Clin: Stupor and Coma Flashcards
What is central transtentorial herniation and the signs/symptoms?
- Herniation into foramen magnum
- Leads to early coma, small pupils, normal EOM’s, posturing and later bilateral fixed pupils
- Respiratory arrest and death
Impaired consciousness means involvement of what 3 things?
- Diffuse or bilateral impairment of both cerebral hemispheres, or
- Failure of brainstem ARAS, or
- BOTH
What is the characteristic signs of someone with diffuse/metabolic injury of the nervous system (i.e., motor signs, consciousness, breathing, and presentation)?
- Confusion and stupor commonly precede motor signs
- Motor signs usually symmetrical
- Pupillary rxns usually preserved
- Asterixis, myoclonus, tremor, seizures common
- Acid-base imbalance with hyper or hypoventilation
- Fluctuating level of consciousness
Rule of thumb for lesion location when pupils are enlarged bilaterally?
Bilateral CN III lesion, post-ictal, or intoxications
Which state of altered consciousness is represented by arousal only to noxious stimuli and not enviornmental, only rudimentary awareness (i.e., purposeful motor response)?
Stupor
The initial signs of a supratentorial mass lesion are usually (global or focal)?
How do the signs progress?
Motor signs are often?
- Initial signs usually focal
- Progression of signs is rostral to caudal (i.e., herniation pushing down)
- Motor signs are often asymmetric
What are the criteria for persistence of brain death?
- 6 hours w/ confirmatory (flat) EEG: performed to tech. standards of AEES
- 12 hours w/o a confirmatory isoelectric EEG
- 24 hours for anoxic brain injury w/o confirmatory isoelectric EEG
What must be known when making the call of brain death?
Cause of the coma should be known, it MUST be adequate to explain the clinical picture, and it MUST be irreversible
Which level of the pons is assessed with the Oculocephalic manuever (Doll’s Eyes) vs. Caloric (oculovestibular) reflex test?
- Oculocephalic = mid pons; assess CN III, IV, and VI
- Caloric = lower pons
What is the location of the lesion if the eyes have a ping-pong nystagmus?
Bihemispheric, midbrain
Which test can be done to clinically document someone as being brain dead?
- Apnea test
- Disconnect ventilator –> Catheter w/ 100% O2 and observe chest wall and abdomen for movement
- No respiratory movements for 8 mins (PCO2 >60mmHg
What are specific interventions that can be done to reduce ICP?
- Elevate head of bed
- Intubate and hyperventilate to PCO2 of 20 mmHg
- Use mannitol for ischemic lesions
- Use decardron for tumor, abscess, and perhaps cerebral hemorrhage
What defines unresponsivness in someone who is truly brain dead?
Absence of?
- Unresponsive to ALL sensory input, including pain and speech
- Absent brainstem reflexes
What is Decorticate vs. Decerebrate posturing and where is the lesion for each?
- Decorticate = arms flexed, legs extended (hemispheric)
- DEcrebrate = all extremities Extended (brainstem)
During a general medical exam of the skin of a patient with impaired consciousness what should be considered with dry skin?
- Hypothyroid
- Drugs (anticholinergics, TCA’s)