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Neuro Coma
CM Neurology Coma
| Question | Answer |
|---|---|
| Definition of coma | A patient is said to be in coma if she is unable to sense or respond to external stimuli or inner needs. |
| Coma is not | a disease. It is an expression of an underlying pathologic process |
| __________is a high level function that permits understanding of self and environment. This function resides diffusely in the cerebral cortex. | Awareness |
| _______is a more primitive function and refers to a primitive set of responses that are contained totally within the brainstem. | Arousal |
| Arousal can occur without | awareness |
| What must occur for loss of consciousness to occur? | Either both cerebral hemispheres must be damaged or there must be a brainstem lesion |
| Number one cause of coma | Metabolic cause (50%); of these 50% from drug ingestion. 5-10% of these from hypoglycemia |
| Sudden onset of coma suggests | cardiac arrest, subarachnoid hemorrage (oftentimes secondary to aneurysm), brainstem infarct or hemorrhage, bicerebral hemispheric infarct |
| Causes of coma with slower onset | drug overdose, hypoxia, hypoglycemia, subarachnoid hemorrhage, acute hydrocephalus, vascular malformation, meningitis and encephalitis, metabolic (uremia; hepatic failure), hypertensive encephalopathy |
| COMA Physical exam | Skin (trauma, needle marks, rash), Head (battle's sign, racoon's eyes, rinorrhea or otorrhea, fundoscopic exam), Neck, Breath, Cardiac, Sensation |
| Mastoid fx that causes a a retroauricular hematoma | Battle's sign |
| Racoon eyes suggest | Orbital fracture |
| Rhinorrhea or otorrhea suggest | basilar skull fx |
| Needle marks can suggest | recreational drugs or insulin |
| Neck stiffness may suggest | meningitis or subarachnoid hemorrhage |
| Sign of increased intracranial pressure | papilledema (trauma or hypertensive encephalopathy) |
| Fruity breath | Ketoacidosis |
| Fetor Hepaticus | the smell of liver dx |
| General exam needs to be completed including a | rectal with stool guaiac |
| If checking sensation, watch for | purposeful withdrawal bilaterally, absent response unilaterally, facial grimace, posturing |
| What do you do in posturing? | Take your knuckles and rub forcefully on the sternum |
| Decorticate posturing | Patient brings arms upward. hemispheric or diencephalic dysfunction due to destructive lesions or metabolic abnormality. Upper brain |
| Decerebrate posturing | arms down and wrists turned out. midbrain or upper pons dysfunction on a structural or metabolic basis. |
| Posturing response does not tell the difference between | structural and metabolic |
| This type of respiratory pattern is commonly caused be metabolic dysfunction | Central neurogenic hyperventilation (sepsis, DKA) |
| Ataxic Breathing (biot's respiration) | Damage to the medullary respiratory centers. Common among dying patients |
| Respiratory pattern associated with pontine infarction | Apneustic |
| Cheyne's Stokes Respiratory Pattern | Bilateral hemispheric lesions. Most commonly seen in non-neurologic disorders (CHF). |
| The most common reason for noting unreactive pupils is | an inadequate light source |
| reactive pupils indicate that | the midbrain is intact |
| Miposition (3-5mm) nonreactive pupils indicate | midbrain damage |
| Blown pupil is a sign of | Cranial Nerve III compression (aneurysm, mass lesion) |
| A dilated nonreactive pupil may also be caused by | DM and some drugs (especially atropine, scopolamine) |
| small reactive pupils | are seen in pontine damage (infarct or hemorrhage) or with some drug use (opiates, pilocarpine). |
| bilateral midposition unreactive pupils | can be seen with hypothermia |
| Eyes deviate _____ a unilateral hemispheric lesion and ______ a unilateral brainstem lesion | toward; away |
| Oculocephalic reflex (doll's) | Take head in both hands and rapidly turn to right. (eyes should go to opposite direction of head; head turns right, eyes turn left) |
| Oculo-Vestibular Reflex | Shut off one ear with ice cold water and eyes should go to that side. Quick of phase of nystagmus to the opposite side. No eye moevemnt at all -brainstem lesion, no nystagmus - cortical lesion |
| The oculo-vestibular response does not distinguish between | metabolic and structural causes of coma |
| Abnormal resposne to corneal sensation suggests | pontine lesion |
| Don't do an MRI or CT on a coma patient until | they are stabilized |
| Lowest possible glasgow coma scale score | 3 |
| What score indicates coma? | <8. |
| Glasgow coma scale tests | eye, verbal, motor responses |
| How many points does a patient get for opening their eyes in response to pain? | 2 |
| Techniques to apply pain to ilicit a response | knuckle on fingernail bed, supraorbital or sternum |
| How many grades are there for each Glasgow test? | Eye - 4, Verbal - 5, Motor - 6 |
| Brain dead characteristics | no purposeful movements, no pupillary responses, no EOMs, no corneal reflexes, no spontaneous respirations or movements. DTRs can be present. There are NO documented recoveries from brain death in an adult patient. |
| Vegetative States | Almost all pts in coma will eventually wake up to some degree. Eyes may open in response to verbal stimuli. Can live off a ventilator and are cardio stable. |
| Which drug has shown some promise in vegetative pts? | benzodiazapenes. |