Aspects of Neurological Examination

Question 1

What are the different criteria for an eye score in GCS?

Answer 1

• 4 - opens voluntarily
• 3 - opens to voice
• 2 - opens eyes to pain
• 1 - does not open eyes

Question 2

What are the criteria for scoring the motor score for GCS?

Answer 2

• 6 - following commands
• 5 - localising to pain
• 4 - normal flexing to pain
• 3 - Abnormal (decorticate) flexion to pain
• 2 - Abnormal (decerebrate) extension to pain
• 1 - No movement

Question 3

What are the different criteria for the verbal scoring of GCS?

Answer 3

• 5 - Speaking normally
• 4 - confused
• 3 - abnormal words/ incomplete sentences
• 2 - mumbling/noises
• 1 - no sound

Question 4

How would you note a brisk or exaggerated reflex in case notes?

Answer 4

+++

Question 5

How would you note a normal reflex in case notes?

Answer 5

++

Question 6

How would you note a diminished reflex in case notes?

Answer 6

+

Question 7

How would you note an absent reflex in case notes?

Answer 7

-

Question 8

If assessing plantar response, what would be a positive babinski’s sign?

Answer 8

Large toe extends and other toes abduct

Question 9

If assessing plantar response, what would be an abnormal plantar response?

Answer 9

Only large to extends

Question 10

If assessing plantar response, what would be an abnormal plantar response?

Answer 10

Only large to extends

Question 11

If assessing plantar response, what would be classed as no response?

Answer 11

No movement of large toe

Question 12

If assessing plantar response, what would be a withdrawal response?

Answer 12

Large toe and other toe extends, ankle dorsiflexes

Question 13

What is grade 0 of the MRC power grading scale?

Answer 13

No muscle contraction

Question 14

What is grade 1 of the MRC power grading scale?

Answer 14

Filcker of contraction but no movement

Question 15

What is grade 2 of the MRC power grading scale?

Answer 15

Joint movement when effect of gravity eliminated

Question 16

What is grade 3 of the MRC power grading scale?

Answer 16

Movement against gravity but not against examiner’s resistance

Question 17

What is grade 4 of the MRC power grading scale?

Answer 17

Movement against resistance but weaker than normal

Question 18

What is grade 5 of the MRC power grading scale?

Answer 18

Normal power

Question 19

What are the components to decroticate posturing?

Answer 19

1. Facilitation of the rubrospinal tract and medullary reticulospinal tracts - disinhibition of red nucleus due to disconnection from cortex leads to biased flexion of upper extremities as tone from these tracts outweighs the medial and lateral vestibulospinal and pontine reticulospinal tract which facilitates extension in the upper extremities.
2. Disruption of lateral corticospinal tract - reduces motor neuron activity in the lower spinal cord supplying flexor muscles of the lower extremities. The pontine reticulospinal and the medial and lateral vestibulospinal biased extension tracts greatly overwhelm the medullary reticulospinal biased flexion tract.

The effects on these two tracts (disruption of corticospinal and facilitation of rubrospinal) by lesions above the red nucleus is what leads to the characteristic flexion posturing of the upper extremities and extensor posturing of the lower extremities.

Question 20

Why does decerebrate posturing occur?

Answer 20

Lesions below the red nucleus cause disruption of supply to flexors. However, vestibulospinal tracts are unaffected, meaning that extensors predominate. This leads to the arms and legs being extended and rotated internally. The patient is rigid, with the teeth clenched.

Question 21

What does decorticate posturing indicate?

Answer 21

There may be damage to areas including the cerebral hemispheres, the internal capsule, and the thalamus. It may also indicate damage to the midbrain

Question 22

What does decerebrate postuing indicate?

Answer 22

Indicates brain stem damage, specifically damage below the level of the red nucleus (e.g. mid-collicular lesion). It is exhibited by people with lesions or compression in the midbrain and lesions in the cerebellum, and is commonly seen in pontine strokes

However - The traditional neuroanatomic correlates of decorticate and decerebrate postures do not hold as true for humans as for animals. As an example, often, decerebrate posturing is assumed in patients with bilateral cerebral lesions well above the red nucleus

Question 23

What does progression from decorticate to decrerebrate posturing indicate?

Answer 23

Progression from decorticate to decerebrate posturing is often indicative of uncal (transtentorial) or tonsilar brain herniation

Question 24

Where is the red nucleus?

Answer 24

Located in the tegmentum of the midbrain next to the substantia nigra and comprises caudal magnocellular and rostral parvocellular components

Question 25

What is the function of the rubrospinal tract?

Answer 25

The tract is responsible for large muscle movement as well as fine motor control, and it terminates primarily in the cervical spinal cord, suggesting that it functions in upper limb but not in lower limb control. It primarily facilitates flexion in the upper extremities

Question 26

What is the function of the vestibulospinal tract?

Answer 26

The vestibulospinal tract is an upper motor neuron tract consisting of two sub-pathways:

• The medial vestibulospinal tract projects bilaterally from the medial vestibular nucleus within the medial longitudinal fasciculus to the ventral horns in the upper cervical cord (C6 vertebra). It promotes stabilization of head position by innervating the neck muscles, which helps with head coordination and eye movement. Its function is similar to that of the tectospinal tract.
• The lateral vestibulospinal tract provides excitatory signals to interneurons, which relay the signal to the motor neurons in antigravity muscles. These antigravity muscles are extensor muscles in the legs that help maintain upright and balanced posture.