title: Pallidal stimulation for parkinsonism: improved brain activation during sequence learning.
abstract: We used (15)O-labeled water and positron emission tomography to assess the effect of deep brain stimulation of the internal globus pallidus on motor sequence learning in Parkinson's disease. Seven right-handed patients were scanned on and off stimulation while they were performing a motor sequence learning task and a kinematically matched motor execution reference task. The scans were performed after a 12-hour medication washout. Stimulation parameters were adjusted for maximal motor improvement; experimental task parameters were held constant across stimulation conditions. Internal globus pallidus stimulation improved motor ratings by 37% (p < 0.01). During the sequence learning task, stimulation improved performance as measured by several correct anticipatory movements (p < 0.01) and by verbal report (p < 0.001). Concurrent positron emission tomography imaging during learning demonstrated significant (p < 0.01) increases in brain activation with stimulation in the left dorsolateral prefrontal cortex, bilaterally in premotor cortex, and in posterior parietal and occipital association areas. Stimulation did not affect the activity of these regions during the performance of the motor execution reference task. These findings suggest that internal globus pallidus deep brain stimulation can enhance the activity of prefrontal cortico-striato-pallidothalamic loops and related transcortical pathways. Improved sequence learning with stimulation may be directly related to these functional changes.
authors.affiliation: Center for Neurosciences, North Shore-Long Island Jewish Research Institute, Manhasset, NY 11030, USA.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Fukuda
authors.forename: Maria Felice
authors.initials: MF
authors.lastname: Ghilardi
authors.forename: Maren
authors.initials: M
authors.lastname: Carbon
authors.forename: Vijay
authors.initials: V
authors.lastname: Dhawan
authors.forename: Yilong
authors.initials: Y
authors.lastname: Ma
authors.forename: Andrew
authors.initials: A
authors.lastname: Feigin
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Mentis
authors.forename: Claude
authors.initials: C
authors.lastname: Ghez
authors.forename: David
authors.initials: D
authors.lastname: Eidelberg
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004599:Electric Stimulation Therapy; D005260:Female; D005917:Globus Pallidus / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D020734:Parkinsonian Disorders / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy*; D014055:Tomography, Emission-Computed