Parkinson's disease Flashcards
what is Parkinson’s
a neurodegenerative condition resulting in the death of dopamine containing cells in the substantia nigra (in the basal ganglia)
what is the pathophysiology of Parkinson’s Disease
a disorder of the basal ganglia and the loss of dopamine neurons in the substantia nigra pars compacta
what is dopamine
a natural neurotransmitter found in the brain that plays a major role in communicating across systems
what are the 2 main pathways that initiate/ prevent movement in the basal ganglia
- direct pathway
- indirect pathway
what is the direct pathway
excitatory pathway
- stimulates movements
what is the indirect pathway
inhibitory pathway
- inhibtis movements
common motor symptoms of Parkinon’s
- tremors
- rigidity/ lead pipe arm (stiff muscles moving through full range and stiffness remains constant at any speed)
- spacticity - if speed increases then will become more stiff (cogwheel - juddering effect)
- bradykinesia
- postural instability
- walking difficulties e.g. start hesitation, short shuffling steps
- freezing during movements
- loss of expression - face can freeze so stays the same (masked face)
- speech problems
what is bradykinesia
slowness of movement ad speed
or
progressive hesitations/ halts as movements are continued
what is the usual postural instability
usually hunched which moves centre of mass forward which can cause impaired walking
what speech problems do parkinsons patients have
- Softened voice.
- Reduced volume to your voice.
- Speaking in an unchanging pitch (monotone).
common non-motor impairment symptoms of Parkinson’s disease
- cognitive decline
- mood changes
- loss of smell
- sleep dysfunction: insomnia, nightmares, sleep walking
- constipation
- anxiety/ depression
why does Parkinson’s disease cause symptoms
- nerve cells containing dopamine in the basal ganglia (an area of the brain that controls movement) become impaired and/or die
- dopamine is a neurotrasnmitter so without it, signals sent from the brain down the efferent pathway can be interrupted or not sent altogether.
- the same goes for the afferent pathways
describe the diagnosis of parkinson’s
- difficult to detect in early stages
- has various stages of development
- needs functional imaging (SPECT & PET scans)
how is Parkinson’s managed medically
- using drugs to relieve symptoms however the pathological process cannot be halted
why is levodopa used as a drug for parkinson’s patients
converts into dopamine
- having more dopamine in the body will mean that more signals can be sent up afferent pathway and down efferent pathway to minimis symptoms
why are dopamine agonsists used as a drug for Parkinson’s patients
it mimics the effects of dopamine
why are COMT inhibitors used as a PD medication
COMT is an enzyme in the body
- when a person takes levodopa, COMT can deactivate levodopa before it enters the brain and CNS, so COMT inhibtors prevent this from happening
why are Mao-B inhibtors used as PD medication
MAO-B enzymes naturally break down severla chemicals in the brain, including dopamine, inhibting this process makes mroe dopamine available
why is deep brain stimulation used as a medication for PD
- electrodes are inserted into a targeted area of the brain, using MRI and, at times, recording of brain cell activity during the procedure.
- a second procedure is performed to implant an impulse generator battery which is similar to a heart pacemaker and approximately the size of a stopwatch. It is places under the collarbone or in the abdomen and delivers an electrical stimulation to targeted area of the brain that control movement.
why is the benefit of physiotherapy to a PD patient
- stretching can improve ROM - postural muscles become stiff which causes hunched posture so can be improved
- falls prevention
- improve mobility
- cueing - audible visual
- aids and adaptions
- onwards referral: long term conditions
- increase indenpendence of patient
- family support
- education
Why does death of dopamine containing cells in the brain cause Parkinson’s disease symptoms?
There’s not enough dopamine to regulate the direct and indirect pathways
why might parkinson’s patients have a hunched back
no impulses to stand up straight sent down efferent pathway form basal ganglia due to lack of dopamine neaurons
why do Parkinons patients have a masked face
a lack of dopamine in the brain can stop your facial muscles working as impulses arent carried through to the muscles
