Staged Ax 2 - Neuroscience

What is a dermatome?

An area of skin innervated by a single spinal nerve root

What is a myotome?

A group of muscles innervated by a single spinal nerve root

What is the root value in each instance? Patella tendon

L2, L3, L4

What is the root value in each instance? Triceps

C6, C7, C8

What is the root value in each instance? Biceps

C5, C6

What is the root value in each instance? Brachioradialis

C5, C6

What is the root value in each instance? Achilles

S1, S2

Describe a simple stretch reflex

Stimulus - patella hammer strikes the tendon

Stretch is picked up by the muscle spindle

Sensory information travels to grey matter of the spinal cord via a sensory neuron

Sensory neuron synapses with an alpha motor neuron

Motor neuron carries the impulse back to the muscle which then contracts

What is a typical plantar response?

Normal plantar response = downward flexion of the toes

What does plantar response indicate?

Positive Babinski sign (dorsiflexion of big toe and fanning of other toes) indicates an upper motor neuron issue.

Loss of descending inhibitory control over spinal reflex circuits

visual fields

state the typical range for superior, inferior and temporal (lateral) visual fields.

Superior - 50 degrees

Inferior - 60 degrees

Temporal/lateral - 90 degrees

Why are intact visual fields important for everyday life?

Input from visual fields allows us to get a complete picture of the external environment

Safe and effective navigation for functional ability

scanning

- which Cranial nerves are involved in scanning?

Cranial nerves 3, 4 and 5

How do we use scanning ability in everyday life?

o   Reading

o   Driving + Walking (scanning for hazards)

o   Shopping (scanning shelves)

• fixing

which Cranial nerves are involved in fixing?

Cranial nerves 3 and 4

How do we use fixing in everyday life

-       Walking and navigation: fixing on landmarks or steps to maintain orientation/prevent falls

-       Driving – to monitor the road, signs and mirrors simultaneously

Briefly explain the vestibular ocular reflex

Reflex that stabilises your vision by moving your eyes in the opposite direction to the movement of your head at the same speed.

Identify components of normal gait - Stance phase

Stance phase 60% of gait cycle:

• Initial contact (foot touches ground, heel strike in typical presentation)

• Loading response (taking weight onto leg, with knee in slight flexion)

• Midstance (stood on one leg whilst opposite leg swings through

• Terminal stance (heel up off ground)

• Pre-swing (up on toes before swing phase)

Identify components of normal gait - Swing phase

Swing phase 40% of gait cycle:

• Initial swing

• Mid swing

• Terminal swing

HOW and WHY are the components of normal gait altered in the context of Stroke?

• Uneven weight bearing - due to weakness or fear of putting weight on affected leg

• Spasticity in muscles - neural problem with overactivity - could lead to too much plantarflexion or hyperextension of the knee

• Reduced dorsiflexion - weakness in tibialis anterior or spasticity in gastrocnemius/soleus

• Quick step through to avoid weight bearing

• Lack of propulsion/push off - weakness in plantar flexors

• Hip hitching, circumduction and vaulting - as a means to compensate for poor foot clearance/propulsion

HOW and WHY are the components of normal gait altered in the context of Parkinson’s Disease?

• Bradykinesia - reduced movements

• Postural instability and balance issues

• Slow shuffling gait pattern

• Flexed at knees and hips when mobilising - muscle rigidity and loss of brains automatic control of posture

• Kyphotic posture

• Jutting out chin to compensate for kyphosis

• Reduced trunk movement and arm swing

• Increased time in double stance

• FREEZING - need a large amplitude of movement to initiate steps

• FESTINATION - high step count and reduced step length