Parkinson's Disease Flashcards
what are the parts of the basal ganglia
- caudate
- putamen
- globus pallidus
- Subthalamic nucleus
- substantia nigra
- striatum
describe the direct pathway
- Turns up motor activity and due to disinhibition
- thinking about movement in cortex
- causes excitation in striatum
- which inhibits the inhibition of the globus pallidus on the motor thalamus
- the motor thalamus excites the motor cortex allowing for movement
Describe the indirect pathway
in the basal ganglia
- the globus pallidus internus inhibits motor thalamus there for decreasing excitatory thalams input to cortext and TURNS DOWN motor activity
- subthalamic nucleus excites inhition of motor thalamus
- cortext excites striatum which inhibits the globus pallidus externus
- which inhibits the subthalamic nucleus which excites the globus pallidus internus
Striatal interneurons cholinergic
- uses dopamine and ACh used within the basal ganglion
- ACh can be excitatory or inhibitory depending on receptor
- this turns down direct pathway and turns up indirect pathway = less motor activity
Neurotransmitters that can affect the basal ganglia
- Glutamate (+)
- GABA (-)
- Dopamine (+/-)
- Acetlycholine (+/-)
Thalamus
- reduced inhibition of motor nuclei of thalamus: you get voluntary movement
Pedunculopontine Nucleus
- reduced inhibition increases activitiy of PPN
- directly stimulates LMN/involved with postural control
- gets information and sends it to motor cortex
- stimulates: reticulospinal tract, vestibulospinal tract, LMN for postural control
Motor control of complex movements
- basal ganglia activated by sensorimotor assoication areas
- perception of environment used to make movement
- striatum stores movement programs for complex voluntary movements
- CPG may be stored in basal ganglion
- any motor circuits for tasks is stored in basal ganglia
complex movements
- movement programs in striatum are modified by reciprocal connections
- striatum with substantia nigra
- globus pallidus with subthalamic nuceli
- all parts work together
Basal ganglia disorders
generally cause what kinds of physiological issues
- loss of balance of excitation/inhibition
- loss of control exerted on striatum
- loss of control exerted on globus pallidus
- loss of control exerted on motor thalamus and PPN
Parkinson’s disease what are symptoms related to
caused by/pathophysiology
- motor symptoms
- symptoms related to decreased in dopamine due to degeneration of neurons in substantia
nigra compacta - development of alpha-synuclein deposts, lewy body
- development of abnormal proteins that imped transmission (usually develop years before symptoms start)
Parkinsons
Brain pathology stage
- stage 1: olfactory bulb, CN I, CN IX, CN X (changes in smell, vitals, orthostatic hypotension
- Stage 2: pons - CN 5-8 chewing, fascial expression, vestibular symptoms
- Stage 3: substantia nigra - start to see motor symptoms due to dopamine production
- Stage 4: hypothalamus, thalamus, cortex (thinking, weight control, BP)
- Stage 5: sensory assoication areas, prefrontal cortex (personality, execuative function)
- Stage 6: primary motor and sensory cortex
Parkinson’s disease
symptoms
- hypokinesia: less movement/little movement
- akinesia: no movement
- bradykinesia: slow movement
- tremor: resting ususally
- abnormal postural adjustments
- rigidity: no spasticity, no velocty dependent and usually in both directions
Parkinson’s disease
other signs/symptoms
- gait abnormalities (freezing/festinating gait)
- micrographia: writing gets really small
- swallowing impairments/dysphagia: thick liquids to give time to swallow
- speech impairments
Parkin’s disease
non motor symptoms
- REM sleep: hard time falling/staying asleep
- cognition-related disorders: visual-perception impairments
- mood related disorders: depression, anxiety, apathy
- sensory dysfunction: loss of taste, smell, GI symptoms (fullness/consitpation)
- Dysautonomia: orthostatic hypotension
Parkinson’s disease
what do symptoms result in
decreased movement initiation/reaction time related to
- inadequate force generation
- decreased rate of force generation
- insufficient ROM to allow movement
- reduced motivation to move
- abnormal postural control
Parkinson’s disease rating:
minimal assist; tremor unilateral if present
stage 1
can help stay in stage 2-3 with exercise
Parkinson’s disease rating:
minimal bilateral or midline involvement balance not impaired
stage 2
make see some patients in this stage
can help stay in stage 2-3 with exercise
Parkinson’s disease rating:
impaired righting reflexes, unsteadiness when turning or rising from chair
some activities are restricted but patient can live indpendently and continue some forms of employment
- stage 3
- usually when we see them
can help stay in stage 2-3 with exercise
Parkinson’s disease rating:
all symptoms present and severe
standing and walking possible only with assistance
- stage 4
can help stay in stage 2-3 with exercise
Parkinson’s disease rating:
confined to bed or wheelchair
- stage 5
can help stay in stage 2-3 with exercise
Parkinson’s treatment
medication
- increase dopamine levels via levadopa (L-dopa, sinemet, rytari)
- meds + PT
Other medications for parkinson’s disease
- Dopamine agonists (mirapex, Requip): if you want to use your own dopamine maybe able to stay in 2-3 functioning level
- COMT inhibitors: breaks down dopamine
- MAO-B inhibitors
- Anticholinergics: reduce parasympathetic/unwanted movement
- cholinesterase inhibitors: allows Ach to act longer usually for cognition
- Amantidine: affects basal ganglia-limits dyskinesia
- Adenosine receptor antagonist: keeps dopamine in your system longer
- Pimavanserin for psychosis
Parkinson’s treatment DBS
- surgery: deep brain stimulation
- deep brain stimulation - pt is awake during surgery
