18. Basal Ganglia Flashcards
what are the components of the basal ganglia
caudate
putamen
globus pallidus
stubstantia innominata
subthalamic nucleus
nucleus accumbens
what is the purpose of the skeletomotor loop
and what are its parts
contol facial, limb & trunk Ms
input: putamen
output: globus pallidus/ substantia nigra
what is the purpose of the oculomotor loop
& what are its components
control saccadic eye movements
input: caudate nucleus
output: substantia nigra & globus pallidus
what is the purpose of the associative loop
& what are its components
cognition & executive behavioral fxn
input: caudate nucleus
output: substantia nigra & globus pallidus
what is the purpose of the limbic loop
& what are its components
participate in motivational/regulation of behavior and emotion
input: ventral striatum
output: ventral pallidum, globus pallidus & substantia nigra
what is the classic triad of parkinson’s disease
tremor
rigidity (cogwheel rigidity = resting tremor + rigidity)
bradykinesia
-may also have hypokinesia, postural instabilty, dementia or visuoperceptive impairment
(can affect walking, speech & facial expression)
what are the causes of parkinsonian syndrome
- idiopathic
- encephalitis lethargiva
- head trauma
- MPTP
- CO & manganese posioning
- neuroleptivs (DA blocking drugs)
- wilson disease - hepatolenticular degneration
how do you treat parkinsons
increase DA levels (add or prevent breakdown)
deep brain stimulation
what is the cause of huntington’s chorea
degeneration of neurons in straitum leading to decreased GABA
what are characteristics of huntingtons
auto dom (HTT gene = CAG triNT repeat)
=involuntary, jerky & rapid movement
- dementia
- unsteady gait, slurred speech, irreg breathing, unable to keep tongue in protrusion
=depression bc of the significat changes in the brain
Huntington’s disease treatment
tetrabenazine (5HT antagonist)
typical antipsychotic (antagonize DA)
reserpine/tetrabenazine (deplete DA)
What is Ballismus
flailing, flinging movement of whole extremity
- contralat to lesion of subthalamic nucleus
- related to stroke, inflam or tumor
what is chorea
spontaneous, rapid, jerky arrhythmic & involuntary movement
=purposeless of fragments of motor programs
what is Jones criteria
symptoms for acute rheumatic fever
- joints (arthritis)
- heart
- nodules (subcutaneous)
- erythema marginatum
- Sydenham’s chorea (childhood chorea)
(can turn to rheumatic <3 disease after <3 valve damage)
what is athetosis
inability to sustain body part in one position (often seen in chorea)
=slow, writhing, continous movements
-seen w/ DA blocking drugs or hypoxic-ishmeic injury
what is focal dystonia
(writer’s cramp)
persistence/fixing of posture at extreme of an athetoid movement of either extremities or trunk
-involuntary & sustained M contracture of extensors/flexors of hand
nonpainful - severly illegible hand writing
what structures are apart of striatum
caudate nucleus
putamen
what does the paleostriatum include
globus pallidus
what does the dorsal basal nuclei include
caudate nucleus
putament
globus pallidus
what does the lentirbular nucleus contain
putamen
globus pallidus
what does the ventral striatum contain
nucleus acumbens
olfactory nucleus
what does the ventral palladium contain
substantia innominata
what does the striatal complex contain
caudate nucleus
putamen
nucleus acumbens
olfactory tubercle
what does the palladial complex contain
globus pallidus
substantia innominata
what part of the basal ganglia path present for both the direct & indirect path
cortex –> (glu) –> striatum –> substantia nigra pars compacta –> DA –> striatum
the type of DA receptor determines if the path will be direct or indirect after this point
what is the path of the indirect path
cortex –> striatum -> substantia nigra pars compacta-> striatum –>
globus pallidus (ext part) –> subthalamic nucleus –> globus pallidus (int part) & substantia nigra pars reticulata –> thalamus –> supplementary motor area
what is the path of the direct path
cortex –> striatum –> substantia nigra pars compacta –> striatum –>
globus pallidus (int part)/substantia nigra pars recticulata –> thalamus –> supplementary motor area
