Ideomotor apraxia is a disorder affecting patients with stroke and a variety of other brain lesions. The disorder involves problematic timing, sequence, and spatial organization of gestured movements. As a result, patients suffer from incorrect temporal and spatial components to movements as evidenced during pantomime of transitive and intransitive movements. The errors can be seen in left and right hemisphere damaged patients during intransitive movements, but lesions predominate in the left hemisphere for inability to pantomime transitive movements. Thus far, damage to parietofrontal circuits has been implicated in significantly contributing to this disorder. These circuits, which pave the way for sensorimotor processing, are of clear interest in the nature of praxis. In the present study, we plan to evaluate further the parietofrontal circuits in these patients. Using EEG, we will analyze the movement related cortical potentials (MRCP) in these patients compared to controls to evaluate any cortical planning differences. We will analyze how the circuits play a role in transitive and intransitive movements in normal subjects and patients with Ideomotor apraxia. Each patient will make a series of movement during 64 channel EEG and EMG recordings. Following recordings, analysis will be made of the event related desynchronization (ERD) and the MRCP. Further analysis will look at the activation of the parietofrontal circuitry in patients using correlation and coherence methods. For the same purposes, MEG studies will be performed to assess similar measures.
We will study normal volunteers and patient groups between the ages of 18-80 years of age within the following parameters: INCLUSION CRITERIA: Normal subjects. Patients diagnosed with Ideomotor apraxia with a single left hemisphere lesion. Patients with Ideomotor apraxia with corticobasal ganglionic degeneration. EXCLUSION CRITERIA Normal subjects: abnormal neurologic examination or history of neurologic disorders. Ideomotor apraxic patients: a second neurologic disorder including more than one brain lesion or the inability to cooperate fully. Normal and Ideomotor apraxic patients: cognitively impaired subjects will not be accrued (for the purposes of this study, patients that can provide full informed consent for the study are not considered cognitively impaired). For MRI studies, patients with metallic implants to remove potential risks from this procedure. For MRI purposes, women who are pregnant are excluded from this part of the protocol. Therefore, all women of childbearing potential will have a pregnancy test performed, which must be negative, before proceeding.