Persistent Vegetative State

SECRETS OF EVALUATION

CEREBRAL CATACLYSM

“Coma in the ICU”

Persistent Vegetative State “Locked In” Syndrome AKINETIC MUTISM SEVERE ENCEPHALOPATHY “LOCKED OUT” SYNDROME Apallic State

THE BRAIN IS THE INSTRUMENT

OF AWARENESS

BRAIN

CONSCIOUSNESS

OUTSIDE WORLD

DECARTES’ BRAIN

CONSCIOUSNESS IS IN THE BRAIN

OUTSIDE WORLD

MODERN VIEW

A MODULAR VIEW OF BRAIN FUNCTION

Consciousness

Arousal Content

AROUSAL

BRAINSTEM ARAS

BRAINSTEM STRUCTURES OF AROUSAL

MIDBRAIN

RETICULAR ACTIVATING SYSTEM

WAKES UP THE CORTEX

CONTENT

CEREBRAL CORTEX

LIMBIC SYSTEM

MEDIAL FRONTAL LOBE

TO LOSE CONSCIOUSNESS

Brainstem Bilateral Cortices

ANATOMY OF AWARENESS

Reticular Activating system Thalamus Cortex

ARAS

CORTEX

LIMBIC

SYSTEM

MEDIALFRONTAL

LOBE

LOCUSCERULEUS

PERIAQU

GRAY

THALAMUSTHALAMUS

MODULAR VIEW OF CORTICAL ACTIVATORS

CEREBRAL CORTEX

lethargic

obtunded/delerious

electric silence

burst suppression

slowing

disorganized/fast

alpha

ANESTHESIA AND COMA:

restfulwaking

braindeath

deepcoma

COMA

“CEREBRAL SHUTDOWN”– RENAL SHUTDOWN MODEL

» E.G. SPINAL SHOCK, CONCUSSION

COMA

RECOVERY

PVS

DEATH

COMA + TIME PVS

PVS

Awake but not aware– Jennett & Plum 1972

CONCEPT OF PERSISTENT VEGETATIVE STATE

Arousal but no content to consciousness Brain cut off from environment Awareness?? Return of sleep wake cycle Preservation of primitive reflexes Learned complex behavior incompatible with

PVS Expectation: No return of Sapience

PVS (DEF’N-1)

No Awareness of Self or Environment Intact Sleep-Wake Cycles (awake) Preservation of Hypoth. and Autonomic

Function No Sustained Purposeful or Voluntary

Behavioral Response

PVS (DEF’N cont’d)

No Language Comprehension or Expression

Bowel and Bladder Incontinence Full Chew and Swallow not Present

PERSISTENT VEGETATIVE STATE

Severe Bilateral Cortical injury “apallic state”– traumatic– Vascular

Permanent Damage to brainstem arousal structures

INCOMPATIBLE WITH PVS

COORDINATED CHEWING SWALLOWING

VERBAL OUTPUT SUSTAINED VISUAL FOLLOWING FOLLOWING COMMANDS PURPOSIVE MOVEMENTS NORMAL EEG

PVS (AAN Pos’n Statement)

No pain or suffering (sapience gone) Artificial nutrition and hydration may be

d/c’d Withdrawing treatment is equivalent to

withholding it

PVS (AAN Pos’n Statement cont’d)

Dx of permanent Unconsc can be made with high certainty

Once dx’d Medical Care is of no value to the patient

Pt’s & Family Wishes (not Caregiver) are paramount

PVS

“Lights are on but no one home.”

PVS

RECOVERY

DEATH

RECOVERY IN PVS:

NONTRAUMATIC– VERY RARE AFTER 3 MOS.

TRAUMATIC– VERY RARE AFTER 1 YEAR

“COMA VIGIL”

RETURN OF SLEEP WAKE CYCLES “AWAKE BUT UNAWARE” EYES OPEN NO EVIDENCE OF COGNITION MINIMAL VISUAL FOLLOWING AND

REACTION TO THREAT NO OR MINIMAL SPONT. MOTOR MOV’T NOW CALLED PVS

“APALLIC STATE”

NO CLOAK OR MANTLE (No Cortex) Kretchmer 1941 Eyes Open Primitive Visual Following Uncommunicative and Unresponsive

ENCEPHALOPATHY

REVERSIBLE PROCESS AFFECTING BRAIN FUNCTION

» METABOLIC

» INFECTIOUS

NEUROWELTANSCHUUNG

ASSOCIATIVE

EFFERENT AFFERENTEFFERENT AFFERENT

OUTSIDE WORLD

ASSOCIATIVE

AFFERENTEFFERENT

OUTSIDE WORLD

ARTIST

ASSOCIATIVE

EFFERENTAFFERENT

ATHLETE, ENTREPRENEUR

OUTSIDE WORLD

ASSOCIATIVE

EFFERENT AFFERENT

WORLD

PHILOSOPHER, MATHEMATICIAN

ASSOCIATIVE

AFFERENT

OUTSIDE WORLD

LOCKED-IN SYNDROM: “DE-EFFERENTED STATE” AMPUTATED EFFERENT LIMB

PONS

LOCKED-IN

De-efferented state No motor output

LOCKED-IN

Bilateral basal pontine stroke Severe Guillian-Barre Severe Myasthenia Myopathy

LOCKED-IN SYNDROME

“De-Efferented State Consciousness Maintained vertical willful eye movements Altered REM sleep Absent horizontal eye movements Lesion in Ventral Pons

PSEUDO-COMA

“Locked in” Syndrome “Locked out” Syndrome

ASOCIATIVE BRAIN

EFFERENT

OUTSIDE WORLD

QUINLAN’S BRAIN: DEAFFERENTED“LOCKED-OUT”

LOCKED-OUT

De-afferented state Cutting off Sensory Input to Brain

THALAMUS

“NO ONE…BUT THRU ME”

AFFERENT WAYSTATION TO CORTEX

THALAMUS

LOCKED-OUT

Bilateral Thalamic lesions Disconnection from Environment amputation of sensory function

ASSOCIATIVE BRAIN

(Cortex)

(Pure thought)

THALAMUS PONSDeafferentiation(sensory bottleneck)

Deefferentiation(Motor bottleneck)

OUTSIDE WORLD

Sensory input Motor output

MEDIAL FRONTAL LOBE

MOTIVATION “PUSH”

“AKINETIC MUTISM”

Cairns 1941 patient w/ craniopharyngioma Eyes open “giving promise of Speech” Bilateral CINGULATE Gyrus Destruction Or lesion in anterior third ventricle

AKINETIC MUTISM (Vigilant Type)

Bouts of Excitement or Agitation Intermittent aimless aggressivity Restless More alert and ready to be Aroused Lesion: subfrontal or Cintulate,

orbitomedial frontal lobes

AKINETIC MUTISM (somnolent type)

Inertia, somnolence, lethargy, “abulia” paralysis of vertical gaze and other eye

movements Primitive Visual Following Diencephalo-mesencephalic Jxn at post.

extent of iiird Ventr. Bifurc. or Basilar Mesenceph. Brrs.

AKINETIC MUTISM

Circumscribed Vascular Lesions Patients may not be entirely mute

LIMBIC SYSTEM

EMOTIONAL COLOR

LOCUS CERULEUS

PERIAQUEDUCTAL GRAY

DREAM AND SLOW WAVE SLEEP

CONDITION AWAKE AWARE LESION EEG EVR

PVS S/WCYCLES

NO BILAT. CORTEX, ORTHALAMUS

LOW & SLOW ORUNREACTIVE ALPHA

SER OUTBAER OK

YES

LOCKED-IN AWAKE YES PONS OR PERIPHERY NEAR NORMAL BAER ABN.SER NL

YES

COMA NO NO BILAT CORTEX ORBRAINSTEM

LOW & SLOW ORUNREACTIVE ALPHA

VARIABLE YES OR NO

DEGEN. YES REDUCED VARIABLE NL OR SLOW VARIES YES

PROGNOSIS

HOW MUCH VISIBLE DAMAGE??

CEREBRAL HEMORRHAGE

HUGE FATAL STROKE

LARGE EMBOLISM

HYPERTENSIVE ENCEPHALOPATHY

MODULAR VIEW OF AWARENESS

HOW TO EVALUATE STATES OF AWARENESS

WHAT ACTUALLY HAPPENS

PROGNOSIS