Coma and PVS

Question 1

coma

Answer 1

*severely depressed responsiveness
*defined by Glasgow Coma Scale

Question 2

acute encephalopathy

Answer 2

*rapidly developing pathobiological process in brain
*within hours, days, less than 4 weeks

Question 3

delirium

Answer 3

*clinical state characterized by combination of features (DSM-V)
*disturbance in awareness, attention, and cognition, short period, acute change, fluctuates, not explained by neurological disorder, direct consequence of medical condition

Question 4

brain lesions that cause coma

Answer 4

*diffuse cortical damage; global anoxia
*diencephalon injury; tumor
*caudal diencephalon and upper midbrain paramedian basial stroke
*brainstem lesions involving ARAS

note - brainstem lesions may be very large without causing coma if they don’t involve the ARAS bilaterally

Question 5

ascending arousal system

Answer 5

*cholinergic system - INPUT into the reticular nucleus, thalamus, and upper brainstem
*cortical activation (glutamate, norepinephrine, etc)

Question 6

NREM sleep vs coma

Answer 6

*BOTH have EEG patterns (increased high voltage slow waves) and both have lack of activity of ascending arousal system
*sleep = intrinsically regulated inhibition of arousal system
*coma = impairment of the arousal system by damage, diffuse dysfunction of its diencephalon/forebrain targets

Question 7

approach to patient with coma

Answer 7

1. evaluate/treat circulation, airway, breathing, and cervical spine
2. exclude/treat hypoglycemia or opioid/benzodiazepine overdose
3. serum chemistries, arterial blood gas, urine toxicology screen
4. emergent cranial CT (CT angio brain if appropriate) to determine if coma etiology is structural or vascular

Question 8

“house” approach for etiology of coma

Answer 8

1) structural
2) vascular
3) electric
4) chemisty/metabolic

Question 9

examples structural etiologies of coma

Answer 9

-subdural hygroma causing midline shift and falcine herniation
-left MCA ischemic stroke, causing malignant cerebral edema and uncal herniation
-right basal ganglia hemorrhage with intraventricular hemorrhage
-obstructive hydrocephalus causing bilateral midbrain compression

Question 10

example vascular etiologies of coma

Answer 10

-brainstem infarcts caused by acute basilar artery thrombus

Question 11

metabolic causes of coma/altered mental status

Answer 11

*hypoglycemia
*hypoxemia
*toxin accumulation
*neurotransmitter deficiency or surplus

Question 12

diagnostic evaluation of altered mental status

Answer 12

*history
*physical exam
*labs
*imaging

Question 13

important history for altered mental status

Answer 13

*onset
*recent symptoms
*injury
*known medical illness (ex a-fib)
*psych history
*access to drugs (therapeutic or recreational)

Question 14

important physical exam for altered mental status

Answer 14

*ABC (airway, breathing, circulation)
*vitals - BP, HR, RR, respiratory patterns, O2 sats
*systemic exam (nuchal rigidity, trauma, ingestion/njection/illness)
*neuro exam:
-mental status: GCS, arousal, awareness
-brainstem reflexes (pupil eye mvmts, corneal, oculovestibular, oculocephalic, cough/gag)
-muscle (motor response, reflexes, tone)
-sensory/cerebellar !!
-fundoscopy

Question 15

Cheynes-Stokes respiratory pattern in coma patient

Answer 15

*characterized by cyclical episodes of apnea and hyperventilation
*INTACT brainstem respiratory reflexes

Question 16

hyperventilation respiratory pattern in coma patient

Answer 16

indicative of:
-bihemispheric lesions
-midbrain
-pons

Question 17

apneic respiratory pattern in coma patient

Answer 17

indicative of:
-bilateral pons
-severe metabolic derangement

Question 18

pupil reflexes in acute uncal herniation

Answer 18

*3rd nerve palsy (dilated pupil, down and out)

Question 19

3 P’s of acute lesions to PONS

Answer 19

*paralysis
*pinpoint pupils
*pyrexia (fever)

Question 20

glasgow coma scale

Answer 20

*a numerical scale of 15 that determines a patient’s level of consciousness based on eye opening, verbal response, and motor response
*scored based on best response (not for each limb)
*GCS 8… intubate

Question 21

GCS - eye opening scale

Answer 21

4 = spontaneously
3 = to speech
2 = to pain
1 = no response

Question 22

GCS - verbal response scale

Answer 22

5 = oriented to time, person, and place
4 = confused
3 = inappropriate words
2 = incomprehensible
1 = no response

Question 23

GCS - motor response scale

Answer 23

6 = obeys command
5 = moves to localized pain (actively shoving pain away)
4 = flex to withdraw from pain
3 = abnormal flexion (decorticate posturing)
2 = abnormal extension (decerebrate posturing)
1 = no response

Question 24

brainstem deficits and limb weakness on same side indicates

Answer 24

cortical/subcortical damage

Question 25

brainstem deficits and limb weakness on opposite sides of the body indicates

Answer 25

brainstem damage

Question 26

falcine herniation - syndrome

Answer 26

contralateral leg weakness (if ACA gets compressed)

Question 27

uncal herniation - syndrome

Answer 27

*sluggish then blown pupil *parasympathetic fibers of CN3 *down and out eyeball with ipsilateral ptosis *contralateral paralysis *PCA infarction **Kernohan's notch on autopsy

Question 28

transtentorial herniation - syndrome

Answer 28

diencephalic > mesencephalic > medullary stage

Question 29

management of coma

Answer 29

*ABCs *thiamine, glucose, narcan *emergent neuroimaging *evaluate for acute stroke *evaluate for acute seizures *early differential diagnosis drives early evaluation: structural/nonstructural/metabolic

Question 30

coma: awareness and arousal states

Answer 30

*no arousal *no awareness

Question 31

vegetative state: awareness and arousal states

Answer 31

*full arousal *no awareness

Question 32

minimally conscious state: awareness and arousal states

Answer 32

*full arousal *partial awareness

Question 33

locked-in syndrome: awareness and arousal states

Answer 33

*full arousal *full awareness *NO VOLUNTARY MOVEMENT

Question 34

persistent vegetative state

Answer 34

*unawareness unwakefulness syndrome *a person is AWAKE but is showing NO SIGNS of awareness (opens eyes, wake up and fall asleep at regular intervals, have basic reflexes) *no meaningful responses, such as following an object with their eyes or responding to voice

Question 35

minimally conscious state

Answer 35

*person shows clear but minimal or inconsistent awareness *periods where they can communicate or respond to commands

Question 36

locked-in syndome

Answer 36

*person is both conscious and aware, but completely paralyzed and unable to speak *able to move their eyes, sometimes able to communicate by blinking *REVERSIBLE if caught in time *causes: basilar stroke, central pontine myelinolysis, or pontine hemorrhage

Question 37

akinetic mutism

Answer 37

*abulia (lack of will, drive, or initiative for action, speech, and thought) *akinesia *no cognitive function = no motivation *intact sleep-wake cycle and NO MOTOR, SENSORY, or SPEECH DEFICITS *bilateral basal medial frontal lobe

Question 38

brain death

Answer 38

*NO evidence of BRAIN function *NO evidence of BRAINSTEM function *NO evidence of spontaneous breathing *underlying irreversible brain injury