PARKINSONS1

Question 1

What symptom involves increased muscle tone and rigidity?

Answer 1

Muscle rigidity, stiffness

Question 2

What is a hallmark symptom characterized by shaking at rest?

Answer 2

Tremor at rest

Question 3

What term describes a reduction in voluntary movement, slowness of movement, and difficulty initiating and stopping movements?

Answer 3

Hypokinesia, bradykinesia, motor activity difficult to initiate & stop

Question 4

What function does the basal ganglia perform regarding sensory information?

Answer 4

Converts highly processed sensory information into motor program

Question 5

What is the significance of the multiple circuits within the basal ganglia?

Answer 5

They are involved in various functions, including motor functions and non-motor functions like cognition, motivation, and addiction

Question 6

What percentage of the population over 50 years is affected by Parkinson’s disease?

Answer 6

Affects 1% of the population over the age of 50 yrs

Question 7

What is the primary cause of motor disturbances in Parkinson’s disease?

Answer 7

Loss of DAergic neurons in the nigrostriatal tract

Question 8

What are the expected motor disturbances in Parkinson’s disease?

Answer 8

Hypokinesia - reduced spontaneous movement, leading to symptoms like slowness, stiffness, and difficulty initiating movement

Question 9

What type of disorder is Huntington’s disease?

Answer 9

Progressive, inherited disorder

Question 10

What neurotransmitter-producing neurons are lost in Huntington’s disease?

Answer 10

GABAergic neurons in striatum

Question 11

What motor disturbances are expected in Huntington’s disease?

Answer 11

Hyperkinesia (jerky involuntary movement) and dementia - involuntary movements, cognitive decline, and psychiatric symptoms

Question 12

What is the initial step in adrenaline synthesis?

Answer 12

Tyrosine Hydroxylation

Question 13

Which enzyme catalyzes the conversion of tyrosine to L-DOPA?

Answer 13

Tyrosine hydroxylase

Question 14

Where does the conversion of tyrosine to L-DOPA primarily occur?

Answer 14

In the cytoplasm of catecholamine-producing cells

Question 15

What is the enzyme responsible for the decarboxylation of L-DOPA?

Answer 15

Aromatic L-amino acid decarboxylase (DOPA decarboxylase)

Question 16

What is removed from L-DOPA during its decarboxylation to form dopamine?

Answer 16

Carboxyl group (-COOH)

Question 17

What neurotransmitter is formed as a result of L-DOPA decarboxylation?

Answer 17

Dopamine

Question 18

Which enzyme converts dopamine to norepinephrine?

Answer 18

Dopamine β-hydroxylase

Question 19

Where does the conversion of dopamine to norepinephrine typically occur?

Answer 19

Within synaptic vesicles of nerve terminals in the sympathetic nervous system

Question 20

What is the final step in adrenaline synthesis?

Answer 20

Conversion of Norepinephrine to Epinephrine

Question 21

Where does the final step of adrenaline synthesis primarily occur?

Answer 21

In the adrenal medulla, located above the kidneys

Question 22

Which enzyme catalyzes the conversion of norepinephrine to epinephrine?

Answer 22

Phenylethanolamine N-methyltransferase (PNMT)

Question 23

What group is added to norepinephrine during its conversion to epinephrine?

Answer 23

Methyl group (-CH3)

Question 24

What are the primary symptoms of Parkinson’s Disease (PD)?

Answer 24

Tremor at rest, Muscle rigidity, stiffness, Bradykinesia, motor activity difficult to initiate & stop

Question 25

What was the first neurotransmitter associated with Parkinson's Disease?

Answer 25

Dopamine (DA)

Question 26

In which brain region are dopaminergic (DAergic) neurons lost in Parkinson's Disease?

Answer 26

Substantia nigra

Question 27

What is the characteristic pattern of walking observed in individuals with Parkinson's Disease?

Answer 27

Parkinson's disease gait

Question 28

Describe Braak stages 1 & 2 of Parkinson's Disease progression.

Answer 28

Characterized by early degeneration and disturbances in sleep and olfaction

Question 29

Describe Braak stages 3 & 4 of Parkinson's Disease progression.

Answer 29

50-80% of nigrostriatal neurons are lost, and motor symptoms start to emerge

Question 30

Describe Braak stages 5 & 6 of Parkinson's Disease progression.

Answer 30

Lewy bodies become prominent, and psychiatric symptoms, including dementia, may emerge. Compensation by D1 and D2 receptors also occurs.

Question 31

What impact can Parkinson's disease gait disturbances have on a person's mobility?

Answer 31

Significantly impact mobility and quality of life in advanced stages of the disease

Question 32

What neurotransmitter systems are significantly altered in Parkinson's Disease (PD)?

Answer 32

Dopamine (DA) and gamma-aminobutyric acid (GABA)

Question 33

In a healthy brain, what is the role of dopamine in relation to GABAergic neurons?

Answer 33

Dopamine inhibits GABAergic neurons originating from the substantia nigra, allowing for smooth transmission of signals from the thalamus to cortical areas

Question 34

How does the loss of dopaminergic neurons in PD affect GABAergic activity?

Answer 34

Decreased dopamine levels result in overactivity of GABAergic inhibitory neurons

Question 35

What is the consequence of overactive GABAergic neurons in PD?

Answer 35

Inhibition of the thalamic relay, causing difficulty in initiating and stopping movements, such as bradykinesia and akinesia

Question 36

Besides dopamine and GABA, what other neurotransmitter imbalances are observed in PD?

Answer 36

Acetylcholine (ACh), noradrenaline (NA), serotonin (5-HT), and further disturbances in GABAergic transmission

Question 37

What motor symptoms are associated with hyperactivity of cholinergic neurons in PD?

Answer 37

Tremor and rigidity

Question 38

What is bradykinesia, and what causes it in Parkinson's Disease (PD)?

Answer 38

Bradykinesia involves a reduction in the speed and frequency of voluntary movements, caused by the loss of inhibition of GABAergic cells by dopamine.

Question 39

How does increased activity of GABAergic neurons in the globus pallidus contribute to bradykinesia?

Answer 39

It inhibits cortical areas responsible for initiating movements, resulting in difficulty initiating movements.

Question 40

What are the hallmark motor features of Parkinson's Disease (PD)?

Answer 40

Tremor and rigidity

Question 41

What neurotransmitter systems are involved in the manifestation of tremor and rigidity in PD?

Answer 41

Acetylcholine, noradrenaline, serotonin, and gamma-aminobutyric acid (GABA)

Question 42

How does dopamine inhibition affect cholinergic interneurons in the striatum, and what is the consequence?

Answer 42

Dopamine inhibition strongly suppresses cholinergic interneurons, resulting in their hyperactivity, associated with tremor and bradykinesia.

Question 43

What is the key aspect of neurochemical changes in PD related to motor symptoms?

Answer 43

The imbalance between dopamine and acetylcholine (DA/ACh imbalance)

Question 44

What psychiatric symptoms can manifest in later stages of PD?

Answer 44

Depression, anxiety, and cognitive impairment

Question 45

Besides dopaminergic dysfunction, what other factors contribute to the development of psychiatric symptoms in PD?

Answer 45

Alterations in other neurotransmitter systems and neural circuits

Question 46

What are some factors contributing to the higher incidence of Parkinson's Disease in rural areas compared to urban regions?

Answer 46

Pesticide exposure, Genetic links, Oxidative stress and neuroinflammation, Drug-induced PD

Question 47

How do pesticides like rotenone contribute to the development of Parkinson's Disease?

Answer 47

They selectively inhibit mitochondrial function, inducing Parkinson's Disease in animal models

Question 48

What genetic mutations have been associated with the development of Parkinson's Disease?

Answer 48

Mutations of α-synuclein, Mutation in the parkin gene, Mutations of mitochondrial proteins

Question 49

What role do oxidative stress and neuroinflammation play in Parkinson's Disease?

Answer 49

They contribute to the development and progression of the disease

Question 50

Which medications can induce Parkinson's-like symptoms as side effects?

Answer 50

Antipsychotics, Lithium, valproate (antiepileptic), Some antiemetics

Question 51

What specific neurotoxin has been linked to the development of Parkinson's Disease in some cases?

Answer 51

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)

Question 52

How does MPTP contribute to the development of Parkinson's Disease-like symptoms?

Answer 52

It is metabolized to MPP+ in the brain, damaging dopamine-producing neurons

Question 53

What is the role of oxidative stress and inflammation in the pathogenesis of Parkinson's Disease?

Answer 53

They damage neurons and trigger neurodegenerative cascades, contributing to disease progression