Pharmacology of new and developing intravenous therapies for the management of seizures and epilepsy

Transient postictal dysphagia in older adults with focal structural epilepsy

OBJECTIVE

Seizures can cause transient neurological symptoms, such as hemiparesis and aphasia. However, temporary swallowing changes leading to postictal dysphagia have not been previously described. Therefore, this study evaluated the presence of swallowing disorders following seizure. In addition, dysphagia severity and duration of any recovery from dysphagic symptoms were investigated.

METHODS

The local clinical database of all fiberoptic endoscopic evaluation of swallowing (FEES) examinations performed from 2008 to 2019 was screened for patients diagnosed with seizures, but excluding patients with intensive care unit admission or intubation >24 h. Patient charts were evaluated to identify preexisting dysphagia or potential concurrent medical causes for dysphagia, including hyponatremia, increased intracranial pressure, sepsis, or other encephalopathies associated with infections, or other possible causes at the time of admission. Patients receiving >.5 defined daily doses of benzodiazepines or neuroleptics were also excluded. Age, sex, seizure semiology and etiology, comorbidities, concurrent pneumonia, and dysphagia course during hospitalization were evaluated as predictors of the occurrence of dysphagia or its potential duration.

RESULTS

We identified 41 patients with dysphagia following a seizure, without evidence of any concurrent cause of swallowing dysfunction. These patients all presented with focal structural epilepsy, they had a mean age of 79 ± 11.3 years (range = 44-95 years), and 21 were women. The mean Elixhauser Comorbidity Score was 4.8. Hospital-acquired pneumonia was detected in 21 patients (51.2%). FEES diagnosed mild and severe dysphagia in 21 (51.2%) and 20 (48.8%) patients, respectively. Dysphagia improved significantly (p = .001) during hospitalization, persisting for an average of 3.9 days (median = 3 days, SD = 2.07 days, range = 1-8 days).

SIGNIFICANCE

Dysphagia is a potential transient neurological deficit following seizure. Our findings suggest that older patients, with focal structural epilepsy, are at risk for postictal dysphagia. Further studies are needed to ascertain the prevalence, complications, and predictors of postictal dysphagia. Dysphagia screening may improve early detection in patients with relevant risk factors, as well as reduce the occurrence of aspiration pneumonia.

The real-world effectiveness of intravenous brivaracetam as a second-line treatment in status epilepticus

PURPOSE

Status epilepticus (SE) is defined by abnormally prolonged seizures that may lead to brain damage and death. Our aim was to evaluate the efficacy and tolerability (effectiveness) of intravenous brivaracetam (BRV) as a second-line treatment.

METHODS

Twenty-one patients (median age 68 years ± 17.28) were prospectively recruited between June 2019 and December 2022. Patients were treated with BRV (50-200 mg) as a second-line add-on therapy for SE. We evaluated the response of SE to the administration of BRV in terms of SE termination and recurrence of epileptic seizures at 6, 12, and 24 h, also monitoring safety. The first-line therapy was represented by intravenous benzodiazepines (mainly diazepam).

RESULTS

Almost a quarter of patients had generalized seizures, whereas the vast majority (76.2%) presented focal seizures. In 52.4% of patients, the underlying cause was cerebrovascular. Fourteen (66.7%) patients displayed a good early response in the subsequent 6 h. At 12 and 24 h, 8 (38%) and 11 (52.4%) patients, respectively, did not present seizures.

CONCLUSION

The present study highlights the potential of BRV when used as an early add-on therapy in SE, further confirming its good safety profile.

Propofol mitigates brain injury and oxidative stress, and enhances GABAA receptor α1 subunit expression in a rat model of lithium chloride-pilocarpine induced status epilepticus

Background/aim

Propofol is a positive allosteric modulator of GABAA receptor (GABAAR) and has potent antioxidant activity. The aim of this study was to investigate the effect of propofol on damage to the cerebral cortex and hippocampus in a lithium chloride (LiCl)-pilocarpine animal model of status epilepticus (SE).

Materials and methods

Adult male Sprague Dawley rats were injected with LiCl-pilocarpine to induce SE. They were then randomized and injected 30 min later with vehicle saline (SE+saline), propofol (SE+PPF, 50 mg/kg), Diazepam (SE+DZP, 10 mg/kg), Scopolamine (SE+SCOP, 10 mg/kg), or MK-801 (SE+MK-801, 2 mg/kg). Another group of rats received saline only and served as the naïve control (BLK). The levels of superoxide dismutase (SOD), glutathione (GSH) and malondialdehyde (MDA) in the serum, cortex and hippocampus were analyzed 2 and 24 h posttreatment. The degree of tissue damage in the cortex and hippocampus of individual rats was assessed 24 h posttreatment, together with expression of the GABAAR α1 subunit.

Results

The propofol group showed reduced levels of tissue damage in the cerebral cortex and hippocampus, decreased levels of MDA, and increased levels of GSH compared to the SE+saline group. No changes in SOD level were observed in serum and tissue samples from the cortex and hippocampus of SE+saline rats. Immunohistochemistry and Western blot assays showed that propofol treatment significantly increased the expression of GABAAR α1 subunit in the cortical and hippocampal tissues of SE rats.

Conclusion

Propofol treatment protected against SE-induced tissue injury in the cortex and hippocampus of rats. This was due at least in part to its antioxidant activity and to its induction of GABAAR α1 subunit expression in the brain.

Nanotechnologies for intranasal drug delivery: an update of literature

Scientific research has focused its attention on finding an alternative route to systemic oral and parenteral administration, to overcome their usual drawbacks, such as hepatic first-pass which decreases drug bioavailability after oral administration, off-target effects, low patient compliance and low speed of onset of the pharmacological action in first-aid cases. Innovative drug delivery systems (DDS), mainly based on polymer and lipid biocompatible materials, have given a great prompt in this direction in the last years. The intranasal (IN) route of administration is a valid non-invasive alternative. It is highly suitable for self-administration, the drug quickly reaches the bloodstream, largely avoiding the first pass effect, and can also reach directly the brain bypassing BBB. Association of IN route with DDS can thus become a winning strategy for the controlled delivery of drugs, especially when a very quick effect is desired or needed. This review aims at analyzing the scientific literature regarding IN-DDS and their different ways of administration (systemic, topical, pulmonary, nose-to-brain). In particular, attention was devoted to polymer- and lipid-based micro- and nanocarriers, being the topic of most published articles in the last decade, but the whole plethora of colloidal DDS investigated in recent years for IN administration was presented.

Pharmacotherapy for Nonconvulsive Seizures and Nonconvulsive Status Epilepticus

Most seizures in critically ill patients are nonconvulsive. A significant number of neurological and medical conditions can be complicated by nonconvulsive seizures (NCSs) and nonconvulsive status epilepticus (NCSE), with brain infections, hemorrhages, global hypoxia, sepsis, and recent neurosurgery being the most prominent etiologies. Prolonged NCSs and NCSE can lead to adverse neurological outcomes. Early recognition requires a high degree of suspicion and rapid and appropriate duration of continuous electroencephalogram (cEEG) monitoring. Although high quality research evaluating treatment with antiseizure medications and long-term outcome is still lacking, it is probable that expeditious pharmacological management of NCSs and NCSE may prevent refractoriness and further neurological injury. There is limited evidence on pharmacotherapy for NCSs and NCSE, although a few clinical trials encompassing both convulsive and NCSE have demonstrated similar efficacy of different intravenous (IV) antiseizure medications (ASMs), including levetiracetam, valproate, lacosamide and fosphenytoin. The choice of specific ASMs lies on tolerability and safety since critically ill patients frequently have impaired renal and/or hepatic function as well as hematological/hemodynamic lability. Treatment frequently requires more than one ASM and occasionally escalation to IV anesthetic drugs. When multiple ASMs are required, combining different mechanisms of action should be considered. There are several enteral ASMs that could be used when IV ASM options have been exhausted. Refractory NCSE is not uncommon, and its treatment requires a very judicious selection of ASMs aiming at reducing seizure burden along with management of the underlying condition.

Utilizing Neurons for Digital Logic Circuits: A Molecular Communications Analysis

With the advancement of synthetic biology, several new tools have been conceptualized over the years as alternative treatments for current medical procedures. As part of this work, we investigate how synthetically engineered neurons can operate as digital logic gates that can be used towards bio-computing inside the brain and its impact on epileptic seizure-like behaviour. We quantify the accuracy of logic gates under high firing rates amid a network of neurons and by how much it can smooth out uncontrolled neuronal firings. To test the efficacy of our method, simulations composed of computational models of neurons connected in a structure that represents a logic gate are performed. Our simulations demonstrate the accuracy of performing the correct logic operation, and how specific properties such as the firing rate can play an important role in the accuracy. As part of the analysis, the mean squared error is used to quantify the quality of our proposed model and predict the accurate operation of a gate based on different sampling frequencies. As an application, the logic gates were used to smooth out epileptic seizure-like activity in a biological neuronal network, where the results demonstrated the effectiveness of reducing its mean firing rate. Our proposed system has the potential to be used in future approaches to treating neurological conditions in the brain.