Chapter 39: Disorders of the Basal Motor Nuclei Flashcards
The initiation of movements by the basal motor nuclei depends on projections from the _____ to the striatum (putamen and caudate).
- Substantia nigra
If the neurons in the substantia nigra die, it will be extremely difficult to _____.
- Initiate movements
Death of neurons in the substantia nigra makes it so hard to _____ movement in the facial muscles that the patient doesn’t move the facial muscles.
- Initiate
Immobility of the _____ creates the mask-like face typical of Parkinson’s disease.
- Facial muscles
Parkinson’s disease is due to death of neurons in the _____.
- Substantia nigra
Exposure to broad-spectrum herbicides such as paraquat injures neurons in the substantia nigra and increases the risk of _____.
- Parkinson’s disease
Several _____, of which the most widely used is paraquat, cause Parkinson’s disease in susceptible individuals.
- Herbicides
Caffeine protects neurons in the substantia nigra so that _____ drinkers have half as much risk of Parkinson’s disease as non-drinkers.
- Coffee
Caffeine, certainly, and other components of _____, probably, protect the substantia nigra.
- Coffee
The _____ in _____ and _____ has a neuroprotective effect that halves the risk of getting Parkinson’s disease.
- Caffeine
- Coffee
- Tea
The performance of dying, but not dead, neurons in the _____ can be improved by supplying them with l-dihydroxyphenylalanine (L-DOPA), the immediate precursor of dopamine.
- Substantia nigra
The immediate precursor of dopamine is _____.
- L-DOPA (l-dihydroxyphenylalanine)
Death of neurons in the substantia nigra eliminates the _____ pathway through the lenticular nucleus and allows the _____ pathway to become overactive.
- Direct
- Indirect
The overactive indirect pathway causes the medial globus pallidus to inhibit the stimulation of the premotor cortex by the _____ of the _____.
- Ventral anterior nucleus
- Thalamus
The symptoms of Parkinson’s disease are due to an overactive _____.
- Medial globus pallidus
The symptoms of Parkinson’s disease can be lessened by deep brain stimulation which uses implanted electrodes to decrease the activity of the _____.
- Medial globus pallidus
The most common treatments for Parkinson’s disease are _____ and _____.
- Deep brain stimulation
- L-DOPA
Activity of the medial globus pallidus reduces the output of the ventral anterior nucleus to the _____.
- Premotor cortex
It is very difficult for the primary motor cortex (Brodmann area 4) to _____ movement without input from the premotor cortex (Brodmann area 6).
- Initiate
Death of neurons in the substantia nigra makes it an effort to _____ each step when walking.
- Start
The delay between steps in _____ disease leads to the upper body getting ahead of the feet, a symptom called anterograde walking.
- Parkinson’s
Walking with a pronounced forward lean is called _____ walking.
- Anterograde
Anterograde walking and mask-like face are symptoms of _____.
- Parkinson’s Disease
There is a lack of activity in the ventral anterior nucleus leads to a lack of activity in the _____ and _____.
- Premotor cortex
- Primary motor cortex
Lack of stimulation of the premotor cortex by the _____ causes bradykinesia (Greek: brady=slow, kinesia=movement).
- Ventral anterior nucleus
Bradykinesia is a symptom of _____.
- Parkinson’s Disease
Greatly reduced input from the _____ leads to spontaneous activity in lower motor neurons, especially in the region of the brachial plexus.
- Primary motor cortex
Spontaneous activity in the _____ of the brachial plexus causes a fidgeting movement of the fingers called “pill rolling.”
- Lower motor neurons
“Pill rolling” is a symptom of _____.
- Parkinson’s Disease
James Parkinson called the disease he described “paralysis agitans” because it combined near _____ of the facial muscles with _____.
- Paralysis
- “Pill-rolling”
In addition to “pill rolling” and _____-like face, Parkinson’s disease includes _____
and _____ walking.
- Mask
- Bradykinesia
- Anterograde
Just as excess activity of the medial globus pallidus inhibits desired movement, insufficient activity of the medial globus pallidus causes _____.
- Unwanted movement
The activity of the medial globus pallidus would be most sharply decreased by removal of all stimulation by a stroke in the _____.
- Subthalamic nucleus
A stroke in the _____ causes large-scale unwanted movements called hemiballismus.
- Subthalamic nucleus
Because the basal motor nuclei modulate the activity of the motor cortex whose output crosses in the lower medulla, a stroke in the subthalamic nucleus causes _____ in the _____ limbs.
- Hemiballismus
- Contralateral
The net effect of release of dopamine at synapses in the putamen is to _____ movement.
- Facilitate
An overdose of DOPA is liable to cause _____.
- Unwanted movement
Unwanted movement caused by treating Parkinson’s disease with _____ is called Parkinson’s dyskinesia. (Greek: dys=bad, kinesia=movement.)
- L-DOPA
Unwanted movement due to an overdose of L-DOPA is _____.
- Parkinson’s dyskinesia
Blocking too many dopamine receptors in the putamen with dopamine receptor blocking tranquillizers would have the same effect as loss of neurons in the _____.
- Substantia nigra
An overdose of a dopamine-receptor-blocking tranquillizer causes symptoms similar to those of _____.
- Parkinson’s Disease
The bradykinesia, anterograde walk, and immobile face caused by antipsychotic _____ are called “drug induced Parkinsonism.”
- Dopamine receptor blockers
Neurons respond to overstimulation and understimulation by seeking their basal activity by deleting receptors from their cell membranes during prolonged _____ and adding receptors to their cell membranes during prolonged _____.
- Inactivity
- Activity
Neurons in the putamen respond to the prolonged inactivity induced by dopamine-receptor-blocking tranquilizers by _____ dopamine receptors.
- Adding
After prolonged use of dopamine-receptor-blocking tranquillizers, neurons in the putamen have so many _____ that they are hypersensitive to _____ from the substantia nigra.
- Dopamine receptors
- Dopamine
Hypersensitivity to endogenous dopamine causes _____.
- Unwanted movement
Unwanted movement due to _____ to endogenous _____ as a result of prolonged use of dopamine-receptor-blocking tranquillizers is called “tardive dyskinesia.” (Greek: tardive=delayed.)
- Hypersensitivity
- Dopamine
Tardive dyskinesia occurs after _____ use of _____.
- Prolonged
- Dopamine receptor blocking tranquilizers
_____ is Greek for delayed, and dyskinesia is Greek for _____.
- Tardive
- Bad movement
The popularity of dopamine-receptor-blocking tranquillizers (haloperidol, metoclopramide, etc.) makes _____ a common disorder of movement.
- Tardive dyskinesia
Drug induced Parkinsonism, which mostly affects the limbs, is an order of magnitude less common than _____, which mostly affects the facial muscles.
- Tardive dyskinesia
The first sign of tardive dyskinesia is twitching of the _____.
- Facial muscles
Whereas Parkinson’s disease is caused by death of neurons in the _____, Huntington’s disease (or Huntington’s chorea) is caused by death of neurons in the putamen.
- Substantia nigra
If the indirect circuit neurons (D2) in the putamen die, the neurons in the lateral globus pallidus will _____ the neurons in the subthalamic nucleus, and the neurons in the subthalamic nucleus will not _____ the neurons in the medial globus pallidus.
- Inhibit
- Stimulate
If the direct circuit neurons (D1) in the putamen die, the neurons in the medial globus pallidus will
_____.
- Not be inhibited
If the medial globus pallidus is neither stimulated nor inhibited, it will have only the very small inhibitory effect on the _____ nucleus due to its own spontaneous activity.
- Ventral anterior
Thus, death of the putamen will result in a small amount of spontaneous activity in the slightly inhibited _____ of the _____.
- Ventral anterior nucleus
- Thalamus
The death of the putamen in Huntington’s disease results in small unwanted _____.
- Movement
Huntington’s disease caused by an autosomal dominant gene that causes death of neurons in the _____ and, much later, in the rest of the brain.
- Putamen
Because the Huntington’s disease gene is _____, either parent can pass the gene on to a child of either gender.
- Autosomal
The symptoms of Huntington’s disease appear in middle age after one has already had a 50% chance of passing on the _____.
- Autosomal dominant gene
Huntington’s disease is characterized by many _____.
- Small unwanted movements
The unwanted movements in _____ are smaller in scale than the unwanted movements in hemiballismus because the net stimulatory effect of the direct circuit neurons on the ventral anterior nucleus is still present in hemiballismus.
- Huntington’s Disease
If the putamen is sick rather than dead, the _____ will be smoother than in Huntington’s disease and they will disappear when the putamen _____.
- Unwanted movements
- Recovers
Sydenham’s chorea (Greek: chorea=dance) is temporary unwanted movement due to suppression of activity in the _____ by scarlet fever.
- Putamen
Sydenham’s chorea may last for a year after a bout of _____.
- Scarlet Fever
The unwanted movement in _____ is smooth and dance-like.
- Sydenham’s Chorea
Sydenham’s chorea is an uncommon sequel of _____; Huntington’s disease is a rare and fatal _____ disorder.
- Scarlet Fever
- Hereditary
Patients usually recover from _____, they always die from _____.
- Sydenham’s Chorea
- Huntington’s Disease
The cholinergic neurons in the putamen have the net effect of _____ movement.
- Inhibiting
A deficiency of cholinergic neurons in the putamen or caudare leads to _____.
- Unwanted movement
Tourette’s syndrome is vocal and facial tics due to a hereditary deficiency of _____ in the head of the caudate nucleus.
- Cholinergic neurons
The unintended vocalizations in _____ syndrome are due to a hereditary deficiency of cholinergic neurons in the _____ of the _____ which controls vocalization.
- Tourette’s
- Head
- Caudate nucleus
The tics in Tourette’s syndrome are exacerbated by activation of the direct basal motor circuit and suppression of the indirect circuit by _____.
- Dopamine
_____ syndrome involves tics, mostly of the facial muscles, and unwanted vocal outbursts while awake.
- Tourette’s
Since the coincidence of Tourette’s syndrome in identical twins is only 75%, the genes that cause it require _____ factors for expression.
- Environmental
Tourette’s syndrome is caused by several _____ with variable penetrance.
- Genes
Restless legs syndrome (a.k.a. Willis-Ekbom disease) is the only hyperkinetic disorder of movement that is not due to malfunction of the _____.
- Basal motor nuclei
Restless legs syndrome is due to _____ in the pontine reticular formation due to a common hereditary defect in the D3 receptor.
- Hyperactivity
The defective _____ receptor fails to inhibit leg extensions when dopamine levels fall during sleep.
- D3
Although the defective _____ is recessive, it is common enough to make restless legs the most common disorder of movement.
- D3 gene
There are 3 hereditary disorders of movement: _____, _____, and _____. All are hyperkinesias.
- Tourette’s Syndrome
- Huntington’s Chorea
- Restless Leg Syndrome
_____ is progressive and fatal.
- Huntington’s Chorea
_____ produces facial and vocal tics while awake.
- Tourette’s Syndrome
_____ produces kicks during sleep.
- Restless Leg Syndrome
_____ is an uncommon sequela of scarlet fever.
- Sydenham’s Chorea
Sydenham’s chorea usually disappears in about _____, but antibiotics are usually given to prevent recurrence.
- 1 year
Huntington’s chorea and Sydenham’s chorea are due to failure of a damaged _____ to prevent _____.
- Putamen
- Unwanted movement
Huntington’s chorea and Sydenham’s chorea are due to insufficient activity of _____ neurons in the _____.
- D2
- Putamen
Parkinson’s disease is due to excessive activity of _____ neurons in the _____.
- D2
- Putamen
Parkinson’s disease is due to failure of the _____ neurons in the substantia nigra to inhibit the _____ neurons in the _____.
- Dopaminergic
- D2
- Putamen
Tardive dyskinesia is due to the _____ receptive neurons in the _____ becoming hypersensitive to _____ as they habituate to _____ receptor blockers.
- Dopamine
- Putamen
- Dopamine
- Dopamine
Hemiballism is usually due to a stroke affecting the _____.
- Subthalamic nucleus