What is Parkinson’s Disease (PD)?
Degenerative disorder of the CNS resulting from decreased stimulation to the motor cortex by the basal ganglia (loss of dopamine)
What are the functions of the Basal Ganglia? (4)
Functions
- Execution of complex motor tasks
- Runs well learned and predictable movement sequences (with the Supplementary Motor Area)
- Provides internal cues
- Involved with memory and cognitive function
What 4 nuclei make up the basal ganglia and which one loses cells in PD?
- Striatum
- Globus pallidus
- Subthalamic nuclei
- Substantia nigra (loss of cells)
Describe the basic pathology of PD
- Loss of dopaminergic neurons in the substantia nigra (less than 20% left)
- Lewy bodies
- ???
What is the main problem that physios deal with in PD patients?
Inability to perform simultaneous or sequential motor tasks
- Bilateral tasks
- Walking and talking
- Standing ? i.e. activating muscles in a certain order and at the same time
What are the primary impairments of PD? (6)
Primary impairments
- Bradykinesia
- Hypokinesia
- – most pronounced in complex tasks
- – reduced stride length
- – occurs at all joints in walking (so do whole task training)
- Akinesia
- – Festination often occurs prior to freezing
- – often relevant to environment, e.g. narrow doorways, busy environment
- Tremors
- Rigidity
- Loss of balance = falls risk
- – MUST ask about falling, assess balance and external perturbations
Define:
- Bradykinesia
- Hypokinesia
Bradykinesia = decreased speed of movement
Hypokinesia = decreased amplitude of movement (most common impairment in PD)
Define:
- Akinesia
- Rigidity
Akinesia = no initiation of movement (freezing)
Rigidity (increased stiffness to passive stretch, not like spasticity)
Measurement of PD (measures - 5; field tests - 6)
Measures
- Unified PD rating scale (UPDRS)
- Hoen and Yahr scale (0-5)
- FOGQ
- FES-I
- Berg Balance
Field tests
- 10m walk
- 6min walk
- TUG
- STS
- Timed activities
- Handwriting/Spiral test
Assessment of PD (6)
Assess:
- ROM
- Strength
- Respiratory
- Fitness
- Falls diary
- Dyskinesia
What pharmacological management is generally used in PD?
Levadopa (precursor to Dopamine that can cross the blood-brain barrier)
What are 3 significant side-effects with Levadopa?
Side-effects
- Hypertension
- Dyskinesia
- On/off phenomenon (“turn off” and can’t move when Levadopa decreases)
Name 2 surgical options for PD
- Globus pallidus removal
2. Deep brain stimulation (shown improvements in QOL in advanced PD)
Why are attentional and cueing strategies often effective in PD?
External stimuli instead of internal cues allows alternative circuitries in the brain to be engaged to accomplish tasks, avoiding the defective basal ganglia circuitry (remove automaticity)
How can a falls diary help prevent falls in PD?
Falls diary
- Discover black area times
- Common links (environment, fatigue etc)
What are 4 impairments that contribute to falls in PD?
Freezing, poor balance, loss of muscle strength and flexed posture
Management of falling in PD (3)
Management
- Educate (use info from falls diary)
- Modify environment
- Train impairments
What are 2 ways to treat a flexed posture in PD?
Exercise
Positioning in bed for thoracic extension
Research on training dual tasks in PD
Brauer and Morris 2010
- 20 mins walking step length training with dual task
= longer step (5/6)
= walking speed (3/6)
Research on cueing for hypokinesia in PD
- Spaulding et al 2013
- Visual and auditory both improve stride length
- Auditory also speed and cadence - Canning 2005
- Concentrate on tray = worse than normal
- Concentrate on big steps = normalised speed + stride
Research on akinesia
RESCUE trial
- auditory, somatosensory or visual cues
- 30 mins, 3x week for 3 weeks
= less freezing but no carry-over at 6 wks
Brichetto et al 2006
- gait in varied environments + auditory then cognitive strategies
- 45 mins, 3x week for 6 wks
= Better FOGQ and QoL (1m after)
Research on falls in PD
Stolze et al 2004
- 62% fell within last 12m (more than MND and MS)
Allen et al 2010 - RCT of 48 PD pts - Monthly group exercise class + home program 3x/week for 6m = better STS, decreased freezing = decreased falls risk, fear of falling
Treadmill training in PD?
Merholtz et al 2010 (systematic review)
- gait speed
- stride length
- walking distance
Strength training in PD
Dibble et al 2006 - high-force eccentric resistance training - 3 days/week for 12wks = volume = force = mobility
