Basal Ganglia ppt 18 Flashcards
What are the components of the basal ganglia?
Caudate Nucleus
Putamen
Globus Pallidus (external & internal)
Subthalamic Nucleus
Substantia Nigra (compact and Reticulata)
Where do inputs arrive in the basal ganglia?
at the stratum (caudate nuc and the putamen)
Where do outputs leave from in the basal ganglia?
from the internal globus
Sub. Nigra Reticulata
What is the purpose of the direct pathway?
Allows the thalamus to fire. Facilitates movement
What is the purpose of the indirect pathway?
To inhibit movement
What does a lesion of the Caudate Nucleus cause?
Head of the left caudate nucleus cause?
delayed alternation & disrupt performance on tests involving object reversal.
dysarthric aphasia (difficulty in articulating words)
What are the functions of the basal ganglia?
- Planning and programing movement (preventing oscillations)
- Slow and steady damp movement
- inhibits stretch reflex
- control of normal autonomic and associated movements (arms walking)
- Striatum: sub. gross movement
- GP:provides muscle tone for skilled movement
- Sub Nigra: coordination of impulses for skilled movement.
What are movement disorders of the basal ganglia?
Bradykinesis, Hypokinesia, and Akinesia
Damage to the basal ganglia that results in increased resistant to passive movement
Rigidity.
Plastic, waxy or lead pipe rigidity
What is dystonia?
types?
distorted positions of the limbs
- focal: torticollis,
- blepharospasm: facial and eye muscles
- spasmodic: laryngeal muscles
- writer’s cramp.
Dystonia treatment
small amount of botulinum
What is Ballism?
Movements of the proximal limb muscles with a larger-amplitude,
hemiballismus,unilateral flinging of extremities
cause is a lacunar infarct of the subthalamic nucleus
What is athetosis?
writhing,twisting movements of the limbs, face, (choreoathetosis)
Causes: perinatal hypoxia, Wilson’s Huntington’s disease, and sever neonatal jaundice (kernicterus)
What is chorea?
Dance- continuous involuntary movement.
proximal, distal and respiratory muscles
Basal Ganglia dysfunction- Tics
sudden brief action preceded by urge.
motor, vocal (coprolalia- cursing)
Torrette’s syndrome: persistent
What is Parkinson’s?
Shaking palsy, resting tremor, bradykinesia, rigidity and unsteady gate
Path feature: Lewy bodies
Causes of Parkinson’s
- Idiopathic
- Drugs: reserpine, phenothiazine
- MMP: Methyl-phenyl-tetrahydropyridinum (MPTP), converted by MAO-B into methyl-phenyl-pyridinum (MPP)
- Carbon monoxide
Treatment of Parkinson’s
- Levo-DOPA
- Bromocriptine (dopa antagonist)
- Anticholinergics
- Selegilin (inhibits MAO-B)
- Amantadine (anticholinergic)
- COMT inhibitor (end in apone)
- DBS
What is Huntington’s?
Aut. Dominant
Abnormal movement and intellectual change (Chorea & Dementia)
caused by degeneration of GABAergic pathway
No Treatment- fatal
What is a pathologic hallmark of Huntington’s
The pathologic hallmark is progressive atrophy of the striatum,especially involving the caudate nucleus.
What is willsons?
Hepatolenticular degeneration.
abnormal copper metabolism.
personality change and athetoid movements
Kayser Fleisher ring
What is Kernicterus?
increase indirect bilirubin– damage od GP– death
