Brain activation during ideomotor praxis: imitation and movements executed by verbal command

• Published in: Journal of neurology, neurosurgery and psychiatry Vol. 76; no. 1; pp. 25 - 33
• Main Authors: Makuuchi, M, Kaminaga, T, Sugishita, M
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd 01.01.2005; BMJ; BMJ Publishing Group LTD; BMJ Group
• Subjects: Adult; Apraxia; Biochemistry and metabolism; Biological and medical sciences; blood oxygenation dependent; BOLD; Brain - physiology; Brain Mapping; Central nervous system; Cerebral circulation. Blood-brain barrier. Choroid plexus. Cerebrospinal fluid. Circumventricular organ. Meninges; echo planar imaging; EPI; FB/UM; Female; field of view; finger bending/unbending movement; Fingers & toes; Fingers - physiology; fMRI; FOV; functional magnetic resonance imaging; Fundamental and applied biological sciences. Psychology; Humans; ideomotor apraxia; imitation; Imitative Behavior - physiology; Magnetic resonance imaging; Male; Medical sciences; MNI; Montreal Neurological Institute; Motor Activity - physiology; MRI; Neurology; PET; positron emission tomography; Psychomotor Performance - physiology; Reference Values; Rest - physiology; SPM; statistical parametric mapping; verbal command; Vertebrates: nervous system and sense organs; Nervous system diseases; Central nervous system; Encephalon
• ISSN: 0022-3050; 1468-330X
• DOI: 10.1136/jnnp.2003.029165

Background: Ideomotor apraxia is a disorder of both imitation movements and movements executed by verbal command. Lesion studies have identified the left parietal lobe as the neural correlate for ideomotor praxis (IP), although there are opposing views. Objectives: To localise the neural substrates for IP using functional magnetic resonance imaging. Brain regions activated by both imitation and verbal command movements were tested against a simple self paced movement. Methods: Twenty two young, right handed, healthy subjects were examined. Functional and anatomical data were acquired. The experiment comprised three motor conditions (imitation, movements executed by verbal command, and finger bending/unbending) and a rest condition. All motor tasks were performed using the left hand. Eighteen drawings of left hand postures were presented for the imitation condition. Identical postures were instructed verbally for the verbal command condition. The finger bending/unbending movement was self paced. Blood oxygenation level dependent (BOLD) signal increases were compared during two kinds of IP (imitation and verbal command movements) and during finger bending/unbending movements. Results: The depth of the posterior part of the left intraparietal sulcus and bilateral precunei were activated during both imitation and verbal command movements. The difference in BOLD signal between imitation and verbal command movements was localised in the dorsal and ventral occipital areas. BOLD signal differences for movements executed by verbal command against imitation were observed in the superior temporal areas. Conclusions: The depth of the posterior part of the left intraparietal sulcus and bilateral precunei are the neural substrates for IP.