Basal Ganglia Flashcards
What are the main components of the basal ganglia?
Striatum
Lentiform nucleus
Subthalamic nucleus
Substantia nigra
What are the components of the striatum?
Caudate nucleus
Nucleus accumbens
Putamen
What are the components of the lentiform nucleus?
Putamen Globus palladus (internum and externum)
What are the components of the substantia nigra?
Pars compacta
Pars reticulata
What are the parts of the loop from the association cortex?
Association cortex Caudate Globus palladus Dorsomedial nucleus of thalamus Association cortex
What are the part of the loop from the sensorimotor cortex?
Sensorimotor cortex Putamen Globus palladus Ventral anterior or ventrolateral nucleus of thalamus Sensorimotor cortex
What are the parts of the loop from the limbic cortex?
Limbic cortex Nucleus accumbens Ventral pallidum Dorsomedial nucleus of thalamus Limbic cortex
What is the general outcome of the direct pathway?
What parts make up the direct pathway?
Disinhibition of the thalamus and excitation of the cortex
Cortex, striatum, GPi, thalamus
What is the general outcome of the indirect pathway?
What parts make up the indirect pathway?
Inhibition of the thalamus and little or no excitation of the cortex
Cortex, striatum, GPe, STN, GPi, thalamus
Substantia Nigra Pars Compacta (SNc):
What is the neurotransmitter used and what effect does it have?
What is the effect on the indirect and direct pathways?
What is the net result?
Dopamine - modulatory
Inhibits indirect pathway
Stimulates direct pathway
Net movement
What are the classifications of disorders of the basal ganglia?
What are the disorder in each class?
Hypokinetic - Parkinson’s
Hyperkinetic - Huntington’s, athetosis, hemiballismus
Parkinson’s Disease:
What is the affected region in basal ganglia?
What are the clinical features?
What is the cause?
SNc
Rigidity, stooped posture, tremor, bradykinesis
Idiopathic (maybe genetic)
Huntington’s Disease:
What is the affected region in basal ganglia?
What are the clinical features?
What is the cause?
Straitum (caudate nucleus and medium spiny neurons)
Chorea, dementia, personality changes
Inherited, short arm of chromosome 4
Athetosis:
What is the affected region in basal ganglia?
What are the clinical features?
What is the cause?
Striatum
Slow, writhing movements of hands and fingers
Lesions to striatum
Hemiballismus:
What is the affected region in basal ganglia?
What are the clinical features?
What is the cause?
STN
Wild flailing of one arm and leg
Elderly, stroke, small ganglionic branch of posterior cerebral artery
