Epilepsy and innate immune system: A possible immunogenic predisposition and related therapeutic implications

Regulation of kindling epileptogenesis by hippocampal Toll-like receptors 2

This study examined whether Toll-like receptors 2 (TLR2) contribute to rapid kindling epileptogenesis. A TLR2 agonist, lipoteichoic acid (LTA), LTA antibody (LTA-A), or normal saline (control) was administered daily over 3 consecutive days, unilaterally into ventral hippocampus of adult male Wistar rats. Thirty minutes after the last injection, the animals were subjected to a rapid kindling procedure. The ictogenesis was gauged by comparing afterdischarge threshold (ADT) and afterdischarge duration (ADD) before the treatments, after the treatments prior to kindling, and 24 h after kindling. Kindling progression and retention were analyzed using video recording. The results showed that before kindling, LTA produced an ADT reduction. Neither LTA nor LTA-A affected baseline ADD. On kindling progression, LTA accelerated occurrence of generalized seizures, whereas LTA-A delayed this effect. Treatment with LTA-A reduced the number of secondary generalized complex partial seizures. Twenty-four hours after kindling, the rats of both the saline and LTA groups showed increased hippocampal excitability as compared with prekindling parameters. Administration of LTA-A prevented kindling-induced increase of hippocampal excitability. Immunostaining revealed that LTA-A attenuated the inflammatory response produced by seizures. These findings suggest that the activation of TLR2 in the hippocampus may facilitate limbic epileptogenesis.

The watch-pat in pediatrics sleep disordered breathing: Pilot study on children with negative nocturnal pulse oximetry

OBJECTIVES

The main purpose of this study was to determine the efficacy of Watch-PAT in Pediatric Sleep Disordered Breathing (PSDB) diagnosis in children with symptoms suggestive of PSDB, in which the nocturnal pulse oximetry was negative according to the Brouilette criteria.

METHODS

We enrolled 28 patients aged between 5 and 12 years (mean age: 7.75 ± 1.69), who underwent the registration with Watch-PAT, that utilizes the Peripheral Arterial Tone (PAT), AHI, RDI, body position, snoring, pulse oximetry and actigraphy.

RESULTS

Recording Watch-PAT was indicative of PSDB in 10/28 (35.7%) patients; when it was placed the threshold of AHI > 1 the number of positive patients for PSDB increased to 17/28 (60.7%). Exists a positive correlation between pat-RDI (rho = 0.798, p = 0.005) and the snoring > 40% of the time (rho = 0.656, p < 0.001) were correlated with the pat-AHI values.

CONCLUSION

The recording Watch-PAT appears to permit the defection of a certain number of SDB that might escape to the clinical evaluation and pulse oximetry only.

Autoimmune Ear Disease: Clinical and Diagnostic Relevance in Cogan's Sydrome

The autoimmune inner ear disease is a clinical syndrome with uncertain pathogenesis that is often associated to rapidly progressive hearing loss that, especially at the early stages of disease, may be at monoaural localization, although more often it is at binaural localization. It usually occurs as a sudden deafness, or a rapidly progressive sensorineural hearing loss. In this study a particular form of autoimmune inner ear disease is described, Cogan’s syndrome. Cogan’s syndrome is a chronic inflammatory disorder that most commonly affects young adults. Clinical hallmarks are interstitial keratitis, vestibular and auditory dysfunction. Associations between Cogan’s syndrome and systemic vasculitis, as well as aortitis, also exist. We report a case of a young woman who presented audiological and systemic characteristics attributable to Cogan’s syndrome. In the description of the case we illustrate how the appearance and evolution of the disease presented.

Levetiracetam in Neonatal Seizures as First-line Treatment: A Prospective Study

Aim of the Study:

The aim of this study is to evaluate the efficacy and safety of levetiracetam (LEV) as first-line treatment of neonatal seizures.

Materials and Methods:

This study was conducted in patients of Neonatal Intensive Care Unit of Santo Bambino Hospital, University of Catania, Italy, from January to August 2016. A total of 16 neonates with convulsions not associated with major syndromes, which required anticonvulsant therapy, were included and underwent IV LEV at standard doses.

Results:

All patients responded to treatment, with a variety range of seizure resolution period (from 24 h to 15 days; mean hours: 96 ± 110.95). No patient required a second anticonvulsant therapy. Regarding safety of LEV, no major side-effects were observed.

Conclusions:

To our knowledge, it is one of the few studies confirming the efficiency of LEV as first-line treatment in seizures of this age group. LEV was effective in resolving seizures and was safely administered in the current study.

Seizures and Epilepsies due to Channelopathies and Neurotransmitter Receptor Dysfunction: A Parallel between Genetic and Immune Aspects

Despite intensive research activity leading to many important discoveries, the pathophysiological mechanisms underlying seizures and epilepsy remain poorly understood. An important number of specific gene defects have been related to various forms of epilepsies, and autoimmunity and epilepsy have been associated for a long time. Certain central nervous system proteins have been involved in epilepsy or acute neurological diseases with seizures either due to underlying gene defects or immune dysfunction. Here, we focus on 2 of them that have been the object of particular attention and in-depth research over the past years: the N-methyl-D-aspartate receptor and the leucin-rich glioma-inactivated protein 1 (LGI1). We also describe illustrative examples of situations in which genetics and immunology meet in the complex pathways that underlie seizures and epilepsy.

Histone deacetylase inhibitor SAHA attenuates post-seizure hippocampal microglia TLR4/MYD88 signaling and inhibits TLR4 gene expression via histone acetylation

BACKGROUND

Epilepsy is a common neurological disorder characterized by recurrent unprovoked seizures. Seizure-induced TLR4/MYD88 signaling plays a critical role in activating microglia and triggering neuron apoptosis. SAHA is a histone deacetylase inhibitor that regulates gene expression by increasing chromatin histone acetylation. In this study, we investigated the role of SAHA in TLR4/MYD88 signaling in a rat seizure model.

RESULTS

Sprague-Dawley rats with kainic acid (KA)-induced seizures were treated with SAHA. The expression of TLR4, MYD88, NF-κB P65 and IL-1β in hippocampus was detected at hour 2 and 6 and day 1, 2, and 3 post seizure. SAHA pretreatment increased seizure latency and decreased seizure scores. The expression levels of TLR4, MYD88, NF-κB and IL-1β increased significantly in both activated microglia and apoptotic neurons after KA treatment. The effects were attenuated by SAHA. Chromatin immunoprecipitation assays indicated that the H3 histone acetylation levels significantly decreased while H3K9 levels significantly increased in the KA treatment group. The H3 and H3K9 acetylation levels returned to control levels after SAHA (50 mg/kg) pretreatment. There was a positive correlation between the expression of TLR4 and the acetylation levels of H3K9.

CONCLUSIONS

Histone deacetylase inhibitor SAHA can suppress seizure-induced TLR4/MYD88 signaling and inhibit TLR4 gene expression through histone acetylation regulation. This suggests that SAHA may protect against seizure-induced brain damage.