Magnetoencephalography (MEG) Data Processing in Epilepsy Patients with Implanted Responsive Neurostimulation (RNS) Devices.

Drug-resistant epilepsy (DRE) is often treated with surgery or neuromodulation. Specifically, responsive neurostimulation (RNS) is a widely used therapy that is programmed to detect abnormal brain activity and intervene with tailored stimulation. Despite the success of RNS, some patients require further interventions. However, having an RNS device in situ is a hindrance to the performance of neuroimaging techniques. Magnetoencephalography (MEG), a non-invasive neurophysiologic and functional imaging technique, aids epilepsy assessment and surgery planning. MEG performed post-RNS is complicated by signal distortions. This study proposes an independent component analysis (ICA)-based approach to enhance MEG signal quality, facilitating improved assessment for epilepsy patients with implanted RNS devices. Three epilepsy patients, two with RNS implants and one without, underwent MEG scans. Preprocessing included temporal signal space separation (tSSS) and an automated ICA-based approach with MNE-Python. Power spectral density (PSD) and signal-to-noise ratio (SNR) were analyzed, and MEG dipole analysis was conducted using single equivalent current dipole (SECD) modeling. The ICA-based noise removal preprocessing method substantially improved the signal-to-noise ratio (SNR) for MEG data from epilepsy patients with implanted RNS devices. Qualitative assessment confirmed enhanced signal readability and improved MEG dipole analysis. ICA-based processing markedly enhanced MEG data quality in RNS patients, emphasizing its clinical relevance.

Hippocampal serotonin depletion is related to the presence of generalized tonic-clonic seizures, but not to psychiatric disorders in patients with temporal lobe epilepsy.

OBJECTIVE: Previous studies suggest that concentration of serotonin ([5-HT]) plays a pathogenic role in various types of epilepsy inhibiting seizures. However, most have not considered the clinical variables of epilepsy, and all of these studies included small and heterogeneous samples with refractory epilepsy, regardless of etiology. In this work, we measured [5-HT]s in hippocampal tissues from a large series of patients with refractory temporal lobe epilepsy caused by hippocampal sclerosis who underwent epilepsy surgery and evaluated the relationship between [5HT] and epilepsy-related clinical variables and psychiatric disorders. METHODS: We included 44 patients with refractory unilateral TLE-HS who underwent surgical treatment for epilepsy. Hippocampal samples were collected, and serotonin concentrations were measured with high-pressure liquid chromatography (HPLC). RESULTS: Lower [5-HT]s were correlated with a history of GTC seizures (Student's t-test: p 0.041). There were no differences in [5-HT]s according to the other clinical variables and the presence of psychiatric disorders. SIGNIFICANCE: Our findings demonstrated that serotonin depletion in the hippocampus play an important role in some aspects of the severity of epilepsy (i.e., the presence of GTC seizures) in a homogeneous sample of patients with refractory temporal lobe epilepsy determined by hippocampal sclerosis, but not with the presence of psychiatric disorders.

Intra-hospital lethality among infants with pyogenic meningitis.

Predictor variables of intra-hospital lethality among infants with pyogenic meningitis due to Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae were identified using data from a follow-up study of infants with bacterial meningitis. The infants who were admitted to Couto Maia Hospital from March 1, 1997 to December 31, 1997 presenting with symptoms of bacterial meningitis were identified and included in a database. An analysis of the clinical and laboratory information was performed using EPI info 6.01b and SPSS 6.1 statistical programs. The total mortality rate was 17.1%, and the majority of deaths occurred within 48 hours of hospitalization. Factors associated most frequently with poor outcome included absence of respiratory infection, high cerebrospinal fluid protein, and compromised cranial nerves. Early identification of major risk groups is important to adopt measures to improve prognosis.