First Aid - Neurology - Cerebellum & Basal Ganglia

Front 1

Lentiform?

Back 1

putamen
+
globus pallidus

Front 2

Basal Ganglia

Back 2

Globus Palida internus is the common piece; it tonically INHIBITS the Thalamus & descending paths

Activation of the direct pathway inhibits the GPi, DISinhibiting thalamus/descending pathways
(Stim putamen, inhibit, GPi, disinhibit Thal/desc)

Activation of the indirect pathway results in INHIBITION of the thalamus/descending pathways, through disinhibition of the disinhibition of GPi (complicated?!)
-GPexternus tonically inhibits GPi
-indirect pathway the GPe disinhibition of STN (subthalamic nucleus) --> stimulation of GPi by STN --> GPi to inhibit thalamus/descending pathways

Front 3

depigmentation of substantia nigra pars compacta?

Back 3

Parkinson's Dz

loss of dopaminergic neurons (depigmentation)

TRAPped in your body

Tremor at rest
cogwheel Rigidity
Akinesia
Postural instablity

Front 4

Lewy bodies

Back 4

Parkinson's dz

alpha-synuclein (intracellular inclusions)

Front 5

Pill-rolling tremor

Back 5

Parkinson's dz

Front 6

sudden wild flailing of 1 arm +/- leg

Back 6

Hemiballismus

loss of inhibition of thalamus thru globus pallidus

contralateral subthalamic nucleus lesion
(lacunar stroke in pt w/HTN)

Front 7

chorea, aggression, depression, dementia

Back 7

Huntington's dz

CAG repeat expansion (anticipation)
Caudate loses Ach & Gaba

Nueronal death via NMDA-R binding & glutamate toxicity

Atrophy of striatal nuclei

Front 8

atrophy of striatal nuclei on imaging?

Back 8

Huntington's

Front 9

slow writing movements, especially of fingers

Back 9

Athetosis

basal ganglia lesion (eg Huntington's)

Front 10

action tremor, holding posture

Back 10

Essential/postural tremor

Autosomal Dominant, often + FH
pts often self-medicate with alcohol (decreases tremor)

Tx: beta-blockers

Front 11

tremor at rest

Back 11

Resting tremor

most noticeable distally
pill-rolling tremor of Parkinson's

Front 12

slow, zigzag motion when pointing towards target

Back 12

Intention tremor

associated w/cerebellar dysfxn

Front 13

input to the cerebellum?

Back 13

Contralateral Cortical input via middle cerebellar bpeduncle

Ipsilateral proprioceptive information via Inferior cerebellar peduncle


*climbing & mossy fibers = input

Front 14

output of cerebellum?

Back 14

stimulatory feedback to contralateral cortex to modulate movement

*Purkinje fibers output to deep nuclei of crebellum
*deep nuclei of cerebellum output to cortex via superior cerebellar peduncle

Front 15

cerebellar peduncles?

Back 15

superior - output to contralateral cortex
middle - input from contralateral cortex
inferior - input from ipsilateral proprioception

Front 16

Deep nuclei of the cerebellum?

Back 16

Lateral --> Medial
"don't eat greasy food"

Dentate
Emboliform
Globose
Fastigial

Lateral - voluntary movement of extremities
Medial - balance, truncal coordination, ataxia

Front 17

what happens w/injury to medial cerebellar deep nuclei?

Back 17

propensity to fall toward injured (ipsilateral) side

Front 18

Striatum?

Back 18

putamen (motor)
+
caudate (cognitive)

Front 19

Dopamine effect on basal ganglia?

Back 19

*Dopamine 1 receptors - stimulate excitatory pathway
*Dopamine 2 receptors - inhibit the inhibitory pathway
**both result in INCREASED MOTION