Quantitative Assessment of Motor Neglect.

Background and Purpose: We used differential actigraphy as a novel, objective method to quantify motor neglect (a clinical condition whereby patients mimic hemiplegia even in the absence of sensorimotor deficits), whose diagnosis is at present highly subjective, based on the clinical observation of patients’ spontaneous motor behavior. Methods: Patients wear wristwatch-like accelerometers, which record spontaneous motor activity of their upper limbs during 24 hours. Asymmetries of motor behavior are then automatically computed offline.

The anatomo-clinical picture of the pathological embodiment over someone else's body part after stroke.

Recently, a monothematic delusion of body ownership due to brain damage (i.e., the embodiment of someone else's body part within the patient's sensorimotor system) has been extensively investigated.

A new clinical evaluation of asomatognosia in right brain damaged patients using visual and reaching tasks.

Introduction: The term asomatognosia refers to a unilateral disturbance of body ownership following a cerebrovascular incident. Patients with asomatognosia consider the contralesional limbs as missing or having disappeared from awareness. This neuropsychological disorder modifies body ownership in terms of perceptual experience, visual identification and sense of belonging of contralesional body parts.

Anosognosia for hemianaesthesia: a voxel-based lesion-symptom mapping study.

Brain-damaged patients affected by hemianaesthesia (i.e., the loss of tactile sensibility on the contralesional side of the body) may deny their deficits (i.

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.

Temporal coupling due to illusory movements in bimanual actions: evidence from anosognosia for hemiplegia.

In anosognosia for hemiplegia, patients may claim having performed willed actions with the paralyzed limb despite unambiguous evidence to the contrary. Does this false belief of having moved reflect the functioning of the same mechanisms that govern normal motor performance? Here, we examined whether anosognosics show the same temporal constraints known to exist during bimanual movements in healthy subjects. In these paradigms, when participants simultaneously reach for two targets of different difficulties, the motor programs of one hand affect the execution of the other.

Verbal commands help the execution of endogenous movements in anarchic hand.

Patients with anarchic hand (AH) syndrome exhibit involuntary but seemingly purposeful controlesional upper limb movements. Here we report on the case of a patient (AC) presenting with a right AH following a left medial frontal lesion. Previous literature indicated that endogenous movements, particularly in the presence of distractors, are impaired in AH, whereas exogenous movements are spared.

Modular structure of awareness for sensorimotor disorders: evidence from anosognosia for hemiplegia and anosognosia for hemianaesthesia.

In the present paper, we shall review clinical evidence and theoretical models related to anosognosia for sensorimotor impairments that may help in understanding the normal processing underlying conscious self-awareness. The dissociations between anosognosia for hemiplegia and anosognosia for hemianaesthesia are considered to give important clinical evidence supporting the hypothesis that awareness of sensory and motor deficits depends on the functioning of discrete self-monitoring processes. We shall also present clinical and anatomical data on four single case reports of patients selectively affected by anosognosia for hemianaesthesia.

Bisecting lines with different tools in right brain damaged patients: the role of action programming and sensory feedback in modulating spatial remapping.

In a first experiment we studied, through a line bisection task, (a) the frequency of the selective disruption of far or near space representations in a group of 28 right brain-damaged patients and (b) the effect of tool use on line bisection error in far and near space in order to clarify whether the kind of action performed by the subject influences the extension of space representation, as suggested by previous studies. In a second experiment, carried out on two neglect patients, we asked whether the representation of "near" and "far" space depends on the sensory feedback during the execution of the action or whether it is independent on sensory feedback and more related to the action programmed as a consequence of the kind of tool used. Our data show (a) that dissociations between far and near space neglect are a frequent observation in right brain damaged patients and that most of these patients are able to recode space representations when tools change the spatial relation between the agent's body and the target object; (b) that spatial remapping can be elicited by the kind of action associated to the tool used and by the sensory feedback (either visual or proprioceptive) available during the execution of the task.

Impairments of trunk movements following left or right hemisphere lesions: dissociation between apraxic errors and postural instability.

Stroke patients present with apraxic or postural deficits involving trunk movements. Praxis and posture control have been associated with the functions of the left and the right hemisphere, respectively. For the first time, in this study the occurrence of apraxic and postural components in trunk movement deficits following right and left hemisphere lesions were investigated in the same participants.

Coding of far and near space during walking in neglect patients.

Previous studies have shown that far space can be remapped as near when reached by a stick that artificially prolongs the participants' personal space. In the present study, the authors asked whether a similar remapping occurs when far space is reached not by using a tool but by locomotion. Neglect patients showed more severe neglect in far than in near space in bisection tasks executed from different distances either by pointing to a target line with a projection light pen or by walking across the line.