Neuro-Rehab Face-face Flashcards
what is a MCA stroke?
a stroke where the middle cerebral artery in the brain is blocked by a blood clot
what is the mCA connected to?
the carotid artery
what does the MCA supply?
areas of the brain that control motor, sensory and language functions.
Specifically:
- Primary motor cortex
- Primary somatosensory cortex
- Corticospinal tract
- Basal ganglia
- Internal capsule
why are Mr Brown’s symptoms on his LHS?
The MCA divides into branches on the L and R side of the brain.
These seprate branches supply blood to each of the brains hemispheres.
The stroke must have affected the RHS of his brain
How has Mr Brown’s stroke lead to Paresis?
- Motor cortex damage
- Damage to the Corticospinal Tract
what is the corticospinal tract?
a collection of nerve fibres that carry motor signals from the brain to the spinal cord
what is spasticity?
= increased resistance to a passive movement/stretch that is velocity dependant
How has Mr Brown’s stroke caused spasticity?
His stroke has caused:
- damage to UMNs
- loss of inhibitory control
How does a stroke cause damage to UMNs?
UMNs originate or pass through primary motor cortex and internal capsule (supplied by MCA)
These UMNs usually send inhibitory signals to LMNs in the spinal cord.
When UMNs are damaged by the stroke, this inhibition is lost, leading to overactive reflex arcs in the spinal cord.
what is the consequence of loosing inhibitory control?
results in exaggerated reflexes and overactive muscles (spasticity)
what may be the cause for Mr Brown’s loss of Fine Motor Control?
- Damage to the lateral motor cortex
- Disruption of the Corticospinal Tract
- Loss of sensory feedback
how does damage to the lateral motor cortex imapair fine motor control?
the lateral part of the motor cortex (supplied by the MCA) is responsible for face, hand and UL movements.
Damage to it causes a loss of control, especially in fine, precise movements
what does the corticospinal tract do?
it carries signals from the motor cortex directly to motor neurones controlling the hands
*fine motor control relies heavily on the lateral corticospinal tract
what are the consequences of loss of sensory feedback?
without sensory feedback, making precise coordinated movements is harder.
the MCA supplies the somatosensory cortex- which helps coordinate fine motor control by providing feedback about hand position and touch.
what are the reasons for Mr Brown’s poor balance?
Motor cortex damage –> postural instability
Hemiparesis –> asymmetrical weight bearing
Sensory loss –> impaired proprioception
