranged from 27.1-86.0% with an average scenario score of 61.2% ± 7.7. We showed a moderately strong correlation r = 0.49 between the ITE and the average scenario score.

CONCLUSION

We developed an online interactive EEG interpretation simulator to review basic EEG content and assess interpretation skills using an active retrieval approach. The pilot study showed a moderately strong correlation r = 0.49 between the ITE and the average scenario score. Since the ITE is a measure of clinical practice, this is evidence that the simulator can provide self-directed instruction and shows promise as a tool for assessment of EEG knowledge.

Long-term efficacy and cognitive effects of bilateral hippocampal deep brain stimulation in patients with drug-resistant temporal lobe epilepsy

PURPOSE

Temporal lobe epilepsy patients treated with hippocampal deep brain stimulation (Hip-DBS) have rarely been reported before. Preoperative and postoperative cognitive function is seldom analyzed.

METHODS

Seven patients with drug-resistant temporal lobe epilepsy were included in this study. Bilateral Hip-DBS was performed in these patients. The stimulator was activated 1 month after the implantation. Then, the patients returned for further adjustments 4 months after the surgery and reprogramming every year. The seizure frequency, Wechsler Adult Intelligence Scale-IV, and Wechsler memory scale-IV were assessed blindly as the outcomes at each follow-up.

RESULTS

After a mean 48-month follow-up, the mean seizure frequency significantly decreased (p = 0.011, paired t test; decrease of 78.1%). One patient (14.3%) was seizure-free by the last follow-up; six of seven (85.7%) patients had reductions in seizure frequency of at least 50%; one patient (14.3%) who did not comply with the antiepileptic drug instructions had a less than 50% reduction in seizure frequency. In addition, there were no significant decreases in intelligence or verbal and visual memory from baseline to the last follow-up (p = 0.736, paired t test; p = 0.380, paired t test, respectively).

CONCLUSION

Hip-DBS could provide acceptable long-term efficacy and safety. For patients with drug-resistant temporal lobe epilepsy who are not suitable for resective surgery, Hip-DBS could become a potential therapeutic option.