M Ietswaart | PubMed Health

PubMed2004

Does motor imagery training improve hand function in chronic stroke patients? A pilot study.

OBJECTIVE: To assess the efficacy of motor imagery training for arm function in chronic stroke patients. The relation between mental processes such as attentional and perceived personal control over recovery, and motor imagery was additionally investigated. DESIGN AND SUBJECTS: Twenty patients with long-term motor impairments (mean two years post stroke), were assessed before and after four weeks of training. Ten patients mentally rehearsed movements with their affected arm. Their recovery was compared with patients who performed nonmotor imagery (n =5), or who were not engaged in mental rehearsal (n=5). SETTING: Patients were recruited from the stroke database of Ninewells Hospital, Dundee. Assessment and training were performed at the patients' home. INTERVENTIONS: The motor imagery group was asked to practise daily imagining moving tokens with their affected arm. The nonmotor imagery group rehearsed visual imagery of previously seen pictures. All patients practised physically moving the tokens. MAIN MEASURES: The following variables were assessed before and after training: motor function (training task, pegboard and dynamometer), perceived locus of control, attention control and ADL independence. RESULTS: All patient groups improved on all motor tasks except the dynamometer. Improvement was greater for the motor imagery group on the training task only (average of 14% versus 6%). No effect of motor imagery training was found on perceived or attentional control. CONCLUSIONS: Motor imagery training without supervision at home may improve performance on the trained task only. The relation between movement imagery, attention and perceived personal control over recovery remained unclear.

Female↗

PubMed2001

Memory-driven movements in limb apraxia: is there evidence for impaired communication between the dorsal and the ventral streams?

Memory-driven reaching and grasping movements were analysed in patients with left cerebral hemispheric damage and impaired gesture imitation. The dorsal and ventral streams of the visual pathway model of Milner and Goodale (Milner and Goodale, The Visual Brain in Action, 1995) are thought to operate relatively independently. However, cross-connections between the areas of each pathway are likely to enable interactions essential for higher-level praxis. Apraxic errors such as seen in gesture imitation can possibly be understood as arising from a disconnection of the two visual pathways. If the integrated action of the perceptual and visuomotor systems in patients with apraxia is compromised, then we would expect to find indications of impaired motor programming and misreaching in these patients when making movements driven by stored representations. Such a pattern, however, was not found in our sample of apraxic patients. Patients with limb apraxia produced normal movement kinematics and normal end-point accuracy when making memory-driven reaching movements with or without visual guidance of movement. Furthermore, perceptual information about object size and object distance were incorporated as normal in memory-driven grasping movements of these patients.

Aged↗