Basal Ganglia and Psychiatry

8/13/2019 Basal Ganglia and Psychiatry

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BASAL GANGLIA AND

PSYCHIATRY


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Dr.M.A.Shaheen

Post graduate

Department of psychiatryYenepoya medical college

Dr.V.V.Mohanchandran

Head of departmentDepartment of psychiatry

Yenepoya medical college


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Location


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The caudate nucleus

Putamen

Globus pallidus

Subthalamic nucleus

Substantia nigra

The striatum caudate nucleus and putamen

The corpus striatum caudate nucleus , putamen &

globus pallidus Lentiform nucleus putamen and globus pallidus

Major structures


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3 major afferent systems

the coricostriatal

the nigrostriatal

the thalamostriatal

Outputs globus pallidus(internal)

pars reticularis

Circuits


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Voluntary movement

Postural control

Control of muscle tone

Functions


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Of voluntary movementbradykinesia

Postural abnormalities

Gait abnormalities

parkinsonian

choreiform

Tone changes

Involuntary movements Phonation

Disorders


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The muscle rigidity, tremor at rest, and slowness ininitiation and execution of movement.

Reduction in dopaminergic activity in the basalganglia motor areas, particularly the putamen due togradually reduced innervation from SNc.

Other features - autonomic dysfunction, cognitiveimpairment, and gait/balance difficulties

Parkinsonism


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Ahereditary disease defects in behavior, cognition, and uncontrolled

rapid, jerky movements.

a defect that consists of an expanded CAG repeat in a

gene located on chromosome 4 the basal ganglias show a decrease in activity of the

mitochondrial pathway, complex II-III.

often associated with basal ganglia degeneration.

This degeneration of striatal neurons projecting toGPe leads to disinhibition of the indirect pathway,increased inhibition of STN.

Huntington's Disease


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A neuropsychiatric syndrome with onset inchildhood

Multiple chronic tics.

Obsessive-compulsive behaviors are strongly associated with tourettesdisorder

Abnormal activation of premotor, supplementarymotor, and cingulate motor areas

inhibition of the Globus Pallidus or Substantia Nigraneurons would then disinhibit thalamocortical

circuits

Tourettes syndrome


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Gene Therapy

Many disorders of the basal ganglia are due to thedysfunction of a localized area. Gene therapy is performedby replacing diseased phenotypes with new genetic material.

Lesioning/ablation

Lesionsing is a term that signifies the destruction ofneuronal cells in a particular area. involves unilaterallesioning of the GPi. This process is called pallidotomy.

Deep Brain Stimulationinserting, via stereotaxic surgery, electrodes

into the sensorimotor area of the brain. These electrodesemit high-frequency stimulation to the implanted areas.

internal globus pallidus and the subthalmic nucleus.

Therapeutic Research


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Comprehensive textbook of psychiatry

A.Berardelli,J.C.Rothwell,P.D.Thomson,M.HalletPathophysiology of bradykinesia in parkinsons

disease,Brain(2001). J.W.Mink ,The basal ganglia and involuntary

movements,Neurological Review.

P.McCaffrey ,Neuropathologies of swallowing and

speech,The Neuroscience on the website. Albin R.L., Young A.B., Penney J.B., The functional

anatomy of basal ganglia disorders. TrendsNeurosci (1989) 12: pp 366-375

References

Documents

Basal Ganglia and Psychiatry