DSA35 - Stupor and Coma: Evaluation Steps and Definitions in Neurological Medicine

What are normal levels of consciousness?

-Wakefulness

-Drowsiness

-Sleep

Define Sleep

normal state of unconsciousness from which the individual can typically be easily awakened; includes Non-REM and REM stages

What are the MINIMUM requirements of Consciousness?

-Intact brainstem RAS

-One mostly intact hemisphere of cerebral cortex

-Adequate metabolic milieu (glucose, O2, electrolytes, pH, blood flow)

Define Content of consciousness

AO x 3, Intact language function, appropriate thought and behavior

Define Disorientation

mental confusion characterized by inadequate or incorrect perception of place, time, and identity

Define Dementia

refers to decreased content of consciousness usually with forgetfulness and cognitive decline as prominent features

Define Confabulation

individual’s tendency to conceal his or her cognitive decline or forgetfulness with fictional accounts and details; often seen in Wernicke-Korsakoff encephalopathy

Define Lethargy

pathologically decreased level of consciousness where there may be decreased attention and awareness; usually requires only minimal stimulation to return the individual to a normal wakeful state; person is not alert, disoriented

Define Obtundation

refers to anyone with an abnormally decreased level of consciousness; appears sleepy, responds to moderate stimuli

Define Stupor

refers to decreased level of consciousness, awareness, and attention which typically requires very vigorous stimulation to overcome or the individual may not be able to be fully aroused even with vigorous stimulation; responds with groans and motor withdrawal

Define Vegetative State

A state of wakefulness without awareness and overt communication; can be acute or chronic

Define Coma

Medical emergency - implies either diffuse insult to cerebral hemispheres bilaterally OR focal damage to core of brainstem (RAS); no evidence of wakefulness, awareness of or attention to the environment. No amount of vigorous stimulation can return the individual to a wakeful state

What is the first step in evaluating an "unconscious" patient?

See if the patient responds to your voice

A (higher/lower) Glasgow Coma Scale, or GCS, indicates a deeper coma and poorer prognosis; What is considered normal?

lower; 15 = normal

What is the most common cause of coma in large city hospitals?

Toxic-Metabolic (Non-structural brain injury)

What is the second most common cause of coma in large city hospitals?

Structural brain damage (Supratentorial mass affecting RAS --> Infratentorial mass affecting RAS --> diffuse/multifocal dysfunction)

Comatose patients often require what?

-Endotracheal intubation

-Respiratory assistance

-Indwelling Foley Catheter (after establishing IV access)

Define Decorticate Rigidity (GCS Motor = 3)

Abnormal flexion in Coma motor exam - UEs stay flexed but LEs stay extended; lesion between mantle of brain and up to (but not on) midbrain --> rubrospinal nucleus overactive, and later vestibular nucleus somewhat overactive (but not totally)

Define Decerebrate Rigidity (GCS Motor = 2)

Abnormal extension in Coma motor exam - Rigid extension of the neck and all four limbs; Lesion has NOW reached vestibular nucleus more so, and may reach medulla

Define Locked-In Syndrome

Condition in which pt is awake, aware, and has wake-sleep cycles BUT has complete paralysis EXCEPT for eye movements & blinking (RAS & Cortex are intact, but lesion at caudal pons/proximal medulla)

Define "Doll's Eyes" Test

Tests oculocephalic reflex - hold eyelids open, briskly turn head from side to side to see if eyes have "catch up movement" (conjugate movement intact for brainstem mechanism of MLF)

Define Ice Water Caloric Stimulation

Tests oculovestibular reflex (MORE sensitive than Doll's Eyes) - Place HOB at 30 degrees, irrigate each ear in turn with 50cc of ice cold water and observe for latent/slow conjugate eye movement TOWARDS the cold stimulus (conjugate movement intact for brainstem mechanism of MLF)

Define Corneal Reflex

Blinking in response to corneal stimulation by a cotton wisp; Afferent = CN5, Efferent = CN7

One dilated & fixed pupil indicates what condition?

Uncal herniation on midbrain (affecting CN3)

Large fixed hippus (pathologic constriction & dilation of pupils, despite light) of pupils indicate what condition?

Midbrain tectal injury

Fixed & midposition pupils indicate what condition?

Midbrain injury

Define Cushing's triad

Irregular respirations, bradycardia, and systolic HTN; signifies HIGH ICP

Define Coma Condition:

-Hx: ACUTE = Trauma/SDH/EDH, Stroke/basilar artery, Bacterial Meningitis; SUBACUTE/GRADUAL = Abscess/Neoplasm

-Sx/PE:

--Unresponsive, but some reflex "withdrawal movement" to noxious stimuli on supraorbital ridge, nipple, nail bed bilaterally

(+) Symm/Asymm spasticity of all 4 limbs

(+) Pathological reflexes unilat/bilat

(+) Pupillary abns (CN2-3)

(+) CNN 5 & 7 Abn corneal reflexes

If NOT intubated --> (-) Gag Reflex (CN9-10)

(-) Doll's Eyes/Ice Water Caloric Stimulation

-Dx: XR (cross tabel lateral & AP of C-Spine) BEFORE Doll's Eyes, Labs CT WOC --> Brain MRI

-Tx: Empiric = IV Thiamine --> IV amp of D50W/glucose +/- Nalaxone

Structural Disease of the brainstem

Define Coma Condition:

Only cause coma when lesions are numerous/widespread --> causes herniation of hemispheres (compress RAS)

-Hx: ACUTE = Trauma/SDH/EDH, Stroke/basilar artery, Bacterial Meningitis; SUBACUTE/GRADUAL = Abscess/Neoplasm

-Sx/PE:

--Unresponsive, but some reflex "withdrawal movement" to noxious stimuli on supraorbital ridge, nipple, nail bed bilaterally

(+) Symm/Asymm spasticity of all 4 limbs

(+) Pathological reflexes unilat/bilat

(+) Pupillary abns (CN2-3)

(+) CNN 5 & 7 Abn corneal reflexes

If NOT intubated --> (-) Gag Reflex (CN9-10)

(-) Doll's Eyes/Ice Water Caloric Stimulation

-Dx: XR (cross tabel lateral & AP of C-Spine) BEFORE Doll's Eyes, Labs CT WOC --> Brain MRI

-Tx: Empiric = IV Thiamine --> IV amp of D50W/glucose +/- Nalaxone

Focal Structural Hemispheric damage

Pinpoint pupils indicate what condition?

Narcotic overdose affecting Pons

Define Coma Condition:

RAS globally suppressed by toxins and/or depresses cerebral cortex diffusely

-Hx: Onset young adults mostly, but can be any age; Hx Psych Issues - may have prior events; May have Rx meds at scene

-Sx:

-PE: NO trauma/injury; Abn Neuro due to encephalopathy (miotic & poorly reactive pupils, changes in breathing pattern), (-) Pupillary Light Reflex

-Dx: Brain Imaging (normal or abn), Abn EEG (diffuse slowing of cortical activity), Metabolic Response in Labs (Met Acidosis with ASA OD, or elevated LFTS with Tylenol OD), Urine or Serum Tox

-Tx: Supportive BUT antidotes/emetics to get toxins out

Drug Intoxication (Intentional or Unintentional)

Small, Reactive pupils indicate what condition?

Metabolic disorder

Define Coma Condition:

Condition creates metabolic milieu that cannot sustain diffuse brain function

-Hx: Hx of condition (pt may be ill for a while - DKA/HONC/Hypoglycemia, inflammatory disease); Usually GRADUAL decline of mental/psychomotor function before

-Sx/PE: Encephalopathy findings (Ophthalmoplegia, Nystagmus, Memory loss, confabulation, Peripheral neuropathy, Ataxia) + Asterixis ("flapping tremor") + Organ fail signs

-Dx: Labs (DKA, elevated TSH, elevated ammonia, abnormal liver, uremia, etc) + EEG (diffuse cortical slowing AND "triphasic waves" = hepatic or uremic encephalopathy)

-Tx: Supportive

Systemic Metabolic Disease

What part of the brain is most vulnerable to anoxic, ischemic and metabolic insults (more than the brainstem)?

Cerebral Cortex

(No focal/Focal) neurological findings indicates diffuse/metabolic cause(s) of Coma

No focal

(No focal/Focal) neurological findings indicates structural cause(s) of Coma

Focal

Define Delirium

Acute confusional state - level of consciousness waxes and wanes; decreased, normal or even agitated increase in level of consciousness; often in metabolic encephalopathies, but also in structural brain lesions, infections

Define Coma Condition:

-Hx: MI, arrhythmia, strangulation, drowning, airway occlusion, etc

-Sx/PE: Findings from Hx; either no focal neuro findings OR MANY focal neuro findings (cerebral infarcts)

-Dx: Brain MRI (cerebral Hypoxia or Ischemia, watershed infarcts, cerebral edema, loss of gray-white) + EEG (esp if pt doesn't awaken, cortical slowing or suppression, or sub convulsive status

epilepticus) +/- ECG or CXR

-Tx: Depends

Decreased cerebral perfusion or Hypoxemia

Define Coma Condition:

-Hx: Irreversible cessation of all brain/brainstem function (requires 24 hrs of complete coma & GCS3 to confirm)

-Sx/PE:

(+) APNEA Test (no spontaneous RR)

(-) Pupillary light reflexes

(-) Corneal Reflexes

(-) Withdrawal from painful stimuli

-Dx: Absent EEG or Cerebral Perfusion on Imaging

Brain Death