What is consciousness?
Awareness of self and environment
What is delirium?
- state characterized by disoreintation, fear, irritability, mispreception of sensory stimuli, and visual hallucinations
- lucid periods can alternate with delirius episodes....so you do not always have to present the symptoms above all the time
What are the characteristics of an alert patient?
patient is awake and responds to questioning
What does a lethargic patient do?
- lethargy describes a certain alertness
- a lethargic patient is more than sleepy and falls asleep during questioning, but can still be aroused
What does a stuporous patient present as?
- patient is unresponsive and must be aroused with vigorous and repeated stimuli
- stupor is a degree of alertness much like alert, lethargy, and coma
What does a comatose patient present as?
- a patient who is comatose does not respond to anything and "unarousable"
- coma is a way to describe a patient's alertness
What fall under the differential diagnosis of a coma?
- locked in state
- persistent vegitative state
- akinetic mutism
- cause: infarction of the ventral pons due to thrombosis of the basilar artery
- presentation: paralysis of all 4 extremities and lower cranial nerves, therefore vertical eye movements and eye-lid blinking are the only way to communicate
Persistent Vegetative State
- conditions of people who survive severe brain injury without recovering manifestations of higher mental activity after 1 month of the injury
- no awareness of self or environment
- inability to interact with others
- no evidence of behavioral responses to stimuli
- Bowel and bladder incontinence
- Brainstem and hypothalamus autonomic functions must be spared
- Some cranial nerve reflexes maybe spared
- presentations: unresponsive and will ignore external stimuli; "waxy flexability" (catelepsy) and echolalia (repitition of words); may not blink to threat
- risk factors: Bi-Polar disorder, PTSD, catatonic schizophrenia
- tx: benzodiazepines or anti-pyschotics
- similar to akinetic mutism
- patient has a lack of will
- probably a result of cerebral injuries
- creates problems with rehab, b/c they don't care/don't want to do it
- presentations: silent, alert-looking immobility, sleep-wake cycles have returned, but no evidence for mental activity
- cause: bilateral destruction of cerebral cortex, hydrocephalus, bilateral BG lesions, paramedian lesion in the reticular formation in the midbrain
- patient fakes it
- but cannot be sustained for more than a few minutes because neurologists are mean people and can shock them and make it very uncomfortable for them
Where must a focal lesion be in a patient who has stupor, coma, or delerium?
- In the brainstem
- If the lesion is in the cortex, it is generally multifocal or diffuse
What are three ways comas come about?
- any supratentorial lesion that compresses or damages ascending reticular activating systems
- subtentorial mass that directly damages the brainstem central core
- metabolic disorders that affect brain function
What five things should be noted in a neurological examination of a patient who is comatose?
- state of consciousness which is evaluated by the glasgow scale
- respiratory pattern
- pupil size and reactivity
- ocular motility (occular motor reflexes)
- motor system
Glasgow Coma Scale
- low points are bad, high points good
- broken down into eye (4), verbal (5), motor (6)
If a patient presents with ataxic breathing or slow, regularly breathing where is the damage to this patient?
If a patient presents with apneustic breathing (gasping followed by normal), cluster breathing, ataxic breathing or slow regular breathing, where is the lesion at?
Lower pontine tegmentum
If a patient presents with psuedobulbar paralysis of voluntary control, where does their lesion lie?
If a patient has hyperventilation, then where is their lesion at?
midbrain-rostral pons tegmentum
What are the characteristics of forebrain damage?
- psuedobulbar laughing or crying
- Cheyne-Stokes respiration (oscillation of apnea and tachypnea)
If a pupil size is small and reactive, what is the DX?
metabolic problem and/or diencephalic lesion
If the pupils are dialated, fixed and present unilaterally, what is the DX?
CN III compression
Patients that have pupils that are midposition and fixed likely have what?
A lesion in the midbrain
Pinpoint pupils usually indicates a lesion where?
What is the ciliospinal reflex and what does it test?
- the test consists of pinching the patient and seeing dialation of the pupils
- if marked dialation, then more indicative of coma/sleepthis tests the integrity of the sympathetic pathways
If a patient can blink, what does this indicate?
that the pontine reticular formation is intact
- AKA "Doll's Eyes"
- Positive response is both eyes deviating opposite of the head turn
- then the eyes rapidly return after the head is moved
- Test lateral eyemovents by placing cold water in ear canal and watching eyes deviate that way
- Non-normal response would be no movement
What would you see in a patient that was comatose that told you they had a poor prognosis?
- Absense of Bilateral somatosensory evoked potentials (SSEP) w/1-3 days
- >33ug/L of serum neuron-specific enolase w/1-3 days
- presence of seizures or myoclonus
- Burst Suppression pattern on EEG
What are the 5 criteria for brain death?
- No spontaneous respirations
- Absent Brain Stem reflexes (cold caloric testing, gag reflex, pupillary responses, facial motor reflexes)
- Isoelectric EEG (flat lined)
- Abscence of reversable cause (drug overdose, patient is above 32 C)
What is the apnea test?
Observing the patient's ability to breath and maintain oxygen levels w/o ventillator
What are supportive tests to help declare brain death?
- Nuclear Perfusion
- Cerebral Angiography
- Transcranial Doppler
- Intracranial pressure monitering
- Evoked potential monitering