Manifestations of Brain Injury

What are the two subcategories of brain injury?

• Direct

• Indirect

What are direct brain injury etiologies?

The occur directly in the brain tissue and affect it directly such as infection, trauma, tumors, hemorrhage, and infarction

What are indirect injury etiologies?

Usually metabolic injuries from things like hypoxia, hypoglycemia, electrolyte imbalances, and toxins (urea, ammonia, or drugs)

What are the manifestations of brain injuries (results of significant insults)?

• Changes in level of consciousness

• Alterations in cognitive function

• Alterations in motor function

• Alterations in sensory function

• Focal injury (deficits in one area of the brain that may or may not alter LOC)

• Global injury (Extensive damage that includes a deterioration of LOC)

What is consciousness?

Critical clinical index of nervous system function or the state of awareness of oneself and environment

What are other terms used for consciousness?

• Arousal/Wakefullness

• Content/Cognition

What are the criteria to consider someone to have arousal/wakefullness?

• They are able to pay attention to things in the environment and can maintain consciousness

• They need to have both cerebral hemispheres functional

• Requires functional Reticular Activating System (RAS)

What is content/congition and how is it assessed?

It is about thoughtfulness and processing and can be assessed by asking about person, place, time, and events (tells you if the person is oriented or disoriented)

Is altered level of consciousness a direct yes or no assessment question?

No, it exists on a continuum spectrum so you have to note early or progressive signs of altered level of consciousness

What are the early signs of altered level of consciousness?

• Mild confusion/disorientation

• Blunted responsiveness

What are progressive signs of altered level of consciousness?

• Significant drowsiness (obtundation)

• Complete unresponsiveness (coma)

What are the levels of consciousness that we can chart?

• Full consciousness

• Confusion

• Lethargy

• Obtundation

• Stupor

• Coma

What classifies someone to be full consciousness?

• Awake, alert, and oriented to time, place, and person

• Comprehends spoken and written word and is able to to express ideas

What classifies someone to be at a level of confusion?

• Disoriented to time, place, or person

• Memory difficulty 

• Difficulty following commands

What classifies someone to be at a level of lethargy?

• Oriented to time, place, and person

• Very slow in mental processes, motor activity, and speech

• Responds to pain appropriately 

What classifies someone to be at a level of obtundation?

• Responds verbally with a word

• Arousable with stimulation 

• Responds appropriately to painful stimuli

• Follows simple commands 

• Appears very drowsy 

What classifies someone to be at a level of stupor?

• Unresponsive except to vigorous and repeated stimuli

• Responds appropriately to painful stimuli

• Lies quiet with minimal spontaneous movement

• May have incomprehensible sound and/or eye opening

What classifies someone to be at a level of coma?

• Does not respond appropriately to stimuli

• Sleep like state with eyes closed

• Does not make any verbal sounds

What is the Glasgow Coma Scale?

An organized method to assess level of consciousness

What are the categories of the Glasgow Coma Scale?

• Eye opening

• Verbal response

• Motor response

What are the levels of eye response in Glasgow Coma Scale?

• 4: Spontaneously

• 3: To speech

• 2: To pain

• 1: No response 

What are the levels of verbal response in Glasgow Coma Scale?

• 5: Oriented to time, person, place

• 4: Confused

• 3: Inappropriate words

• 2: Incomprehensible sounds

• 1: No response 

What are the levels of motor response on the Glasgow Coma Scale?

• 6: Obeys command

• 5: Moves to localized pain

• 4: Flex to withdraw from pain

• 3: Abnormal flexion

• 2: Abnormal extension

• 1: No response

What is the best response number for Glasgow Coma Scale?

15

What is the worst response number for Glasgow Coma Scale?

3

What does a low Glasgow Coma Scale number mean?

It has a predicted high mortality rate 

What do pupillary changes mean?

It indicates level of brainstem dysfunction

What do we say for normal pupillary dilation?

We use the acronym PERLA (Pupils are Equal Reactive Round to Light and Accomadation)

What do pupils look like when someone has brain hypoxia or ischemia?

An ominous sign of them being fixed and dilated 

What do pupils look like when someone is hypothermic?

They are fixed and nonreactive

What do pupils look like when there is cranial nerve involvement?

They are sluggish, fixed or dilated

What do pupils look like when someone is on different drugs?

• Cholinergic meds (like Atropine/scopolamine/Ach) they appear fixed and dilated

• Sedatives/Hallucinogens they are fixed, unequal, and have moderate dilation

• Opioids they are pinpoint

What are normal oculomotor responses?

Resting, Spontaneous, and Reflexive eye movements

What are the two main oculomotor response abnormalities?

• Oculocephalic

• Oculovestibuar

How do you test for the Oculocephalic abnormality?

You gently turn the patient's head side to side and observe whether the eyes stay fixed or move with the head

Due to the movement of the eyes while testing for Oculocephalic abnormalities, what is it also called?

The Doll Eyes abnormality or Doll’s Head Reflex

If the eyes in the Oculocephalic reflex are moving in the opposite direction of where the head is turning, what does this mean?

This is a positive doll’s eyes reaction and is a normal reaction meaning the brainstem is intact as well as the cranial nerves 3, 6, and 8

If the eyes in the Oculocephalic reflex are moving in the same direction of where the head is turning or do not move at all, what does this mean?

This is a negative doll’s eyes reaction and means there is damage to the brainstem, cranial nerves, or vestibular system

How do you test for the Oculovestibular abnormality?

You use the cold caloric reflex test which is when you pour ice-cold water into one ear canal which should stimulate the vestibular system and should trigger eye movement

During the Cold caloric reflex, what does it mean if the eyes move towards the cold water (nystagmus opposite stimulus)?

This is a normal response and means the brainstem is intact

During the Cold caloric reflex, what does it mean if the eyes move away from the cold water (nystagmus toward stimulus)?

This is not a normal reaction and means that there are vestibular issues 

During the Cold caloric reflex, what does it mean if there is no eye movement?

This is not a normal reaction and means that there are is brainstem damage

What are motor response tests used to assess?

They help determine brain stem dysfunction and laterality of damage

What types of patients are we testing motor responses on?

Patients who have a decline in level of consciousness because we are using noxious stimuli (aka some form of pain stimulus see if those reflex’s are intact and you don’t want to do that to someone who is aware as it will hurt)

What is the most common noxious stimuli?

Usually a sternal rub, but can also be touching a sterile gauze piece to the open eye, finger pressure to the eyelids, or rolling a rounded object over the thumbnail

What things can noxious stimuli testing tell us about a patient?

• Global vs. unilateral weakness (Is one side weaker than the other?)

• Purposeful vs. non-purposeful movement (Is the brain still coordinating intentional actions?)

• Inappropriate, generalized movement (non-purposeful, widespread motor activity that doesn’t localize to pain or follow a coordinated pattern)

• Posturing patterns (An ominous signs)

• Complete absence of movement (Suggests severe brain dysfunction)

What are the two types of posturing signs?

• Decorticate

• Decerebrate

What is decorticate posturing?

The limbs move towards the core (arms flex, fists form, plantar areas flex, legs internally rotate, etc) which means there is damage above the midbrain

What is decerebrate posturing?

The limbs move into lots of “e” shapes (hands do a reversed fist, the arms abduct, extend and pronate, the neck twists back a little with hyperextendion, etc - no internal rotation) and means there is damage at the midbrain or pons 

Which posturing patterns signifies significant damage?

Decerebrate posturing is a lot worse and signifies severe dysfunction

What does evaluating breathing patterns help us determine?

The level of brain dysfunction

What things do we look at when evaluating breathing patterns?

• Rate

• Rhythm

• Pattern (Patterns can be categorized as hemispheric or brainstem patterns)

What are the types of respiratory patterns?

• Cheyne-Strokes respirations

• Hyperventilation

• Apneustic breathing

• Cluster breathing

• Ataxic breathing

What are Cheyne-Stokes respirations?

A cyclic patterns of alternating hyperpnea and apnea (switching between periods of breathing quickly and breathing really slow or not at all)

What do Cheyenne-Stoke respirations mean?

• Means there is bilateral hemispheric or diencephalic damage (very very bad sign)

• Can also indicate the brainstem is herniating 

• Can be seen in CHF, COPD, OSA, and Uremia patients 

What is hyperventilation breathing pattern?

Very fast respiratory rate

What does hyperventilation indicate?

• Injury in the pons or midbrain

• Respiratory failure

• Hemodynamic shock

• Fever

• Sepsis

• Metabolic dysfunction

• Psychiatric disease

(Not usually when there is brain damage, but can be when the pons or midbrain are damaged)

What is apneustic breathing pattern?

When there are normal breaths but with a prolonged pause at the end of inspiration 

What does apneustic breathing patterns mean?

Usually means that the lower half of the pons is damaged (very ominous sign)

What is clustered breathing?

When there are periodic respirations that are irregular in frequency and amplitude with variable pauses between clusters of breaths (Similar to Cheyenne-Stoke respirations but without a distinct pattern) 

What does cluster breathing indicate?

Indicates damage to the lower pons 

What is ataxic breathing?

Irregular in both rate and tidal volume (no rhyme or reason to the breathing pattern)

What does ataxic breathing mean?

Suggests damage to the medulla