8.3 Movement Disorders

Question 0

Main symptoms of Parkinson’s disease are ____, ____ ____, ____ ____, and difficulty initiating physical and mental activity.

Answer 0

rigidity, muscle tremors, slow movements,

Question 1

Brain disorders that impair ____ also impair mood, memory, and cognition.

Answer 1

movement

Question 2

Parkinsons strikes about ___ to ___ of people over age 65.

Answer 2

1% to 2%

Question 3

In addition to the motor problems, patients are slow on ____ ____, such as imagining events or actions, even when they don’t have to do anything.

Answer 3

cognitive tasks

Question 4

A loss of ____ is often an early symptom of Parkinson’s, and sometimes the first symptom.

Answer 4

olfaction

Question 5

____ and ____ ____ are also common symptoms of Parkinsons, beginning early in the course of the disease.

Answer 5

Depression and memory loss

Question 6

People with Parkinson’s disease are not paralysed or weak. The basal ganglia have cells specialised for learning to start or stop a ____ ____ of ____. Those cells are impaired in Parkinson’s disease, and the result is a difficulty with spontaneous movements in the absence of stimuli to guide their actions.

Answer 6

voluntary sequence of motions

Question 7

The immediate cause of Parkinson’s disease is a gradual progressive death of neurons, especially in the ____ ____, which sends dopamine-releasing axons to the caudate nucleus and putamen. People with Parkinsons disease lose these axons and therefore dopamine.

Answer 7

substantia nigra

Question 8

1. The main route, known as the direct pathway, is this follows: axons from the substantia nigra release ____ that excites the cordate nucleus and putamen.

Answer 8

dopamine

Question 9

2. The caudate nucleus and putamen inhibit the globus pallidus, which in turn inhibits part of the ____.

Answer 9

thalamus

Question 10

3. For people with Parkinson’s disease, decreased output from the substantia nigra means less ____ of the caudate nucleus and putamen, and therefore less ____ of the globus pallidus.

Answer 10

excitation : inhibition

Question 11

4. The globus pallidus, freed from inhibition, increases its (inhibitory) output to the thalamus. So the net result is ____ activity in the thalamus, and therefore also in parts of the cerebral cortex.

Answer 11

decreased

Question 12

5. In summary, a loss of dopamine activity in the ____ ____ leads to less stimulation of the motor cortex and slow onset of movements.

Answer 12

substantia nigra

Question 13

Genes only ____ influence the risk of late-onset Parkinson’s disease.

Answer 13

weakly

Question 14

A toxin that could be responsible for Parkinsons symptoms is ____, a chemical that the body converts to MPP+, which accumulates in, and then destroys, neurons that release dopamine.

Answer 14

MPTP

Question 15

One hypothesis for Parkinson onset is that people are sometimes exposed to ____ ____ in herbicides and pesticides, many of which damage cells of the substantia nigra.

Answer 15

hazardous chemicals

Question 16

Parkinson’s disease is more common than average among ____ and others who have had years of exposure to herbicides and pesticides.

Answer 16

farmers

Question 17

One factor that stands out consistently with Parkinsons is ____ ____ and ____: people who smoke cigarettes or drink coffee have less chance of developing Parkinson’s disease.

Answer 17

cigarette smoking and coffee

Question 18

Animal research indicates that decaffeinated coffee works just as well as regular coffee, and the nicotine-free tobacco works as well as full tobacco, so the effective chemicals are something other than ____ and ____.

Answer 18

caffeine and nicotine

Question 19

Parkinson’s disease probably results from a mixture of causes. What they have in common is damage to the ____.

Answer 19

mitochondria

Question 20

When a neurons mitochondria begins to fail – because of genes, toxins, infections, or whatever – a chemical called _____ clots into clusters that damage neurons containing dopamine. Dopamine-containing neurons are especially vulnerable to damage.

Answer 20

a-synuclein

Question 21

If Parkinson’s disease results from a dopamine deficiency, the logical goal is to ____ ____ ____. A dopamine pill would be ineffective because dopamine does not cross the blood-brain barrier.

Answer 21

restore missing dopamine

Question 22

______, a precursor to dopamine, does cross the barrier. Taken as a daily pill, ______ reaches the brain, we neurons convert it to dopamine. ______ is the main treatment for Parkinson’s disease.

Answer 22

L-dopa

Question 23

However, L-dopa is ____ in several ways. First, it is ineffective for some patients, especially those in the late stages of the disease. Second, it does not prevent the continued loss of neurons. Third, it produces unpleasant side-effects such as nausea, restlessness, sleep problems, low blood pressure, repetitive movements, hallucinations and delusions.

Answer 23

L-dopa is disappointing

Question 24

____ disease is a severe neurological disorder that strikes about one person in 10,000 in the United States.

Answer 24

Huntington’s