Pattern of CBF in the rehabilitation of visuospatial neglect.

The CBF was assessed in seven patients before and after rehabilitation for visuospatial neglect. Two months of treatment produced an increased perfusion both in the right posterior and left anterior areas of the brain. However, only the left anterior CBF increase was correlated with the neglect disorders. The left anterior improvement in CBF was inversely correlated with right-left cerebellum asymmetry in pre- and post-treatment. The present data suggest the role of the frontal eye-fields in the mechanism of recovery of visual exploration in patients with severe neglect.     

Advanced Psychometric Methods for Developing and Evaluating Cut-Point-Based Indicators

In this study, we offer some advice on the use of empirical techniques to create categorical indicators from responses to multiple survey questions that ostensibly compose scales. We discuss the use of advanced psychometric methods, including confirmatory factor analysis for ordered categorical measures (CFA-OCM) and item response theory (IRT), to expand 12 previously published criteria for cut-point development and evaluation offered by Moore et al. (Indicators of Child Well-Being: The Promise for Positive Youth Development. Annals of the American Academy of Political and Social Science. Special Issue: Positive Development: Realizing the Potential of Youth. 591:125–145, 2004). We present an application of this advice by developing categorical cut-points for the social skills and behavior problems subscales of the U.S. National Survey of Children’s Health (NSCH) Social Competence Scale. We used data from the 2007 NSCH, a large cross-sectional, random-digit-dial telephone survey of a representative sample of the noninstitutionalized population of U.S. children 0–17 years of age. Parents of children aged 6 to 17 years (n = 63,364) responded to 4 questions about their children’s behavior problems and 4 questions about their children’s positive social skills. IRT analyses indicated that IRT model-based scores of +1.8 and −0.7 provided suitable high and low cut-points, respectively, for the behavior problems subscale. These cut-points had marginal reliabilities of 0.70 and 0.67 respectively, and corresponded to raw subscale scores of 13 and 8 IRT analyses indicated that an IRT model-based score of −1.8 provided a suitable cut-point for identifying children with low levels of positive social skills. This cut-point had a marginal reliability of 0.63 and corresponded to a raw subscale score of 13. For both subscales and cut-point sets, frequency distributions demonstrated that the cut-points identified sufficient proportions of children generally as well as within demographic subgroups. Our findings indicate that analysts can use raw subscale scores and cut-points of 13 and 8 to identify children with high, moderate, and low levels of behavior problems. Our results demonstrate that, for the positive social skills subscale, the subscale’s psychometric properties only support a single cut-point of 13 that identifies children with low levels of positive social skills. Our study highlights the iterative, empirically-based process that cut-point development should follow and shows the value of modern test theory-based psychometric methods to inform this process.     

Human brain networks: a graph theoretical analysis of cortical connectivity normative database from EEG data in healthy elderly subjects

GeroScience - Moving from the hypothesis that aging processes modulate brain connectivity networks, 170 healthy elderly volunteers were submitted to EEG recordings in order to define age-related...     

Evidence for enhanced functional activity of cervical cord in relapsing multiple sclerosis

Functional MRI (fMRI) was used to assess proprioceptive‐associated cervical cord activity in 24 relapsing multiple sclerosis (MS) patients and 10 controls. Cord and brain conventional and diffusion tensor (DT) MRI were also acquired. fMRI was performed using a block design during a proprioceptive stimulation consisting of a passive flexion‐extension of the right upper limb. Cord lesion number, cross‐sectional area, mean diffusivity (MD) and fractional anisotropy (FA), whole brain and left corticospinal tract lesion volume (LV), gray matter (GM) MD, and normal‐appearing white matter (NAWM) MD and FA were calculated. MS patients had higher average cord fMRI signal changes than controls (3.4% vs. 2.7%, P = 0.03). Compared to controls, MS patients also had a higher average signal change in the anterior section of the right cord at C5 (P = 0.005) and left cord at C5–C6 (P = 0.03), whereas no difference was found in the other cord sections. Cord average signal change correlated significantly with cord FA and brain left corticospinal tract LV, GM‐MD, and NAWM‐FA. This study shows an abnormal pattern of activations in the cervical cord of MS patients following proprioceptive stimulation. Cord fMRI changes might have a role in limiting the clinical consequences of MS associated with irreversible tissue damage. Magn Reson Med 59:1035–1042, 2008. © 2008 Wiley‐Liss, Inc.     

Determinants of disability in multiple sclerosis at various disease stages: a multiparametric magnetic resonance study

OBJECTIVE: To investigate whether diffusion-tensor magnetic resonance imaging and whole brain N-acetylaspartate (WBNAA) proton magnetic resonance spectroscopy can provide complementary pieces of information to achieve a better understanding of the factors associated with disability in multiple sclerosis (MS). DESIGN: Cross-sectional survey. SETTING: Referral hospital-based MS center. PATIENTS: Ten healthy control subjects, 27 patients with a clinically isolated neurological syndrome, 21 patients with relapsing-remitting MS, and 29 patients with secondary progressive MS. MAIN OUTCOME MEASURES: Conventional and diffusion-tensor magnetic resonance imaging, as well as WBNAA proton magnetic resonance spectroscopy, of the brain was performed. T2-hyperintense lesion volumes were measured. The mean values of mean diffusivity (MD) and fractional anisotropy of T2-visible lesions were computed. Histograms of MD and fractional anisotropy values were produced for normal-appearing white matter and gray matter (GM). RESULTS: Patients with a clinically isolated neurological syndrome had a significantly (P=.002) lower WBNAA concentration than control subjects. Patients with relapsing-remitting MS had significantly higher T2 lesion volume (P=.007), mean lesion MD (P=.003), normal-appearing white matter fractional anisotropy peak height (P=.03), and a lower WBNAA concentration (P<.001) than patients with a clinically isolated neurological syndrome. Patients with secondary progressive MS had significantly higher T2 lesion volume (P=.01), lower mean normal-appearing white matter fractional anisotropy (P=.003), higher mean GM MD (P=.004), and lower GM MD peak height (P=.01) than patients with relapsing-remitting MS. Disease duration, GM MD peak height, and WBNAA concentration entered a multivariate model, explaining nearly 70% of the disability variance. CONCLUSIONS: The accumulation of macroscopic lesions and normal-appearing white matter damage seems to occur mainly during the earliest clinical phases of MS, whereas pathological features of GM may be a hallmark of the late progressive stage of the disease. This supports the notion of MS as a "2-stage" disease.     

Pelvic assessment and cephalo-pelvic disproportion in Central Tanzania

Among 201 primigravidae, pelvic assessment was analyzed prospectively during the third trimester to detect patients likely to suffer from cephalo-pelvic disproportion (CPD). If the sacral promontory (SP) was reached by the index finger (9.0-9.5 cm true conjugate) the pelvis was regarded as "suspect". All patients who later developed CPD were in this group. Of the screened primigravidas, 22% were advised to deliver in the hospital. Pelvic assessment is an important screening tool during antenatal care to detect high-risk primigravidas.     

Molecular characterization of Haemophilus ducreyi isolates from different geographical locations

The technique of random amplified polymorphic DNA (RAPD) was adapted and optimized to study Haemophilus ducreyi isolates. A panel of 43 strains isolated from chancroid patients from different countries in Africa, Europe, North America, and Asia were characterized. The strains were also studied with respect to lipooligosaccharide (LOS) migration and immunoblotting patterns and the presence of cytolethal distending toxin genes. The RAPD method with the OPJ20 primer generated nine banding patterns (1 to 9). The majority of the isolates were clustered into two major profiles, 14 and 13 strains into profiles 1 and 2, respectively, and just a few strains revealed patterns 3 and 4. The isolates from Thailand were exceptional in that they showed greater diversity and were represented by six different RAPD patterns, i.e., patterns 3 and 5 to 9. The LOS migration and immunoblotting analyses revealed two different patterns, which indicated long and short forms of LOS; the former was found in 20/23 tested strains. Two strains that expressed the short form of LOS were grouped into RAPD pattern 4. The absence of cdtABC genes was observed in only 4/23 strains, and three of these isolates were assigned to RAPD pattern 4. Our results showed limited genotypic and phenotypic variations among H. ducreyi strains, as supported by the conserved RAPD and LOS profiles shared by the majority of the studied strains. However, the RAPD method identified differences between strains, including those from different geographic areas, which indicate the potential of RAPD as an epidemiological tool for the typing of H. ducreyi isolates in countries where chancroid is endemic.     

Impact of fatigue on the efficacy of rehabilitation in multiple sclerosis

Fatigue is considered to be one of the most common and disabling symptoms among individuals with multiple sclerosis (MS). The aim of this study is to investigate if an intensive, short-term inpatient rehabilitation program is able to improve fatigue in MS, and if fatigue is able to negatively influence the clinical and functional outcome of rehabilitation in MS. One-hundred eighty six consecutively recruited MS patients underwent an intensive, short-term inpatient rehabilitation program. Sixty-four of them were selected for this study according to our inclusion criteria and compared to a control group of 22 MS patients who did not follow a rehabilitation program. We measured fatigue symptoms with the Fatigue Severity Scale (FSS) before and after rehabilitation, and classified patients into fatigued (FMS) in the case of an FSS score ≥36 and into non-fatigued MS (NFMS) in the case of an FSS <36. Expanded Disability Status Scale (EDSS) and Functional Independence Measure (FIM) were used as clinical outcome measures of the efficacy of the rehabilitation program. In our sample, an intensive, short-term rehabilitation treatment is able to determine a significant reduction of fatigue symptoms compared to untreated MS patients (p < 0.0001); however, the presence of fatigue at the beginning of the rehab program seems not to have any impact on the clinical and functional outcome of rehabilitation. An intensive inpatient rehabilitation trial decreases symptom of fatigue in MS patients; furthermore fatigue seems not to modify the amelioration of disability and impairment determined by a rehabilitation program.