Unusual diagnostic findings in temporal lobe epilepsy: A combined MRI and 18F-dopa case study

EANM practice guidelines for an appropriate use of PET and SPECT for patients with epilepsy

Epilepsy is one of the most frequent neurological conditions with an estimated prevalence of more than 50 million people worldwide and an annual incidence of two million. Although pharmacotherapy with anti-seizure medication (ASM) is the treatment of choice, ~30% of patients with epilepsy do not respond to ASM and become drug resistant. Focal epilepsy is the most frequent form of epilepsy. In patients with drug-resistant focal epilepsy, epilepsy surgery is a treatment option depending on the localisation of the seizure focus for seizure relief or seizure freedom with consecutive improvement in quality of life. Beside examinations such as scalp video/electroencephalography (EEG) telemetry, structural, and functional magnetic resonance imaging (MRI), which are primary standard tools for the diagnostic work-up and therapy management of epilepsy patients, molecular neuroimaging using different radiopharmaceuticals with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) influences and impacts on therapy decisions. To date, there are no literature-based praxis recommendations for the use of Nuclear Medicine (NM) imaging procedures in epilepsy. The aims of these guidelines are to assist in understanding the role and challenges of radiotracer imaging for epilepsy; to provide practical information for performing different molecular imaging procedures for epilepsy; and to provide an algorithm for selecting the most appropriate imaging procedures in specific clinical situations based on current literature. These guidelines are written and authorized by the European Association of Nuclear Medicine (EANM) to promote optimal epilepsy imaging, especially in the presurgical setting in children, adolescents, and adults with focal epilepsy. They will assist NM healthcare professionals and also specialists such as Neurologists, Neurophysiologists, Neurosurgeons, Psychiatrists, Psychologists, and others involved in epilepsy management in the detection and interpretation of epileptic seizure onset zone (SOZ) for further treatment decision. The information provided should be applied according to local laws and regulations as well as the availability of various radiopharmaceuticals and imaging modalities.

Association between autophagy-related protein 5 gene polymorphisms and epilepsy in Chinese patients

Autophagy is a highly conserved degradative process that has been associated with a number of neurological diseases. Autophagy-related protein 5 (ATG5) is one of the key genes for the regulation of the autophagy pathway. In this study, we investigated the potential relationship between ATG5 gene polymorphisms and epilepsy in Han Chinese population. We enrolled 112 patients with epilepsy and 100 healthy controls and detected the genotypic and allelic data of 6 single nucleotide polymorphisms (SNPs) in ATG5 (rs2245214, rs510432, rs548234, rs573775, rs6568431 and rs6937876). The associations of 6 SNPs and epilepsy were evaluated. The results revealed the genotypes of overdominant of rs510432 between controls and patients showed significant differences (P_overdominant = 0.003). Subgroup analysis showed a highly significant association of rs510432 with late-onset epilepsy (P_overdominant = 0.006), and rs548234 were associated with the susceptibility to temporal lobe epilepsy (P_codominant = 0.002, P_overdominant = 0.006). Furthermore, ATG5 was not linked to either early-onset epilepsy or drug-resistant epilepsy (p > 0.0083). These results demonstrated an association of an ATG5 gene variant with epilepsy, and stronger associations with several subgroups of epilepsy were identified. Our study may provide novel evidence for the role of ATG5 in epilepsy, and contribute to our understanding of the molecular mechanisms of this chronic neurological disease.

Revisiting the role of neurotransmitters in epilepsy: An updated review

Epilepsy is a neurologicaldisorder characterized by persistent predisposition to recurrent seizurescaused by abnormal neuronal activity in the brain. Epileptic seizures maydevelop due to a relative imbalance of excitatory and inhibitory neurotransmitters. Expressional alterations of receptors and ion channelsactivated by neurotransmitters can lead to epilepsy pathogenesis.

AIMS

In this updated comprehensive review, we discuss the emerging implication of mutations in neurotransmitter-mediated receptors and ion channels. We aim to provide critical findings of the current literature about the role of neurotransmitters in epilepsy.

MATERIALS AND METHODS

A comprehensive literature review was conducted to identify and critically evaluate studies analyzing the possible relationship between epilepsy and neurotransmitters. The PubMed database was searched for related research articles.

KEY FINDINGS

Glutamate and gamma-aminobutyric acid (GABA) are the main neurotransmitters playing a critical role in the pathophysiology of this balance, and irreversible neuronal damage may occur as a result of abnormal changes in these molecules. Acetylcholine (ACh), the main stimulant of the autonomic nervous system, mediates signal transmission through cholinergic and nicotinic receptors. Accumulating evidence indicates that dysfunction of nicotinic ACh receptors, which are widely expressed in hippocampal and cortical neurons, may be significantly implicated in the pathogenesis of epilepsy. The dopamine-norepinephrine-epinephrine cycle activates hormonal and neuronal pathways; serotonin, norepinephrine, histamine, and melatonin can act as both hormones and neurotransmitters. Recent reports have demonstrated that nitric oxide mediates cognitive and memory-related functions via stimulating neuronal transmission.

SIGNIFICANCE

The elucidation of the role of the main mediators and receptors in epilepsy is crucial for developing new diagnostic and therapeutic approaches.