Parkinson's Disease (PD) Overview

Parkinson Disease (PD) Overview

• PD's global burden is expected to double by 2040, becoming the fastest-growing neurologic disorder globally.

Physical Therapy Examination and Intervention

• Examining and intervening early can improve patient outcomes

Global Impact of PD

• Globally, 9.4 million people lived with PD in 2020, and prevalence is projected to more than double by 2040.

Parkinson's Disease in the US

By 2020, 930,000 people in the U.S. had PD

• Estimates suggest numbers in the US will approach 1.2 million by 2030

Causes of PD

• Vast majority of cases are idiopathic, or without clear known cause
• Genetic disposition accounts for 10-15% of PD cases, often involving mutations of the LRRK2 gene.
• Environmental factors can contribute, including exposure to heavy metals, repeated head injury, and certain solvents, herbicides, and pesticides.

Diagnosing PD

• No specific test exists definitively to diagnose PD except at autopsy.
• Diagnosis relies on clinical examination and presentation, noting asymmetry of onset and resting tremor at 4-5Hz.
• A good response to dopaminergic therapy and meds, meaning a >50% improvement in symptoms, aid diagnosis.
• Neuroimaging (CT and MRI) is mainly used to exclude other conditions.

Understanding Disease Progression

• Dopamine production diminishes during the first 5 years post-diagnosis
• 5-20 years post-diagnosis sees diminished dopamine availability.
• After 20 years, there is no dopamine production

Early vs. Late Symptoms

• Early symptoms include micrographic handwriting, decreased speech volume and facial expression, unilateral symptoms, bradykinesia, rigidity, mild gait hypokinesia, and resting tremor.
• Late symptoms include bilateral involvement, festination and freezing, retropulsion, dyskinesia (secondary to medication side effects), swallowing difficulties, and postural instability with falls.

PD Progression Stages

• The Hoehn and Yahr stages describe the progression of PD, from unilateral involvement to wheelchair or bed-bound status, with varying times to transition between stages.

Atypical Parkinson's Conditions

• Mimic PD but are distinct conditions like Progressive Supranuclear Palsy (PSP), Multiple System Atrophy (MSA), and Cortico-Basal Ganglia Degeneration (CBGD)
• Atypical conditions are more rapidly progressive

Atypical Parkinson's: Progressive Supranuclear Palsy (PSP)

• Hallmarks include vision issues such as diplopia and impaired eye movements (particularly downward gaze), changes in personality (irritability and impulsivity), bulbar rigidity, and swallowing deficits.

Atypical Parkinson's: Multiple System Atrophy (MSA)

• Characterized by cerebellar symptoms, urinary symptoms (up to 96%), greater dysautonomia (orthostatic hypotension, supine hypertension), REM behavior disorder, sleep disturbance, and difficulty with breathing, swallowing, and sweating.

Atypical Parkinson's: Cortico-Basal Ganglia Degeneration (CBGD)

• Symptoms include loss of function on one side of the body, involuntary jerky limb movements, and slow, effortful speech with difficulty swallowing.

Common Non-Motor Symptoms

• Significantly impact intervention strategies
• Can include sleep disorders, fatigue, and mood disorders
• Screen for sleep disorders with education on sleep hygiene

Fatigue

• Common, starts early, has varied causes, difficult to treat
• Recommended scales: FSS, FACIT-F, PFS

Understanding Prodromal PD

• From the point of onset to early stage motor skill decline, individuals may progressively demonstrate motor and non-motor symptoms

Orthostatic Hypotension (OH) in PD

• Often related to arterial baroreflex impairment, causing a BP drop during position changes ( 20 mmHg systolic or 10 mmHg diastolic)
• As many as 30-60% of individuals with PD may experience OH.

Cardiovascular Response in PD

• Often blunted to exercise
• Considerations for exercise include monitoring and awareness of signs/symptoms of orthostatic hypotension

Counteracting Inadequate BP Increases During Exercising

• Can be counteracted by increasing oxygen intake and limiting syncope through improved exercise

Neurogenic OH

• Involves damage to or disorders of the nervous system

Non-neurogenic OH

• Volume depletion, N/V, heat or meds often to blame

Heart Rate Incompetence

• Blunted or attenuated during activity and can occur early

Deep Brain Stimulation (DBS) in PD

• Used for patients with increased "off" time or excessive dyskinesia, but doesn't usually benefit non-motor symptoms or postural instability/walking issues.

Physical Therapy Examination Prep

• Ask about their medication schedule

Information Gathering via Referral

• Includes reason for referral, diagnosis, symptom presentation, comorbidities, and goals

Essential Referral Information:

• Dx; distinguishing features for differential dx

Initial Patient Interview

• Comprises duration of dx, symptom patterns, and environmental factors.

PT Subjective Assessment

• Essential details in a thorough PT Subjective Assessment include fall frequency ("near misses"), musculoskeletal issues, fatigue & sedentary behavior
• Cognition and ADL are paramount

Subjective Orthostatic Hypotension Questions

• Includes symptoms like fainting and dizziness, as well as timing throughout the day

Tremors

• Observation occurs at rest, or intensified with stress/exertion

Rigidity

• Only need to assess postural changes

Functional Implications of Bradykinesia:

• Note impairments of size and speed

Examination of Posture

• Awareness related to alignment

Muscle Weakness

• Common in PD
• Strength loss reduces med effectiveness

Impact of Cognition

• Monitor or screen using the MoCA

Functional task assessments

• Involve cognitive gait analysis

Outcome measures

• Track progression or improvement

Core vs PD Edge set Measures

• A balance needs to be struck

Mini Best Test Performance

• This specific test can help determine reactive balance

Gait Speed

• .88m/sec is predictive of someone to ambulate

Key Parkinson's Disease Rating Scales

• This includes activity, behavior, mentation