Early dysfunction of functional connectivity in healthy elderly with subjective memory complaints

It is still an open question whether subjective memory complaints (SMC) can actually be considered to be clinically relevant predictors for the development of an objective memory impairment and even dementia. There is growing evidence that suggests that SMC are associated with an increased risk of dementia and with the presence of biological correlates of early Alzheimer's disease. In this paper, in order to shed some light on this issue, we try to discern whether subjects with SMC showed a different profile of functional connectivity compared with subjects with mild cognitive impairment (MCI) and healthy elderly subjects. In the present study, we compare the degree of synchronization of brain signals recorded with magnetoencephalography between three groups of subjects (56 in total): 19 with MCI, 12 with SMC and 25 healthy controls during a memory task. Synchronization likelihood, an index based on the theory of nonlinear dynamical systems, was used to measure functional connectivity. Briefly, results show that subjects with SMC have a very similar pattern of connectivity to control group, but on average, they present a lower synchronization value. These results could indicate that SMC are representing an initial stage with a hypo-synchronization (in comparison with the control group) where the brain system is still not compensating for the failing memory networks, but behaving as controls when compared with the MCI subjects.     

Hereditary hypophosphatemic rickets with hypercalciuria: case report

We report a case of a male aged 50 years who consulted for renal disease recurrent lithiasis and nephrocalcinosis. The clinical examination showed external signs of rickets/osteomalacia and biochemical data as well as a severe loss of renal phosphate with hypophosphatemia, normal 25 OH vitamin D, high 1,25 OH vitamin D and hypercalciuria. Parathyroid hormone was low and renal ultrasound confirmed the existence of severe bilateral medullary nephrocalcinosis. They also found incipient chronic renal failure and incomplete renal tubular acidosis, both secondary to nephrocalcinosis and unrelated to the underlying disease. The molecular study found a change in homozygosity in intron 5 of gene SLC34A3 (NM_080877.2:c[ 448 +5G>A] + [ 448 +5G>A] ). His three children were carriers of the same variant in heterozygosis and although they were clinically asymptomatic two of them had hypercalciuria. All these data suggest that the patient had hereditary hypophosphataemic rickets with hypercalciuria (HHRH) secondary to an alteration in the sodium dependent phosphate cotransporter located in proximal tubule (NaPi-IIc). The HHRH is transmitted by autosomal recessive inheritance and is an extremely rare form of hypophosphatemic rickets. The diagnosis and treatment are essential to prevent bone sequelae of rickets and nephrocalcinosis. A correct differential diagnosis with other forms of hypophosphatemic rickets has implications on the treatment, as the management based only on phosphorus supplementation usually corrects all clinical and biochemical abnormalities, except for the loss of phosphorus in the urine. The exogenous supply of calcitriol, as advised in other hypophosphatemic rickets, may induce renal calcium deposits and nephrocalcinosis and worsens the prognosis.     

Monitoring complex secundum atrial septal defects percutaneous closure with real time three-dimensional echocardiography

Background: Atrial septal defect (ASD) is one of the most common congenital heart diseases. Nowadays, percutaneous closure is considered the treatment of choice in most of secundum ASDs. Assessment of the defect and procedure monitoring have been usually performed by angiographic balloon‐sizing and/or two‐dimensional (2D) transesophageal echocardiography. However, in complex ASDs these techniques might be inaccurate. Methods: From January 2009 to January 2011 all adult patients with complex ASDs submitted for percutaneous closure were selected. Those defects, where shunts were present through a device previously implanted on the atrial septum or through multiperforated septums, were considered complex ASDs. Two‐dimensional transesophageal echocardiography and real time three‐dimensional (3D) echocardiography were performed simultaneously during the percutaneous closure procedure. Number of orifices, relationships between the defect, catheter, and device, as well as residual shunt were assessed. Results: Seven patients were included. Five patients had a multiperforated septum and in two cases the defect in the septum was through a previously implanted device. In all cases, 3D echocardiography was superior to 2D echocardiography in relation to the assessment of the relationship between the defect and the catheter or the device. Mechanisms responsible for residual shunts through a device were also better assessed by 3D echocardiography. Conclusion: Three‐dimensional echocardiography is a safe and useful technique when monitoring percutaneous closure of ASDs, showing relevant advantages over 2D echocardiography. (Echocardiography 2012;29:729‐734)     

The Isolation of Numerals at the Semantic Level

Abstract

In this study, we examine the case of a patient (NM) who could comprehend and produce numerals despite impairment on comprehension tasks and a high degree of anomia for other categories of words. It will be claimed that NM suffered from an impairment to the semantic system affecting all categories except numerals and the series of days and months. The case of a patient presenting with the exact reverse dissociation has been described a few years ago by Cipolotti et al. (Brain 1991; 114: 619–37). We conclude that NM's pattern of performance provides evidence that numerals constitute a relevant and perhaps a distinct category at the semantic level.     

Suggestive evidence for association between L‐type voltage‐gated calcium channel (CACNA1C) gene haplotypes and bipolar disorder in Latinos: a family‐based association study

Objectives: Through recent genome‐wide association studies (GWASs), several groups have reported significant association between variants in the calcium channel, voltage‐dependent, L‐type, alpha 1C subunit (CACNA1C) and bipolar disorder (BP) in European and European‐American cohorts. We performed a family‐based association study to determine whether CACNA1C is associated with BP in the Latino population. Methods: This study included 913 individuals from 215 Latino pedigrees recruited from the USA, Mexico, Guatemala, and Costa Rica. The Illumina GoldenGate Genotyping Assay was used to genotype 58 single‐nucleotide polymorphisms (SNPs) that spanned a 602.9‐kb region encompassing the CACNA1C gene including two SNPs (rs7297582 and rs1006737) previously shown to associate with BP. Individual SNP and haplotype association analyses were performed using Family‐Based Association Test (version 2.0.3) and Haploview (version 4.2) software. Results: An eight‐locus haplotype block that included these two markers showed significant association with BP (global marker permuted p = 0.0018) in the Latino population. For individual SNPs, this sample had insufficient power (10%) to detect associations with SNPs with minor effect (odds ratio = 1.15). Conclusions: Although we were not able to replicate findings of association between individual CACNA1C SNPs rs7297582 and rs1006737 and BP, we were able to replicate the GWAS signal reported for CACNA1C through a haplotype analysis that encompassed these previously reported significant SNPs. These results provide additional evidence that CACNA1C is associated with BP and provides the first evidence that variations in this gene might play a role in the pathogenesis of this disorder in the Latino population.