Meenakshi Dauwan

Linkage analysis in a Dutch population isolate shows no major gene for left-handedness or atypical language lateralization.

Cerebral dominance of language function and hand preference are suggested to be heritable traits with possible shared genetic background. However, joined genetic studies of these traits have never been conducted. We performed a genetic linkage study in 37 multigenerational human pedigrees of both sexes (consisting of 355 subjects) enriched with left-handedness in which we also measured language lateralization. Hand preference was measured with the Edinburgh Handedness Inventory, and language lateralization was measured with functional transcranial Doppler during language production. The estimated heritability of left-handedness and language lateralization in these pedigrees is 0.24 and 0.31, respectively. A parametric major gene model was tested for left-handedness. Nonparametric analyses were performed for left-handedness, atypical lateralization, and degree of language lateralization. We did not observe genome-wide evidence for linkage in the parametric or nonparametric analyses for any of the phenotypes tested. However, multiple regions showed suggestive evidence of linkage. The parametric model showed suggestive linkage for left-handedness in the 22q13 region [heterogeneity logarithm of odds (HLOD) = 2.18]. Nonparametric multipoint analysis of left-handedness showed suggestive linkage in the same region [logarithm of odds (LOD) = 2.80]. Atypical language lateralization showed suggestive linkage in the 7q34 region (LODMax = 2.35). For strength of language lateralization, we observed suggestive linkage in the 6p22 (LODMax = 2.54), 7q32 (LODMax = 1.93), and 9q33 (LODMax = 2.10) regions. We did not observe any overlap of suggestive genetic signal between handedness and the extent of language lateralization. The absence of significant linkage argues against the presence of a major gene coding for both traits; rather, our results are suggestive of these traits being two independent polygenic complex traits.

Random forest to differentiate dementia with Lewy bodies from Alzheimer's disease

The aim of this study was to build a random forest classifier to improve the diagnostic accuracy in differentiating dementia with Lewy bodies (DLB) from Alzheimers disease (AD) and to quantify the relevance of multimodal diagnostic measures, with a focus on electroencephalography (EEG).

Residual High-Grade Stenosis After Recanalization of Extracranial Carotid Occlusion in Acute Ischemic Stroke

Background and Purpose— Residual stenosis after recanalization of an acute symptomatic extracranial occlusion of the internal carotid artery (ICA) might be an indication for carotid endarterectomy. We evaluated the proportion of residual high-grade stenosis (≥70%, near occlusions not included) on follow-up imaging in a consecutive series of patients with an acute symptomatic occlusion of the extracranial ICA. Methods— We included patients participating in the Dutch Acute Stroke Study (DUST), who had an acute symptomatic occlusion of the extracranial ICA that was diagnosed on computed tomographic angiography within 9 hours after onset of neurological symptoms. Follow-up imaging of the carotid artery had to be available within 7 days after admission. Results— Of the 1021 patients participating in DUST between May 2009 and May 2013, an acute symptomatic occlusion of the extracranial ICA was found in 126 (12.3%) patients. Follow-up imaging was available in 86 (68.3%) of these patients. At follow-up, a residual stenosis of <30% was found in 15 (17.4%; 95% confidence interval, 10.8–26.9) patients, a 30% to 49% stenosis in 3 (3.5%; 95% confidence interval, 0.8–10.2) patients, a 50% to 69% stenosis in 2 (2.3%; 95% confidence interval, 0.1–8.6) patients, and a ≥70% stenosis in 14 (16.3%; 95% confidence interval, 9.8–25.6) patients. A near or persistent occlusion was present in the remaining 52 (60.5%) patients. Conclusions— A residual high-grade stenosis of the extracranial ICA occurs in 1 of 6 patients with a symptomatic occlusion in the acute stage of cerebral ischemia. Because this may have implications for secondary prevention, we recommend follow-up imaging in these patients within a week after the event. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00880113.

Acute nephropathy after contrast agent administration for computed tomography perfusion and computed tomography angiography in patients with acute ischemic stroke

Development of acute nephropathy is a safety concern when using contrastenhanced computed tomography (CT) (1,2). Renal function is often still unknown when patients with acute ischemic stroke undergo CT perfusion (CTP) and CT angiography (CTA). Therefore, we assessed the occurrence of acute nephropathy after CTP and CTA in patients with acute ischemic stroke. Patients with a suspected ischemic stroke and without a known history of renal disease were recruited from the Dutch acute Stroke Study (DUST) (3). All 731 patients underwent CTP and CTA within nine-hours after stroke onset. Creatinine levels were measured at admission and again within three-days. Renal dysfunction on admission was defined as an estimated glomerular filtration rate of <60 ml/min/1·73 m. Acute nephropathy was defined as an increase in creatinine level of either >25% or >44 μmol/L within three-days after admission (4). Renal dysfunction on admission was found in 155 (21·2%) patients. Acute nephropathy occurred in 27 (3·7%) patients. The occurrence of acute nephropathy was not increased in patients with renal dysfunction on admission (1·3%) compared with those without (4·3%). In 11 of the 27 patients with acute nephropathy the creatinine rise reached the threshold of renal dysfunction (Fig. 1). However, treatment was considered to be required in only three patients (0·4%). One of these patients had a history of renal disease that was missed on admission. We demonstrated that acute nephropathy occurs in only a minority of patients with acute ischemic stroke without a known history of renal disease, even if renal dysfunction is present on admission. Therefore, it is safe to perform CTP and CTA in these patients before renal function is known. However, high vigilance for obtaining a history of renal disease is important and we recommend follow-up of renal function in the first days after admission.

Understanding hallucinations in probable Alzheimer's disease : Very low prevalence rates in a tertiary memory clinic

Averaging at 13.4%, current literature reports widely varying prevalence rates of hallucinations in patients with probable Alzheimers disease (AD), and is still inconclusive on contributive factors to hallucinations in AD.

EEG DIRECTED CONNECTIVITY FROM POSTERIOR BRAIN REGIONS IS DECREASED IN DEMENTIA WITH LEWY BODIES: A COMPARISON WITH ALZHEIMER’S DISEASE AND CONTROLS

not available. SATURDAY, JULY 23, 2016 ALZHEIMER’S IMAGING CONSORTIUM (AIC) ICI-02 ALZHEIMER’S DISEASE IMAGING BIOMARKERS AND AGING ICI-02-01 ALZHEIMER’S DISEASE IMAGING BIOMARKERS AND AGING Clifford R. Jack Jr, Mayo Clinic, Rochester, MN, USA. Contact e-mail: jack.clifford@mayo.edu Abstract not available.not available. SATURDAY, JULY 23, 2016 ALZHEIMER’S IMAGING CONSORTIUM (AIC) ICI-03 CONTROVERSY DEBATE: ALZHEIMER’S DISEASE — SINGLE VERSUS MULTIPLE BRAIN NETWORK DISORDER ICI-03-01 CONTROVERSY DEBATE: SINGLE BRAIN NETWORK DISORDER Christian Sorg, University Hospital Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany. Contact e-mail: c.sorg@lrz.