Clinical analysis of first-ever acute ischemic stroke involving the territory of paramedian mesencephalic arteries

To determine one-year clinical outcome of patients with first-ever acute ischemic stroke involving the territory of paramedian mesencephalic arteries (PMAS), we conducted a prospective study evaluating the cognitive functions of 28 patients with PMAS. Neuropsychological tests were performed during the first month of stroke onset and at the 12^th month of follow-up. There were 12 women and 16 men. Mean age of onset for women and men was 70 years and 65 years, respectively. Progressing strokes occurred in 62% of patients and 96% developed a full-blown picture of the clinical triad of akinetic mutism, hypersomnolence, and bilateral blepharoptosis and ophthalmoparesis. Involuntary movements occurred in 6, and focal myoclonus in 4 patients. The top four associated risk factors were hypertension (68%), hyperlipidemia (57%), diabetes mellitus (46%), and atrial fibrillation (36%). Unilateral midbrain infarctions occurred in 12 patients and bilateral lesions in 16. Thalamic infarctions were unilateral in 10 and bilateral in 13 cases. Three of the 28 (11%) patients died of recurrent cerebral infarctions within 1 year of the onset of PMAS. The recurrent infarctions involved the basilar artery territory in two cases and the carotid system in another. One patient died of acute myocardial infarction. Of the 24 patients who had survived the stroke by 1 year, 20 (71%) developed dementia. We conclude that first-ever ischemic stroke with PMAS is not a benign syndrome. Most patients developed dementia by 1 year after the stroke.     

Germ-line mutation of KCNQ2, p.R213W, in a Japanese family with benign familial neonatal convulsion

Background: Benign familial neonatal convulsion (BFNC) is an autosomal‐dominantly inherited epilepsy of neonates. The KCNQ2 and KCNQ3 genes have been cloned as the responsible genes for BFNC. Detection of mutations in these genes is helpful for confirmation of BFNC or differential diagnosis of convulsive disorders in the neonatal period. Methods: A Japanese family with BFNC was investigated. Two siblings were clinically diagnosed as having BFNC. KCNQ2 and KCNQ3 were screened for mutations using a combination of polymerase chain reaction and denaturing high‐performance liquid chromatography. Nucleotide substitutions were confirmed by direct sequencing. Results: In the affected siblings a C‐to‐T heterozygous substitution was detected at nucleotide 683 (c.683C>T) in KCNQ2, leading to substitution of arginine with tryptophan at amino acid position 213 (p.R213W) in the S4 voltage‐sensing domain of the KCNQ2 protein. The detected mutation may disrupt this highly conserved region among potassium channel proteins. The c.683C>T substitution in KCNQ2 was not present in the parents. KCNQ3 was also analyzed and a single nucleotide polymorphism, c.1241A>G (National Center for Biotechnology Information (NCBI), SNP ID: rs2303995), was detected in the index family. Conclusions: Two siblings with BFNC had a novel heterozygous missense mutation, p.R213W, in KCNQ2. This mutation may affect potassium gating, leading to neuronal excitability or convulsions in the patients. Furthermore, neither of the parents had the p.R213W mutation, indicating that it was a germ‐line mutation. The possibility of recurrence of such a germ‐line mutation in the next siblings should be explained during genetic counseling.     

Imaging P-glycoprotein transport activity at the human blood-brain barrier with positron emission tomography

BACKGROUND: Numerous knockout mouse studies have revealed that P-glycoprotein (P-gp) significantly limits drug distribution across the mouse blood-brain barrier (BBB). To determine the importance of P-gp at the human BBB, we developed a state-of-the-art, noninvasive, quantitative imaging technique to measure P-gp activity by use of carbon 11-labeled verapamil as the P-gp substrate and cyclosporine (INN, ciclosporin) as the P-gp inhibitor. METHODS: In brief, 11C-verapamil (approximately 0.2 mCi/kg) was administered to healthy volunteers (n = 12 [6 women and 6 men]) as an intravenous infusion over a period of approximately 1 minute before and after at least a 1-hour infusion of cyclosporine (2.5 mg x kg(-1) x h(-1)). Arterial blood samples and brain positron emission tomography images were obtained at frequent intervals for 45 minutes. Both blood and plasma radioactivity contents were determined in each verapamil sample. The content of verapamil and its metabolites in the 20- and 45-minute plasma samples was determined by a rapid solid-phase extraction method. The brain uptake of 11C-radioactivity (brain area under the curve [AUCbrain ]/blood area under the curve [AUCblood]) was determined in the presence and absence of cyclosporine. RESULTS: The AUCbrain/AUCblood ratio of 11C-radioactivity was increased by 88% +/- 20% (1.02 +/- 0.18 versus 0.55 +/- 0.10, P < .001) in the presence of cyclosporine (mean blood concentration, 2.8 +/- 0.4 micromol/L) without affecting 11C-verapamil metabolism or plasma protein binding. The corresponding increases for the brain white and gray matter were 84% +/- 13% and 84% +/- 18%, respectively. CONCLUSIONS: This is the first time that P-gp activity at the human BBB has been measured. The modest inhibition of human BBB P-gp by cyclosporine has implications for P-gp-based drug interactions at the human BBB. Our method for imaging P-gp activity can be used to identify multidrug-resistant tumors or to determine the contribution of P-gp polymorphism, inhibition, or induction to interindividual variability in drug response.     

Left atrial appendage occlusion for ischemic stroke prevention in patients with non-valvular atrial fibrillation: clinical expert opinion and consensus statement for the Asian-Pacific region

Journal of Interventional Cardiac Electrophysiology - To develop a consensus statement for left atrial appendage occlusion (LAAO) in Asian-Pacific patients with non-valvular atrial fibrillation...