Finger tapping, handedness and grey matter amount in the Rolando's genu area

The morphology of the central sulcus (CS), at the level of the hand primary motor cortex, has been shown to be related to hand preference and skill. Differences in the cerebral functional organisation of left and right-handers have been described, notably with respect to hemispheric specialisation, which might cause the neural substrate of hand dominance or skill to differ between the two groups. Here, we further explored the relationship between the anatomical variability of the central sulcus and hand skill in two groups of young male subjects differing by handedness (n = 56 right-handers and n = 55 left-handers). Grey matter volume (GMV) in the upper region of the central sulcus was estimated with Voxel Based Morphometry, using a probabilistic region of interest approach, while hand motor skill was measured with the finger tapping test. No significant anatomical differences could be evidenced between the two hand preference groups, a rightward hemispheric asymmetry being observed in both samples. However, multiple regression analyses showed that, in the right-handed group, the maximum tapping rate of the right hand correlated positively with the left central sulcus GMV, but negatively with the right. Similar analyses showed that, in left-handers, the maximum tapping rate of the non-dominant right hand was strongly correlated with the GMV of the ipsilateral CS but not significantly with that of the contralateral CS. These results may be due to differences in the organisation of motor systems between these two groups, possibly concerning a left hemispheric specialisation for fast repetitive movements in right-handers, which would be different in left-handers.     

No epsilon4 gene dose effect on hippocampal atrophy in a large MRI database of healthy elderly subjects

The effect of ApoE genotype on grey matter (GM) atrophy was studied on a cohort of 750 healthy elderly volunteers (age range 63-75 years). High-resolution T1-weighted MR images were processed using both voxel-based morphometry and region of interest analysis for hippocampal volume estimation. Significant decrease of grey matter in epsilon(4) homozygous subjects (n = 12), as compared both to epsilon(4) heterozygous subjects (n = 175) and to noncarrier (n = 563) subjects, was found bilaterally in the medial temporal lobe, including the hippocampus, and extending over the superior temporal gyrus. By contrast, no significant difference was observed between epsilon(4) heterozygous subjects and noncarriers at the level of the medial temporal lobe. Follow-up of the cohort cognitive performances over 4 years after their MRI exam revealed that, as compared to noncarrier subjects, the relative risk of cognitive impairment was 5.9 for epsilon(4) homozygous subjects (P = 0.03), while it was not different from 1 for epsilon(4) heterozygous subjects (P = 0.92). These findings indicate that, in the age range of this cohort, ApoE-4 effects on cortical atrophy and cognitive performances of healthy elderly are limited to epsilon(4) homozygous subjects.     

Wavelet-based cluster analysis: data-driven grouping of voxel time courses with application to perfusion-weighted and pharmacological MRI of the rat brain

MRI time series experiments produce a wealth of information contained in two or three spatial dimensions that evolve over time. Such experiments can, for example, localize brain response to pharmacological stimuli, but frequently the spatiotemporal characteristics of the cerebral response are unknown a priori and variable, and thus difficult to evaluate using hypothesis-based methods alone. Here we used features in the temporal dimension to group voxels with similar time courses based on a nonparametric discrete wavelet transform (DWT) representation of each time course. Applying the DWT to each voxel decomposes its temporal information into coefficients associated with both time and scale. Discarding scales in the DWT that are associated with high-frequency oscillations (noise) provided a straight-forward data reduction step and decreased the computational burden. Optimization-based clustering was then applied to the remaining wavelet coefficients in order to produce a finite number of voxel clusters. This wavelet-based cluster analysis (WCA) was evaluated using two representative classes of MRI neuroimaging experiments. In perfusion-weighted MRI, following occlusion of the middle cerebral artery (MCAO), WCA differentiated healthy tissue and different regions within the ischemic hemisphere. Following an acute cocaine challenge, WCA localized subtle differences in the pharmacokinetic profile of the cerebral response. We conclude that WCA provides a robust method for blind analysis of time series image data.     

Fetal toxic effects of angiotensin II receptor antagonists: case report and follow-up after birth

OBJECTIVE: To report a child born with renal impairment following severe anhydramnios due to maternal exposure to an angiotensin II receptor type 1 (AT1) antagonist, valsartan, and hydrochlorothiazide during the first 28 weeks of pregnancy. CASE SUMMARY: A hypertensive woman treated with valsartan 80 mg/day, hydrochlorothiazide 12.5 mg/day, prazosin 10 mg/day, lysine acetylsalicylate 100 mg/day, and levothyroxine 250 microg/day became pregnant. At 28 weeks' gestational age, severe anhydramnios associated with high beta2-microglobulin levels in the fetal blood cord was observed. Upon discontinuation of valsartan, fetal renal prognosis improved. In this case, using the Naranjo probability scale, the renal insufficiency of the child was probably related to valsartan. At the age of 2.5 years, the child presented with only mild chronic renal insufficiency. Growth parameters were within the normal range, and there was no evidence of developmental delay. DISCUSSION: Exposure to AT1 antagonists during the second part of pregnancy can lead to abnormalities similar to those observed after exposure to angiotensin-converting enzyme inhibitors, that is, reduced fetal kidney perfusion that may result in oligoamnios and neonatal renal insufficiency. Fourteen previous reports of maternal exposure to AT1 antagonists during this period have been published. In 6 cases, fetal or neonatal death occurred; in 2 cases, pregnancy was terminated because of complete anhydramnios or fetal abnormalities; in 1 case, renal insufficiency persisted at 8 months of age; in 2 cases, kidney function was fairly normal at birth; and in 4 cases, including the one described here, neonatal renal failure improved in the first year of life. CONCLUSIONS: AT1 antagonists should be avoided throughout pregnancy. If these agents are prescribed accidentally to a pregnant woman, monitoring of amniotic fluid volume and beta2-microglobulin fetal blood levels after discontinuation of the AT1 antagonist can provide critical data for advising parents on pregnancy and fetal outcome.     

Phenomenology: a scientific approach to lived experiences

Phenomenology is a philosophical current which intends to observe and describe the meaning attributed to an experience from the consciousness of the person who is living it. While it can be applied to different domains, especially to human care it describes subjective phenomenon such as suffering or quality of life. It constitutes as a real discipline, with its epistemology, its specific data (the individual's narration), its method of analysis to find the speech units of significance, and collaboration between researcher and participant (who becomes a co-researcher). Validity of the method is defined by the fact that the phenomenon becomes intelligible. In the representation of the disease and of the patient, the method is close to ethical principles like respect of autonomy and optimization of quality of life.     

The person of trust, a new tool in the physician-patient relationship

THE NOTION OF A PERSON OF TRUST: Introduced by the law dated March 4th 2002, the person of trust is there to accompany the patient in all his/her measures of care; this person is also conceived as an helper in medical decisions or when the patient participates in biomedical research protocols. DESIGNATION MODALITIES: Any adult, unprotected patient can designate a person of trust, whose intervention is not only limited to hospitalisation (the nursing staff are obliged to propose such a person), but can also intervene during care at home or at the doctor's. The designation is made in writing and can be revoked at any time. The person of trust can be a relative, a friend or even the treating physician. A SPECIFIC ROLE: The person of trust can be of help in medical measures in routine medicine when the patients needs to be accompanied, and in the case of diagnosis or serious prognosis, and when the patient is incapable of expressing him/herself.     

Can rotation osteotomy remain effective for more than ten years?

Trochanteric rotation osteotomies displace the necrotic zone of the femoral head outside the major acetabular weight-bearing zone and rotate the head anteriorly or posteriorly.Nineteen consecutive patients were selected for rotation osteotomy based on age,absence of progressive disease, and preoperative imaging studies predicting that rotation osteotomy would move the entire necrotic zone away from the acetabular roof. Factors associated with failure were head flattening and necrosis deeper than one third of the femoral head diameter. Among patient subsets with identical disease stages, outcomes seemed better after posterior rotation than after anterior rotation. Rotation osteotomies,fixed by a nail plate, can be recommended in a few selected patients with shallow necrosis involving less than one third of the femoral head diameter and without osteoarthritis or head flattening. Under these conditions, good outcomes may be achieved for 10 years or longer.