Flashcards in Neurology: Stupor and Coma Deck (21):
What two things must be intact to remain conscious?
1. Cerebral Hemispheres
2. Reticular Activating System
if either is lost the patient goes into a coma
What are some structural causes of comas?
-hemorrhage (usually damaged cerebral hemispheres)
-infarct (mainly in brainstem: RAS)
-tumor or abscess
What is the most common diffuse cause of comas?
Hypoxia in the brain.
-can result from drowning, MI, stroke
What are the top two causes of coma in general?
Alcoholism and Trauma
What are the 3 levels for checking alertness?
If a patient is unconsious, what can decorticate and decerebrate postures tell the physician?
Decorticate: means lesion is in the thalamus and hemispheres
Decerebrate: means the lesion is in the midbrain
Assessing the respiratory pattern of a comatose patient is important. Describe Cheyne-Stokes and what it means?
CS: alternating loud and quiet breathing
Indicates heart failure or a lesion in the thalamus or higher
Assessing the respiratory pattern of a comatose patient is important. Describe central neurogenic hyperventilation and what it indicates.
Shallow rapid breathing. Indicates a midbrain lesion.
Assessing the respiratory pattern of a comatose patient is important. Describe apneustic breathing and what it means.
Patients will have slow breathing, holding breaths in for extended periods of time and then holding exhalation for an extended period of time. Indicates pontine lesion.
Assessing the respiratory pattern of a comatose patient is important. What does apnea or gasping indicate?
Medullary lesion, location of the primary respiratory center
Will a patient show nystagmus in a coma?
No, the cerebral hemispheres need to be intact for nystagmus to occur.
What 4 signs would indicate a lesion at the thalamus or higher?
1. Cheyne-Stokes breathing
2. Small Reactive pupils
3. Decorticate posturing
4. Brainstem reflexes intact
4 signs that the lesion is at the midbrain in a comatose patient.
1. Central neurogenic hyperventilation
2. Mid-position fixed pupils
3. Decerebrate posturing
4. EOM impaired (depending on location of lesion in midbrain)
5 things that occur in a coma caused by a pontine injury.
1. Apneustic respiration
2. Mitotic Pupils (pin point)
3. Absent EOM
4. Absent corneal reflex
4 things that occur in a coma caused by a medullary lesion.
1. Gasping or apnea
3. Absent gag reflex
4. BP or HR irregularities
What is the first thing to remember when treating a comatose patient that presents to the ER?
Secure an airway.
Describe the presentation of an uncal herniation.
Blown Pupil, ptosis, eye deviation down and out.
-uncus herniates into tentorial notch (area between cerebral peduncles) compressing CN III as it exits the midbrain.
Patients will have impaired consciousness distinguishing the eye problems from aneurysm or diabetic infarct.
Patients may also have bouncy reflexes usually contralateral to the side of the herniation. (Herniation may be big enough to manifest bilateral hyperreflexia)
What is necessary to confirm and diagnose brain death?
-Absent cerebral and brainstem responses
-Absent cerebral blood flow
-A known diagnosis
-Absence of drug intoxication and hypothermia (both of which can mimic brain death but resolve when the problem is corrected)
(not all of these are needed)
In the Glasgow Coma Scale, describe the scale of 1-4 for the eyes.
1. Never open
2. open with pain
3. open to verbal stimuli
4. open spontaneously
In the Glasgow Coma Scale, describe the scale of 1-5 in verbal response.
1. No response
2. incomprehensible sounds
3. inappropriate words
4. disoriented and coverses