bgcc, cerebellar control circuit test 3 #1

Where is the basal ganglia control circuit (BGCC) located

located within deep brain tissue, just superior to the brainstem and cerebellum

the BGCC includes what structures

caudate nucleus

putamen

substantia nigra

globus pallidus

subthalamic nuclei

the entire BGCC has strong connections to the (?) and will regulate and influence many (?). It is thought to be especially important in (?)

1. frontal cortices

2. executive functions

3. working memory

working memory

ex:

an active system that stores and manipulates info at the same time

ex: following multi step directions. performing mental math

the bgcc depends on an accurate balance of many (?) amd what is the most prominent one?

1. neurotransmitters

2. dopamine

what is one of the most common disorders associated with a loss of dopamine in the BGCC especially in the substantia nigra

parkisons disease

the BGCC is important in the following

10 bullets

• motor control and coordination — its primary responsibility

• muscle tone

• memory especially working memory

• posture

• eye movements

• movements associated with goal-directed behavior

• gross and fine motor movements

• sequencing of movement

• new motor learning

in communication, the BGCC (like the UMN) serves as a source of (?) to the LMN

input

like the UMN, it too will refine the signal sent out by the LMN so that movements are ……

graded, smooth and flowing

in the BGCC movements are

sequenced and coordinated

loss of dopamine the BGCC may produce the following

(list shows clearly aligned with those observed in patients with parkisons’s disease)

• tremor

• Bradykinesia or slowness of movement

• Postural instability: Patients are frequently stooped.

• Unwanted and involuntary movements (not tremor-like)

• Cognitive-linguistic changes: Primarily within EF.

• Festinating gait/speech: Short, rapid-fire bursts of movement or speech. Speech sounds very pressed.

• Reduced arm swinging, especially when walking.

• Loss of heel-toe movements. Inability to direct the head towards a stimulus;instead, the person uses whole body movements to locate the stimulus.

other impairments

• masked like facial expressions

• difficulty initiating or stopping movements

• problems in regulating emotions and emotional control. paranoia may be common

• development of addictive behaviors

damage within the BGCC can give rise to two different types of movement disorders

• hypokinesia

• hyperkinesia

hypokinesia

too little movement

hyperkinesia

too much movement

hypokinesia is most closely associated with PD and may produce a type of dysarthria called

hypokinetic dysarthia

pd is caused by

a loss of the nuerotransmitter dopamine within the substantia nigra of the bgcc

hypokinetic dysarthria will most often affect the areas of

phonation

articulation

prosody

hypokinetic dysarthria phonation

voice is weak, breathy, thin, lacks intensity or loudness

hypokinetic dysarthria articulation

slow and imprecise

hypokinetic dysarthria prosody

monopitch

hyperkinesia or too much movement will manifest in two different types

1. chorea or choreatic movements

2. dystonia

both are unwanted and involuntary types of movements either can give rise to hyperkinetic dysarthria

chorea or choreatic movements

random, dancelike movements that affect prosody (monopitch) the most

both are unwanted and involuntary types of movements either can give rise to hyperkinetic dysarthria

dystonia

slow, sustained, repetitive movements that affect articulation (imprecision ) the most

both are unwanted and involuntary types of movements either can give rise to hyperkinetic dysarthria

Chorea (4 bullets

• dance-like, involuntary movements

• movements are random, rapid, unpredictable

• movement is constant

• face, trunk, nuck, extremities may all be involved

dystonia (4 bullets)

• slow movements

• movements are sustained. slower and repetitive

• movement may wax and wane

• focal, segmental or generalized movement

hyperkinesia is most often seen in

• huntingtons disease or chorea

• tardive dyskinesia

• tourettes syndrome

• brainstem stroke

what is huntingtons disease

• a genetic condition, adult or juvenile onset. first clinical indicators are radical changes in personality and mood, followed by declines in swallowing and cognitive- linguistic skills. movements are also affected

tardive dyskinesia

a condition that produces unwanted and involuntary movements in single muscles or groups of muscles secondary to the prolonged use of psychiatric drugs that are used to treat significant mental health conditions

• stopping the drugs will not alleviate the unwanted movements; they are permanent

cerebellum equals

little brain

cerebellum does what

• coordinates movements

• controls posture, balance and fine motor movement

• involved in motor learning

the cerebellum plays a large role in the coordination of

skeletal muscle activity

the cerebellum also serves as a source of (?) to the LMN by making sure that movements flow are

• input

• coordinated and are seamless and smooth

the cerebellum is especially important in fine motor control as it helps with

rapid, alternating muscle movements that are required for adequate speech production

the cerebellum is made up of 2 hemispheres that are joined by

a fibrous track called the vermis

the cerebellum has 3 lobes

anterior lobe

posterior lobe

flocculonodular lobe

anterior lobe

controls posture, gait or walking and truncal tone

posterior lobe

mediates skilled and finely-tuned movements

flocculondular lobe

regulates equilibrium or balance

trauma to the cerebellum may produce the following impairments

Ataxic dysarthria. Unlike other forms of dysarthria, irregular articulatory breakdowns will be present. Areas most compromised by this type of dysarthria are articulation and prosody.

• Articulation: Drunken-like quality to speech, slurred/slushy,.

• Prosody: Monopitch.

• Truncal gait or ataxic gait. Very unsteady, appear as if they are about to fall

nystagmus

• involuntary eye movements

• impairments of equilibrium and balance