Early Rivaroxaban Use After Cardioembolic Stroke May Not Result in Hemorrhagic Transformation: A Prospective Magnetic Resonance Imaging Study.

BACKGROUND AND PURPOSE: Early anticoagulation after cardioembolic stroke remains controversial because of the potential for hemorrhagic transformation (HT). We tested the safety and feasibility of initiating rivaroxaban ≤14 days after cardioembolic stroke/transient ischemic attack. METHODS: A prospective, open-label study of patients with atrial fibrillation treated with rivaroxaban ≤14 days of transient ischemic attack or ischemic stroke (National Institute of Health Stroke Scale <9). All patients underwent magnetic resonance imaging <24 hours of rivaroxaban initiation and day 7. The primary end point was symptomatic HT at day 7. RESULTS: Sixty patients (mean±SD age 71±19 years, 82% stroke/18% transient ischemic attack) were enrolled. Median (interquartile range) time from onset to rivaroxaban was 3 (5) days. At treatment initiation, median National Institute of Health Stroke Scale was 2 (4), and median diffusion-weighted imaging volume was 7.9 (13.7) mL. At baseline, HT was present in 25 (42%) patients (hemorrhagic infarct [HI]1=19, HI2=6). On follow-up magnetic resonance imaging, no patients developed symptomatic HT. New asymptomatic HI1 developed in 3 patients, and asymptomatic progression from HI1 to HI2 occurred in 5 patients; otherwise, HT remained unchanged at day 7. CONCLUSIONS: These data support the safety of rivaroxaban initiation ≤14 days of mild-moderate cardioembolic stroke/transient ischemic attack. Magnetic resonance imaging evidence of petechial HT, which is common, does not appear to increase the risk of symptomatic HT.

Expression of alpha-7 and alpha-4 nicotinic acetylcholine receptors by GABAergic neurons of rostral ventral medulla and caudal pons.

Rostral ventral medulla (RVM) contains significant numbers of local GABAergic neurons which may subserve respiratory chemosensory and baroreceptor reflexes. Nicotinic mechanisms stimulate release of GABA in certain brainstem neurons. Whether the GABAergic neurons at RVM express nicotinic cholinergic receptors (nAChRs) is not known. We used glutamic acid decarboxylase 67-kDa isoform (GAD67) and parvalbumin (PV) as anatomical markers to identify the GABAergic neurons of the RVM and caudal pons and performed double labeling to evaluate the expression of alpha-7 and alpha-4 nAChRs by GAD67 and PV-imnunoreactive (ir) cells at these sites. GAD67-ir cells were found at the ventrolateral pontomedullary border in areas adjacent to the A5 noradrenergic cell group and overlapping the facial nucleus lateral subnuclei and para-facial zones. Of 205 GAD67-ir cells labeled at these sites, 74% exhibited immunoreactivity for alpha-7 nAChRs. Alpha-4 immunoreactivity was also present in 35% of GAD67-ir cells at these sites. The PV-ir cells of RVM and caudal pons were found medial to the facial nucleus and lateral to the pyramid in a column distinct from the GAD67-ir cells. Virtually all the PV-ir cells demonstrated immunoreactivity for alpha-4 nAChR (95%) and alpha-7 (93%) subunits of nAChRs. Differential expression of GAD67 and PV by neurons at the pontomedullary border implies that PV may not be a valid marker for GABAergic neurons. The expression of alpha-4 and alpha-7 nAChRs by GAD67-ir cells suggests nicotinic cholinergic modulation of GABAergic signaling at these ventrolateral pontomedullary sites.

Lemierre's syndrome resulting from streptococcal induced otitis media and mastoiditis: a case report.

INTRODUCTION: Lemierre's syndrome is an extremely rare and almost universally fatal disease characterized as thrombophlebitis of the internal jugular venous system with subsequent metastatic infection. Fusobacterium necrophorum is the most common organism implicated in causation of Lemierre's syndrome. Group A Streptococcus has mainly been observed as a polymicrobial organism in the syndrome. We report a rare finding of a rare disease where Group A Streptococcus was the sole organism triggering Lemierre's syndrome. To our knowledge, this is only the third recorded patient with such an occurrence. CASE PRESENTATION: We describe a 9-year-old African American boy, who presented with otitis media and mastoiditis that culminated in Lemierre's syndrome. Isolates bore only Group A Streptococcus. The patient was appropriately treated and responded with full recovery from the syndrome. CONCLUSION: Since Lemierre's syndrome is classically detected by clinical diagnosis, these findings should prompt clinicians to consider Group A Streptococcus as an alternative catalyst. It should be pondered that patients who present with typical Group A streptococcal infections have the possibility for developing Lemierre's syndrome. Though this complication appears to be rare, early diagnosis and prompt intervention have proven critical in survival outcome. Indeed, what would seem to be a routine case of strep throat or otitis media easily treated with antibiotics could end up being an unalterable progression to death unless Lemierre's syndrome is immediately diagnosed and treated.