Parkinson's Disease Flashcards
Definition of PD
Neurodegenerative disease and movement disorder caused by degeneration of dopaminergic neurons in the substantia nigra
Area of NS affected
CNS: basal ganglia (substantia nigra) degeneration.
Extrapyramidal pathway affected
Epidemiology of PD
- Incidence: 4 per 100,000 in 20-49 years. 196 per 100,000 in 85-89 years.
- Prevalence: increases with age. Overall 100-180 per 100,000. 40 per 100,000 in 40-49 years. 1,900 per 100,000 80+ years.
- Higher incidence/prevalence in males
- 6 million worldwide
- 12,000 in Ireland
Cause of PD
- Synucleinopathy (neurodegenerative diseases characterised by the abnormal accumulation of aggregates of alpha-synuclein protein in neurons)
- Multifactorial: mix o genetic and environmental factors (pesticides, herbicides, MPTP)
- Family history in 20-30%
Course of PD
Gradual onset and progression. Early signs include tremor, bradykinesia, rigidity, hypophonia.
1. Preclinical
2. Prodromal
3. Clinical phase
Prognosis of PD
- PD reduces life expectancy (largely due to dementia)
- About 25–40% of the patients with PD eventually develop dementia
- Risk of dementia is 1·7–5·9 times higher in pts with PD than in healthy people
- Risk factors for dementia include: age at onset, disease duration or severity, APOE genotype.
Cardinal features of PD
TRAP
*Tremor – usually a tremor at rest (pill
rolling). Typically disappears with
action and during sleep
*Rigidity – Increased muscle tone and
increased resistance to movement
*Akinesia/Bradykinesia – Slowness in
initiation and execution of
movements
*Postural instability – causes falls
*Other - freezing
Motor symptoms of PD
- Tremor, bradykinesia, rigidity, postural instability
- Hypomimia (reduced faciala expression), dysarthria, dysphagia, sialorrhea
- Shuffling gait
- Micrographia
Non-motor symptoms of PD
- Cognitive impairment, bradyphrenia, WFDs
- Depression, apathy
- Sensory: anosmia, ageusia, pain, parasthesias
- Dysautonomia
- Sleep disorders
what is bradyphrenia?
Slowness of thought, delayed responses and lack of motivation
what is anosmia?
loss of smell
what is ageusia?
loss of taste
Diagnosing PD
- Usually diagnosed by an experienced neurologist typically over at least a five
year period
- UK Brain Bank Criteria
- MDS Clinical Diagnostic Criteria for Parkinson’s Disease
- National Institute of Neurological Disorders and Stroke (NINDS) diagnostic criteria for PD
Consider:
1. Hallmark clinical features
2. Neuroimaging to exclude other conditions only
3. Response to drug treatment
Rating Scales for PD
*Unified Parkinson’s Disease Rating Scale
*Hoehn and Yahr Scale
Treatment for PD
- Symptom-management
- Aimed at restoring neurochemical balance either by anticholinergic agents or with drugs that enhance dopaminergic pathway
- Best delayed until symptoms warrant it due to drug side effects.
- Pharmacological
- Surgical
- Rehabilitation
Medication for PD
- Levodopa: Gold Standard, chemical building-block that your body converts into dopamine.
- Dopamine Agonist: act like dopamine to stimulate nerve cells
- Enzyme Inhibitors: Prevent breakdown of dopamine.
Others:
* Anticholinergics and Amantadine – used for treatment of tremor
* Apomorphine (a strong subcutaneous/infusion dopamine agonist)
* Glutamate antagonist (e.g., Amantadine- mild effect)
* COMT inhibitors (e.g., Comtess- block enzyme breaking down levodopa)
* MAO-B inhibitors (e.g., Selegine, block an enzyme preventing breakdown of dopamine)
* Some PD medication (dopamine agonists & levodopa) can lead to impulsive/ compulsive behaviour (ICD)
e.g. excessive shopping, gambling
How does L-Dopa work?
- Natural substrate for the synthesis of dopamine
- Able to cross blood brain barrier so can reach its site of action following oral administration
- Effect on speech/swallowing
Efficacy limited after 2-5 years by:
1. Motor fluctuations: “on-off” is unpredictable - switch from benefit from medication (“on”) to an akinetic-rigid state (“off”)
2. Dyskinesias: involuntary movements occurring in association with drug treatment
Surgical tx for PD
- Deep Brain Stimulation: requires thorough case hx to determine if appropriate.
- Benefit of DBS on voice and speech quality varies between studies.
- Patients can report more severe symptoms such as: exacerbation of slurred speech, adverse impact on rhythm, intonation, articulation
and intelligibility, interference with social interaction.
Role of SLT
- Communication: speech, voice, language ax and tx.
- Eating, drinking, swallowing ax and tx
- AAC
- Capacity ax
- Ax for Deep Brain Stimulation
- Education , support and counselling
Features of dysarthria in PD
Hypokinetic dysarthria:
* Low volume
* Imprecise articulation
* Dysphonia
* Monotone
* Monopitch
* Abnormal rate
* Palilalia (involuntary repetition of syllables)
Speech ax tools for PD
- AIDS
- Frenchay AX
- UPDRS subsection
- DIP
- Speech sample
Speech tx for PD
Traditional therapy:
*Pacing boards
*Rate control drills
*Increased respiratory support
*Increased vocal cord adduction
*Increasing stress
*Focus on subsystems
*LSVT
Dysphagia in PD
- May involve oral, pharyngeal or
oesophageal phases of swallowing - May be present in every stage of the disease.
- Associated with increased risk of aspiration pneumonia and mortality
- Variability in rate of dysphagia reported in literature: 18.5% to 100%
- Pneumonia is a main cause of death in IPD (4- 30%)
- Age, disease duration and dementia all seem to contribute.
Clinical evaluation for PD:
- Case history
- Presentation
- Oro-facial
- Swallow trials
Case history
- Time since PD diagnosis
- Rate of progression
- Comorbid symptoms/conditions
- Pharmacological Tx of PD
- Response to medications
- Surgical Tx
- Chest status
- ?weight loss
- Time taken to complete meals?
- Choking episodes?
- Avoiding certain foods?
- Swallowing tablets?
Presentation
- Alertness
- Posture/positioning
- Mobility
- Cognition/memory
- Language (able to give report?)
- Feeding ability (i.e. Tremor?
Dyskinesia?) - Salivary control
- Confusion
- Hypokinetic dysarthria?
- Impact of dysphagia on QOL
Oro-facial
- Masked facial expression?
- Open mouth posture?
- Involuntary movements?
- Dry oral muscosa
- Drooling?
- Tardive dyskinesia?
- Dentition
- Rate & range of lingual movement?
- Rule out asymmetry
- Voice quality
- Cough response (vol/spon)
Swallow trials
- Self-feeding ability?
- Rate of feeding?
- Anterior spillage?
- Delayed oral phase? (tongue
pumping) - Prompt pharyngeal swallow?
- Weak hyo-laryngeal excursion?
- Cough response?
- Voice quality post swallow?
- Oral residue? (ant/lat sulci)
- Time taken to complete?
- Effort involved?
- Improvement with volume/taste
Common VFS findings
Oral prep/oral phase
* anterior spillage of fluids
* repetitive tongue pumping
* prolongation of oral transit time
* difficulty with bolus formation
* impaired mastication
* difficulty initiating swallow
* premature spillage of material
into pharynx
* residue post swallow on the
tongue surface, in lateral sulci
and in the vallecular sinuses
Pharyngeal phase:
* delayed pharyngeal initiation of
swallow
* reduced pharyngeal peristalsis
* reduced posterior motion of the
tongue base towards PPW, leading
to residue both in the valleculae
* reduced hyo-laryngeal excursion
leading to residue in pyriform
sinuses
* silent aspiration on fluids before
swallow due to pharyngeal reflex
delay
* Benefit from chin tuck/smaller
volumes of fluid,
taste/temperature changes
Dysphagia tx for PD
- Timing of medication (L-Dopa)
- Postural changes (e.g. chin tuck)
- Compensation (e.g. volume change)
- Lip, tongue & laryngeal elevation exercises?? (Logemann
1998) - Diet modification (e.g. thickened drink)
- Biofeedback (sEMG)
- Verbal cueing
- Sensory stimulation (iced water, sour taste)
- LSVT (El Sharkawi et al, 2003)
- Expiratory Muscle Strength Training (EMST)
Drooling in PD
- Involuntary loss of saliva- social embarrassment
- 56% (32-74% range) prevalence of drooling in PD based
on 8 studies in a systematic review
Management options include:
* Swallow reminder device
* Sour sweets
* Chewing gum
* Dysphagia Treatment
* Postural changes
* Hyoscine patch
* Botox to parotid glands
* Radiation to salivary glands
Atypical Parkinsonian Syndromes (APS)
- Encompass a collective of rare neurodegenerative diseases including:
- Progressive supranuclear palsy (PSP)
- Multiple system atrophy (MSA)
- Corticobasal syndrome (CBS)
- Dementia with Lewy Bodies (DLB)
- Characterised by rapid disease progression and decreased life expectancy (Roach et al.,
2020) - Can be particularly debilitating and are not yet well understood
- Dysarthria or dysphagia within 1 year of disease onset was a distinguishing feature for
APS (specificity, 100%) (Muller et al 2001)
Progressive Supranuclear Palsy
- Rare progressive disease causing degeneration of neurons in the brainstem, basal
ganglia and cerebellum
Typically characterised by:
* Postural instability – tend to fall backward
* Supranuclear vertical gaze palsy leading to impaired vision
* Dementia
* Dysarthria
* Dysphagia
Two subtypes: Richardson syndrome (PSP-RS) and PSP-parkinsonism (PSP-P)
- Poor prognosis: Rapidly progressive, mean duration of survival of 10 years
- Cause: Tauopathy
- Average age of onset in the mid-60s
- Disease duration approximately 6-9 years
PSP vs PD
PD:
*Cause: dopamine loss in substantia nigra
*Tremor: present
*Eye movement: normal
*Cognitive decline: gradual
*Response to Levodopa: good response
*Prognosis: slow progression
PSP:
*Cause: tau protein accumulation
*Tremor: absent
*Eye movement: vertical gaze palsy
*Cognitive decline: early executive dysfunction and dementia
*Response to Levodopa: poor
*Prognosis: rapid
Dysphagia in PSP
- PSP is associated with early onset of dysphagia when compared with IPD
- Aspiration pneumonia is the principal cause of death
Speech in PSP
- Hypokinetic and mixed
hypokinetic–spastic dysarthria
observed most frequently - AOS sometimes present (19.5%)
Main features of PSP
Onset in 6th to 7th decade
* More men than women affected
* Initial features loss of balance,
gait disorder & falling
* Akinetic-rigid state with
symmetrical signs & prominent
axial rigidity follows
* Trunk & neck hyperextended
* Wide-eyed stare
* Furrowing of forehead
* Deepening of other facial
creases
* Pseudobulbar palsy
* Dysarthria
* Dysphagia
* Frontal lobe features
* Dementia
What is multiple systems atrophy?
- Synucleinopathy
- Affects balance, movement and the autonomic nervous system.
- REM, muscle stiffness and behaviour changes
- Prevalence ranging from 31%-78%
- Mixed dysarthria with combinations of hypokinetic, ataxic, and spastic components
Dementia with Lewy Bodies
- Synucleinopathy
- Fluctuating cognition with pronounced variations in attention and alertness
- Recurrent visual hallucinations
- REM sleep behaviour disorder which may precede cognitive decline
- One or more spontaneous cardinal feature of parkinsonism –
bradykinesia, rest tremor, or rigidity - Hypophonic/monotonous speech predominated in DLB
Corticobasal Syndrome (CBS)
- Tauopathy
- Characterised by involuntary movements including
rigidity, tremor, dystonia, and myoclonus - Often associated with apraxia, cortical sensory deficits,
and alien limb phenomena - Condition typically affects one side of the body more
than the other and makes it difficult for patients to see
and navigate through space
Dual Tasking/Divided Attention in Parkinson’s Disease (PD)
Challenges in Dual-Tasking in PD
*Motor Impairment
*Cognitive Dysfunction
*Basal Ganglia Dysfunction
*Decreased Automaticity: more conscious effort, competing with cognitive tasks.
Effects of Dual-Tasking in PD
*Motor Task Impairment: Slower walking, poor coordination, and increased falls when combining motor and cognitive tasks
*Cognitive Task Impairment: worsens during simultaneous motor tasks.
*Freezing of Gait (FOG): Episodes of freezing are more likely when multitasking.
*Increased Cognitive Load
Research Findings
*Slower Gait: Slower walking speed when performing cognitive tasks simultaneously.
*Worsened Gait/Balance
*FOG Triggers
*Levodopa Effects: improves motor function but may not significantly improve dual-tasking performance; cognitive function may remain impaired or worsen.
Strategies to Improve Dual-Task Performance
*Physical Therapy
*Cognitive Training
*Compensatory Strategies: Use task simplification, prioritization, and external cues to aid multitasking.
*Assistive Devices: Use canes, walkers, or specialized shoes to reduce falls and support dual-tasking.
*Controlled Dual-Task Training: Structured practice in a safe environment to improve multitasking abilities.
