Approach to Patients with Seizures and Epilepsy: A Guide for Primary Care Physicians.

Seizures and epilepsy are common neurologic conditions that are frequently encountered in the outpatient primary care setting. An accurate diagnosis relies on a thorough clinical history and evaluation. Understanding seizure semiology and classification is crucial in conducting the initial assessment. Knowledge of common seizure triggers and provoking factors can further guide diagnostic testing and initial management. The pharmacodynamic characteristics and side effect profiles of anti-seizure medications are important considerations when deciding treatment and counseling patients, particularly those with comorbidities and in special populations such as patient of childbearing potential.

Arteritis and Large Vessel Occlusive Strokes in Children After COVID-19 Infection.

We describe 2 previously healthy children who suffered disabling arterial ischemic strokes because of acute intracranial large vessel occlusion within 3 to 4 weeks of coronavirus disease 2019 (COVID-19) infection. Both children presented from communities with high COVID-19 case rates in the Southwest United States. An 8-year-old American Indian girl experienced severe iron deficiency anemia requiring blood transfusion and presented with bilateral middle cerebral artery (MCA) distribution strokes 3 weeks later. She underwent emergent mechanical thrombectomy of the left MCA with successful clot retrieval but experienced reocclusion of that artery 5 hours after intervention. She also had evidence of cerebral arteritis on catheter angiography and vessel wall imaging, and clot pathology revealed recently formed, unorganized platelet- and fibrin-rich thrombus with sparse clusters of erythrocytes, degenerated histiocytes, few eosinophils, and rare neutrophils. A 16-year old African American boy demonstrated evidence of arteritis on brain magnetic resonance angiography and serological markers of cardiac and renal injury accompanied by positive lupus anticoagulant antibodies. The children described in this report express clinical features inconsistent with focal cerebral arteriopathy, including elevated markers of systemic inflammation in both bilateral MCA strokes in one case and multiple organ system dysfunction in the other case. Neither patient fulfilled criteria for multisystem inflammatory syndrome in children, given absence of fever. These cases illustrate that systemic postinfectious arteritis with cerebrovascular involvement may complicate COVID-19 infection in previously healthy school-aged children, and their presentations may overlap but not fulfill criteria for multisystem inflammatory syndrome in children or focal cerebral arteriopathy.

Utilizing minimally purified secreted rAAV for rapid and cost-effective manipulation of gene expression in the CNS.

BACKGROUND: Recombinant adeno-associated virus (rAAV) is widely used in the neuroscience field to manipulate gene expression in the nervous system. However, a limitation to the use of rAAV vectors is the time and expense needed to produce them. To overcome this limitation, we evaluated whether unpurified rAAV vectors secreted into the media following scalable PEI transfection of HEK293T cells can be used in lieu of purified rAAV. METHODS: We packaged rAAV2-EGFP vectors in 30 different wild-type and mutant capsids and subsequently collected the media containing secreted rAAV. Genomic titers of each rAAV vector were assessed and the ability of each unpurified virus to transduce primary mixed neuroglial cultures (PNGCs), organotypic brain slice cultures (BSCs) and the mouse brain was evaluated. RESULTS: There was ~ 40-fold wide variance in the average genomic titers of the rAAV2-EGFP vector packaged in the 30 different capsids, ranging from a low ~ 4.7 × 1010 vector genomes (vg)/mL for rAAV2/5-EGFP to a high of ~ 2.0 × 1012 vg/mL for a capsid mutant of rAAV2/8-EGFP. In PNGC studies, we observed a wide range of transduction efficiency among the 30 capsids evaluated, with the rAAV2/6-EGFP vector demonstrating the highest overall transduction efficiency. In BSC studies, we observed robust transduction by wild-type capsid vectors rAAV2/6, 2/8 and 2/9, and by capsid mutants of rAAV2/1, 2/6, and 2/8. In the in vivo somatic brain transgenesis (SBT) studies, we found that intra-cerebroventricular injection of media containing unpurified rAAV2-EGFP vectors packaged with select mutant capsids resulted in abundant EGFP positive neurons and astrocytes in the hippocampus and forebrain of non-transgenic mice. We demonstrate that unpurified rAAV can express transgenes at equivalent levels to lysate-purified rAAV both in vitro and in vivo. We also show that unpurified rAAV is sufficient to drive tau pathology in BSC and neuroinflammation in vivo, recapitulating previous studies using purified rAAV. CONCLUSIONS: Unpurified rAAV vectors secreted into the media can efficiently transduce brain cells in vitro and in vivo, providing a cost-effective way to manipulate gene expression. The use of unpurified virus will greatly reduce costs of exploratory studies and further increase the utility of rAAV vectors for standard laboratory use.

Ifngr1 and Stat1 mediated canonical Ifn-γ signaling drives nigrostriatal degeneration.

Brain expression of AAV-Ifn-γ leads to reactive gliosis, nigrostriatal degeneration and midbrain calcification in wild type mice. This mouse model phenocopies idiopathic basal ganglia calcification which is associated with Parkinsonian symptoms. To understand how the nigro-striatal pathway is selectively vulnerable to Ifn-γ, we determined if the phenotype is driven by canonical signaling intermediates, Ifngr1 and Stat1. Using focused bioinformatic analysis and rotarod testing, we show that neuroinflammation and motor abnormalities precede the appearance of midbrain neuropathologies in the brains of Ifn-γ mouse model. To test whether canonical Ifn-γ signaling is a key driver of progressive nigrostriatal degeneration, we overexpressed Ifn-γ in the brains of Ifngr1-/- and Stat1-/- mice. Expression of Ifn-γ in Ifngr1-/- mice did not result in any neuroinflammation, midbrain calcinosis or nigrostriatal degenerative pathology. Interestingly, in Stat1-/- mice, Ifn-γ expression resulted in gliosis without recapitulating the neurodegenerative phenotype. Overall, our data shows that canonical Ifn-γ signaling triggers midbrain calcinosis and nigrostriatal neurodegeneration, providing mechanistic insights into cytokine-driven selective neuronal vulnerability. Our study establishes the broader relevance of inflammatory signaling in neurodegenerative diseases and can potentially identify novel immunological targets for Parkinsonian syndromes.