Analysis of Clinical Characteristics, Background, and Paroxysmal Activity in EEG of Patients with Juvenile Myoclonic Epilepsy

Juvenile myoclonic epilepsy (JME) appears in adolescence with myoclonic, absence, and generalized tonic clonic (GTC) seizures with paroxysmal activity of polyspike and slow wave (PSW), or spike and wave (SW) complexes in EEG. Our aim was to analyze the clinical characteristics, background EEG activity, and paroxysmal events in 41 patients with JME. Background EEG activity was analyzed with visual, quantitative (QEEG), and neurometric parameters. Our JME patients started with absence seizures at 11.4 ± 1.5 years old, myoclonic seizures at 13.6 ± 2.5 years, and GTC seizures at 15.1 ± 0.8 years. The seizures presented in awakening at 7:39 h with sleep deprivation, alcoholic beverage intake, and stress as the most frequent precipitant factors. Paroxysmal activity was of PSW and fast SW complexes with 40.5 ± 62.6 events/hour and a duration of 1.7 s. Right asymmetric paroxysmal activity was present in 68.3% of patients. Background EEG activity was abnormal in 31.7% of patients with visual analysis. With QEEG beta AP (absolute power) increase and AP delta decrease were the most frequent abnormalities found. Spectral analysis showed that 48.7% of patients had normal results, and 26.83% and 24.4% had higher and lower frequencies than 10.156 Hz, respectively. We concluded that, with visual analysis, background EEG activity was abnormal in a few patients and the abnormalities increased when QEEG was used.

Familial adult myoclonic epilepsy (FAME): clinical features, molecular characteristics, pathophysiological aspects and diagnostic work-up

Familial adult myoclonic epilepsy (FAME) is a rare autosomal dominant disorder characterized by myoclonus and seizures. The genetic variant underlying FAME is an intronic repeat expansion composed of two different pentamers: an expanded TTTTA, which is the motif originally present at the locus, and an insertion of TTTCA repeats, which is usually located at the 3′ end and likely corresponds to the pathogenic part of the expansion. This repeat expansion has been identified so far in six genes located on different chromosomes, which remarkably encode proteins with distinct cellular localizations and functions. Although the exact pathophysiological mechanisms remain to be clarified, it is likely that FAME repeat expansions lead to disease independently of the gene where they occur. We herein review the clinical and molecular characteristics of this singular genetic disorder, which interestingly shares clinical features with other more common neurological disorders whose etiology remains mainly unsolved.

Clinical and genetic characteristics of juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy (JME) is reported as a clinically and genetically heterogeneous disease with a high risk of inheritance. The aim of the study was to establish phenotype features and genetic risk factors for juvenile myoclonic epilepsy to advance existing approaches of prevention, treatment, and observation of patients with JME. Methods: anamnestic; clinical; neurophysiological (EEG); neuroradiological (MRI), neuropsychological; laboratory (DNA-diagnostics). JME starts with absences more frequently in females as compared to males (32.0% vs. 15.4%), and with GTCS and myoclonic in males as compared to females (46.2% and 36.5% vs. 36.0% and 31.2%, respectively). The 1st phenotype of JME was more frequently encountered in male individuals in comparison with female ones (55.8% vs. 34.7%), and the 2nd phenotype was more frequently encountered in female individuals in comparison with male ones (16.9% vs. 5.8%). Homozygous carriage of the T allele of the GJD2 gene (rs3743123) was associated with the development of JME in the study population, OR = 2.66 (95% CI 1.24 to 5.74). 41.5% of patients with JME have a slow metabolizer pharmacogenetic status, which is a risk factor for pseudo-pharmacoresistance and the development of adverse drug reactions.