6
T/F: Modified Ashworth scale has little correlation with functional ability
True
MAS score:
No increase in MT
0
What is the issue is the patient is prescribed too much baclofen and now they have no tone?
May be unable to walk
When a child with CP is walking, they are using co contraction of quads and hamstrings. Does this increase or decrease their energy expenditure?
Decreases their energy expenditure... so changing their gait can decrease energy efficiency
What is the issue with removing tone in children? Will they have normal walking pattern?
No.. they will not have normal walking pattern because they never developed proper motor plan in the first place
- Increases with increasing speed of stretch (velocity dependent)
- Varies with the direction of joint movement
- Increases rapidly above a threshold speed or joint angle
- Hypothesized to be caused by a lack of normal presynaptic inhibition
Spastic
MAS score:
Slight increase in MT, catch/release, increase at end of range
1
- Abnormal, involuntary muscle movements that can be mild or severe, and can even be painful in nature
- Athetosis, chorea, levodopa-induced, tardive or delayed dyskinesia, myoclonus dyskinesias
Dyskinesia
- More sensitive to differentiate children with mild to moderate quadriceps spasticity
- Lower leg dropped and allowed to oscillate like a pendulum
- Electrogoniometer positioned on knee to record amplitude of first swing from full knee extension to full knee flexion
Pendulum test
- Lowering excitation into motor neuron pools
- Selective dorsal rhizotomy: surgical procedure that selectively cuts problematic nerve roots in the spinal cord
- Intrathecal or oral baclofen: prescribed to inhibit the motor neuron pools
- Botulin toxin injections: used to interrupt muscle contraction
- Medications
Interventions for spasticity
- Movement disorder in which involuntary sustained or intermittent muscle contractions cause twisting and repetitive movements and/or abnormal postures
- Commonly triggered by attempts of voluntary movement and may fluctuate over time
- Mostly absent at rest only becomes apparent during active movements
- Hypertonia not always present in dystonia
- Commonly been associated with damage to basal ganglia (not always seen)
- Cerebellum, brainstem, or sensory cortex damage can cause dystonia
Dystonic
Form of dyskinesia that may occur due to the long-term use of levodopa
Levodopa-induced or Parkinson's dyskinesia
- Move joint and extremity slowly to reduce amount of spasticity
- Joint contractures can develop as a result of limited movement across joints
- Weakness and paresis during movement
- Compensate for weakness with contraction to create sufficient tension for postural control and movement
- Hypertonicity can be used for optimal motor function
- May limit the degrees of freedom
- More contraction muscle activity may have better energy efficiency for overground ambulation
- Therapy to reduce tone may be detrimental
Treatment considerations for spasticity
Form of dyskinesia associated with the use of antipsychotic medications, often used to treat schizophrenia
Tardive or delayed dyskinesia
Form of dyskinesia often seen in Huntington's disease, structural damage of the brain, and caused by medications. Chorea refers to quick movements of the limbs and can resemble dancing
Chorea
-"An on-going, random appearing sequence of one or more discrete movements or movement fragments"
- Varied timing, duration, direction, and body location
- Distinguished from dystonia by unpredictable and continuous nature of movements and from athetosis by the presence of discrete movements within the continuing sequence of movements
Chorea
- "A rhythmic back and forth or oscillating involuntary movement about a joint axis"
- Rhythmic alternating movement with relative symmetry in speed
- Types: Resting, postural, action, intention
Tremor
- "Slow, continuous, involuntary writhing movement that prevents maintenance of a stable posture"
- Characterized by smooth continuous random movements not composed of identifiable fragments of movement
- Dyskinetic CP = higher resting metabolic rate
Athetosis
- Gross lack of coordinated movements
- Generally originates from damage to the cerebellum
- Normal strength with no hypertonia
- Movements are jerky and inaccurate
- Types: limb, truncal, gait
Ataxia
Form of dyskinesia seen in progressive myoclonic encephalopathy. Movements are severe and very disabling
Myoclonus dyskinesia
- Excessively low resistance to passive stretch
- Hypothesized from loss of efferent or afferent activity to lower motor neurons
- Injuries to lower motor neurons
- Muscular or connective tissue diseases (EX: spinal muscular atrophy and congenital malformation of connective tissue)
- Reduction in descending input from brain to activate alpha and gamma motor neurons
- Childhood neuromuscular disorders - CP and Down syndrome - from decreased descending inputs
- Relationship between hypotonia and delayed motor development in infants born preterm or deemed as high risk
- Kinesthetic sense
- Coordinated movement difficult
- Tend to move less
- Less coordination in midranges of movement
- Balance between activation of agonist and antagonist may be disrupted
Hypotonicity
- Extreme type of hypertonicity
- Caused by changes in transcortical long latency reflex activity or disruption of basal ganglia's normal interaction with motor cortex anterior to central sulcus
- Defined as resistance to passive joint movement present at very low speeds of movement, independent of imposed speed, with no speed or angle threshold
- Simultaneous contraction of agonist and antagonist muscle may occur
- After being moved, limb does not tend to return toward a particular position of extreme joint angle
- Voluntary movement in distal muscle group does not lead to involuntary movements, although rigidity may worsen
Rigidity
- Most widely accepted classification system
- Severity of motor disability is rated on a 5-point scale
- Describes functional abilities in sitting, walking, and wheeled mobility
- Characterizes motor abilities for children based on childs age: birth to 18 years old
- Before 2nd birthday
- Between 2nd birthday
- Between 4th and 6th
- Between 6th and 12th
- Between 12th and 18th
- The descriptions for 6-12 year and 12-18 year age ranges reflect potential impact of environmental and personal factors on mobility
- May be more reliable and valid than other systems
- Judgement on functional ability rather than classify by neurological symptoms
- Most children usually do not change between levels; they will change how functional they are within levels, but do not change
Gross motor function classification system -- expanded and revised (GMFCS E&R)
Type of rigidity that is described as resistance uniform through the ROM
Leadpipe rigidity
A type of rigidity that is defined as a series of jerks throughout the movement
- Thought was people who were symptom magnifying "faking" were doing this motion
Cogwheel rigidity