MOTOR NEGLECT ASSOCIATED WITH A DISCRETE PARIETAL LESION

The syndrome of motor neglect may follow brain lesions affecting front al, subcortical, and parietal structures. However, pure motor neglect has not been previously associated with a lesion confined to the parie tal lobe. We observed a 79-year-old right-handed man with right-sided limb akinesia and motor neglect without concomitant sensory or visuosp atial neglect. MRI showed a left posterior parietal infarct sparing th e primary sensorimotor cortex. Transcranial magnetic stimulation showe d comparable thresholds for electromyographic activation of the muscle s of the right and left arm and normal central motor conduction times, indicating functional integrity of the motor cortex. This case demons trates that a discrete parietal lesion can produce a pure intentional disorder, independent of sensory or visuospatial neglect.