Flashcards in Chapter 11 Deck (67):
What is the basic function of the basal ganglia?
To modulate thalamo-cortical activity
What executive commands does the basal ganglia process?
Initiation of appropriate movement
Suppression of inappropriate movement
What are the structures of the basal ganglia?
located in the cerebrum
located in the cerebrum
located in the cerebrum
located within the diencephalon
located within the midbrain
globus pallidus and putamen
caudate and putamen
junction of caudate and putamen
part of ventral striatum
Where is dopamine from and to?
from substantia nigra to striatum
What is the role of dopamine?
adjusts the signals to the output nuclei; the output nuclei provide the appropriate level of inhibition to their target nuclei
What does output of the basal ganglia motor circuit regulate?
muscle contraction, muscle force, multijoint movements, and the sequence of movements
The basal ganglia effects movements through inhibition of:
ventrolateral pednculopontine nucelus (PPN)
midbrain locomotor region (MLR)
Basal ganglia inhibition of motor thalamus:
To provide an appropriate level of facilitation in the motor cortex (such as corticospinal tracts), and ultimately a normal level to the LMNs that innervate muscles for voluntary movements
Basal ganglia inhibition of ventrolateral pedunculopontine nucleus (PPN)
inhibit reticulospinal neurons which, in turn, provide the normal level facilitation to LMNs that innervate contraction of postural and girdle muscles, thus controlling muscle tone
Inhibition of midbrain locomotor region (MLR):
the midbrain locomotor region stimulates the reticulospinal neurons that activate central or stepping pattern generators (CPG or SPG), eliciting rhythmical lower limb movements similar to walking or running
Role of putamen:
receive input from premotor and motor cortex
Role of subthalamic nucleus and substantia nigra compacta:
process information within the basal ganglia circuit
Role of globus pallidus internus:
send output to motor areas of the cerebral cortex (via the motor thalamus), PPN and the midbrain locomotor region
Besides motor control, parts of the four basal ganglia-thalamic loops include:
behavioral flexibility and control
What do all five loops of the basal ganglia contribute to?
prediction of future events, selecting desired behaviors, preventing undesired behaviors, motor learning, shifting attention, and spatial working memory
Motor loop of basal ganglia:
movement selection and action
Where in the cerebral cortex does the motor loop go?
motor and premotor cortex
What basal ganglia is included in the motor loop?
putamen, globus pallidus
Which thalamic nuclei are included in the motor loop?
Role of oculomotor loop of basal ganglia?
decisions about eye movements and spatial attention; initiation of fast eye movements
Where in the cerebral cortex does the oculomotor loop go?
dorsolateral prefrontal cortex
What basal ganglia is included in the oculomotor loop?
head of caudate, globus pallidus
Which thalamic nuclei are included in the oculmotor loop?
Role of behavioral flexibility and control loop:
recognition of social disapproval, self-regulatory control, selecting relevant knowledge from irrelevant, maintaining attention, stimulus response learning
Where in the cerebral cortex does the behavioral flexibility and control loop go?
ventrolateral prefrontal and lateral orbital cortex
What basal ganglia is included in the behavioral flexibility and control loop?
head of caudate, substantia nigra reticularis
Which thalamic nuclei are included in the behavioral flexibility and control loop?
Role of limbic loop:
links limbic, cognitive and motor systems; identifies value of stimuli; involved in reward guided behaviors, monitors error in predictions, concerned with seeking pleasure
Where in the cerebral cortex does the limbic loop go?
medial orbital and medial prefrontal cortex
What basal ganglia is included in the limbic loop?
ventral striatum, ventral pallidum
Which thalamic nuclei are included in the limbic loop?
too little movement
What does excessive inhibition lead to?
What does inadequate inhibition result in?
What is the most common basal ganglia disorder?
What does parkinson's disease interfere with?
both voluntary and automatic movements
What are the three subtypes of Parkinson's disease?
akinetic or rigid
Motor symptoms of PD:
Non motor symptoms of PD
What is Unified PD Rating scale (UPDRS)
Is a clinical tool used to evaluate the course of PD,
PT intervention for PD:
Physical therapy/occupational therapy (PT/OT) improves mobility and functional status in individuals with Parkinson's disease.
Speech therapy is provided for voice training
PT for PD can reduce what symptoms:
Lack of coordination
Is the collective name for primary neuro-degenerative diseases that cause signs similar to PD
Parkinson-Plus Syndrome include:
progressive supranuclear palsy, dementia with Lewy bodies, and multiple system atrophy
Progressive supranuclear palsy (PSP)
Is characterized by the early onset of gait instability with a tendency to fall backward, axial rigidity, freezing of gait, depression, psychosis, rage attacks, and supranuclear gaze palsy
Dementia with Lewy bodies
Causes early, generalized cognitive decline, visual hallucinations, and Parkinsonism
Multiple system atrophy:
Is a progressive degenerative disease affecting the basal ganglia, cerebellar and autonomic systems; the peripheral nervous system; and the cerebral cortex
What is multiple system atrophy characterized by:
corticospinal tract dysfunction
Encompasses disorders with signs that mimic PD but the cause is known to be toxic, infectious, or traumatic
Signs of parkinsomism:
subacute, bilateral onset with rapid progression, early postural tremor, and involuntary movements of the face and mouth
Abnormal involuntary movements are characteristics of
Some types of cerebral palsy
Autosomal dominant hereditary disorder causes degeneration in many areas of the brain, most prominently in the striatum and cerebral cortex
Signs include dementia and chorea
Genetic, usually nonprogressive, movement disorders are characterized by involuntary sustained muscle contractions, causing abnormal posture, twisting, and repetitive movements
Causes vocal and motor tics.
Involves abrupt, repetitive, stereotyped movements
onset during childhood
Choreoathetotic Cerebral Palsy
a type of cerebral palsy
abnormal involuntary movements
associated with lesions involving both the basal ganglia and ventrolateral thalamus
abrupt, jerky movements