Neuro: Basal Ganglia Disorders

Front 1

The classic physiology of Parkinson's disease is due to loss of _________________ in the ______________.

Back 1

loss of dopaminergic producing neurons in the substantia nigra pars compacta.

results in an overall lack of movement

Front 2

In the normal brain, dopamine from the substantia nigra compacta has

A. an excitatory effect on the D1 receptors in the struatum and an inhibitory effect on the D2 receptors
B. an inhibitory effect on the D1 receptors in the struatum and an excitatory effect on the D2 receptors

Back 2

A. an excitatory effect on the D1 receptors in the struatum and an inhibitory effect on the D2 receptors

Front 3

What are the components of the "direct loop" for the basal ganglia in a normal brain?

Back 3

dopamine from substantia nigra pars compacta --> excitatory effect on D1 receptors in striatum --> inhibits the substantia nigra reticulata in the globus pallidus interna --> activates motor thalamus --> motor cortex

Front 4

What are the components of the "indirect loop" for the basal ganglia in a normal brain?

Back 4

dopamine from substantia nigra pars compacta --> inhibitory effect on D2 receptors in striatum --> inhibit GPe --> STN (subthalamic nucleus) --> activates the SNr and GPi

Front 5

Cortical excitation of the indrect pathway [ inhibits / stimulates ] movement and cortical stimulation of the direct pathway [ inhibits / stimulates ] movement.

Back 5

Cortical excitation of indirect pathway = inhibits ;
Cortical excitation of direct pathway = stimulates

Dopamine from SNpc leads to facilitation of movement through both pathways because of the difference in receptors in the direct and indirect pathways.

Front 6

What are the four cardinal features of Parkinson's disease?

Back 6

bradykinesia (slowness of movement in rapid alternating movements), resting tremor, rigidity and festinating gat (small steps, difficulty starting gait).

Front 7

What are the current treatments for Parkinson's disease?
(hint: 3 + 1 being worked on)

Back 7

1. L-DOPA + carbidopa
2. pallidotomy
3. deep brain stimulator
(4. in progress is fetal tissue cell transplantation)

Front 8

What are some side effects of the L-DOPA + carbidopa treatment for Parkinson's disease?

Back 8

dyskinesias common. also possible are psychosis or orthostatic hypertension. Dopaminergic agonists can cause abnormal sexual urges or compulsive gambling too.

Front 9

True or False:

The deep brain stimulator is actually used as an "off-switch" when implanted into the GPe.

Back 9

FALSE.

off switch, yes, but it is not implanted in the GPe, it is implanted into the subthalamic nucleus(STN) or GPi.

Front 10

In Parkinson's Disease, switching off ________ will restore activity to the motor cortex.

A. subthalamic nucleus and globus pallidus externa
B. globus pallidus externa and nigra reticulata
C. subthalamic nucleus and globus pallidus interna

Back 10

C. subthalamic nucleus and globus pallidus interna

Front 11

After deep brain stimulation treatment, there is overall marked improvement in all the motor features of the Parkinson's disease with the exception of ____________ which is sometimes improved and sometimes worsened by the surgery.

Back 11

speech

note: the non-motor features of Parkinson's disease such as dementia are not improved by surgery. Patients may or may not continue with the same medications.

Front 12

Match the disease to the part of the motor nucleus it is associated with.

1. Parkinson's disease
2. Essential tremors

A. cerebellar receiving nucleus of the thalamus
B. pallidal receiving area of the motor nucleus

Back 12

1. B
2. A.

Front 13

Which of the following is NOT a potential cause of dystonia (co-contraction of antogonistic muscles disease)?

A. mutations in the DYT1 gene
B. hypoxia
C. head injury
D. spinal cord injury
E. stroke
F. bilirubin encephalopathy

Back 13

D. spinal cord injury

all others CAN cause dystonia