Spasticity Flashcards
what is spasticity?
- type of neurological driven muscle stiffness
is there a clear definition of spasticity?
- inconsistently defined
- constantly adapting
what is a definition of spasticity regarding motor movement?
- motor disorder characterised by a velocity- dependent increase in tonic stretch reflexes (muscle tone) with exaggerated jerks
what does spasticity result from?
- hyperexcitability of the stretch reflex
what is the definition of spasticity regarding sensory aspects?
- disordered sensori- motor control, resulting from an upper motor neuron lesion
what does spasticity present with?
- intermittent or sustained involuntary activation of muscles
what does spasticity increase?
- increases resistance to movement
what are the two categories that cause spasticity?
- neural (hypertonia)
- non- neural (biomechanical)
what are the 3 further divisions of neural hypertonia?
- spasticity
- rigidity
- dystonia
what are the two divisions of non- neural cause?
- soft tissue contracture
- thixotropy
what is soft tissue contracture?
- shortening of the muscle, tendon, joint capsule
what is rigidity? what does it affect?
- neurological muscle stiffness or inflexible muscles
- affects antagonist and agonist
what is rigidity not dependent on?
- not velocity dependent
what are the two main types of rigidity?
- cogwheel
- lead pipe
what is thixotropy?
- stiffness is impermanent because it forms only when the muscle is stationary for some time and is reduced upon active or passive movement
what increases with time and what is reduced in thixotropy?
- resistance to movement increases with time
- reduced by movement
what is dystonia?
- movement disorder characterised by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements, postures or both
what are dystonic movements typically?
- typically patterned, twisting, and may be tremulous
what is dystonia often initiated or worsened by?
- initiated/ worsened by voluntary action and associated with overflow muscle activation
what is an upper motor neuron lesion?
- designated as any damage to the motor neurons that reside above nuclei of cranial nerves of the anterior horn cells of the spinal cord
what are positive signs?
- addition to behaviour
what are negative signs?
- loss of behaviour
what are the six positive signs of spasticity?
- positive babinski
- spasticity
- clonus
- spasms
- hyperreflexia
- associated reactions
what are the three negative signs of spasticity?
- weakness
- loss of dexterity
- fatigue
what are three examples of upper motor neuron lesions?
- stroke
- traumatic brain injury
- MS
what are the three examples of lower motor neuron lesions?
- guillain barre syndrome
- polio
- spinal muscular atrophy
what condition affects upper motor neuron and lower motor neuron?
- motor neuron disease (MND)
what is clonus?
- rhythmic oscillating stretch reflex
what is clonus potentially linked to?
- linked to hyperreflexia
how many oscillations occur in clonus ?
- 5 to 10 oscillations
what is fatiguing clonus?
- where the patient is unable to stop spasms by themselves
- require the stretch to be stopped
what is non- fatiguing clonus?
- stops by itself
what are associated reactions?
- effort- dependent phenomenon causing an involuntary increase in upper limb muscle tone, with awkward and uncomfortable postures
what are associated reactions useful indicatives of?
- indicative of effort
how prevalent is spasticity in stroke?
- 33%
how prevalent is spasticity in severe brain injury?
- 75%
how prevalent is spasticity in severe multiple sclerosis?
- 60%
what does presentation of spasticity vary with? (3)
- size of lesion
- location of lesion
- age of lesion
what are the three common lower limb pattern?
- focal spasticity with hyperextension of the hallux
- multifocal spasticity involving the lower limb
- regional spasticity involving the left leg and arm
what are the common upper limb patterns?
- flexion/ adduction/ medial rotation of GH joint
- elbow flexion
- pronation
- wrist flexion
- finger flexion
what is the pathophysiology of spasticity?
- a lesion to the CNS causes the loss of descending inhibition and disrupts the balance between excitatory and inhibitory supraspinal control, leading to hyperexcitability or reflexes
what are upper motor neuron lesion symptoms largely caused by? what contributes?
- parapryradimal fibre dysfunction
- only small input from lateral corticospinal tract
what is the main tract that inhibits spinal reflex activity? where is it?
- main tract that inhibits spinal reflex activity is the dorsal reticulospinal tract
- runs very close to the lateral corticospinal tract
what does a single lesion frequently affect?
- frequently effects both tracts
- produces a picture reflecting the combined lesion
what tract makes a small contribution and what tract produces most of the symptoms?
- corticospinal tract lesion makes a small contribution but the parapyramidal dorsal reticulospinal tract produces most of the symptoms & signs
what is spasticity pathophysiology also potentially due to? what does this explain?
- spasticity due to neuroplastic changes within the CNS
- explains some delay in the onset of spasticity
why does hyperexcitability occur?
- reflex arc lost connection to the brain
- muscle spindle senses lengthening so triggers another nerve to contract that muscle
