Motor neglect.

Motor neglect is characterised by an underutilisation of one side, without defects of strength, reflexes or sensibility. Twenty cases of frontal, parietal and thalamic lesions causing motor neglect, but all without sensory neglect, are reported. It is proposed that the cerebral structures involved in motor neglect are the same as those for sensory neglect and for the preparation of movement. As in sensory neglect, the multiplicity of the structures concerned suggests that this interconnection is necessary to maintain a sufficient level of activity. Predominance of left sided neglect by right sided lesions suggests that the left hemisphere is dominant for deliberate activity; hemispheric dominance could be applied to sensory neglect where conscious awareness would play the role of deliberate activity.