T2 L10: Motor learning and neurological symptoms Flashcards
Describe the simple motor pathway
Motor cortex of the brain gives info to an upper motor neuron that passes that info onto a lower motor neuron which will pass it onto a muscle
What is the difference between upper and lower motor neurones?
Upper motor neurones begin in the brain. Lower motor neurones begin in the spinal cord
Which motor control centres are responsible for high level strategy functions?
Association areas of the neocortex and basal ganglia
Which motor control centres are responsible for middle level tactics functions?
The motor cortex and cerebellum
Which motor control centres are responsible for low level execution functions?
Brainstem and spinal cord
Give an example of strategy, tactics and execution function of the brain in tennis
Strategy: Different choices of serve Eg. direction, spin, previous responses of the opponent
Tactics: The instructions to execute the serve
Execution: delivery of the serve
What is the only cortical tract to directly synapse with motor neurones?
Pyramidal tracts
Which layer are pyramidal cells predominantly derived from?
Layer 5 (V)
Which spinal tract is for flexion of upper limbs and where does it originate?
The Rubrospinal tract originating in the red nucleus
Which spinal tract is for balance and where does it originate?
The vestibulocochlear nucleus originating in the vestibular nucleus
Which spinal tract is for vision and alerting and where does it originate?
The tectospinal tract originating in the tectum
Where is the tectum?
In the midbrain (Also known as the superior colliculus)
Which spinal tract is for extending arms and legs and where does it originate?
The reticulospinal tract originating in the reticular formation
What are the 5 descending spinal tract pathways?
Tectospinal, medial and lateral vestibulospinal, reticulospinal, and rubrospinal
What causes decorticate posturing?
A lesion above the red nucleus
What is Decorticate posturing?
A person is stiff with bent arms, clenched fists, and legs held out straight
What is Decerebrate posturing?
Involves the arms and legs being held straight out, the toes being pointed downward, and the head and neck being arched backward.
What causes Decerebrate posturing?
A lesion below the red nucleus
What are the symptoms of damage to the motor cortex and corticospinal tract?
Eg. Caused by a stroke
There will be some preserved upper limb flexion and lower limb extension Increased tone (Spasticity), brisk reflexes, Extensor Plantar/Babinski reflex, Clonus Patient will maintain a posture but a contracture will be left because the red nucleus is having more if an impact
All caused by a loss of descending inhibition
What is the Babinski reflex?
It’s a normal reflex in children but not in adults. It when the toes raise up instead of curling inwards when the sole of the foot is stimulated (A tickle)
What is Clonus?
Involuntary and rhythmic muscle contractions. It can be found at the ankle, patella, triceps surae, wrist, jaw, biceps brachii
Why is the Babinski reflex normal in children?
Because their corticospinal tracts don’t develop fully until they reach age 2
What is Bell’s Palsy?
A temporary weakness or lack of movement affecting 1 side of the face
What is a Parasagittal Meningioma?
A meningioma that fills the parasagittal angle
How does a Parasagittal Meningioma present itself?
A bilateral leg weakness and spasticity
What are the 4 arteries in which a stroke can occur?
Anterior cerebral artery
Middle cerebral artery
Posterior cerebral artery
Anterior choroidal artery
What are the symptoms of a middle cerebral artery occlusion?
Proximal lesion affects internal capsule
Complete Hemiparesis
Distal lesion may spare leg area of the motor cortex but secondary swelling and ischaemia may compromise function
What is Complete Hemiparesis?
Weakness on the entire side of the body
Which areas does the anterior cerebral artery supply?
Supplies the frontal lobes including the leg area of motor cortex
What is Abulia?
Loss or impairment of the ability to make decisions or act independently
What are the symptoms of an Anterior cerebral artery stroke?
More leg paresis than arm paresis
Abulia
