CNS Class 8 - Spasticity Flashcards
Some key characteristics that occur soon after the __________-causing event (after the CNS shock stage) include:
- Hyperreflexia
- Reflex cascade
- Reversion to early motor system patterns
- Altered reflex patterns
- Muscle tone abnormalities
- Motor control abnormalities
- Contracture effects
Spasticity
Primacy of the basic excitatory reflexes (e.g. stretch reflex, withdrawal reflex, joint protective reflexes), which are operating with poor/absent HMC modulation.
Hyperreflexia
T/F - Hyperreflexia involves exaggerated responses to noxious stimuli, but not normal stimuli.
False - Hyperreflexia involves exaggerated responses to BOTH noxious AND normal stimuli.
When one stimulus results in activation of a sequence of reflex responses that spreads in either/both directions from the original activation.
Reflex Cascade (aka. Domino Reflex, Reflex Spillover, Spastic Reaction)
A reflex cascade typically includes ______ at affected joints.
Clonus
When the spasticity causing lesion causes the motor system to revert to where flexion is the normal comfortable resting position for affected joints.
Flexion Dominance
T/F - The most common position of spasticity is the “fetal position.”
True
The following positions are examples of _______ dominance:
- Flexed elbow
- Bent wrist
- Pronated forearm
- Clenched fist
- Thumb in palm
Flexion
__________ reflex is normal in the young infant and part of the basic full body withdrawal reflex pattern. It is replaced by a new version as the CNS matures.
Babinski’s
In the infant, plantar stimulation causes reflex toe _________ and ankle ____________. This is not functional for standing and walking, therefore it is replaced with the opposite actions.
Extension
Dorsiflexion
The term used when Babinski’s reflex is present abnormally.
Babinski’s Sign
Alternating activation of agonist and antagonist stretch reflex responses acting on a joint, which causes a “reverberating” back-and-forth action.
Clonus
Abnormal antagonist contractions that occur during voluntary agonist effort. When observing clinically, it looks like rigidity.
Spastic Co-Contractions
Muscle contraction present at rest, leading to a holding position that is very sensitive to stretch.
Spastic Dystonia
T/F - With spasticity, resting tone can fluctuate from being too high or too low, which can present with posture changes and walking.
True
T/F - With spasticity, muscle tone cannot change dramatically with emotion or pain.
False - With spasticity, muscle tone CAN change dramatically with emotion or pain.
T/F - With spasticity, there is diminished gross motor control and synergistic stabilization patterns become stereotyped.
False - With spasticity, there is diminished FINE motor control and synergistic stabilization patterns become stereotyped.
Some effects of ____________, which are present with spasticity include:
- Reduced ROM
- Less specificity of movements
- Early activation of protective reflexes
- Ischemia & pain leading to muscle irritability
Contractures
Some key characteristics that develop within 6 months after the __________-causing event include:
- 1a neuronal sprouting
- Reduced spinal cord availability of GABA
Spasticity
1a neuronal sprouting is a phenomenon in which 1a neurons add ___________ (axon terminal branches), increasing their number of synapses on their partner alpha motor neuron in the stretch reflex.
Telodendria
T/F - 1a neuronal sprouting lessens spasticity because it contributes to hyporreflexia.
False - 1a neuronal sprouting INTENSIFIES spasticity because it contributes to HYPERREFLEXIA.
With 1a neuronal sprouting, 1a is now shooting a much larger amount of _____________ at the alpha cell body. This means that muscle _____ elongation causes an exponentially more intense reflex reaction to contract the muscle.
Acetylcholine
Belly
If there is less availability of GABA, this reduces the strength/duration of the ______ reflex and this response will be weaker and shorter in duration.
GTO
If there is less availability of ________, this intensifies spasticity by reducing the GTO’s capacity to counteract the stretch reflex response.
GABA
T/F - Neuronal sprouting and reduced GABA makes the stretch reflex significantly stronger/hyperreflexic and the GTO reflex weaker.
True
