Tadeu Kubo

Evaluation of hippocampal volume based on MR imaging in patients with bipolar affective disorder applying manual and automatic segmentation techniques.

To compare the hippocampal volumes in patients with bipolar disorder (BD) and healthy controls, obtained by applying different segmentation methods (manual, Freesurfer [FS], and FSL).

Diffusion tensor MRI evaluation of the corona radiata, cingulate gyri, and corpus callosum in HIV patients

To evaluate the white matter integrity of the corona radiata, cingulate gyri, and corpus callosum in patients with human immunodeficiency virus (HIV) infection through diffusion tensor imaging (DTI).

Cuneus and fusiform cortices thickness is reduced in trigeminal neuralgia

BackgroundChronic pain disorders are presumed to induce changes in brain grey and white matters. Few studies have focused CNS alterations in trigeminal neuralgia (TN).MethodsThe aim of this study was to explore changes in white matter microstructure in TN subjects using diffusion tensor images (DTI) with tract-based spatial statistics (TBSS); and cortical thickness changes with surface based morphometry. Twenty-four patients with classical TN (37-67 y-o) and 24 healthy controls, matched for age and sex, were included in the study.ResultsComparing patients with controls, no diffusivity abnormalities of brain white matter were detected. However, a significant reduction in cortical thickness was observed at the left cuneus and left fusiform cortex in the patients group. The thickness of the fusiform cortex correlated negatively with the carbamazepine dose (p = 0.023).ConclusionsSince the cuneus and the fusiform gyrus have been related to the multisensory integration area and cognitive processing, as well as the retrieval of shock perception conveyed by Aδ fibers, our results support the role of these areas in TN pathogenesis. Whether such changes occurs as an epiphenomenon secondary to daily stimulation or represent a structural predisposition to TN in the light of peripheral vascular compression is a matter of future studies.

Right and left ventricular function and myocardial scarring in adult patients with sickle cell disease: a comprehensive magnetic resonance assessment of hepatic and myocardial iron overload

BackgroundPatients with Sickle cell disease (SCD) who receive regular transfusions are at risk for developing cardiac toxicity from iron overload. The aim of this study was to assess right and left cardiac volumes and function, late gadolinium enhancement (LGE) and iron deposits in patients with SCD using CMR, correlating these values with transfusion burden, ferritin and hemoglobin levels.MethodsThirty patients with SCD older than 20 years of age were studied in a 1.5 T scanner and compared to age- and sex-matched normal controls. Patients underwent analysis of biventricular volumes and function, LGE and T2* assessment of the liver and heart.ResultsWhen compared to controls, patients with SCD presented higher left ventricular (LV) volumes with decreased ejection fraction (EF) with an increase in stroke volume (SV) and LV hypertrophy. The right ventricle (RV) also presented with a decreased EF and hypertrophy, with an increased end-systolic volume. Although twenty-six patients had increased liver iron concentrations (median liver iron concentration value was 11.83 ± 9.66 mg/g), only one patient demonstrated an abnormal heart T2* < 20 msec. Only four patients (13%) LGE, with only one patient with an ischemic pattern.ConclusionsAbnormal heart iron levels and myocardial scars are not a common finding in SCD despite increased liver iron overload. The significantly different ventricular function seen in SCD compared to normal suggests the changes in RV and LV function may not be due to the anemia alone. Future studies are necessary to confirm this association.

Gray Matter Volume in Left Rostral Middle Frontal and Left Cerebellar Cortices Predicts Frontal Executive Performance in Alcoholic Subjects

BACKGROUND Alcoholic subjects manifest important deficits in frontal executive function, yet maintain cognitive mental status within normal range. METHODS This study searched for volumetric measurements of segmented brain structures obtained from magnetic resonance imaging (MRI) that would predict executive functions and cognitive mental status in alcoholic subjects. The frontal assessment battery (FAB) and the Mini-Mental State Examination (MMSE) were applied to alcoholic subjects who underwent MRI. Cortical and subcortical segmentation and corrections were performed using FreeSurfer. Multiple linear regressions analyses having volumetric measures of segmented brain structures as predictors for FAB or MMSE scores as dependent measures were conducted. Sixty alcoholic subjects, 52 males, mean age of 47.2 ± SD 10.4 years, with heavy use of alcohol (mean 284.4 ± SD 275.9 g of alcohol/d) over a long time (mean 32.4 ± SD 11.1 years), showed FAB 11.1 ± SD 3.2 and MMSE of 25.2 ± SD 4.1. RESULTS Multiple regression analyses having left and right side of each segment as predictors showed that gray matter volumes of rostral middle frontal cortex and cerebellar cortex (p < 0.001), in which only the left side of these structures showed significant partial effects in the full model (p < 0.05), showed to predict FAB performance. They were even more predictive when considered together (p < 0.001), in which both left rostral middle frontal cortex (p < 0.05) and left cerebellar cortex (p < 0.01) predictors had significant partial effects in the full model. None of brain structures was predictive of MMSE performance. CONCLUSIONS We have concluded that volumetric measurements of left rostral middle frontal and cerebellar cortices seem to be able to predict the frontal executive performance but not the cognitive mental status in alcoholic subjects.

Migraine improvement correlates with posterior cingulate cortical thickness reduction

Objective The main goal of this study was to correlate migraine improvement, after prophylactic therapy, with cortical thickness changes. Methods Cortical thickness maps were obtained with magnetic resonance imaging (MRI) from 19 patients with migraine before (first scan) and after (second scan) prophylactic treatment, and these were compared with controls using the FreeSurfer MRI tool. Cortical changes were correlated with the headache index (HI). Results Anincrease incortical thickness was found in the right cuneus and precuneus, somatosensory and superior parietal cortices in both patient scans, compared with the controls. No changes were observed in the left hemisphere. Following correction for multiple comparisons, no areas changed from the first to the second scan. Regression analysis showed a significant negative correlation between the HI improvement and cortical thickness changes in the left posterior cingulate, a region involved with nociception and, possibly, the development of chronic pain. Conclusion There were changes in cortical thickness in patients with migraine relative to controls in areas involved with vision and pain processing. Left posterior cingulate cortical changes correlated with headache frequency and intensity.

Working memory and left medial temporal cortical thickness

Objective To perform a pilot study to investigate the association between working memory and cortical thickness in a sample of attention deficit/hyperactivity disorder (ADHD) children. Methods Seventeen children aged 7-10 years diagnosed with ADHD and 16 healthy children underwent a magnetic resonance scan for cortical thickness measurements. Data was correlated with working memory performance using the Backwards Digit Span subtest of the Wechsler Intelligence Scale for Children. Results Working memory impairment, evidenced by lower scores on the Backwards Digit Span, was observed in patients with ADHD compared to healthy controls. There was a direct correlation between working memory and cortical thickness of the left medial temporal lobe (Spearmans correlation coefficient: 0.499; p < 0.005). Conclusions Our data suggests, for the first time, a correlation between working memory, evaluated by the Backwards Digit Span, and left medial temporal cortical thickness.