parkinson's disease Flashcards
what is PD
- the most common serious movement disorder
- a degenerative condition of the basal ganglia
pathophysiology of PD
- synucleiopathy
- degeneration of dopaminergic neurons in substantia nigra of midbrain
synucleiopathy
neurodegenerative diseases characterised by the abnormal accumulation of aggregates of alpha-synuclein protein
?% of neurons die before the disease is clinically apparent
70-80%
is PD’s onset gradual or rapid
gradual
is PD’s progression gradual or rapid
gradual
is PD symmetrical or asymmetrical
asymmetrical
most common initial feature of PD
resting tremor in one hand (pill rolling)
prevalence of PD
- increases with age
- 40 in 100,000 (40-49 y/o)
- 1900 in 100,000 (> 80 y/o)
rising PD prevalence with ?
age and men
rising PD incidence with ?
men
? people with PD in ROI
estimated 12,000 (no published prevalence studies)
PD is set to ? in 20 years
double
PD prognosis
- reduces life expectancy
- 24-40% develop dementia
untreated PD patients prognosis (historically)
- severely disabling degree of immobility
- risk of bronchopneumonia, septicemia, or pulmonary embolus after 7-10 years
?% of PD patients with develop dementia
25-40%
why does dementia develop in PD
spread of degeneration and Lewy bodies to the cerebral cortex and limbic structures
factors that influence the risk of dementia in PD
- age of onset
- disease duration/severity
- APOE genotype
what is largely responsible for reduced life expectancy in PD
dementia
treatments are ?
symptomatic but improve life expectancy
causes of secondary parkinsonism
- drug induced
- post encephalitis
- post head injury
types of atypical parkinsonian syndromes
- progressive supranuclear palsy (PSP)
- multiple systems atrophy (MSA)
- corticobasal syndrome (CBS)
- dementia with lewy bodies (DLB)
IPD is ?% of all parkinonism
≥80%
types of parkinsonisms
- ideopathic parkinson’s disease (IPD)
- secondary parkinsonism
- atypical parkinsonian syndromes
in IPD, what is consistent with increased prevalence
age after 50 (steady) and 60 (steep)
cause of IPD (genes, etc.)
- unknown
- environmental and genetic factors implicated
family history in ?% of IPD
20-30%
IPD onset before 30 suggests ?
hereditary form on parkinsonism
cardinal features of IPD
TRAP
- tremor
- rigidity
- akinesia/bradykinesia
- postural instability
tremor in IPD
- usually at rest
- pill rolling common
- disappears with action and during sleep
rigidity in IPD
- increased muscle tone
- increased resistance to movement
akinesia/bradykinesia in IPD
slowness in initiation and execution of movements
postural instability in IPD
causes falls
motor symptoms of PD
- tremor, bradykinesia, rigidity, postural instability
- dysarthria, dysphagia, sialorrhea
- decreased arm swing, shuffling gait, festination
- micrographia, curring food, feeding, hygiene, slow ADL
non-motor symptoms of PD
- cognitive impairment, WFD
- depression, apathy, fatigue
- sensory symptoms (anosmia, pain, paresthesias)
- dysautonomia (orthostatic hypotension, constipation, urinary and sexual dysfunction, abnormal sweating), weight loss
- sleep disorders (REM behaviors, vivid dreams, daytime drowsiness, restless leg syndrome)
how to diagnose PD
- clinical diagnosis
- no definitive test
who diagnoses PD
neurologists
timeframe to diagnose PD (and why)
- 5+ years
- to distinguish from other parkinsonisms
types of diagnostic criterias for PD
- UK Brain Bank Criteria
- MDS Clinical Diagnostic Criteria for Parkinson’s Disease
what to consider when diagnosing PD
- hallmark clinical features (TRAP)
- neuroimaging to exclude other conditions
- response to treatment
why is correct diagnosis important
prognostic and therapeutic reasons
?% of patients are incorrectly diagnosed
25%
common reasons for misdiagnosis of PD
presence of essential tremor, vascular parkinsonism, and atypical parkinsonian syndromes
when should PD diagnosis be reviewed
- regularly
- if atypical features develop
single photon emission computed tomography (SPECT)
- medical imaging technique
- find issues with blood flow in the brain
- diagnose or check on vascular brain disorders
UK Brain Bank Criteria
Step 1
- bradykinesia
- rigidity, resting tremor, or posural instability
Step 2
- exclude other causes of parkinsonism
Step 3
- (at least 3) unilateral onset, resting tremor, progressive, persistent asymmetry, good response to levodopa, levodopa-induced dyskinesia
differential PD diagnosis includes
- essential tremor
- atypical parkinsonian syndromes
- alzheimer’s disease
- cerebro-vascular disease
PD assessment/rating scales
- Unified Parkinson’s Disease Rating Scale
- Hoehn and Yahr Scale
- Modified Hoehn and Yahr Scale
Unified Parkinson’s Disease Rating Scale
- more holistic assessment
- mentation, behavior, and mood (intellectual impairment, thought disorder, depression, motivation)
- ADL (speech, salivation, swallowing)
Hoehn and Yahr Scale
- impairment-based assessment
- scale from 1-5
- 1: unilateral involvement only
- 5: wheelchair bound or bedridden unless aided
PD treatment
- no cure
- symptomatic
PD treatment is aimed at ?
restoring neurochemical balance
PD treatment is best delayed until when and why)
- until symptoms (functional, occupational, or social) warrant it
- due to drug side effects
3 most common PD medications
- levodopa
- dopamine agonist
- enzyme inhibitors
levodopa
- gold standard
- replaces dopamine
- chemical building block that the body converts into dopamine
- cross blood brain barrier to reach site of action after oral administration
dopamine agonist
acts like dopamine to stimulate nerve cells
enzyme inhibitors
prevents breakdown of dopamine
less common PD medications
- anticholinergics and amantadine
- apomorphine
- glutamate antagonist
- COMT inhibits
- MAO-B inhibitors
anticholinergic and amantadine
used for treatment of tremor
apomorphone
a strong subcutaneous/infusion dopamine agonist
which PD medication can lead to impulsive/compulsive behavior (e.g. gambling)
- dopamine agonists
- levodopa
levodopa efficacy limited by
complications of motor fluctuations and dyskinesias after 2-5 years
levodopa motor fluctuations
- wearing off (doses produce short-lived effects and return of symptoms before next dose)
- unpredictable switch from medication benefit (on) and an akinetic-rigid state (off)
dyskinesias
involuntary movements associated with drug treatment
2 drug-related dyskinesias and symptoms
- peak dose dyskinesia (high dopamine; twisting, turning movements)
- wearing off dystonia (low dopamine; painful, sustained muscle contractions)
where do wearing off dystonias usually occur
in the feet
how many times is levodopa usually taken in a day
3 around meal times
how does levodopa progress with the disease (and why)
- higher, more frequent levodopa doses are needed
- due to decreasing short and long duration responses to medication and an inability to store excess dopamine
- therapeutic window of meds without dyskinesias narrow
primary surgical intervention
deep brain stimulation (DBS)
surgical intervention for PD
- will not stop disease progression
- may control movement symptoms
- strict candidacy criteria
how does deep brain stimulation (DBS) effect speech
- benefit on voice and speech quality is controversial
- varies between studies
- can worsen slurred speech, social interaction, and dysarthria subsystems
MDT members
- neurology/GP
- CNS
- SLT
- OT
- PT
- dietician
- SW
- neuropsychologist
- pharmacist
SLT managment in PD
- communication (speech, voice, language)
- FEDS
- specialist AAC
- capacity assessment
- assessment for DBS
- education, support, and counselling
- drooling
typical dysarthria in PD
hypokinetic dysarthria
hypokinetic dysarthria
- low volume
- imprecise articulation
- dysphonia
- monotone
- monopitch
- abnormal rate
- palilalia
speech assessments for PD
- AIDS
- frenchay dysarthria Ax
- UPDRS
- dysarthria impact profile
- record a speech sample
speech treatment for PD
- pacing boards
- rate control drills
- increased respiratory support
- increased vocal fold adduction
- increasing stress
- focus on speech subsystems
- LSVT
LSVT
- Lee Silverman Voice Treatment
- focused on 1 speech subsystem (minimum cognitive load)
- high effort intensive treatment
- high level evidence
- long term carryover
- treat phonation first
- impact on rate, articulation, resonance
direct effects of LSVT
- deep breath
- open mouth
- improved articulation
- reduce rate
indirect effects of LSVT
- improved vocal cord adduction
- improved facial expression
- reduced vocal instability (e.g. tremor)
- improved swallow
dysphagia PD may involve which phases of swallowing
oral, pharyngeal, or esophageal phases
dysphagia may be present in ? stage of the disease
every stage
dysphagia in PD is associated with ?
increased risk of aspiration pneumonia and mortality
what is the main cause of death in IPD
pneumonia
in PD what factors independently contribute to dysphagia
- age
- disease duration
- dementia
clinical evaluation components
- case history
- presentation
- OMA
- swallow trials
PD case history
- time since diagnosis
- rate of progression
- comorbid symptoms/conditions
