Flashcards in Coma-Aversano Deck (18):
What is a coma?
- The state in which the patient cannot be aroused to make purposeful responses
- No response to painful stimuli
What is consciousness?
Awareness of one's self and the environment
What can cause a coma?
1. Bilateral diffuse cerebral hemisphere dysfunction
2. Brainstem involvement of the ascending reticular activating system
What are the majority of comas due to?
- Metabolic and other diffuse disorders affecting the entire brain (w/o focal findings).
• Metabolic encephalopathy can cause profound coma w/ preserved pupillary responses
• Gradual onset of coma is consistent w/ metabolic process
What are the categories of diagnoses in patients admitted to hospital w/coma of unknown etiology?
1. Metabolic and other diffuse disorders (65%)
2. Supratentorial mass lesions (20%)
3. Subtentorial lesions (13%)
4. Psychiatric disorders (2%)
What does Cheyne Stokes Respiration (crescendo, decrescendo breathing) indicate?
Disorder in hemisphere (above brainstem)
What is cluster breathing?
- Ataxic breathing
What is apneustic breathing?
Less deep breathing
What should you assume about pupillary response?
All asymmetry is abnormal
What do pinpoint pupils indicate?
What do blown pupils indicate?
Tentorial herniation pinching CN III
What do midsize unreactive pupils indicate?
Damage to midbrain
Where is the dysfunction is there is an absence of Doll's Eyes (eyes move normally/in direction head moves)?
If caloric testing is abnormal, where is the problem?
What is the corneal reflex testing?
- Afferent arch = CN V
- Efferent arc = bilateral blink = CN 7
Where do eyes deviate in hemispheric lesion? Pontine lesions?
- In hemisphereic lesions, eyes deviate toward the side of the lesion.
- In pontine lesions, eyes look away from the lesion
What do decorticate and decerebrate posturing indicate?
- Decorticate posture = lesion above the brainstem (red nucleus)
- Decerebrate posture = lesion below the brainstem (red nucleus)