Video-EEG Study of Psychogenic Nonepileptic Seizures: Differential Characteristics in Patients with and without Epilepsy

Summary:  Purpose: Psychogenic nonepileptic seizures (PNES) are episodes that may resemble epileptic seizures (ES) but are not associated with abnormal electrical discharges in the brain. Video-EEG recording of a typical episode is considered the best diagnostic tool available. PNES are, however, also documented in patients with epilepsy (PNES/ES). The purpose of this study was to assess this comorbid population, focusing on the differences between patients with PNES/ES and patients with PNES alone.
Methods: We reviewed 110 PNES episodes, occurring spontaneously or induced by means of suggestion techniques, recorded in our video-EEG laboratory over a period of eight years. We identified two subgroups of patients, consisting of 85 PNES cases and 25 PNES/ES cases, and assessed any differences in their characteristics by reviewing a number of variables (age, sex, clinical features, antiepileptic therapy, age of onset, time to diagnosis, pathological history, and length of follow-up).
Results: The comparison between the two subgroups revealed that PNES/ES patients displayed some statistically significant differences when compared with PNES alone patients, i.e., younger age, a higher percentage of spontaneously activated events, a shorter disease duration, a longer time to PNES diagnosis, and a lower percentage lost at follow-up.
Conclusions: This study confirms that PNES is a common, though probably underestimated, occurrence in epilepsy services. Our results shed light on some different characteristics between PNES and PNES/ES patients.     

Discontinuing monoclonal antibodies targeting CGRP pathway after one-year treatment: an observational longitudinal cohort study

BackgroundMonoclonal antibodies anti-calcitonin gene-related peptide (mAbs anti-CGRP) pathway are effective and safe on migraine prevention. However, some drug agencies limited these treatments to one year due to their high costs. This study aimed at evaluating the effect of discontinuing mAbs anti-CGRP on monthly migraine days (MMDs) and disability in high-frequency episodic (HFEM) and chronic migraine (CM) patients.MethodsThis observational longitudinal cohort study was conducted at 10 Italian headache centres. Consecutive adult patients were followed-up for three months (F-UP1–3) after discontinuation of a one-year erenumab/galcanezumab treatment. The primary endpoint was the change in F-UP MMDs. Secondary endpoints included variation in pain intensity (Numerical Rating Scale, NRS), monthly acute medication intake (MAMI), and HIT-6 scores. We also assessed from F-UP1 to 3 the ≥50% response rate, relapse rate to CM, and recurrence of Medication Overuse (MO).ResultsWe enrolled 154 patients (72.1% female, 48.2 ± 11.1 years, 107 CM, 47 HFEM); 91 were treated with erenumab, 63 with galcanezumab. From F-UP1 to F-UP3, MMDs, MAMI, NRS, and HIT-6 progressively increased but were still lower at F-UP3 than baseline (Friedman’s analysis of rank, p < .001). In the F-UP1–3 visits, ≥50% response rate frequency did not differ significantly between CM and HFEM patients. However, the median reduction in response rate at F-UP3 was higher in HFEM (− 47.7% [25th, − 79.5; 75th,-17.0]) than in CM patients (− 25.5% [25th, − 47.1; 75th, − 3.3]; Mann-Whitney U test; p = .032). Of the 84 baseline CM patients who had reverted to episodic migraine, 28 (33.3%) relapsed to CM at F-UP1, 35 (41.7%) at F-UP2, 39 (46.4%) at F-UP3. Of the 64 baseline patients suffering of medication overuse headache ceasing MO, 15 (18.3%) relapsed to MO at F-UP1, 26 (31.6%) at F-UP2, and 30 (42.3%, 11 missing data) at F-UP3. Lower MMDs, MAMI, NRS, and HIT-6 and higher response rate in the last month of therapy characterized patients with ≥50% response rate at F-UP1 and F-UP3 (Mann-Whitney U test; consistently p < .01).ConclusionMigraine frequency and disability gradually increased after mAbs anti-CGRP interruption. Most patients did not relapse to MO or CM despite the increase in MMDs. Our data suggest to reconsider mAbs anti-CGRP discontinuation.     

The Dlx5 homeodomain gene is essential for olfactory development and connectivity in the mouse

The distalless-related homeogene Dlx5 is expressed in the olfactory placodes and derived tissues and in the anterior-basal forebrain. We investigated the role of Dlx5 in olfactory development. In Dlx5(-/-) mice, the olfactory bulbs (OBs) lack glomeruli, exhibit disorganized cellular layers, and show reduced numbers of TH- and GAD67-positive neurons. The olfactory epithelium in Dlx5(-/-) mice is composed of olfactory receptor neurons (ORNs) that appear identical to wild-type ORNs, but their axons fail to contact the OBs. We transplanted Dlx5(-/-) OBs into a wild-type newborn mouse; wild-type ORN axons enter the mutant OB and form glomeruli, but cannot rescue the lamination defect or the expression of TH and GAD67. Thus, the absence of Dlx5 in the OB does not per se prevent ORN axon ingrowth. In conclusion, Dlx5 plays major roles in the connectivity of ORN axons and in the differentiation of OB interneurons.     

Use of levetiracetam in treating epilepsy associated with other medical conditions

OBJECTIVE: This prospective, open-label study was conducted to evaluate the effectiveness, tolerability, and safety of levetiracetam in patients with epilepsy in whom unfavorable metabolism, complex drug interactions, or direct toxic effects of antiepileptic drugs (AEDs) had caused a worsening of comorbid conditions. METHODS: Study design included the introduction of levetiracetam, discontinuation of other AEDs, and a serial assessment comprising electroencephalograms and blood tests at baseline and 2, 6, and 12 months. Of 21 patients, 16 had partial and five generalized epilepsy. Concomitant pathologies were gastroenterological (six), vascular (four), endocrinological (four), or complex conditions including hematological (four) or dermatological (three) disease. A change of regimen was necessitated by drug-drug interactions in four patients, direct real or potential toxic effects of previous AEDs in 13, and a combination of interactions/toxic effects in four. RESULTS: After 12 months, 12 patients were seizure-free, nine had reductions in seizure frequency of 50-75%, and improvement in concomitant medical conditions was observed. No side effects were reported. CONCLUSION: Levetiracetam appears to be effective, well tolerated, and safe in patients with epilepsy and other medical conditions that are difficult to manage because of drug interactions or AED-related side effects.     

Future trends in drugs for migraine prophylaxis

Migraine prevention hinges on a variety of non-specific drugs that mainly reduce neuronal hyperexcitability, the putative pathophysiological hallmark for migraine. The improved knowledge about migraine circuitry and neurobiology has prompted research to develop new specific migraine preventive medications targeted to innovative sites and mechanisms. Drugs designed to inhibit cortical spreading depression, for example tonabersat, might offer a useful option for the management of migraine with aura but not for migraine without aura. Inducible nitric-oxide synthase (iNOS) inhibition seems ineffective as a prophylactic strategy. Results are awaited from recent and ongoing phase II trials with glutamate receptor antagonists, third-generation antiepileptics, melatonin agonists, vitamin D3 and statins.     

The role of anti-CGRP antibodies in the pathophysiology of primary headaches

Calcitonin gene-related peptide (CGRP), a potent vasodilator and pain-signaling neuropeptide, is a validated therapeutic target for migraine and cluster headache. Four anti-CGRP monoclonal antibodies (mAbs) have been developed, representing the first specific, mechanism-based, migraine prophylactic treatment. CGRP mAbs demonstrated good efficacy coupled to excellent tolerability and safety in 5 phase II clinical trials. Notably, CGRP mAbs induced complete migraine remission in a patients’ subset. To date, more than 20 phase III trials using CGRP mAbs for of episodic and chronic migraine and cluster headache prevention are ongoing. Future investigations will shed light on migraine endophenotypes predictive of good CGRP mAbs responsiveness and provide answers on their long-term cardiovascular safety.     

Association of intronic variants of the KCNAB1 gene with lateral temporal epilepsy

The KCNAB1 gene is a candidate susceptibility factor for lateral temporal epilepsy (LTE) because of its functional interaction with LGI1, the gene responsible for the autosomal dominant form of LTE. We investigated association between polymorphic variants across the KCNAB1 gene and LTE. The allele and genotype frequencies of 14 KCNAB1 intronic SNPs were determined in 142 Italian LTE patients and 104 healthy controls and statistically evaluated. Single SNP analysis revealed one SNP (rs992353) located near the 3'end of KCNAB1 slightly associated with LTE after multiple testing correction (odds ratio=2.25; 95% confidence interval 1.26-4.04; P=0.0058). Haplotype analysis revealed two haplotypes with frequencies higher in cases than in controls, and these differences were statistically significant after permutation tests (Psim=0.047 and 0.034). One of these haplotypes was shown to confer a high risk for the syndrome (odds ratio=12.24; 95% confidence interval 1.32-113.05) by logistic regression analysis. These results support KCNAB1 as a susceptibility gene for LTE, in agreement with previous studies showing that this gene may alter susceptibility to focal epilepsy.