PD Lecture Again Flashcards
Resting tremor impairment
- Involuntary rhythmic oscillatory movement - present in 75% of patients and may decrease with disease progression.
- 3.5-7hz - pill rolling
- asymmetric distribution across arms, legs, face.
- Disappears with voluntary movement. During posture holding like an outstretched arm can stop for a period of time (resetting)
- tremor generally responsive to L dopa through inhibition of Ventral Intermediate nucleus of thalamus
Brain structures involved with resting tremor?
- GPi, STN, and ventral intermediate nucleus of thalamus involved in tremor production.
- Cerebello - thalamo - cortical circuit involved in amplifying tremor.
Rigidity in PD
NOT spasticity
— in PD rigidity is the increase in muscle tone manifested as a speed-independent resistance to passive movement.
cogwheel or lead pipe type
— likely a combination of spinal reflex and brainstem dysfunction including non dopaminergic NT systems.
Reflexes in rigidity with PD
Muscle stretch reflex — normally there are M1-M3 responses.
— M1 20-40ms UE, M1 35-40ms LE
— longer latency reflexes >40ms thought to be related to rigidity in persons with PD
Cutaneous-muscular reflexes: normally 3 parts: E1, l1, E2
— reduced l1 i nPD
Bradykinesia in PD
Slowness of movement including “sequence effect: which is a progressive decrease in speed and amplitude of repetitive continuous movements like gait or writing
— probably a network dysfunction in circuitry of BG, motor cortex, and cerebellum.
What does bradykinesia look like during a simple discrete movement?
- Correct agonist recruited
- Duration of agonist EMG burst is generally normal
- Decreased size of the initial agonist burst.
- Movement achieved through a series of small agonist bursts
- Timing of subsequent agonist/antagonist preserved
- Rate of force development issues due to changes in motor unit structure/function.
Posture in PD
A change in posture towards flexion which can lead to pain. MAY contribute to falling.
— Secondary flexibility restrictions will arise as a result of this posture, rigidity, and bradykinesia.
— Reduced trunk flexibility can cause problems in preserving balance and performing ADLs
Steady state standing balance in PD
Generally, increased sway in ML direction. Mixed (normal or increased) in studies examining AP sway
— postural predisposition to loss of balance (forward)
Dynamic standing balance in PD
Impairments in ANTICIPATORY postural adjustments — tend to me too small and can be incomplete or requiring multiple bursts of muscle activity.
Loss of automatic righting and protective (stepping and grabbing) REACTIVE postural control.
— more likely to co-contract agonist/antagonist around a joint. So less likely to show sequential muscle activation in response to a platform perturbation.
— Will likely take multiple steps with shorter step lengths (esp. backwards)
Other body structure/function impairments
- Pain in MSK system
- Pain in GI system — constipation
- Central pain — vague sense of tension from pain
- Restless and painful feeling in legs
- Pins and needles, deafness, deviating sensibility for temp
- Decreased sense of smell - could even be an early sign of PD
- Insufficient stamina
- Orthostatic hypotension 30-60% prevalence range in literature — OH increases with PD duration, disease severity, age, and L dopa use.
- Dystonia — more so in off period
- Sleep difficulties
- Hallucinations
- Mood disorders — depression
- Cognitive impairment
What kind of cog impairments
Bradyphrenia
Attention
Executive function
Multi/dual task ability
Impulse control
Dementia develops in 40-70% of patients during disease.
— not like Alzheimer’s because visual hallucinations are more and severe memory problems are less.
What does walking in PD look like
- Flexed posture with anterior displaced COM
- Shorter step length, reduced foot clearance/shuffling steps due to bradykinesia
- Loss of associated arm movement
- Festinating gait — consequence of decreased step length/sequence effect and increased cadence. (Terminated by catching CM, freezing, or fall)
- Freezing — episodic inability to generate an effective step.
Freezing gait
Most typical gait dysfunction with advanced disease — in 96% of persons with PD
Common during step initiation, moving through barriers and turning
Pedunculopontine nucleus function in brainstem may contribute to freezing of gait.
Falling in PD
2-6x greater change of falling than age matched counterparts.
9x greater chance of recurrent falls
Increased risk for hip and non vertebral fractures.
Evidence shows that fall rates can be reduced but not the number of fallers.
Intrinsic vs. Extrinsic factors of falling
Intrinsic — posture, balance
Extrinsic — doorsteps, lighting play a smaller role than intrinsic factors.
falling under dual task conditions are common
Forward falls vs. Non forward falls
Forward falls — associated with freezing gait, occur more during walking and turning and are usually more severe than falls in other directions
Non forward falls — occur more during sitting/standing/turning and are associated with more balance impairment and rigid-akinetic subtype PD
Limitations in transfers in PD
Rising from chair, sitting down, gettin gin and out of bed, turning in bed all big problems with PD
have to identify if it is due to problems of rolling over in bed or other reasons
Bed mobility may even be worse than gait or become limited sooner than gait so CANNOT IGNORE THIS PROBLEM
Limitations in reaching and grasping/manipulating objects
Particularly a problem when performing compound activities like getting dressed and eating
Speed and joint mobility are reduced.
Participating and QOL
Participation highly related to mobility-related QOL and may be most impacted by ability to stand up from a chair and freezing gait.
Due to visible disease specific features and irrespective of disease severity, some persons with PD feel exposed while participating in events such as meetings, bdays, or other gatherings.
— there’s a lot of prep that has to happen to go anywhere and stamina is also an issue.
Objectives of PT for PD
Improve QOL — by improving and preserving independence, mobility, safety, and well being through exercise
Treatment guided by stages of PD
When is PT indicated
- Patient is limited in one or more activities (posture, transfers, reaching, balance and gait)
- Patient has or is at risk of decreased physical capacity caused by inactivity
- Patient has increased risk of falling
- Patient has the need for information or advice on this disorder, natural course, and prognosis.
- Patient has increased chance of pressure sores.
