Term
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Definition
| Sleepy but easily aroused |
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Term
|
Definition
| excessively sleepy but normal cognition when awakened |
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Term
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Definition
| mental blunting, decreased alertness |
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Term
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Definition
| eyes open only briefly after vigorous stimulation before returning to deep sleep. Cognition impaired |
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Term
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Definition
| Eyes Remain Closed after vigorous stimulation |
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Term
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Definition
| disoriented, misperception of sensory stimuli, hallucinations. Vacillates between quiet, sleepy periods and hyper-vigilance/agitation |
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Term
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Definition
Awake but apathetic, no spontaneity.
Cognitive function my be normal with virorous stimulation |
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Term
| What usually occurs in a patient with severe bifrontal lobe damage (lobotomy)? |
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Definition
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Term
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Definition
silent, alert-appearing immobility.
No mental activity with vigorous stimulation |
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Term
| If akinetic mutism lasts more the 30 days what is the patient said to be in? |
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Definition
| Persistent Vegitative state |
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Term
| What usually occurs in a patient wi disease of frontal lobes and hypothalamus? |
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Definition
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Term
| If a patients appears to be in a vegetative state but has fragments of awareness and meaningful interaction what are they said to be in? |
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Definition
| Minimally Conscious State, MCS |
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Term
| What are the 2 components of consciousness? |
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Definition
|
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Term
| What does the the content of consciousness refer to? |
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Definition
Awareness of:
One self
Environment |
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Term
| How is wakefulness achieved? |
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Definition
| neural circuits the mediate sleep-wake cycles |
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Term
| What is the ascending arousal system? |
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Definition
| Rostral Brainstem area responsible for sleep-wake cycles achieved by neural circuits |
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Term
| What does disruption of the Ascending arousal system cause? |
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Definition
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Term
| What is caused by disease affecting the content of consciousness? |
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Definition
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Term
| Where were lesions found in patients with encephalitis lethargica, (1916)? |
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Definition
| rostral periaquductal grey matter and posterior 3rd ventricle |
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Term
| Where lesions found that cause insomnia? |
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Definition
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Term
| Where is the sleep promoting area? |
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Definition
| ventrolateral preoptic nucleus |
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Term
| What does a brainstem transection at the level of the cervical medulla cause? |
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Definition
| quadriplegia and respiratory arrest |
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Term
| At what point does a lesion of the brainstem affect wakefulness defined by the EEG pattern? |
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Definition
| upper pontine and midbrain level |
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Term
| What type of brain wave pattern on EEG is characterixtic for the awake state? |
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Definition
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Term
| What type of brain wave pattern on EEG is seen in sleep and in some patients with coma? |
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Definition
| "synchronized", high voltage slow waves |
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Term
| Where are the 4 Primary lesions that cause coma? |
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Definition
1. Extensive, acute bihemispheric disease
2. Lesions of the diencephalon (thalamus & hypothalamus)
3. Lesions of midbrain peri-aquiductal grey
4. Involvement of upper one third of pontine tegmentum. |
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Term
| What do all the primary lesion areas have in common except for bihemispheric lesions? |
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Definition
| include the reticular grey formation |
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Term
| Where is the paramedian tegmental area? |
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Definition
| ventral to the aqueduct of Sylvius from midbrain to the rostral pons |
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Term
| What do Lesions below the rostral pons disrupt? What does it cause? |
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Definition
corticospinal and corticobulbar tracts bilaterally
Leave patient quadriplegic with paralyzed lower face - unable to speak, swallow, or breath on own, but conscious, aware, can see and hear, and usually retain eye movement control |
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Term
| T/F Lesions confined to the upper pons can cause coma even in the absence of midbrain & thalamic injury. |
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Definition
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Term
| What is the reticular activating system? |
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Definition
| areas of the reticular formation that could when damaged result in coma |
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Term
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Definition
| intralaminar nuclei of the thalamus, the tegmentum of midbrain, and tegmentum of upper 1/3rd pons |
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Term
| Where do the LDT and PPT project to and what does it cause? |
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Definition
Project to thalamic relay nuclei and inhibit it from firing
Increases wakefulness and thalamus in "transmission" mode |
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Term
| What does increased bursting by thalamic relay neurons promote? |
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Definition
| synchronization of cortical activity and induces sleep |
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Term
| What directly activates the cortex? |
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Definition
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Term
|
Definition
| misperception of incoming stimuli |
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Term
| How do monoaminergic inputs avoid misperception? |
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Definition
| improve the signal to noise ratio |
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Term
| Where is the sleep promoting center in the brain? |
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Definition
| Ventro-Lateral Preoptic nucleus, VLPO |
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Term
| What inhibitory neurotransmitter does the VLPO depoly? |
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Definition
|
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Term
| What parts of the brain sends feedback to the AAS? |
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Definition
Thalamus
Limbic System
Frontal and association cortex |
|
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Term
| What pathways mediate emotional memories? |
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Definition
| Feedback pathways to the AAS |
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Term
| What does loss of feedback to the AAS cause? |
|
Definition
| apathy and indifference to sensory stimuli |
|
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Term
| What are the 2 broad categories coma is divided into? |
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Definition
|
|
Term
| what are structural causes of coma? |
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Definition
Supratentorial mass lesions
Acute obstructive hydrocephalus
Infratentorial mass lesions |
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Term
| What are Metabolic causes of coma? |
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Definition
Reversible injury - sedative overdose
Irreversible injury - hypoxia in cardiac arrest |
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Term
| What type of coma will show focal deficits on exam and an abnormal CT or MRI? |
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Definition
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Term
| In a patient with a blow to the side of the head who has early loss of pupil reactivity to light, what should be done immediately? |
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Definition
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Term
| What nerve is entraped by a transtentorial herniation of the uncus? |
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Definition
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Term
| What symptoms will develop after pupillary abnormality cause by an uncal herniation? |
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Definition
ptosis and weakness of ocular movement
increased lethargy and contralateral hemiparesis
Contralateral Babinski sign |
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Term
| What artery can become trapped in an uncal herniation? What can this cause? |
|
Definition
posterior cerebral artery
ipsilateral ischemia and stroke |
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Term
| What are small hemorrhages in the brainstem called? |
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Definition
|
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Term
| What gets caught between the herniating temporal lobe and the upper brainstem? |
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Definition
|
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Term
| What does a falcine herniation cause? |
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Definition
| trap and compress anterior cerebral arteries against the falx to cause ischemic stroke in the parasagittal cortex |
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Term
| What can produce diffuse and symmetrical pressure on the brain medial and downward to cause central herniation? |
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Definition
| metabolic insults - hypoxia or cerebral edema that accompanies fulminant liver failure |
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Term
| What is a late sign of central herniation? |
|
Definition
| Decorticate or flexor posturing followed by decerebrate or extensor posturing |
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Term
| What is an early warning sign of central herniation? |
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Definition
| Cheyne-Stokes respirations |
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Term
| What are Cheyne-Stokes respirations? |
|
Definition
| characterized by apneic spells interspersed with hyperventilation periods |
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Term
| What are the symptoms of central herniation? |
|
Definition
| Lethargy -> small reactive pupils -> Constrictive pupillary tone is lost, pupils become fixed in midposition |
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Term
| How does a Central Herniation proceed through the brain stem? |
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Definition
Rostral -> Caudal deterioration
Thalamus(Reticular grey area) -> Hypothalamus(Central Sympathetic Tracts)-> Midbrain (Edinger-Westphal nuclei) |
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Term
| Where are infratentorial lesion found? |
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Definition
| below the cerebellar tentorium in the posterior fossa. |
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Term
| What are examples of Intrinsic Infratentorial lesions? |
|
Definition
Directly damage the brainstem
-Top of the basilar arter ischemic stroke
-Pontine hemorrhage |
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Term
| What are examples of Extrinsic Inratentorial Lesions? |
|
Definition
Compress and Distort the brainstem
-Cerebellar hemorrhage, Infarction, Brain Tumor |
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Term
| What do Primary Brainstem Lesions cause? |
|
Definition
Segmental Cranial Nerve Deficits
Ascending tract dysfunction
- Pain and Temperature (Spinothalamic)
- Fine touch, vibration and proprioceptive (medial lemniscus)
Descending (Corticospinal, central sympathetic) tract dysfunction - motor pathways
Early cerebellar signs |
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Term
| What is the clinical syndrome of a Pontine hemorrhage? |
|
Definition
Coma is abrupt
Pupils are pinpoint
Decerebrate rigidity or Flaccid Quadriplegia
Horizontal gaze paresis
Ocular bobbing |
|
|
Term
| What is the largest category of coma etiologies? |
|
Definition
|
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Term
| What are some examples of Metabolic Encephalopathy? |
|
Definition
hyponatremia
hypoglycemia/hyperglycemia
hypothermia
uremia
hepatic failure
thiamine deficiency
hypoxia
drug intoxications |
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Term
| How is a metabolic encephalopathy recognized? |
|
Definition
Neuro-exam - "non-focal"
Head CT - Negative
Pupils stay reactive to light!!
Asterixes, multifocal myoclonus and tremor |
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Term
| What are the most common etiologies for Asterixes, multifocal myoclonus and tremor? |
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Definition
| Uremia, Liver failure, Hypoxia |
|
|
Term
| What metobolic conditions can pupils become dilated and fixed? |
|
Definition
atropine poisoning
botulism and glutethimide intoxication |
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Term
| What account for about 90% of cases in the elderly? |
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Definition
Dehydration
Drug Intoxication
Infection |
|
|
Term
| What can mimic metabolic encephalopathy? |
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Definition
|
|
Term
| How can a new metabolic encephalopathy be mistaken for an acute structural lesion? |
|
Definition
| unmask an old lesion, like a stroke, and create focal weakness |
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Term
| What is the immediate management of coma? |
|
Definition
ABC's
-Secure Airway
-Cardiac monitor
-IV access & Blood drawing
Stabilize Neck
History
Exam
Empirical D50, Thiamine, Naloxone
(All preformed simultaneously) |
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|
Term
| If you find normal vital signs in someone who is not responding to voice or nailbed pinch, what should be considered? |
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Definition
|
|
Term
| What is the most helpful in making a diagnosis when assessing a comatose patient? |
|
Definition
|
|
Term
| What does the presence of retinal venous pulsations mean? |
|
Definition
| No increased intracranial pressure |
|
|
Term
| What is Central neurogenic hyperventilation attributed to? |
|
Definition
Midbrain lesions
neurogenic pulmonary edema |
|
|
Term
| What is Cluster and ataxic breathing associated with? |
|
Definition
| caudal pontine or medullary lesions |
|
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Term
| What types of noxious stimuli can be used to arouse patients who do not respond to voice command? |
|
Definition
supraorbital pressure nailbed pinch Sternal rub
(do NOT use titty twisters) |
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Term
| What is the flexor response (decorticate posturing) to pain due to? |
|
Definition
| loss of coritcal control of brainstem motor centers |
|
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Term
| What is the Extensor response (decerebrate posturing) due to? |
|
Definition
| loss of red nucleus and rubrospinal tract in the midbrain |
|
|
Term
| what is the hierarchy of motor responses following brain injury? |
|
Definition
Obeys
Localizes
Withdraws
Abnormal flexion (decorticate posturing)
Extensor response (decerebrate posturing)
No Response |
|
|
Term
| What is the Glasgow coma score based on? |
|
Definition
| Eye opening, Motor response, verbal response |
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|
Term
| What is the prognosis of a patient with a score 8 or below? |
|
Definition
|
|
Term
| What is the prognosis for a Glasgow coma score of 3? |
|
Definition
|
|
Term
| At day 3 abscence of what reflexes caries a poor prognosis for non-traumatic coma? |
|
Definition
| absence of pupillary light and corneal reflex |
|
|
Term
| Absence of what at 3 days carries a poor prognosis in hypoxic coma? |
|
Definition
| purposful motor movements |
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