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Flashcards in Aspects of Neurological Examination Deck (26):
1

 

 

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

 

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

2

 

 

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

 

  • 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

 

3

 

 

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

 

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

4

 

 

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

 

+++

5

 

 

How would you note a normal reflex in case notes?

 

++

6

 

 

How would you note a diminished reflex in case notes?

 

+

7

 

 

How would you note an absent reflex in case notes?

 

-

8

 

 

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

 

Large toe extends and other toes abduct

9

 

 

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

 

Only large to extends

10

 

 

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

 

Only large to extends

11

 

 

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

 

No movement of large toe

12

 

 

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

 

Large toe and other toe extends, ankle dorsiflexes

13

 

 

What is grade 0 of the MRC power grading scale?

 

No muscle contraction

14

 

 

What is grade 1 of the MRC power grading scale?

 

Filcker of contraction but no movement

15

 

 

What is grade 2 of the MRC power grading scale?

 

Joint movement when effect of gravity eliminated

16

 

 

What is grade 3 of the MRC power grading scale?

 

Movement against gravity but not against examiner's resistance

17

 

 

What is grade 4 of the MRC power grading scale?

 

Movement against resistance but weaker than normal

18

 

 

What is grade 5 of the MRC power grading scale?

 

Normal power

19

 

 

What are the components to decroticate posturing?

  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.

20

 

 

Why does decerebrate posturing occur?

 

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.

21

 

 

What does decorticate posturing indicate?

 

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

22

 

 

What does decerebrate postuing indicate?

 

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

23

 

 

What does progression from decorticate to decrerebrate posturing indicate?

 

 

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

24

 

 

Where is the red nucleus?

 

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

25

 

 

What is the function of the rubrospinal tract?

 

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

26

 

 

What is the function of the vestibulospinal tract?

 

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.