Tone and spasticity Flashcards
what is spasticity?
condition in which there is abnormal increases in muscle tone or stiffness of a muscle, which might interfere with movement, speech, or be associated with discomfort or pain
velocity is dependent from spasticity
what are the causes of spasticity?
usually damage to UMN pathways within the brain, brainstem, or spinal cord.
associated with SCI, MS, CP, CVA, TBI,ALS, hereditary spastic paraplegias, and some metabolic disorders
what are the symptoms of spasticity
hypertonicity
clonus
exaggerated DTRs
muscle spasms
Secondary:
scissoring (involuntary crossing of the legs)
contractures
what is the normal resting muscle tone?
the amount of tension in a resting muscle
assessed by PROM and normally minimal
contributing factors are:
intrinsic and passive stiffness of the muscle
descending motor commands
level of background excitability in spinal cord
proprioceptive information
what is NORMAL MUSCLE RESTING TONE?
Intrinsic and passive stiffness of the muscle provide normal muscle resting tone.
At rest, there are weak bonds between actin and myosin (without power stroke).
Immobility facilitates these bonds.
Stretch following immobility = feel increased resistance
Stretch following a prolonged contraction = feel increased resistance
Slow, gentle stretch = gentle detachment
Fast stretch = remain attached contributing to increased stiffness
Titin
Elastic properties provide mobility AND resistance
with regards to spasticity what is joint resistance to movement and cocontraction
joint resistance to movement = elastic + contractile muscle forces
Cocontraction:
simultaneous contraction of agonist and antagonist muscles
frequently used for functional stability:
wrist for distal movement
LEs for standing
commonly see with new motor learning
what is muscle synergies?
Coordinated muscular action
Normal function
Type II afferents (muscle spindles, joint receptors, cutaneous and subcutaneous touch and pressure)
Interneurons connect to motor neurons for muscles at other joints for spinal cord regulated coordinated function (frequently used patterns)
Term adopted by clinicians
Pathologic synergies
Example: Patient post TBI or CVA
UMN lesion
Voluntary flexion of shoulder is accompanied by unwanted, simultaneous, obligatory flexion of the elbow
what is a associated reaction with spasticity
spontaneous movement
involuntary movement when something else happens (yawn, strain, etc.)
what is hypertonia? how does it occur? what are the two types? when willl you see these two types?
Abnormal resistance to passive stretch
Occurs in UMN and some basal ganglia lesions
2 Types:
Spasticity = velocity dependent hypertonia
CVA or TBI (cerebrum injury)
May present with clasp-knife response
Rigidity = constant resistance/velocity independent hypertonia
Decerebrate and decorticate rigidity
Cogwheel or lead-pipe rigidity in basal ganglia lesion
what is hyperreflexia
exaggerated DTRs
Abnormal cutaneous reflexes
what is the babinski sign?
postive or negative
positive is normal for infants <7 mo old
what is clonus
involuntary, repeating, and rhythmic muscle contractions
Two types:
sustained or Unsustained
Unsustained clonus fades after a few beats, even with maintained muscle stretch.
Sustained clonus is always pathologic in origin and is produced when a lack of UMN modulation allows the activation of oscillating neural networks in the spinal cord.
what is the clinical assessment for Spasticity?
Observation for posturing at rest
Resistance to PROM
Passive drop into gravity
Voluntary activation followed by passive drop into gravity
Easy movement
Associated reaction
Challenging movement
Associated reaction
Observation for impact on function
explain the Modified Tardieu scales of spasticity
0-4 grading
0: being no resistance throughout the course of the passive movement
1: slight resistance throughout the course of the passive movement, with no clear catch at perishes angle
2: clear catch at precise angle, interrupting the passive movement followed by releases
3: fatigable clonus (<10 seconds when maintained with pressure) occurring at precise angle
4: infaticabile clonus (>10 seconds when maintaining pressure) occurring at a precise angle
explain the modified ash worth scale
look it up slide 20
