Accounting for repeat intervention costs in the economic comparison of laser interstitial thermal therapy and anterior temporal lobectomy for treatment of refractory temporal lobe epilepsy.

OBJECTIVE: Laser interstitial thermal therapy (LITT) is an alternative to anterior temporal lobectomy (ATL) for the treatment of temporal lobe epilepsy that has been found by some to have a lower procedure cost but is generally regarded as less effective and sometimes results in a subsequent procedure. The goal of this study is to incorporate subsequent procedures into the cost and outcome comparison between ATL and LITT. METHODS: This single-center, retrospective cohort study includes 85 patients undergoing ATL or LITT for temporal lobe epilepsy during the period September 2015 to December 2022. Of the 40 patients undergoing LITT, 35 % (N = 14) underwent a subsequent ATL. An economic cost model is derived, and difference in means tests are used to compare the costs, outcomes, and other hospitalization measures. RESULTS: Our model predicts that whenever the percentage of LITT patients undergoing subsequent ATL (35% in our sample) exceeds the percentage by which the LITT procedure alone is less costly than ATL (7.2% using total patient charges), LITT will have higher average patient cost than ATL, and this is indeed the case in our sample. After accounting for subsequent surgeries, the average patient charge in the LITT sample ($103,700) was significantly higher than for the ATL sample ($88,548). A second statistical comparison derived from our model adjusts for the difference in effectiveness by calculating the cost per seizure-free patient outcome, which is $108,226 for ATL, $304,052 for LITT only, and $196,484 for LITT after accounting for the subsequent ATL surgeries. SIGNIFICANCE: After accounting for the costs of subsequent procedures, we found in our cohort that LITT is not only less effective but also results in higher average costs per patient than ATL as a first course of treatment. While cost and effectiveness rates will vary across centers, we also provide a model for calculating cost effectiveness based on individual center data.

Accuracy of Valproic Acid Concentration Correction Based on Serum Albumin.

BACKGROUND: Patient-specific factors can alter the pharmacokinetic disposition of valproic acid. Specifically, the free fraction of valproic acid can increase substantially in patients with hypoalbuminemia or as serum drug concentrations rise due to saturable protein binding. Direct measurement of free serum drug concentrations allows for accurate assessment of drug levels, but the assay may not be readily available in all institutions. The effect of hypoalbuminemia on free fraction has been quantified and serves as the basis of an equation used to "correct" measured total valproic acid concentrations. The aim of this study was to evaluate the accuracy of the equation. METHODS: This retrospective study included adult patients with measurable free and total valproic acid concentrations between July 2014 and June 2017. The primary aim was to assess the relationship between measured and predicted free valproic acid concentrations. Free levels were categorized as subtherapeutic, therapeutic, or supratherapeutic based on the reference range of 7-23 mg/L. Concordance was defined as measured and predicted concentrations falling within the same category. RESULTS: The analysis included 174 patients with a median age of 58 years and a median albumin of 3 g/dL. The majority of patients were hospitalized (88.5%). Concordance occurred in 56.9% of samples. A Spearman's correlation coefficient of 0.60 (p < 0.001) was found between the measured and predicted free valproic acid concentrations. Concordance of concentrations was 42% for ICU patients, 63% for floor patients, and 65% for outpatients. Of those with discordant concentrations, 97% of the predicted concentrations underestimated the measured concentrations. CONCLUSIONS: There is discordance between predicted and measured free serum valproic acid concentrations when using the proposed equation. Because of the potential impact of underestimation and variability of free valproic acid concentrations, a measured free level is the ideal option for therapeutic drug monitoring of valproic acid.

Effect of lunar phase on frequency of psychogenic nonepileptic events in the EMU.

INTRODUCTION: Studies of the effect of a full moon on seizures have yielded mixed results, despite a continuing prevailing belief regarding the association of lunar phase with human behavior. The potential effect of a full moon on psychogenic nonepileptic events has not been as well studied, despite what anecdotal accounts from most epilepsy monitoring unit (EMU) staff would suggest. METHODS: We obtained the dates and times of all events from patients diagnosed with psychogenic nonepileptic events discharged from our EMU over a two-year period. The events were then plotted on a 29.5-day lunar calendar. Events were also broken down into lunar quarters for statistical analysis. RESULTS: We found a statistically significant increase in psychogenic nonepileptic events during the new moon quarter in our EMU during our studied timeframe. CONCLUSION: Our results are not concordant with the results of a similarly designed past study, raising the possibility that psychogenic nonepileptic events are not influenced by lunar phase.

Musicogenic seizures-STXBP1 encephalopathy with reflex seizures.

Mutations in the gene encoding syntaxin binding protein 1 (STXBP1) have been implicated in a wide variety of epileptic encephalopathies. Although the recognized phenotypes of patients with STXBP1 encephalopathies have broadened in recent years, no case of reflex seizures, particularly musicogenic seizures, has been reported in the literature. We present an 18-year-old woman with STXBP1 encephalopathy and seizures that are stereotypically reproducible in response to a variety of audible stimuli. An 18-year-old woman with a history of profound intellectual disability, confirmed STXBP1 genetic defect via genetic testing, and seizures beginning as infantile spasms during childhood, who presented to the epilepsy monitoring unit for seizure characterization. Her mother reported reproducible seizures triggered by a particular cell phone ringtone, music from a certain automobile television commercial and certain beeping alarm sounds. In response, the patient had clinically stereotyped seizures associated with staring, behavioral arrest, followed by eye deviation to the left, tonic stiffening in upper and lower extremities, and labored breathing lasting between 30 s and 2 min. These seizures were reliably reproducible within a few seconds of exposure to the auditory stimulus. During hospitalization, mother played one of the cell phone ringtones known to trigger seizures for the patient, which resulted in induction of a seizure characterized by diffuse electrodecrement, subsequent emergence of frontal-predominant theta which was followed by progressive diffuse attenuation and semi-rhythmic slowing over the right posterior quadrant. This is the first case to describe musicogenic or other reflex seizures in a patient with STXBP1 encephalopathy.

Headache characteristics among patients with epilepsy and the association with temporal encephaloceles.

Purpose: Our aim was to determine if headaches characteristic of possible Idiopathic Intracranial Hypertension (IIH) and in general were more prevalent in patients with versus without temporal encephaloceles (TEs) among patients with epilepsy. Methods: Electronic medical records were reviewed retrospectively. Among 474 patients with epilepsy, 103 patients (21.7%) had at least one TE diagnosed on initial MRI or on retrospective review by a board-certified neuroradiologist, while 371 patients had no TE present. The patients were grouped into one of four categories depending on their headache characteristics (IIH-like, peri-ictal, other, or no headaches). Analysis of the categories was performed using a Chi Square test. Results: Patients with TEs were more likely to experience headaches of any type than no headaches and more likely to experience IIH-like headaches than to have other headaches or no headaches compared to patients without TEs. Interestingly, patients with TEs were also more likely to experience peri-ictal headaches compared to patients without TEs. However, patients with TEs were no more likely or unlikely to have other (non-IIH or peri-ictal) headaches vs no reported headaches and were not more or less likely to have elevated opening pressure. Conclusion: On retrospective review, patients with TEs and epilepsy were more likely to exhibit headache features characteristic of IIH or to have peri-ictal headaches compared to epilepsy patients without TEs. These findings underscore the need for careful and thorough history of associated headaches in patients with epilepsy so that those patients at risk for TEs can undergo careful inspection of MRI to evaluate for their presence, which may represent a focus for seizures.

Unilateral SREDA in a Patient With Stroke.

Subclinical rhythmic electrographic discharges in adults (SREDA) is a well-known benign EEG phenomenon. However, the occurrence of SREDA is rare, and atypical forms are even more elusive, with only few cases reported in the literature. Herein, we describe a case of a 77-year-old woman with a left middle cerebral artery stroke and paroxysms of rhythmic, sharply contoured activity over the right central head region, mimicking focal seizures on EEG, that were determined to represent atypical SREDA. To our knowledge, no case of SREDA with a contralateral structural cerebral abnormality has been described, and its occurrence offers some limited insight as to the mechanisms underlying this mysterious entity.

Seasonal and spatial variability of nitrosamines and their precursor sources at a large-scale urban drinking water system.

Nitrosamines are considered to pose greater health risks than currently regulated DBPs and are subsequently listed as a priority pollutant by the EPA, with potential for future regulation. Denver Water, as part of the EPA's Unregulated Contaminant Monitoring Rule 2 (UCMR2) monitoring campaign, found detectable levels of N-nitrosodimethylamine (NDMA) at all sites of maximum residency within the distribution system. To better understand the occurrence of nitrosamines and nitrosamine precursors, Denver Water undertook a comprehensive year-long monitoring campaign. Samples were taken every two weeks to monitor for NDMA in the distribution system, and quarterly sampling events further examined 9 nitrosamines and nitrosamine precursors throughout the treatment and distribution systems. NDMA levels within the distribution system were typically low (>1.3 to 7.2 ng/L) with a remote distribution site (frequently >200 h of residency) experiencing the highest concentrations found. Eight other nitrosamines (N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitroso-di-n-propylamine, N-nitroso-di-n-butylamine, N-nitroso-di-phenylamine, N-nitrosopyrrolidine, N-nitrosopiperidine, N-nitrosomorpholine) were also monitored but none of these 8, or precursors of these 8 [as estimated with formation potential (FP) tests], were detected anywhere in raw, partially-treated or distribution samples. Throughout the year, there was evidence that seasonality may impact NDMA formation, such that lower temperatures (~5-10°C) produced greater NDMA than during warmer months. The year of sampling further provided evidence that water quality and weather events may impact NDMA precursor loads. Precursor loading estimates demonstrated that NDMA precursors increased during treatment (potentially from cationic polymer coagulant aids). The precursor analysis also provided evidence that precursors may have increased further within the distribution system itself. This comprehensive study of a large-scale drinking water system provides insight into the variability of NDMA occurrence in a chloraminated system, which may be impacted by seasonality, water quality changes and/or the varied origins of NDMA precursors within a given system.