EEG and EMG Analysis of Ideomotor Apraxia

Overview

This study will examine how the brain operates during execution and control of voluntary movement and what goes wrong with these processes in disease. It will use electroencephalography (EEG) and electromyography (EMG) to compare brain function in normal subjects and in patients with-a disorder affecting patients with stroke and other brain lesions. These patients have problems with timing, sequence and spatial organization of certain types of movements. EEG measures the electrical activity of the brain. The activity is recorded using wire electrodes attached to the scalp or mounted on a Lycra cap placed on the head. EMG measures electrical activity from muscles. It uses wire electrodes placed on the skin over the muscles. Adult healthy normal volunteers and patients with ideomotor apraxia with a single left brain lesion may be eligible for this study. Study participants will be asked to make certain movements with their arms or hands, such as waving and using scissors. Brain and muscle activity will be measured during these tasks with EEG and EMG recordings. Patients may be asked to repeat these tests over time as their condition changes (such as during recovery from a stroke) to gain information about the recovery process.

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.