Initial experience with a novel remote-guided magnetic catheter navigation system for left ventricular scar mapping and ablation in a porcine model of healed myocardial infarction

Objective: This study examined the feasibility of using a remote magnetic catheter navigation system (MNS) in concert with an EAM system to perform detailed left ventricular scar mapping and ablation in a porcine model of healed myocardial infarction.
Background : Substrate-based catheter ablation of ventricular tachycardia (VT) involves detailed electroanatomical mapping (EAM) of the ventricles. While a safe and effective procedure, VT ablation is nonetheless uncommonly performed, due in part to the technical challenges related to ventricular mapping.
Methods: Using a prototype EAM system (CARTO-RMT), seven chronically infarcted swine were mapped using either: (i) a standard manually manipulated catheter or (ii) a magnetic remotely manipulated (Niobe) catheter. A total of 191 ± 54 and 221 ± 64 points were acquired to map the chamber either manually or remotely, respectively.
Results: Procedure times were longer remotely (94 ± 22 vs. 59 ± 19 minute, P = 0.004; and 27 ± 8 vs. 18 ± 3 sec/point, P = 0.04), but this became less apparent with increased operator experience. However, the fluoroscopy time was significantly shorter with remote mapping (56 ± 56 vs. 244 ± 67 sec/map, P = 0.03). The calculated scar size was comparable between the two methods (16.3 ± 4.9 vs. 16.4 ± 4.8 cm², P = 0.37). Pathologic examination confirmed that the MNS was able to precisely deliver radiofrequency lesions to the scar borders. Using the MNS, the error to reach an evenly distributed set of endocardial targets was 6.6 ± 3.6 mm and 4.6 ± 2.0 mm, using transseptal and retrograde approaches, respectively.
Conclusions: Ventricular mapping using this remote navigation paradigm is technically possible and requires minimal fluoroscopy exposure, potentially facilitating ventricular substrate mapping and ablation.     

Developmental coordination disorder in children with attention-deficit-hyperactivity disorder and physical therapy intervention

Although physical therapy (PT) is effective in improving motor function in children with developmental coordination disorder (DCD), insufficient data are available on the impact of this intervention in children with combined attention-deficit-hyperactivity disorder (ADHD) and DCD. This prospective study aimed to establish the prevalence of DCD among a cohort of patients with ADHD, characterize the motor impairment, identify additional comorbidities, and determine the role of PT intervention on these patients. DCD was detected in 55.2% of 96 consecutive children with ADHD (81 males, 15 females), mostly among patients with the inattentive type (64.3% compared with 11% of those with the hyperactive/impulsive type, p<0.05). Mean age was 8 years 4 months (SD 2 y). Individuals with both ADHD and DCD more often had specific learning disabilities (p=0.05) and expressive language deficits (p=0.03) than children with ADHD only. Twenty-eight patients with ADHD and DCD randomly received either intensive group PT (group A, mean age 9 y 3 mo, SD 2 y 3 mo) or no intervention (group B, mean age 9 y 3 mo, SD 2 y 2 mo). PT significantly improved motor performance (assessed by the Movement Assessment Battery for Children; p=0.001). In conclusion, DCD is common in children with ADHD, particularly of the inattentive type. Patients with both ADHD and DCD are more likely to exhibit specific learning disabilities and phonological (pronunciation) deficits. Intensive PT intervention has a marked impact on the motor performance of these children.     

Quantitative EEG asymmetry correlates with clinical severity in unilateral Sturge-Weber syndrome

PURPOSE: Sturge-Weber syndrome (SWS) is a neurocutaneous disorder with vascular malformations of the skin, brain, and eye. SWS results in ischemic brain injury, seizures, and neurologic deficits. We hypothesized that a decrease in quantitative EEG (qEEG) power, on the affected side, correlates with clinical severity in subjects with SWS. METHODS: Fourteen subjects had 16-channel scalp EEG recordings. Data were analyzed using fast Fourier transform and calculation of power asymmetry. Blinded investigators assigned scores for clinical neurological status and qualitative assessment of MRI and EEG asymmetry. RESULTS: The majority of subjects demonstrated lower total power on the affected side, usually involving all four frequency bands (delta, theta, alpha, and beta). qEEG asymmetry correlated strongly with neurologic clinical severity scores and MRI asymmetry scores. qEEG data generally agreed with the MRI evidence of regional brain involvement. In MRI-qEEG comparisons that did not agree, decreased power on qEEG in a brain region not affected on MRI was more likely to occur in subjects with more severe neurologic deficits. CONCLUSIONS: qEEG provides an objective measure of EEG asymmetry that correlates with clinical status and brain asymmetry seen on MRI. These findings support the conclusion that qEEG reflects the degree and extent of brain involvement and dysfunction in SWS. qEEG may potentially be a useful tool for early diagnosis and monitoring of disease progression in SWS. qEEG may prove useful, in severely affected individuals with SWS, for determining regions of brain dysfunction.     

Effect of comorbid tics on a clinically meaningful response to 8-week open-label trial of fluoxetine in obsessive compulsive disorder

Currently, there are limited published data evaluating the effects of tics on serotonin reuptake inhibitor (SRI) monotherapy responses in treating obsessive-compulsive disorder (OCD). One retrospective case-controlled analysis of OCD patients treated with SRI monotherapy showed lesser improvement in OCD symptoms in patients with tics than those without. However, more recently there were preliminary reports of OCD subjects treated with SRI monotherapy which did not demonstrate poorer response in subjects with tics or Tourette's Syndrome (TS). The specific aim of this study was to investigate whether the presence of comorbid chronic tics affected "clinically meaningful improvement" [McDougle, C.J., Goodman, W.K., Leckman, J.F., Barr, L.C., Heninger, G.R., Price, L.H., 1993. The efficacy of fluvoxamine in obsessive-compulsive disorder: effects of comorbid chronic tic disorder. Journal of Clinical Psychopharmacology 13, 354-358] of OCD in an 8-week open-label trial of fluoxetine monotherapy. Seventy-four adult subjects (13 patients with comorbid chronic tics and 61 patients without tics) with a primary DSM-IV OCD diagnosis were treated with up to 40mg fluoxetine for 8 weeks and had at least one post-baseline evaluation. The results indicate that there was a significant response by time in both fluoxetine-with-tic subjects and fluoxetine-without-tic subjects. Additionally, there were 3 (23.0%) OCD subjects with tics who had clinically meaningful improvement versus 16 (26.2%) OCD subjects without tics that demonstrated similar levels of improvement. These findings indicate that OCD patients with or without chronic tic disorders did not have a differential response to an 8-week open-label trial of fluoxetine. Limitations include the relatively low number of tic subjects and the open-label nature of the study. Additional data are needed on how comorbid tics may affect SRI treatment response in OCD.     

Diffusion tensor anisotropy in adolescents and adults

We acquired diffusion tensor images on 33 normal adults aged 22-64 and 15 adolescents aged 14-21. We assessed relative anisotropy in stereotaxically located regions of interest in the internal capsule, corpus callosum, anterior thalamic radiations, frontal anterior fasciculus, fronto-occipital fasciculus, temporal lobe white matter, cingulum bundle, frontal inferior longitudinal fasciculus, frontal superior longitudinal fasciculus, and optic radiations. All of these structures except the optic radiations, corpus callosum, and frontal inferior longitudinal fasciculus exhibited differences in anisotropy between adolescents and adults. Areas with anisotropy increasing with age included the anterior limb of the internal capsule, superior levels of the frontal superior longitudinal fasciculus and the inferior portion of the temporal white matter. Areas with anisotropy decreasing with age included the posterior limb of the internal capsule, anterior thalamic radiations, fronto-occipital fasciculus, anterior portion of the frontal anterior fasciculus, inferior portion of the frontal superior longitudinal fasciculus, cingulum bundle and superior portion of the temporal axis. Sex differences were found in the majority of areas but were most marked in the cingulum bundle and internal capsule. These results suggest continuing white matter development between adolescence and adulthood.     

The specificity of cognitive vulnerabilities to emotional disorders: anxiety sensitivity, looming vulnerability and explanatory style

Mood and anxiety disorders share considerable phenomenological and diagnostic overlap. Several models have advanced the understanding of the phenomenological overlap of anxiety and depression; however, identification of disorder-specific etiological mechanisms remains elusive. Recently, research has advanced several cognitive vulnerability-stress models proposing that one's characteristic way of attending to, interpreting, and remembering negative events contributes vulnerability to psychopathology. These cognitive vulnerabilities may elucidate specific etiological mechanisms that distinguish mood and anxiety pathology. The present study examines the specificity of three cognitive vulnerability constructs, the looming cognitive style, anxiety sensitivity, and explanatory style, in the prediction of latent anxiety disorder symptoms and latent depression symptoms. Structural equation modeling analyses indicated that the looming cognitive style demonstrated specificity predicting only anxiety disorder symptoms whereas anxiety sensitivity and a pessimistic explanatory style predicted both anxiety disorder and mood disorder symptoms. Implications for future research are discussed.     

Interpretation biases in victims and non-victims of interpersonal trauma and their relation to symptom development

Previous studies examining information processing in posttraumatic stress disorder (PTSD) have focused on attention and memory biases, with few studies examining interpretive biases. The majority of these studies have employed lexically based methodologies, rather than examining the processing of visual information. In the present study, victims (N=40) and non-victims (N=41) of interpersonal trauma viewed a series of short positive, neutral, and threatening filmstrips of social situations with ambiguous endings. Participants were then asked about their perceptions and interpretations of the situations. Victims perceived threatening situations as more predictable and more quickly increasing in risk than non-victims. Trauma status interacted with the perceived predictability of positive situations and the perceived speed with which neutral situations reached their conclusion to predict anxious symptoms. In addition, trauma status interacted with the perceived increase in risk of positive situations to predict PTSD symptoms. The implications of these findings for theories of PTSD are discussed.     

Reduction of right medial pulvinar volume and neuron number in schizophrenia

Several studies have described a reduction of pulvinar volume and/or neuronal number in schizophrenia (SZ). In order to better localize these changes, we assessed volume and neuronal number of the pulvinar and several of its subdivisions in postmortem material from subjects with chronic SZ and subjects with no psychiatric history. Total pulvinar volume and neuronal number were significantly lower in SZ and these differences were significant in only in its medial division. The medial pulvinar interconnects various heteromodal cortical regions suggesting that these deficits may contribute to the abnormalities of higher order integrative functions characteristic of schizophrenia.     

A novel mutation in ferroportin implicated in iron overload

BACKGROUND/AIMS: Hereditary iron overload is associated with mutations in a number of genes involved in the regulation of iron metabolism. In this study we examined the molecular basis of iron overload in an individual from New Zealand and characterised the molecular and cellular defect. METHODS: We analysed the ferroportin gene and a control population was screened using allele-specific PCR and denaturation analysis. Molecular characterisation was performed by immunofluorescence microscopy analysis of transfected cells. We analysed the ferritin levels of cells expressing wild-type and mutant ferroportin to define the nature of the molecular defect on iron transport. RESULTS: We identified a novel nucleotide substitution (c. 1014T>G) in the ferroportin gene leading to the S338R mutation. This mutation is not a common polymorphism. Cellular analysis of the mutant protein indicates that this amino acid change does not affect the localisation of the protein or its ability to transport iron. CONCLUSIONS: The S338R mutation results in a mutated ferroportin associated with iron overload and is predicted insensitive to regulation by the iron regulatory hormone hepcidin.