BB EOYS1 Flashcards
Which supplies the medial portion of the globus pallidus?
anterior choroidal artery (AChA)
middle cerebral artery (MCA)
anterior cerebral artery (ACA).
posterior cererbral artrey (PCA)
lenticulostriate artery
Which supplies the medial portion of the globus pallidus?
anterior choroidal artery (AChA)
middle cerebral artery (MCA)
anterior cerebral artery (ACA).
posterior cererbral artrey (PCA)
lenticulostriate artery
Which supplies the anterior and inferior of the globus pallidus?
anterior choroidal artery (AChA)
middle cerebral artery (MCA)
anterior cerebral artery (ACA).
posterior cererbral artrey (PCA)
lenticulostriate artery
Which supplies the anterior and inferior of the globus pallidus?
anterior choroidal artery (AChA)
middle cerebral artery (MCA)
anterior cerebral artery (ACA).
posterior cererbral artrey (PCA)
lenticulostriate artery
Which supplies the superior and posterior of the globus pallidus?
anterior choroidal artery (AChA)
middle cerebral artery (MCA)
anterior cerebral artery (ACA).
posterior cererbral artrey (PCA)
lenticulostriate artery
Which supplies the superior and posterior of the globus pallidus?
anterior choroidal artery (AChA)
middle cerebral artery (MCA)
anterior cerebral artery (ACA).
posterior cererbral artrey (PCA)
lenticulostriate artery
A 65-year-old man was brought by his daughter to his provider due to tremors and increasing stiffness in both arms and legs. This has led the patient to fall twice while attempting to turn. On examination, the patient had increased muscle tone, resting tremors, and difficulty initiating movements when asked to move. A single-photon emission computed tomography (SPECT) was done, showing reduced uptake in the striatum. How would this reduced uptake affect the pathways?
A. It reduces inhibitory signals projected to the subthalamus.
B. It increases inhibitory signals projected to the subthalamus.
C. It reduces the stores of neurotransmitters present in the globus pallidus externus.
D. It increases inhibitory signals projected to the substantia nigra pars reticularis.
A 65-year-old man was brought by his daughter to his provider due to tremors and increasing stiffness in both arms and legs. This has led the patient to fall twice while attempting to turn. On examination, the patient had increased muscle tone, resting tremors, and difficulty initiating movements when asked to move. A single-photon emission computed tomography (SPECT) was done, showing reduced uptake in the striatum. How would this reduced uptake affect the pathways?
A. It reduces inhibitory signals projected to the subthalamus.
B. It increases inhibitory signals projected to the subthalamus.
C. It reduces the stores of neurotransmitters present in the globus pallidus externus.
D. It increases inhibitory signals projected to the substantia nigra pars reticularis.
Which of the following outputs to the superior colliculi?
globus pallidus external
globus pallidus internal
substantia nigra, pars reticula
subthalamic nuclei
Which of the following outputs to the superior colliculi?
globus pallidus external
globus pallidus internal
substantia nigra, pars reticula
subthalamic nuclei
What is the most common type of tremor in PD? [1]
pill-rolling’ rest tremor; looks like you are trying to roll a pill between your thumb and index
Basal ganglia input zones:
Where do the caudate nucleus and putamen have fibres inputing into / orginating from? [3]
- Cerebral cortex - specifically the frontal cortex: primary motor cortex and parietal cortex: primary somatosensory cortex
- substantia nigra pars compacta (from the midbrain)
- Local circuit neurons within the corpus striatum (GABAergic)
Describe the indirect pathway of the dorsal ganglia
Excitation of dorsal striatum causes the release of dorsal striatum GABA (inhibitory)
This causes projects onto globus pallidus external segment: causes increased inhibition of GPe
This causes the globus pallidus external segment to release inhibitory GABA onto the subthalamic nucleus: causes reduced inhibition of STN
This causes the subthalamic nucleus to release inhibitory GABA onto the globus pallidus internal segment: which increases the activation of GPi
This causes the globus pallidus internal segment to release inhibitory GABA onto the motor thalamus: which creates increased inhibition of motor thalamus
OVERALL DEACTIVATION OF MOTOR THALAMUS -> decreased motor cortex activation.
NO GO pathway.
Describe the effect of the activation of the D2 dopaminergic receptors
The D2 dopaminergic receptor activated:
- decreases cAMP
- Decreaes the sensitivity of striatal GABA neurons to glutamate (makes the glutatemate LESS EXCITABLE)
- Causes increased inhibition of the sub-thalamic nucleus
- This means get increaed inhibition of the GPi
- This causes less inhibition of the VL / VA
End result: INCREASED MOTOR ACTIVITY
Explain pathophysiology of Parkinsons disease [2]
-Loss of dopaminergic neurons in the substantia nigra, which project to and innervate the dorsal striatum.
- Less D1 and D2 activation
- The indirect pathway is therefore faciliated and becomes dominant
Name the 3 classic symptoms of Parkinsons disease [3]
bradykinesia, tremor and rigidity.
Name the symptoms of HD [4]
chorea - movement disorder that causes sudden, unintended, and uncontrollable jerky movements of the arms, legs, and facial muscles.
personality changes (e.g. irritability, apathy, depression) and intellectual impairment
dystonia
saccadic eye movements - abruptly change the point of fixation.
Describe what ballismus and Athetosis are [2] and what they’re caused by [2]
Athetosis:
* slow, involuntary regular writhing movements of the fingers, hands, toes and feet (in some cases, arms, legs, neck and tongue
* Lesions to the striatum; often a result of cerebral palsy
Ballismus:
* a type of chorea, usually involving violent, involuntary flinging of one arm and/or one leg (usually one side of the body is affected: Hemiballismus). The movements are wider and more intense than chorea
* Damage to subthalamic nucleus
What is the name for this symptom?
Lesions to which region causes this symptom?
Subthalamic nuclei
Substantia nigra
Pre supplementary motor area
Lentiform nucleus
Dorsal striatum
athetosis
Lesions to which region causes this symptom?
Subthalamic nuclei
Substantia nigra
Pre supplementary motor area
Lentiform nucleus
Dorsal striatum
What is the name for this symptom?
Lesions to which region causes this symptom?
Subthalamic nuclei
Substantia nigra
Pre supplementary motor area
Lentiform nucleus
Dorsal striatum
Ballismus
Subthalamic nuclei
Substantia nigra
Pre supplementary motor area
Lentiform nucleus
Dorsal striatum
Which mitochondrial metabolite is toxic to dopaminergic pathways? [1]
MPP+
The genetic link between familial PD is due to a link between which protein? [1] Which gene codes for this protein? [1]
Is PD genetic or environmental? [1]
genetic link with the protein alpha-synuclein coded by SNCA (duplications or triplications cause autosomal dominant familial PD)
disease emergence may be due to interactions environment x genes
Describe the link between mitochondrial toxicity and dopaminergic neurons [1]
What process is diruspted as a result of ^ [1]
The compound MPTP is a toxin which can be transformed into the metabolite MPP+ which is neurotoxic for dopaminergic neurons
Dysfunction of complex I of the mitochondrial respiratory chain
can lead to increased oxidative stress
Describe the mechanism of creation of dopamine [3]
L-tyrosine –> L-Dopa (Decarboxylated to create..) –> Dopamine
Dopamine binds to which two receptors? [2]
What are the subtypes of these receptors? [5]
D1-like Family Receptors:
* D1 & D5 subtypes
D2-like Family Receptors
* D2, D3 & D4 subtypes
Which drug used to treat Huntingdons Disease works by the mechanism of action depicted by A? [1]
Tetrabenazine
acts primarily as a reversible high-affinity inhibitor of mono-amine uptake into granular vesicles of presynaptic neurons by binding selectively to VMAT-2
Which treatment used in PD is good at managing tremors
Haloperidol
Ritotigone
L-DOPA
Orphenadrine
Which treatment used in PD is good at managing tremors
Haloperidol
Ritotigone
L-DOPA
Orphenadrine: anticholinergic
Damage to which of the following would cause someone to not be able to inhibit a response to a stimulus
A
B
C
Damage to which of the following would cause someone to not be able to inhibit a response to a stimulus
A: dorsolateral pre-frontal cortex
B
C
Pharmacological management of Parkinson’s disease
Name three drugs that are monoamine oxidase inhibitors [3]
Describe their MoA [1]
- rasagiline
- selegiline (in PBL)
- safinamide
MAO-B inhibitors stop Monoamine oxidase type B breaking down dopamine into DOPAC or homovanillic acid
Pharmacological management of Parkinson’s disease
Name 2 COMT inhibitors [2]
entacapone
tolcapone
Brain areas involved decision making & movement planning:
Which area of the brain is where conscious intentions are formed and we become aware of motor movement? [1]
Name another key function of this area? [1]
The posterior parietal cortex
Also provides a representation of the body and how it is situated in space
Broadmann areas 39 & 40
Prefrontal cortex:
Dorsolateral prefrontal cortex
What is this region of the pre-frontal cortex involved with? [3]
Planning of goal-directed behaviours AND simulating the consequences of plans
Initiating, inhibiting and swtiching executive behaviour: input to the basal ganglia about stop / start
Involved with:
Problem-solving
Goal-driven attention
Planning
Decision making
Working memory
dorsolateral prefrontal cortex:
Lesions in Brodmann area 46 affects which functions? [1]
Attention and working memory: affects ability to inhibit a response to a stimulus
supplementory motor area:
Location:
Broadmann area? [1]
Lobe? [1]
Role? [2]
Location:
medial part of BA 6; frontal cortex
Role:
* Orgnaises actions that are internally guide according to preferences and goals: choosing objects
* Determines response threshold to initiate movement - the urgency of movement
* Response to start or stop a movement (interconnects to basal ganglia)
e.g which object to choose (in alignment with goals)
plan sequence of learned actions - e.g. playing piano
Extrapyramidal tracts:
Describe the course of the lateral vestibulospinal tract [1]
Which type of muscles does it synapse onto? [1]
Fibres descend ipsilaterally though the anterior funiculus of the same side of the spinal cord, synapsing on the extensor antigravity motor neurons: help maintain upright and balanced posture.
Describe the function and path of the rubrospinal tract [2]
Function: Controls muscle tone in flexor muscle groups; Inhibits extensor tone
Path:
- Arises from the red nucleus in the brainstem
- crosses at medulla
- terminates primarily in the cervical and thoracic portions of the spinal cord
