Determination of cognitive hemispheric lateralization by "functional" transcranial Doppler cross-validated by functional MRI

BACKGROUND AND PURPOSE: Changes of blood flow velocity in the right and left middle cerebral artery (MCA) induced by cognitive demands are detectable by means of "functional" transcranial Doppler sonography (fTCD). Functional MRI (fMRI) is an alternative method for mapping brain activity. The purpose of this study was to determine whether fTCD can detect hemispheric lateralization and to cross-validate fTCD with fMRI. METHODS: Bilateral continuous MCA monitoring of 14 healthy, right-handed subjects with TCD was performed while the subjects underwent a visuospatial task, and the hemispheric blood flow velocity shift was calculated. Identical stimulus and response patterns were used in fMRI. Blood oxygenation level-dependent fMRI was performed with the use of a gradient-echo echo-planar sequence on a 1.5-T scanner. Statistical maps were computed on a voxel-by-voxel basis, hemispheric ratios for activated pixels were computed, and a group study was performed separately for the male and female subgroups. RESULTS: Statistical analyses (t test) showed a significantly higher mean peak blood flow velocity increase (P<0.05) of the right MCA (111.3+/-7.0%) compared with the left MCA (107.1+/-6.1%). fMRI demonstrated bilateral activation in the superior parietal lobulus (Brodmann area 7) with a right/left ratio of 1.95. Concordant differences between the female and male subgroups could be visualized with both methods. CONCLUSIONS: Both methods succeeded in discriminating a blood flow shift to the right hemisphere induced by a complex cognitive visuospatial task. fMRI cross-validates the findings of fTCD. Our study suggests that fTCD can investigate the close relationship between brain activity and blood flow and lateralize higher cognitive functions reliably.     

The representation of the plegic hand in the motor cortex: a combined fMRI and TMS study

TMS mapping and fMRI were used to investigate changes in the motor cortex representation of the hand in a patient with complete loss of right hand function following traumatic avulsion of the cervical roots C7 and C8. Both TMS and fMRI demonstrated an expansion of the motor representation of the forearm into the hand area contralateral to the injured side. fMRI of the hand area, however, revealed that this area could still be activated when the patient was instructed to imagine finger tapping with his plegic hand. These results indicate that the plegic hand is still represented in the motor cortex, despite the fact that the same cortical area is also now active during movements involving forearm muscles.     

Cerebrofacial venous metameric syndrome—spectrum of imaging findings

Cerebrofacial venous metameric syndrome (CVMS) is a complex craniofacial vascular malformation disorder in which patients have a constellation of venous vascular malformations affecting soft tissues, bone, dura, and neural structures including the eye and brain. It is hypothesized that a somatic mutation responsible for the venous abnormalities occurred prior to migration of the neural crest cells, and because of this, facial, osseous, and cerebral involvement typically follows a segmental or “metameric” distribution. The most commonly recognized form of CVMS is Sturge-Weber syndrome. However, a wide spectrum of CVMS phenotypical presentations exist with various metameric distributions of slow-flow vascular lesions including facial venous vascular malformations, developmental venous anomalies, venous angiomas, cavernous malformations (cavernomas), dural sinus malformations, and maybe even vascular tumors such as cavernous hemangiomas. Awareness of the various manifestations as described herewith is important for treatment and screening purposes.     

Clinical performance of the HPV DNA Array genotyping assay in detection of CIN2+ lesions with BS GP5+/6+ MPG Luminex tested cervical samples

Human papillomavirus (HPV) detection is used for screening of cervical cancer and genotype-specific persistence has shown to be mandatory for dysplasia development. Aim of this study was to evaluate the clinical performance of HPV DNA Array for cervical intraepithelial neoplasia 2+ (CIN2+) lesion detection. HPV DNA Array is a polymerase chain reaction-based assay that targets E1 sequences of 29 HPV types (6, 11, 16, 18, 26, 31, 33, 35, 39, 40, 42, 44, 45, 51, 52, 53, 54, 56, 58, 59, 66, 67, 68, 69, 70, 73, 82, 85, and 97). The clinical evaluation was performed against the reference assay, BS-GP5+/6+ multiplex genotyping (MPG)-Luminex, with 600 cervical smear samples of a referral population. HPV DNA Array detected CIN2+ lesions with a sensitivity of 90.2%, identical to that of MPG-Luminex. Detection of CIN3+ lesions was with a sensitivity of 90.3%, as compared with 88.7% of MPG-Luminex. It demonstrated very good agreement for HPV detection, irrespective of type, of 91.5% (κ = 0.832). HPV DNA Array is a simple and robust assay, with a short protocol of 4 hours hands-on time and automated readout by ELISpot AiDot software. It permits testing of up to 96 samples in one run and may be considered for use in organized screening programs and low resource settings.     

Neurohumoral response and clinical effectiveness of continuous aortic flow augmentation in patients with decompensated heart failure

The increasing number of patients with progressive or exacerbated heart failure that is refractory to medical treatment necessitates the development of innovative cardiac assist devices. The aim of this study was to investigate whether a new percutaneously inserted system, which allows continuous aortic flow augmentation (CAFA), could be shown to be clinically effective with neurohormonal benefit in patients admitted with decompensated heart failure. Patients with exacerbations of chronic heart failure were recruited for the study. A percutaneous circulation assist device (Cancion system) promoting CAFA was implanted for up to 4 days in each patient. Clinical improvement was evaluated by measuring the clinical status according to the New York Heart Association (NYHA) classification and biochemical parameters including troponin and B-type natriuretic peptide (BNP) as markers of cardiac necrosis and cardiac overload; these parameters were measured before, during, and after CAFA treatment. The decrease in BNP was determined after implantation, reaching, on average, a maximum decrease of 57% at 72 h (P = 0.04). The neurohumoral response remained significant (P < 0.05) up to 120 h after implantation, with a decrease in BNP levels of 37%, on average, compared to baseline values. Troponin I did not show any significant change during mechanical assistance (P > 0.2). All patients had improved clinical status according to the NYHA classification, and the improvement lasted for more than 1 week. Percutaneous heart-assist devices promoting CAFA offer clinical improvement and a neurohumoral response, with a significant BNP reduction in severe exacerbation of chronic heart failure that is refractory to medical treatment.