Annamaria Berti

Executed and Imagined Bimanual Movements: A Study across Different Ages.

Movements with both hands are essential to our everyday life, and it has been shown that performing asymmetric bimanual movements produces an interference effect between hands. There have been many studies--using varying methods--investigating the development of bimanual movements that show that this skill continues to evolve during childhood and adolescence. In the current study we used a spatial bimanual task to delineate the development of bimanual movements not only during different stages of childhood but also during late stages of adulthood. Furthermore, we used the same task as a window to observe the involvement of motor imagery through the same age groups. For this study we recruited participants from 4 different age groups and asked them to perform congruent and noncongruent bimanual movements in a Real condition, where participants moved both hands, and in an Imagery condition, where they had to imagine 1 hands movements while actually using the other hand. Our results showed that, with actual movement execution, the interference between motor programs of the 2 hands is higher in children (6-10 years old) than in younger adults (20-30 years old), while it tends to increase again in the elderly adults (60-80 years old). Interestingly, in the Imagery condition, the interference was present only among 10-year-old and 20- to 30-year-old participants, suggesting that motor imagery, not yet developed in young children and compromised by age in the elderly subjects, did not modulate motor performance in these last 2 groups.

Long-lasting amelioration of walking trajectory in neglect after prismatic adaptation.

In the present study we explored the effect of prismatic adaptation (PA) applied to the upper right limb on the walking trajectory of a neglect patient with more severe neglect in far than in near space. The patient was asked to bisect a line fixed to the floor by walking across it before and after four sessions of PA distributed over a time frame of 67 days. Gait path was analyzed by means of an optoelectronic motion analysis system. The walking trajectory improved following PA and the result was maintained at follow-up, 15 months after treatment. The improvement was greater for the predicted bisection error (estimated on the basis of the trajectory extrapolated from the first walking step) than for the observed bisection error (measured at line bisection). These results show that PA may act on high level spatial representation of gait trajectory rather than on lower level sensory-motor gait components and suggest that PA may have a long-lasting rehabilitative effect on neglect patients showing a deviated walking trajectory.

Awareness of Symptoms Amelioration Following Low-frequency Repetitive Transcranial Magnetic Stimulation in a Patient With Tourette Syndrome and Comorbid Obsessive-compulsive Disorder

Ministry of Education and Research (BMBF, Panic Net Subproject C4; EUROSTARS E! 7675 PONS) and sponsoring for an Investigator Initiated Trial by Astra Zeneca. Dr. Klingberg received public grants not related to this research from the German Ministry of Education and Research (grant no. 01GV0618) and from the German Research Foundation (grant no. KL1179/3-1, KL1179/2-1). B. Wasserka reported no biomedical financial interests or potential conflicts of interest.

Bimanual non-congruent actions in motor neglect syndrome: a combined behavioral/fMRI study.

In Motor Neglect (MN) syndrome, a specific impairment in non-congruent bimanual movements has been described. In the present case-control study, we investigated the neuro-functional correlates of this behavioral deficit. Two right-brain-damaged (RBD) patients, one with (MN+) and one without (MN−) MN, were evaluated by means of functional Magnetic Resonance Imaging (fMRI) in a bimanual Circles-Lines (CL) paradigm. Patients were requested to perform right-hand movements (lines-drawing) and, simultaneously, congruent (lines-drawing) or non-congruent (circles-drawing) left-hand movements. In the behavioral task, MN− patient showed a bimanual-coupling-effect, while MN+ patient did not. The fMRI study showed that in MN−, a fronto-parietal network, mainly involving the pre-supplementary motor area (pre-SMA) and the posterior parietal cortex (PPC), was significantly more active in non-congruent than in congruent conditions, as previously shown in healthy subjects. On the contrary, MN+ patient showed an opposite pattern of activation both in pre-SMA and in PPC. Within this fronto-parietal network, the pre-SMA is supposed to exert an inhibitory influence on the default coupling of homologous muscles, thus allowing the execution of non-congruent movements. In MN syndrome, the described abnormal pre-SMA activity supports the hypothesis that a failure to inhibit ipsilesional motor programs might determine a specific impairment of non-congruent movements.