MOVEMENT DISORDERS

Question 1

what is the lentiform nucleus made up of?

Answer 1

putamen and globus pallidus

Question 2

what is the corpus striatum made up of?

Answer 2

neostriatum and palleostriatum

Question 3

what are the three main functions of the basal ganglia?

Answer 3

control movement
prevent involuntary movement
control behaviour

Question 4

what is the neostriatum made up of?

Answer 4

caudate nucleus and putamen

also just referred to as the striatum

Question 5

the palleostriatum contains which structure?

Answer 5

globus pallidus

Question 6

the indirect pathway is regulated by which dopaminergic receptor?

Answer 6

D2

Question 7

the direct pathway is regulated by which dopaminergic receptor?

Answer 7

D1

Question 8

what is the function of the direct pathway?

Answer 8

stimulate voluntary movement

Question 9

what is the function of the indirect pathway?

Answer 9

inhibit involuntary movement

Question 10

in the direct pathway, what is the resting function of the globus pallidus interna?

Answer 10

inhibit the thalamus using GABA

Question 11

which structures are involved in the indirect pathway but not in the direct pathway?

Answer 11

sub thalamic nucleus

globus pallidus externa

Question 12

the resting function of the globus pallidus interna is…

Answer 12

inhibition of the thalamus- hence preventing involuntary movement

Question 13

where is dopamine released from in both the direct and indirect pathways?

Answer 13

substantia nigra PARS COMPACTA

Question 14

what is the function of the substantia nigra pars reticulata in the direct pathway?

Answer 14

at rest, SNPret inhibits the thalamus
when inhibited by GABA from striatum, the ‘brake’ on the thalamus is lifted

SAME FUNCTION AS GPINTERNA

Question 15

which pathway is associated with an INCREASE in GABA inhibition from striatum?

Answer 15

They both are

Question 16

which pathway is associated with a DECREASE in GABA inhibition from the GP externa?

Answer 16

INDIRECT pathway

Question 17

what is the effect of dopamine on both the direct and indirect pathways?

Answer 17

overall net increase in movement by ACTIVATION of the direct pathway and INHIBITION of the INDIRECT pathway

Question 18

what is the effect of D2 receptor activation on the globus pallidus interna?

Answer 18

INCREASED glutamate ++++

indirect pathway

Question 19

what is the effect of D1 receptor activation on the globus pallidus interna?

Answer 19

INCREASED GABA ++++

direct pathway

Question 20

in the indirect pathway, what is the resting function of the globus pallidus externa?

Answer 20

INDIRECT inhibition of the GP interna via sub thalamic nuclei

Question 21

what are medium spiny neurones? What receptors do they express?

Answer 21

GABAergic inhibitory neurones that make up 96% of striatum neurone population. Either have D1 or D2 phenotype

Question 22

what neuropeptide is associated with the D1 pathway?

Answer 22

Dynorphin

Question 23

what neuropeptide is associated with the D2 pathway?

Answer 23

Enkephalin

Question 24

tonic Da release from SN favours activation of which pathway?

Answer 24

D2 - increased inhibition e.g. at rest

Question 25

phasic dopamine release from SN favours activation of which pathway?

Answer 25

D1 - increased activation e.g. when active

Question 26

what are the 4 cardinal symptoms of PD?

Answer 26

bradykinesia
postural instability
resting tremor
rigidity

Question 27

what are the craniofacial symptoms of PD?

Answer 27

hypomimia (lack of facial expression)
dysphagia (incorrect speech)
hypophonia (quiet voice)

Question 28

what gait is associated with parkinsons?

Answer 28

Shuffling gait aka. parkinsonian gait

shuffling
stooped posture
freezing - inability to move forwards

Question 29

what are the two types of bradykinesia?

Answer 29

akinesia

hypokinesia

Question 30

what is akinesia?

Answer 30

inability to perform spontaneous movement

Question 31

what is hypokinesia?

Answer 31

in addition to being slow, movements are also smaller than desired e.g. micrographia

Question 32

what are the non-motor features of parkinsons?

Answer 32

pain
anosmia
constipation/GI problems
REM sleep behaviour disorder

Question 33

what are central pattern generators?

Answer 33

neural circuits in the brainstem that control subconscious movements e.g. walking and breathing

lack of dopamine inhibits CPGs and causes bradykinesia

Question 34

what changes are seen in muscle fibres types in PD patients?

Answer 34

increased inhibition of type Ib fibres (golgi tendon stretch)

increased activation of type II fibres (these control muscle fibres when static)

Question 35

what drug targets the glu neurones between the thalamus - cortex - basal ganglia?

Answer 35

amantadine (NMDA receptor antagonist)

reduces dyskinesia by 40%

Question 36

what drug is given subcutaneously via infusion to administer tonic dopamine?

Answer 36

apomorphine

Question 37

what is neuroleptic malignant syndrome?

Answer 37

fever, confusion, rigidity and tachycardia following rapid withdrawal of PD meds

Question 38

what is the cause of dyskinesia in parkinsons?

Answer 38

Glutamate excess caused by increased dopamine (due to pulsatile release etc.)

Question 39

What is chorea disorder?

Answer 39

hyperkinetic disrder that is opposite to PD

underactive indirect pathway
overactive indirect pathway

uncontrolled movement

Question 40

what is Huntingdons disease?

Answer 40

autosomal dominant CAG repeats

selective D2 neurone death, followed by direct pathway loss as disease progresses

Question 41

what is tourettes syndrome?

Answer 41

caused by loss of basal ganglia interneurones in the striatum (both GABA and Ach)