Coma Flashcards
Coma examination components
-Neurological exam of altered consciousness -Vital signs -Respiratory patterns -LOC -Pupils -Ocular movements -Motor responses
Neurological exam of altered consciousness
-Normal=no external stimulation needed -Somnolent=When not stimulated patient will drift off -Obtunded=External stimulus leads to abnormal waking, then goes back to sleep -Coma=no wakefulness but still will get eye movement responses and pupillary response
Cheyne-stokes respirations
-Waxes and wanes -Caused by bilateral lesions around the brain diencephalon
Central neurogenic hyperventilation
-Lesions in midbrain, only left with respiratory patterns from pons and medulla
Apneustic respirations
-Pons damaged, only medulla left for respiration
Ataxic respirations
-Lower troubles in medulla
Pupillary light reaction problem localization
- Metabolic-small and reactive
- Diencephalic-small and reactive
- Tectal-large and fixed
- CN II (uncal)-dilated in one eye, fixed
- Pons-pinpoint
- Midbrain-midposition, fixed
Decorticate posturing
- Abnormal flexor response of the arm with extension of the legs
- Same as spastic hemiparesis
- Lesion above the level of the red nucleus in the midbrain
Decerebrate posturing
- Abnormal extensor response of the arm and leg
- Lesion caudal to the red nucleus
- Release of vestibulospinal output
Bilateral midbrain stage
- Sustained regular hyperventilation. Rarely cheyne stokes.
- Midposition fixed pupils
- Impaired eye movement, may be disconjugate
- Usually motionless, sometimes decerebrate
Bilateral diencephalic stage
- Cheyne stokes
- Small pupils with small range of contraction
- Absent nystagmus
- Motionless or decorticate
Bilateral pontine stage
- Eupneic or slow and irregular breathing
- Fixed midposition pupils
- No response to oculocephalic or oculovestibular tests
- Motionless and flaccid, bilateral babinski
Unilateral diencephalic stage
- Eupneic or cheyne stokes breathing
- Small pupils with small range of contraction
- Full conjugate eye turning
- Appropriate motor response to noxious orbital roof pressure
- Bilateral babinski
Late third nerve stage
- Regular sustained hyperventilation or cheyne-stoke
- Ipsilateral dilated pupil that does not constrict
- Ipsilateral eye can’t move medially
- Decorticate or decerebrate response
Uncal herniation
- Can cause a midbrain coma
- Reversible
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