PowerPoint Presentation

Basal Ganglia

Motor function&Deep Brain stimulation ByMedhat Ali

Basal Ganglia(BG)The basal ganglia are large nuclei that receive information from the association cortex, and are involved primarily with the planning and initiation of movements.The basal ganglia also have two major relay nuclei, the substantia nigra, and the subthalamic nucleus, which receive information from the striatum, process it in different ways, and project to the globus pallidus.The Basal ganglia communicate with the premotor cortex and supplementary motor area via nuclei in the thalamus.

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BG anatomy 11/5/16Medhat3

The circuit of the basal ganglia

The basal ganglia are part of a loop that begins and ends in the cerebral cortex. The cerebral cortex (motor, somatosensory and association areas) projects to striatum (caudate and putamen) then to globus pallidus and substantia nigra then to thalamus, and finally back to prefrontal association, premotor and motor cortex, the regions involved in selecting movements and behaviours. The overall function of this loop is to select a particular movement or sequence of movements, or behaviours, while suppressing others,

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Neural structures involved in the control of movement

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BG Volitional role

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Basal Ganglia and Eye movement

The substantia nigra tonically suppresses the superior colliculus. This inhibition prevents distracting visual input from triggering unwanted saccadic eye movements. When a saccade is desired, the caudate/putamen inhibits a region of the substantia nigra. This removes the brakes from a region of the superior colliculus, releasing the selected saccade. 11/5/16Medhat7

Basal ganglia &Parkinson patients These patients have difficulty initiating movement because of degeneration of the dopaminergic projection from substantia nigra pars compact pf basal ganglia. Under-activity in direct pathway produces too much inhibition of thalamus and prevents the initiation of movements. 11/5/16Medhat8

The Basal Ganglia

NormalParkinson

Normal and abnormal spike in Parkinson11/5/16Medhat9

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Mechanism of development dyskinesia in Parkinson disease (deficit in direct pathway)11/5/16Medhat11

Mechanism of increased tension and tremors in Parkinson disease 11/5/16Medhat12

DEEP BRAIN STIMULATION(DBS)intervention treatment for Parkinson Disease (Brain pacemaker)

SURGICAL PROCEDURE Two holes were drilled into the skulls. Implant two thin wires with electrode. The loose end of the wires are attached to the pacemaker device implanted in the chest.

Implanting stimulating electrodes in patients brain (fully alert)

Stimulatingelectrodes Pulsegenerator 11/5/16Medhat14

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Parkinson disease :Treatment results using Deep Brain Stimulation (Video) Post-operationPre-operation

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Summarized Video about function of BG 11/5/16Medhat16

ReferencesUnderstanding the Brain: The Neurobiology of Everyday Life by The University of Chicago By Professor Peggy Mason (Coursera online learning) NEUSCI5E 5th Edition : Leanord WhiteBergman, Zvi Israel, Hadassah University Hospital, Jerusalem DBShttp://ktthebest4u.blogspot.com.eg/2014/11/parkinsons-disease.htmlSinauer associates Inc. (From Input to Output )Video

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