The Value of Magnetoencephalography to Guide Electrode Implantation in Epilepsy

To investigate if Magnetoencephalography (MEG) can add non-redundant information to guide implantation sites for intracranial recordings (IR). The contribution of MEG to intracranial recording planning was evaluated in 12 consecutive patients assessed pre-surgically with MEG followed by IR. Primary outcome measures were the identification of focal seizure onset in IR and favorable surgical outcome. Outcome measures were compared to those of 12 patients matched for implantation type in whom non-invasive pre-surgical assessment suggested clear hypotheses for implantation (non-MEG group). In the MEG group, non-invasive assessment without MEG was inconclusive, and MEG was then used to further help identify implantation sites. In all MEG patients, at least one virtual MEG electrode generated suitable hypotheses for the location of implantations. No differences in outcome measures were found between non-MEG and MEG groups. Although the MEG group included more complex patients, it showed similar percentage of successful implantations as the non-MEG group. This suggests that MEG can contribute to identify implantation sites where standard methods failed.     

The Viral Susceptibility of the Haloferax Species

Viruses can infect members of all three domains of life. However, little is known about viruses infecting archaea and the mechanisms that determine their host interactions are poorly understood. Investigations of molecular mechanisms of viral infection rely on genetically accessible virus–host model systems. Euryarchaea belonging to the genus Haloferax are interesting models, as a reliable genetic system and versatile microscopy methods are available. However, only one virus infecting the Haloferax species is currently available. In this study, we tested ~100 haloarchaeal virus isolates for their infectivity on 14 Haloferax strains. From this, we identified 10 virus isolates in total capable of infecting Haloferax strains, which represented myovirus or siphovirus morphotypes. Surprisingly, the only susceptible strain of all 14 tested was Haloferax gibbonsii LR2-5, which serves as an auspicious host for all of these 10 viruses. By applying comparative genomics, we shed light on factors determining the host range of haloarchaeal viruses on Haloferax. We anticipate our study to be a starting point in the study of haloarchaeal virus–host interactions.     

Subacute encephalopathy with seizures in alcoholics (SESA syndrome): report of an unusual case.

Subacute encephalopathy with seizures in alcoholics (SESA syndrome) is a rare neurologic disorder complicating the chronic abuse of alcohol. This acute or subacute condition is characterized by transient neurologic deficits, seizures and severe lateralized abnormalities on the electroencephalogram (EEG). Our case demonstrates that in SESA syndrome, convulsive (generalized tonic-clonic) and nonconvulsive (complex partial) seizures may coexist.     

Regional Differences in the Sensitivity of MEG for Interictal Spikes in Epilepsy

MEG interictal spikes as recorded in epilepsy patients are a reflection of intracranial interictal activity. This study investigates the relationship between the estimated sources of MEG spikes and the location, distribution and size of interictal spikes in the invasive ECoG of a group of 38 epilepsy patients that are monitored for pre-surgical evaluation. An amplitude/surface area measure is defined to quantify and rank ECoG spikes. It is found that all MEG spikes are associated with an ECoG spike that is among the three highest ranked in a patient. Among the different brain regions considered, the fronto-orbital, inter-hemispheric, tempero-lateral and central regions stand out. In an accompanying simulation study it is shown that for hypothesized extended sources of larger sizes, as suggested by the data, source location, orientation and curvature can partly explain the observed sensitivity of MEG for interictal spikes.