Posttraumatic Epilepsy and Dementia Risk

Importance

Although both head injury and epilepsy are associated with long-term dementia risk, posttraumatic epilepsy (PTE) has only been evaluated in association with short-term cognitive outcomes.

Objective

To investigate associations of PTE with dementia risk.

Design, Setting, and Participants

The Atherosclerosis Risk in Communities (ARIC) study initially enrolled participants from 1987 to 1989 and this prospective cohort study uses data through December 31, 2019, with a median follow-up of 25 years. Data were analyzed between March 14, 2023, and January 2, 2024. The study took place in 4 US communities in Minnesota, Maryland, North Carolina, and Mississippi. Of 15 792 ARIC study participants initially enrolled, 2061 were ineligible and 1173 were excluded for missing data, resulting in 12 558 included participants.

Exposures

Head injury was defined by self-report and International Classification of Diseases (ICD) diagnostic codes. Seizure/epilepsy was defined using ICD codes. PTE was defined as a diagnosis of seizure/epilepsy occurring more than 7 days after head injury. Head injury, seizure/epilepsy, and PTE were analyzed as time-varying exposures.

Main Outcomes and Measures

Dementia was defined using cognitive assessments, informant interviews, and ICD and death certificate codes. Adjusted Cox and Fine and Gray proportional hazards models were used to estimate dementia risk.

Results

Participants had a mean (SD) age of 54.3 (5.8) years at baseline, 57.7% were female, 28.2% were of self-reported Black race, 14.4% were ultimately categorized as having head injury, 5.1% as having seizure/epilepsy, and 1.2% as having PTE. Over a median follow-up of 25 (25th to 75th percentile, 17-30) years, 19.9% developed dementia. In fully adjusted models, compared with no head injury and no seizure/epilepsy, PTE was associated with 4.56 (95% CI, 4.49-5.95) times the risk of dementia, while seizure/epilepsy was associated with 2.61 (95% CI, 2.21-3.07) times the risk and head injury with 1.63 (95% CI, 1.47-1.80) times the risk. The risk of dementia associated with PTE was significantly higher than the risk associated with head injury alone and with nontraumatic seizure/epilepsy alone. Results were slightly attenuated in models accounting for the competing risks of mortality and stroke, but patterns of association remained similar. In secondary analyses, the increased dementia risk associated with PTE occurring after first vs second head injury and after mild vs moderate/severe injury was similar.

Conclusions and Relevance

In this community-based cohort, there was an increased risk of dementia associated with PTE that was significantly higher than the risk associated with head injury or seizure/epilepsy alone. These findings provide evidence that PTE is associated with long-term outcomes and supports both the prevention of head injuries via public health measures and further research into the underlying mechanisms and the risk factors for the development of PTE, so that efforts can also be focused on the prevention of PTE after a head injury.

Laser interstitial thermal therapy after failed anterior temporal lobectomy and amygdalohippocampectomy can improve seizure outcome

Anterior temporal lobectomy and amygdalohippocampectomy (ATL) is the gold standard surgical treatment for drug resistant mesial temporal lobe epilepsy (mTLE). Nevertheless, seizure recurrence after ATL is not uncommon. Insufficient resection of the mesial temporal structures remains one of the most common reasons for ATL failure. Extending the resection leads to improved seizure outcome in a majority of patients. However, repeat craniotomy can be higher risk for the patient and also can be technically challenging due to scarring and altered anatomy. Laser interstitial thermal therapy (LITT) is a novel minimally invasive alternative to ATL, and it has been shown to be safe and effective. However, it is unclear if LITT has a role in managing post-ATL mTLE patients with recurrent seizures and residual epileptogenic structures. LITT is an attractive option for post-ATL patients with residual mesial structures because the surgery is minimally invasive, and it allows precise targeting and real time confirmation of tissue ablation under MRI guidance. We present a case of an mTLE patient with recurrent seizures after ATL who achieved long-term seizure-freedom after successfully undergoing LITT to ablate the residual hippocampus. This approach, if demonstrated to be safe, effective and durable, can benefit select post-ATL mTLE patients.

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Persistent seizures at long-term follow-up after anterior temporal lobectomy (ATL) is not uncommon.

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Residual mesial temporal lobe is one of the most common reasons for seizure recurrence after ATL.

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Laser interstitial thermal therapy (LITT) is a minimally invasive surgery with advantages of intraoperative MRI guidance.

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LITT can be used to selectively ablate residual mesial temporal structures in post-ATL patients with recurrent seizures.

Photosensitive epilepsy

Objective

The objective of this phase 2a study was to assess the activity of PF-06372865, a positive allosteric modulator (PAM) of α2/3/5 subunit-containing GABAA receptors with minimal activity at α1-containing receptors, which are believed to mediate many of the adverse events associated with benzodiazepines, in the epilepsy photosensitivity model as a proof-of-principle of efficacy.

Methods

Seven participants with a photoparoxysmal response to intermittent photic stimulation (IPS) at baseline were randomized in a double-blind, 4-period cross-over study examining single doses of 17.5 and 52.5 mg PF-06372865, 2 mg lorazepam (active control), and placebo. Standardized photosensitivity ranges (SPRs) to IPS were recorded at screening, predose, and 1, 2, 4, and 6 hours postdose. The primary endpoint was the average least squares mean change in the SPR in the participant's most sensitive eye condition, across all time points.

Results

Both doses of PF-06372865 produced a marked and statistically significant mean reduction in SPR compared to placebo, which was similar in degree to lorazepam. There was complete suppression of SPR in 6/7 participants following PF-06372865 or lorazepam administration. PF-06372865 was safe and well-tolerated.

Conclusion

PF-06372865 demonstrated highly robust efficacy. This demonstrates anticonvulsant activity of a novel α2/3/5-subtype selective GABAA PAM in humans. Further study of the antiepileptic properties of PF-06372865 is warranted.

Clinicaltrials.gov identifier

NCT02564029.

Classification of evidence

This study provides Class II evidence that for people with a stable photoparoxysmal response to intermittent photic stimulation, PF-06372865 reduces the SPR.

Common data elements for epilepsy mobile health systems

OBJECTIVE

Common data elements (CDEs) are currently unavailable for mobile health (mHealth) in epilepsy devices and related applications. As a result, despite expansive growth of new digital services for people with epilepsy, information collected is often not interoperable or directly comparable. We aim to correct this problem through development of industry-wide standards for mHealth epilepsy data.

METHODS

Using a group of stakeholders from industry, academia, and patient advocacy organizations, we offer a consensus statement for the elements that may facilitate communication among different systems.

RESULTS

A consensus statement is presented for epilepsy mHealth CDEs.

SIGNIFICANCE

Although it is not exclusive, we believe that the use of a minimal common information denominator, specifically these CDEs, will promote innovation, accelerate scientific discovery, and enhance clinical usage across applications and devices in the epilepsy mHealth space. As a consequence, people with epilepsy will have greater flexibility and ultimately more powerful tools to improve their lives.

Influence of titration schedule and maintenance dose on the tolerability of adjunctive eslicarbazepine acetate: An integrated analysis of three randomized placebo-controlled trials

OBJECTIVE

To examine the influence of titration schedule and maintenance dose on the incidence and type of treatment-emergent adverse events (TEAEs) associated with adjunctive eslicarbazepine acetate (ESL).

METHODS

Data from three randomized, double-blind, placebo-controlled trials were analyzed. Patients with refractory partial-onset seizures were randomized to maintenance doses of ESL 400, 800, or 1200mg QD (dosing was initiated at 400 or 800mg QD) or placebo. The incidence of TEAEs was analyzed during the double-blind period (2-week titration phase; 12-week maintenance phase), according to the randomized maintenance dose and the titration schedule.

RESULTS

1447 patients were included in the analysis. During the first week of treatment, 62% of patients taking ESL 800mg QD had ≥1 TEAE, vs 35% of those taking 400mg QD and 32% of the placebo group; dizziness, somnolence, nausea, and headache were numerically more frequent in patients taking ESL 800mg than those taking ESL 400mg QD. During the double-blind period, the incidences of common TEAEs were lower in patients who initiated ESL at 400mg vs 800mg QD. For the 800 and 1200mg QD maintenance doses, rates of TEAEs leading to discontinuation were lower in patients who began treatment with 400mg than in those who began taking ESL 800mg QD.

CONCLUSIONS

Initiation of ESL at 800mg QD is feasible. However, initiating treatment with ESL 400mg QD for 1 or 2 weeks is recommended, being associated with a lower incidence of TEAEs, and related discontinuations. For some patients, treatment may be initiated at 800mg QD, if the need for more immediate seizure reduction outweighs concerns about increased risk of adverse reactions during initiation.

Adjunctive eslicarbazepine acetate: A pooled analysis of three phase III trials

OBJECTIVE

To assess the safety and efficacy of once-daily (QD) adjunctive eslicarbazepine acetate (ESL).

METHODS

This post-hoc pooled analysis of three randomized, placebo-controlled trials (2093-301, -302, -304) involved adults with refractory partial-onset seizures (POS) receiving 1-3 antiepileptic drugs (AEDs). All studies included 8-week baseline, 2-week titration, and 12-week maintenance periods. Patients were randomized equally to placebo, ESL 400mg (studies 301, 302), 800mg, or 1200mg QD. The primary endpoint was standardized seizure frequency (SSF; per 4weeks); secondary endpoints included responder rates (maintenance period), and incidence of treatment-emergent adverse events (TEAEs), TEAEs leading to discontinuation, serious AEs (SAEs), and deaths.

RESULTS

The safety and efficacy analysis populations totaled 1447 and 1410 patients, respectively. SSF was significantly reduced versus placebo with ESL 800mg (p=0.0001) and 1200mg (p<0.0001) but not 400mg (p=0.81). There were no significant interactions between treatment effect and age, gender, race/ethnicity, geographic region, epilepsy duration, or concomitant AED use. Incidences of TEAEs and TEAEs leading to discontinuation increased with ESL dose. Incidences of the most frequent TEAEs were lower for patients who initiated dosing at 400 versus 800mg QD, regardless of titration regimen and maintenance dose. SAE incidence was <10%; there were 3 deaths (placebo, n=2; ESL 800mg, n=1).

CONCLUSIONS

ESL (800 and 1200mg QD) was effective and well tolerated as adjunctive therapy for adults with refractory POS.

Ghost-Pill-Buster: A Case Study of Intact Levetiracetam Extended-Release Tablets after Dissolution Testing

BACKGROUND

Orally administered medications in extended-release (ER) dosage forms continue to play a pivotal role in the treatment of various central nervous system disorders. For certain ER dosage forms, pharmaceutical scientists have been familiar with the passage of intact tablet-like objects in patients' feces after administration of ER tablets or capsules based on water-insoluble or slowly dissolving excipients. Nevertheless, because of lack of awareness of the "ghost pill" phenomenon, anxiety has ensued among some patients and clinicians, who have less understanding of how drugs are released from these tablets once ingested. It has been brought to the attention of the US Food and Drug Administration (FDA) that epilepsy patients administered with Teva's levetiracetam ER tablets have noticed intact tablets in their stools and been concerned that they were not getting the needed dose of the drug. In response to neurologists' clinical reporting, the FDA has conducted investigations to confirm a minimal risk of incomplete drug release of Teva's drug product.

OBJECTIVE

The objective of this study was to evaluate the risks of incomplete drug release associated with the passing of intact levetiracetam ER tablets, by conducting in vitro dissolution testing.

METHODS

Dissolution testing of Teva's drug product was performed in accordance with the US Pharmacopeia monograph for levetiracetam ER tablets in phosphate buffer and bio-relevant buffers at different pH values. In addition, dissolution testing was conducted with split and crushed tablets. At the end of the dissolution testing, all samples were visually inspected for any undissolved pieces.

RESULTS

Approximately 90 % of levetiracetam had been released in all dissolution media after 8 h of dissolution. The levetiracetam ER tablets after dissolution testing remained fully intact in all dissolution media. The rates of drug release were significantly faster from split and crushed tablets than that from whole tablets.

CONCLUSION

On the basis of these findings, Teva's levetiracetam ER tablets may appear intact in the stools but have released the drug successfully. The FDA has requested Teva to revise its product labeling to include remarks regarding the potential passing of intact tablets. Since patients who notice ghost pills in their stools may impetuously crush or split the tablets of subsequent doses on their own, healthcare providers should instruct patients to swallow whole tablets throughout the treatment, in accordance with the drug label.

Sabril® registry 5-year results: Characteristics of adult patients treated with vigabatrin

Vigabatrin (Sabril®), approved in the US in 2009, is currently indicated as adjunctive therapy for refractory complex partial seizures (rCPS) in patients ≥ 10 years old who have responded inadequately to several alternative treatments and as monotherapy for infantile spasms (IS) in patients 1 month to 2 years of age. Because of reports of vision loss following vigabatrin exposure, FDA approval required a risk evaluation mitigation strategy (REMS) program. Vigabatrin is only available in the US through Support, Help, And Resources for Epilepsy (SHARE), which includes a mandated registry. This article describes 5 years of demographic and treatment exposure data from adult patients (≥ 17 years old) in the US treated with vigabatrin and monitored in the ongoing Sabril® registry. Registry participation is mandatory for all US Sabril® prescribers and patients. A benefit-risk assessment must be documented by the physician for a patient to progress to maintenance therapy, defined as 1 month of vigabatrin treatment for patients with IS and 3 months for patients with rCPS. Ophthalmologic assessments must be documented during and after completion of therapy. As of August 26, 2014, a total of 6823 patients were enrolled in the registry, of which 1200 were adults at enrollment. Of these patients, 1031 (86%) were naïve to vigabatrin. The majority of adult patients (n=783, 65%) had previously been prescribed ≥ 4 AEDs, and 719 (60%) were receiving ≥ 3 concomitant AEDs at vigabatrin initiation. Prescribers submitted an initial ophthalmological assessment form for 863 patients; an ophthalmologic exam was not completed for 300 (35%) patients and thus, were considered exempted from vision testing. Of these patients, 128 (43%) were exempted for neurologic disabilities. Clinicians discontinued treatment in 8 patients because of visual field deficits (VFD) (5 patients naïve to vigabatrin and 3 patients previously exposed). Based on Kaplan-Meier survival estimates, it is estimated that approximately 71%, 55%, and 40% of adult patients naïve to vigabatrin would remain in the registry at 3, 6, and 12 months, respectively. These demographic data suggest that a proportion of adult patients remain on vigabatrin long-term despite the risks of adverse events and significant underlying AED resistance and neurologic disease.

ADJUNCTIVE PERAMPANEL RCT FOR PGTC SEIZURES

We assessed efficacy and safety of perampanel (selective noncompetitive AMPA receptor antagonist) for primary generalised tonic-clonic (PGTC) seizures. Patients ≥12years with confirmed IGE; ≥3 PGTC seizures/8 weeks prior to randomization; receiving 1–3 concomitant AEDs were recruited. Trial consisted of 4–week screening; 4–8 week Baseline, 1:1 Randomization (perampanel titrated over 4 weeks to 8mg or highest tolerated dose versus placebo), 13–week Maintenance, 4–week Follow-up and Extension Phases. 164 patients were randomized; full analysis set included 81 patients each on perampanel and placebo. Median percent change in PGTC seizure frequency/28 days during Titration/Maintenance versus Baseline was –76.5% with perampanel versus –38.4% placebo; P<0.0001. 50% PGTC seizure responder rate was 64.2% with perampanel versus 39.5% placebo; P=0.0019. During Maintenance, 30.9% of perampanel patients were free of PGTC seizures versus 12.3% placebo. Treatment-emergent AEs (TEAEs) occurred in 82.7% of perampanel and 72.0% placebo patients; most common dizziness, fatigue, headache, somnolence, irritability. Serious TEAEs occurred in 6 (7.4%) perampanel and 7 (8.5%) placebo patients (one death in the perampanel group [accidental drowning; not treatment-related],one with placebo). In conclusion, adjunctive perampanel treatment up to 8mg improved seizure control in PGTC seizure patients, with almost 1/3 free of PGTC seizures during Maintenance. Perampanel was well tolerated. Study sponsor: Eisai Inc.

Response of the medial temporal lobe network in amnestic mild cognitive impairment to therapeutic intervention assessed by fMRI and memory task performance

Studies of individuals with amnestic mild cognitive impairment (aMCI) have detected hyperactivity in the hippocampus during task-related functional magnetic resonance imaging (fMRI). Such elevated activation has been localized to the hippocampal dentate gyrus/CA3 (DG/CA3) during performance of a task designed to detect the computational contributions of those hippocampal circuits to episodic memory. The current investigation was conducted to test the hypothesis that greater hippocampal activation in aMCI represents a dysfunctional shift in the normal computational balance of the DG/CA3 regions, augmenting CA3-driven pattern completion at the expense of pattern separation mediated by the dentate gyrus. We tested this hypothesis using an intervention based on animal research demonstrating a beneficial effect on cognition by reducing excess hippocampal neural activity with low doses of the atypical anti-epileptic levetiracetam. In a within-subject design we assessed the effects of levetiracetam in three cohorts of aMCI participants, each receiving a different dose of levetiracetam. Elevated activation in the DG/CA3 region, together with impaired task performance, was detected in each aMCI cohort relative to an aged control group. We observed significant improvement in memory task performance under drug treatment relative to placebo in the aMCI cohorts at the 62.5 and 125 mg BID doses of levetiracetam. Drug treatment in those cohorts increased accuracy dependent on pattern separation processes and reduced errors attributable to an over-riding effect of pattern completion while normalizing fMRI activation in the DG/CA3 and entorhinal cortex. Similar to findings in animal studies, higher dosing at 250 mg BID had no significant benefit on either task performance or fMRI activation. Consistent with predictions based on the computational functions of the DG/CA3 elucidated in basic animal research, these data support a dysfunctional encoding mechanism detected by fMRI in individuals with aMCI and therapeutic intervention using fMRI to detect target engagement in response to treatment.

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Patients with aMCI show increased fMRI activation in DG/CA3 relative to controls.

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Low dose levetiracetam treatment decreases excess DG/CA3 activation in aMCI.

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Low dose levetiracetam treatment normalizes decreased entorhinal activation in aMCI.

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Low dose levetiracetam treatment improves task related memory performance in aMCI.

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Targeting excess hippocampal activity has therapeutic potential in amnestic MCI.

Dosing feasibility and tolerability of intranasal diazepam in adults with epilepsy

OBJECTIVE

To determine the feasibility of administering a diazepam nasal spray formulation (diazepam-NS) to adults with epilepsy during a generalized tonic-clonic seizure or in the postictal period following a tonic-clonic or other seizure type, to assess pharmacokinetics and to assess tolerability.

METHODS

An open-label study was conducted in patients admitted to the epilepsy monitoring unit. Eligible patients received a single dose of diazepam-NS approximating 0.2 mg/kg. Plasma diazepam concentrations were measured serially up to 12 h postdose, and maximum observed plasma concentration (Cmax ); time to maximum concentration (Tmax ); and the area under the plasma concentration-time curve for time zero to last sampling time (AUC0-12 ) were estimated and dose-normalized. Pharmacodynamic assessments included Kaplan-Meier analysis to determine the time-to-next seizure. Safety and tolerability were assessed.

RESULTS

Of the 78 patients who consented, 30 had treatment and pharmacokinetic data. Ten patients were treated during a convulsive tonic-clonic seizure, seven within 5 min following the last clonic jerk, and 13 in the postictal period ≥ 5 min after a tonic-clonic or following other seizure-types. Diazepam median Tmax was 45 min. Dose-normalized mean Cmax and AUC0-12 values of diazepam were comparable among patients regardless of the timing of diazepam-NS administration in relation to seizure. Of those treated, 65% were seizure-free during the 12-h observation period and 35% had post-dose seizures. Treatment was well tolerated, with no unexpected safety findings: 74% had mild and 25% had moderate adverse events. Nasopharyngeal signs were resolved by 12 h postdose.

SIGNIFICANCE

Diazepam can be delivered in effective therapeutic concentrations by a nasal spray device during the convulsive phase of tonic-clonic seizures or in the postictal periods following tonic-clonic or other seizure types.

Modeling a genetic risk for schizophrenia in iPSCs and mice reveals neural stem cell deficits associated with adherens junctions and polarity

Defects in brain development are believed to contribute toward the onset of neuropsychiatric disorders, but identifying specific underlying mechanisms has proven difficult. Here, we took a multifaceted approach to investigate why 15q11.2 copy number variants are prominent risk factors for schizophrenia and autism. First, we show that human iPSC-derived neural progenitors carrying 15q11.2 microdeletion exhibit deficits in adherens junctions and apical polarity. This results from haploinsufficiency of CYFIP1, a gene within 15q11.2 that encodes a subunit of the WAVE complex, which regulates cytoskeletal dynamics. In developing mouse cortex, deficiency in CYFIP1 and WAVE signaling similarly affects radial glial cells, leading to their ectopic localization outside of the ventricular zone. Finally, targeted human genetic association analyses revealed an epistatic interaction between CYFIP1 and WAVE signaling mediator ACTR2 and risk for schizophrenia. Our findings provide insight into how CYFIP1 regulates neural stem cell function and may contribute to the susceptibility of neuropsychiatric disorders.

Treatment strategies in the postictal state

Postictal behaviors and symptoms often require special assessment and treatment. We review risk factors for postictal delirium and psychosis and management of agitated and confused behaviors in patients after seizures. Medical and emergency staff require careful training to manage behaviors associated with postictal delirium and psychosis in order to protect patients while their confusion resolves. Treatment of postictal states requires recognition of underlying neurological and systemic disorders associated with seizures and delirium such as metabolic disorders and nonconvulsive seizures. There is incomplete information about the causes and optimal treatments for seizure-related psychosis, however, postictal behaviors can usually be managed safely.

A randomized, double-blind, placebo-controlled, parallel-group study of rufinamide as adjunctive therapy for refractory partial-onset seizures

PURPOSE

Efficacy and safety of adjunctive rufinamide (3,200 mg/day) was assessed in adolescents and adults with inadequately controlled partial-onset seizures receiving maintenance therapy with up to three antiepileptic drugs (AEDs).

METHODS

This randomized, double-blind, placebo-controlled, parallel-group, multicenter study comprised a 56-day baseline phase (BP), 12-day titration phase, and 84-day maintenance phase (MP). The primary efficacy variable was percentage change in total partial seizure frequency per 28 days (MP vs. BP). Secondary efficacy outcome measures included ≥50% responder rate and reduction in mean total partial seizure frequency during the MP. Safety and tolerability evaluation included adverse events (AEs), physical and neurologic examinations, and laboratory values. Pharmacokinetic and pharmacodynamic assessments were conducted.

RESULTS

Three hundred fifty-seven patients were randomized: 176 to rufinamide and 181 to placebo. Patients had a median of 13.3 seizures per 28 days during BP; 86% were receiving ≥2 AEDs. For the intent-to-treat population, the median percentage reduction in total partial seizure frequency per 28 days was 23.25 for rufinamide versus 9.80 for placebo (p = 0.007). Rufinamide-treated patients were more than twice as likely to have had a ≥50% reduction in partial seizure frequency (32.5% vs. 14.3%; p < 0.001) and had a greater reduction in median total partial seizure rate per 28 days during the MP (13.2 vs. 5.2; p < 0.001). Treatment-emergent AEs occurring at ≥5% higher incidence in the rufinamide group compared with placebo were dizziness, fatigue, nausea, somnolence, and diplopia.

CONCLUSIONS

Adjunctive treatment with rufinamide reduced total partial seizures in refractory patients. AEs reported were consistent with the known tolerability profile of rufinamide.

Adjunctive rufinamide in Lennox-Gastaut syndrome: a long-term, open-label extension study

OBJECTIVE

This open-label extension evaluated the long-term efficacy and tolerability of rufinamide in patients with Lennox-Gastaut syndrome (LGS) who had previously completed a 12-week double-blind study.

MATERIALS AND METHODS

In total, 124 patients (aged 4-37 years), receiving 1-3 concomitant antiepileptic drugs, were treated with rufinamide approximately 25-60 mg/kg/day. Efficacy was assessed by seizure frequency; tolerability by adverse events (AEs) and laboratory tests.

RESULTS

Overall, patients were treated with rufinamide for a median (range) of 432 (10-1149) days. Reductions in seizure frequency were observed throughout the study; during the last 12 months of treatment, 41.0% and 47.9% of patients had > or = 50% reduction in total and tonic-atonic seizure frequency, respectively. The most common AEs were vomiting (30.6%) and pyrexia (25.8%).

CONCLUSIONS

In this open-label extension, rufinamide appeared to be an effective long-term adjunctive therapy for the treatment of LGS-associated seizures in children and young adults.

Efficient nonlinear light emission of single gold optical antennas driven by few-cycle near-infrared pulses

Individual nanometer-sized plasmonic antennas are excited resonantly with few-cycle laser pulses in the near infrared. Intense third-harmonic emission of visible light prevails for fundamental photon energies below 1.1 eV. Interband luminescence and second harmonic generation occur solely at higher driving frequencies. We attribute these findings to multiphoton resonances with the d-band transitions of gold. The strong third-order signal allows direct measurement of a subcycle plasmon dephasing time of 2 fs, highlighting the efficient radiation coupling and broadband response of the devices.

Safety and tolerability of rufinamide in children with epilepsy: a pooled analysis of 7 clinical studies

Rufinamide is a novel antiepileptic agent recently approved in the United States for adjunctive treatment of seizures associated with Lennox-Gastaut syndrome. To help inform clinical decision making, the authors analyzed safety and tolerability data from the entire pediatric population in the rufinamide epilepsy clinical development program. The analysis population comprised 212 rufinamide-treated (age range 3-16 years) and 197 placebo patients (age range 4-17 years) in the double-blind studies, and 391 patients receiving rufinamide in the double-blind and/or open-label extensions. The most common adverse effects observed in rufinamide-treated patients in the double-blind studies were somnolence, vomiting, and headache. Changes in laboratory values, vital signs, and weight were generally clinically insignificant. This pooled analysis of data from pediatric patients in clinical studies of rufinamide for the treatment of seizures, mainly as adjunctive therapy, suggests a favorable safety and tolerability profile in this patient population.

Improved coverage of fungal diversity in polluted groundwaters by semi-nested PCR

Traditional methods used for studying communities of aquatic hyphomycetes are based on the detection and identification of their asexual spores under a microscope. These techniques limit detection to aquatic fungi present in sufficient quantity and capable of sporulating under laboratory conditions. Our objective was to develop a molecular approach to detect and monitor all types of fungi (i.e. strictly or facultatively aquatic) in harsh habitats (i.e. groundwater wells and heavily polluted surface water) where fungal biomass may become limited. We developed a semi-nested PCR protocol for fungal 18S ribosomal RNA genes coupled to subsequent analysis of the PCR products by Temperature Gradient Gel Electrophoresis (TGGE) to monitor the fungal community structure in aquatic habitats characterized by a pollution gradient. Our TGGE-protocol was compared with the traditional morphological approach and revealed a higher diversity in groundwaters and in some polluted surface waters. Thus, PCR-TGGE is a promising alternative in particular in habitats with low fungal biomass. The dynamics of fungal biomass and sporulation rates during the first weeks of leaf colonization showed that habitats with adverse ecological conditions allow only reduced fungal growth, which might subsequently impact upper trophic levels and thus interfere with key ecological processes of leaf decomposition.

Unexpected high stiffness of Ag and Au nanoparticles

We studied the compressibility of silver (10 nm) and gold (30 nm) nanoparticles, n-Ag and n-Au, suspended in a methanol-ethanol mixture by x-ray diffraction (XRD) with synchrotron radiation at pressures up to 30 GPa. Unexpectedly for that size, the nanoparticles show a significantly higher stiffness than the corresponding bulk materials. The bulk modulus of n-Au, K(0)=290(8) GPa, shows an increase of ca. 60% and is in the order of W or Ir. The structural characterization of both kinds of nanoparticles by XRD and high-resolution electron microscopy identified polysynthetic domain twinning and lamellar defects as the main origin for the strong decrease in compressibility.

Aquatic hyphomycete communities as potential bioindicators for assessing anthropogenic stress

With a profound knowledge of how physico-chemical parameters affect these communities, microbial communities could be used as indicators for environmental changes and for risk assessment studies. We studied aquatic hyphomycete communities in rivers and aquifers from sites shaped by intense mining activities (namely the "Mansfeld region") and chemical industry (cities of Halle and Bitterfeld) in Central Germany. Environmental stress factors such as high concentrations of heavy metals, sulphate, and nitrate as well as low concentrations of oxygen significantly reduced the diversity and biomass of hyphomycetes in the investigated samples. Redundancy analysis (RDA) indicates that variations in water chemistry cause a significant proportion of the change in fungal community structure (86.2%). Fungi were negatively correlated with high metal and nutrient concentrations. RDA also showed a strong influence of organic matter on individual species, with Anguillospora longissima (Sacc. et Syd.), Clavatospora longibrachiata (Ingold), Clavariopsis aquatica (De Wild), Flagellospora curvula (Ingold), Heliscus lugdunensis (Sacc. et Thérry), Tumularia aquatica (Ingold) and Lemonniera aquatica (De Wild) being most sensitive. We propose that aquatic hyphomycete communities can be used as sensitive and integrative indicators for freshwater quality.

Three-dimensional atom probe characterization of alloy element partitioning in cementite during tempering of alloy steel

Hardness measurements confirm that the martensitic microstructure of an alloy steel, AISI/SAE 4340, is significantly more resistant to softening, compared to the martensitic microstructure of a high-purity Fe-0.4% C alloy, at tempering temperatures, 300-400 degrees C, just above the temperatures where cementite replaces transition carbides in the martensitic matrix. Three-dimensional atom probe (3DAP) analyses of the 4340 steel show that Si rejection from the cementite is first detected after low-temperature tempering for times of 1 h. After 10-h tempering at 400 degrees C, Mn and Cr contents are increased, and Ni contents decreased, in cementite according to their carbide- and non-carbide-forming tendencies, respectively. The results are discussed with respect to the diffusivity of the substitutional alloying elements in the 4340 steel, and the effect that such diffusion-controlled redistribution would have on maintaining fine distributions of cementite that resist softening during tempering.

Speech Recognition Impairments in Patients with Intractable Right Temporal Lobe Epilepsy

PURPOSE

To evaluate speech recognition in patients with focal intractable epilepsy and surgical resections in the nondominant (right) hemisphere.

METHODS

Speech recognition was tested prospectively, under different listening conditions, in 22 patients with right temporal lobe (11 patients) or extra-temporal lobe epilepsy. All were left-hemisphere dominant for language on preoperative intracarotid sodium amobarbital testing.

RESULTS

All patients demonstrated normal auditory recognition of words and environmental sounds before and after surgery. However, when real-world listening conditions were simulated by using acoustically degraded (filtered) words, patients with temporal lobe epilepsy performed significantly worse than patients with frontal or parietooccipital lobe epilepsy before and after surgery (p<0.0001).

CONCLUSIONS

Patients with intractable right temporal lobe epilepsy are at risk for speech recognition impairments in real-world listening environments, independent of surgery. The impact of speech recognition difficulties on verbal communication, coupled with the prevalence of adverse listening environments, underscores the importance of testing speech recognition under different listening conditions in patients with intractable right temporal lobe epilepsy.

Current understanding of delayed anticonvulsant hypersensitivity reactions

Hypersensitivity syndrome (HSS) reactions are one of the most feared idiosyncratic drug reactions and are most common with exposure to antiepileptic drugs (AEDs), sulfonamides, nonsteroidal antiinflammatory drugs, corticosteroids, and allopurinol. HSS is associated with chemotoxic and T-cell-mediated inflammatory injuries in barrier tissue systems that contain cytochrome oxidases (e.g., skin, mucosa, liver, and lungs) and can be seen as a derangement in the defense system against xenobiotics-bioactive foreign molecules. The mechanisms for anticonvulsant HSS are incompletely understood but involve genetic susceptibility, with accumulation of AEDs and oxidized metabolites causing major histocompatibility complex (MHC) and non-MHC-dependent clonal activation of T cells and subsequent cytokine/chemokine production in T cells, keratinocytes, and other target cells. This review discusses the classification and possible mechanisms for anticonvulsant HSS.

Improved tolerability and efficacy in epilepsy patients with extended-release carbamazepine

The authors conducted a 3-month, prospective, open-label study assessing the effects of switching from immediate-release carbamazepine formulations to an equal total daily dose of carbamazepine extended-release capsules (CBZ-ERC) in adolescents and adults with epilepsy. Using validated, epilepsy-specific measures the authors found that switching to CBZ-ERC significantly improved patients' adverse events and quality-of-life measures. Switching to CBZ-ERC also improved seizure control.

Mortality in epilepsy: driving fatalities vs other causes of death in patients with epilepsy

OBJECTIVES

To estimate the risk to public safety posed by drivers with epilepsy, the authors compared annual totals and disease-specific risk for fatal crashes associated with seizures and other medical conditions. They compared individual risks for fatal crashes due to seizures and other causes of mortality in patients with epilepsy.

METHODS

The authors analyzed Multiple-Cause of Mortality data files from death certificates provided by the National Center for Health Statistics (NCHS) for the years 1995-97. They analyzed International Classification of Diseases-9 codes for underlying causes of death and other major conditions and determined disease-specific rates of fatal crashes associated with seizures and other medical conditions.

RESULTS

An average of 44,027 US drivers died annually as a result of motor vehicle crashes during 1995-97; however, only 86 (0.2%, range 82 to 97) of these deaths were associated with seizures in mortality reports. The incidence rate of fatal crashes for patients with seizures was 2.3 times the rate for patients with cardiovascular and hypertensive diseases and 4.6 times the rate for patients with diabetes. The proportionate mortality ratio for motor vehicle crashes in patients with seizures was low (0.2); most patients with epilepsy died of common cardiovascular and systemic disorders.

CONCLUSION

Fatal driver crashes due to seizures are uncommon. This finding supports the current public policy of permitting patients whose seizures are controlled to drive.

Site-Specific Binding of the 9.5 Kilodalton DNA-Binding Protein ORF80 Visualized by Atomic Force Microscopy

Atomic force microscopy (AFM) has been used to examine the binding properties of the DNA-binding protein ORF80 to DNA. ORF80 is a 9.5 kDa protein that binds site-specifically to double-stranded DNA of the sequence TTAA-N(7)-TTAA. Direct sizing of the protein complexes on DNA fragments from the plasmid pRN1 with AFM shows that the protein ORF80 binds preferentially to two positions. These positions agree well with the ORF80 binding sites determined by footprinting analysis. The measurements allow an estimate of the stoichiometry of the DNA-protein complexes. In contrast to previous results, the single-molecule experiments suggest that only a low number of ORF80 molecules bind to a DNA-binding site.

Aquatic hyphomycetes in polluted groundwater habitats of central Germany

Polluted groundwater wells located in a former copper shale mining district (11 sites; Mansfelder Land, Central Germany) and in meadows of the Mulde and Elbe rivers (2 sites) were assessed for occurrence and species richness of aquatic hyphomycetes. Water temperatures at all sites were relatively low and fluctuated less than in surface waters. Oxygen concentrations were always below saturation, whereas sulfate, nitrate, and phosphate levels reached extremely high values in several of the wells. Relatively high levels of Pb, Mn, and Fe were found in some of the wells, but overall few concentrations of individual metals and metalloids exceeded European guidelines for drinking water. Pollen tube growth inhibition, used to assess cytotoxicity of the water, ranged between 4 and 50%. Between 1 and 10 distinct species of aquatic hyphomycetes colonized sterile Alnus glutinosa leaves exposed at the Mansfelder Land sites; for the meadow sites, 8-20 species were found. Heliscus lugdunensis and Anguillospora sp. were the two most widespread species. Fungal colonization occurred much more slowly than in surface water, as demonstrated by scanning electron microscopy and the release of conidia from recovered leaves. The conidial output from exposed alder leaves ranged from 0.2 to 95 conidia mg (-1) dry mass, corresponding to 10% of the values for contaminated surface waters in the same region. Overall, groundwater appears to be a marginal habitat for aquatic hyphomycetes, but may nevertheless play a vital role as long-term reservoir facilitating rapid recolonization following a collapse in fungal communities in surface waters.