1. ΔMS
Ken Uchino, M.D.
Assistant Professor of Neurology
UPMC Stroke Institute

2. DEFINITION
 COMA: the complete absence of
awareness of self and the
environment even when the subject
is externally stimulated

3. ΔMS
 Confusion
 Drowsy—Inability to sustain wakefulness
without external stimuli
 Obtundation—aroused by vigorous stimuli,
interacts briefly
 Stupor—arounsed only by vigorous and repated
stimuli, but not interactive
 Coma

4. ΔMS
 IT’S A SPECTRUM:
ALERT
”DROWSY”
”OBTUNDED”
”STUPOROUS”
COMATOSE
 ….much better to just describe what you
see!

5. ANATOMY
 RETICULAR ACTIVATING
SYSTEM:
– a primitive, evolutionarily conserved
diffuse (reticular) network of neurons
throughout the brain
– some more concentrated areas “nuclei” or
“centers”
– originates in brainstem
– ascends through diencephalon via which it
connects to rest of brain

6. ANATOMY
 Two major anatomic patterns of coma:
1. Diffuse cerebral injury (2/3)
or
2. Focal injury to the brainstem
(1/3)

7. DIFFUSE CEREBRAL
INJURY
 Trauma
– Concussion, diffuse axonal injury
 Vascular
– Global hypoxia-ischemia
– Hypertensive encephalopathy
 Infectious
– Sepsis
– Meningitis, encephalitis
 Epileptic
– Post-ictal state
– Non-convulsive status epilepticus

8. DIFFUSE CEREBRAL
INJURY
 Metabolic:
– Electrolyte abnormalities:
 pH disturbance
 Hyper or hyponatremia
 Hyper or hypoglycemia
 Hyper or hypocalcemia
– Organ failure
 liver, kidney
– Thiamine or vitamin B12 deficiency
– Drug intoxication or withdrawal

9. FOCAL BRAINSTEM INJURY
 Direct hit to the brainstem
– Brainstem stroke or tumor
 Secondary pressure onto the brainstem
– Trauma
 Subdural or epidural hematoma
– Vascular
 Subarachnoid hemorrhage
 Intracerebral hemorrhage
– Neoplasm
– The mass raises intracranial pressure and herniation
onto the brainstem.

10. Case 1
 50 yo man sent confused from homeless
shelter.
 History not obtainable. ? EtOH abuse
 PE: Afebrile, tachycardic. Mildy
hypertensive.
 Really groggy. When aroused, very
confused, dysarthric.

11. Case 1
 CT normal
 Labs: WBC 15, otherwise CBC, Chem 7,
LFTs normal.
 EtOH level undetcable,
 Urine tox: negative for drugs of abuse.
 Presumed dx: toxic encephalopathy, EtOH
withdrawal

12. Case1
 Febrile in the evening.
 The resident attempts to perform LP.
 After attempt at decubitous position…
 Attempted sitting up (with help of nurse and
attending physician)…
 Green fluid comes out.

13. ΔMS H&P
 1. Recent events:
– When was the patient last seen?
– How was the patient discovered?
– Were there any preceding neurologic complaints?
– Was there any recent trauma or toxic exposure?
 2. Medical istory
 3. Psychiatric history
 4. Medications
 5. Use of drugs or alcohol

14. General Physical Exam
 Vitals
– Is there a fever?
– Severe hypertension?
 Skin
– Trauma, jaundice, needle marks
 Head
– Fractures, lacerations
 Neck (do not manipulate if suspect Fx!)
– Stiffness?
 Neurologic exam…

15. Coma exam
 Describe:
 Observe then stimulate:
– Level of consciousness
 Brain stem Exam
– Fundi, Pupils, Corneals, EOM, Gag and cough
 Extremities

16. Coma Exam: Level of
Consciousness
 Awake
 “Opens eyes to voice,” “grimaces to pain,”…
 Localizes pain—pain where ?(central vs.
peripheral)
 Any abnormal response? Patterned response?
– Flexor posturing (Decorticate)
– Extensor posturing (Decerebrate)
– Myoclonus?
 Respiratory pattern?
– “Riding the vent” vs. overbreathing

17. Respiration
 Cheyne- Stokes pattern
– diencephalic/ diffuse
– CHF
 hyperventilation
– midbrain
 apneustic pattern
– pons
 ataxic respiration
– medulla
 …interesting, but not really useful in the
field!

18. Testing LOC
 First, a verbal command:
– Specific command (hard): “Show me two
fingers!”
 not “squeeze my hand”
– Midline command (easier): “Open your eyes”
 eye lid apraxia?
 Try it again with a noxious stimulus

19. Testing LOC: Noxious
– Head:
stimulus
 ear pinch, cotton swab to nares, supraorbirtal ridge pressure,
pin to nares
– Body
 Sternal rub, shoulder pinch
 Areolapossibly the most sensitive spot you can find…It also
helps you identify the malingering patients.
– Extremities
 Pinch arm or calf, Nailbed pressure, plantar stimulation
 Response
 Localization
 Withdawal
 Flexor (decorticate) posturing
 Extensor (decerebrate) posturing

20. Posturing
 Extensor posturing (Decerebrate)
– Hips and shoulders extend, adduct, and internally rotate
– Knees and elbows extend
– Forearms hyperpronate, Wrists and fingers flex
– Feet plantar flex and invert
– Trunk extends, Head retracts
 Flexor posturing (Decorticate)
– Shoulders adduct, internally rotate, and flex slightly;
elbows flex; forearms pronate; and wrists and fingers
flex
– Lower extremities extend, adduct, and internally rotate
– Hip, knee, and ankle may flex in a spinal reflex known
as triple flexion

21. A picture speaks…
• It means that the
patient is not
conscious.
• The cortex isn’t
communicating.
• It’s not well
localizing.

22. Brains stem reflexes: pupils
 critical in distinguishing metabolic from
structural etiologies of coma

23. Brainstem reflexes: pupils
 Dilated, unreactive pupils
– third nerve compression
– sympathetic agonist drugs (cocaine)
– cholinergic antagonists (atropine)
 Small reactive pupils +/- Horner’s syndrome
– hypothalamus/diencephalon injury
– damage to sympathetic input
– opiates, cholinergic agonist drugs

24. Brainstem reflexes: pupils
 fixed midposition pupils
– midbrain
– i.e. loss of sympathetic and para- sympathetic
inputs (Edinger- Westphal)
 small unreactive/ minimally reactive pupils
– pons, cholinergic poisoning

25. Brain stem reflexes:
extraocular movements
 Horizontal conjugate gaze is mediated by:
– Frontal eye fields
– Pontine gaze centers
 In unresponsive patients, conjugate eye
movments can be elicited by:
– Oculocephalic reflex (Doll’s eye)
– Oculovestibular reflex (Cold water calorics)

26. Brain stem reflexes: EOM
 First, observe at rest
– Roving
– Not moving
– Gaze deviation
 Hemispheric lesion:
“eyes look at the lesion”
 Pontine damage: “eyes
look away from the
lesion”
 Seizure: “eyes look
away from the lesion.”

27. Brainstem reflexes: EOM
 Conjugate
– A good sign, but do they move appropriately?
 Dysconjugate
– A bad sign, but why?
 Just relaxed muscles?
 Impaired EOM?

28. Brainstem reflexes: EOM
 Next, try the reflexes:
 1. Oculocephalic (aka Doll’s eye) reflex:
– Presence indicates that the brainstem is intact
 2. Coculovestibular (caloric) reflex:
– Tonic deviation towards the cold ear

29. Brainstem reflexes
 Corneal Reflexes:
– CN 5 & 7
– pontine lesion
 Gag Reflex:
– afferent component
 IX
– efferent component
X

30. Brainstem reflexes
EYE
 Pupils:
– II in
– III out
 EOM:
– VIII in
– III, (IV), VI out
 Corneals:
– V in
– VII out
 Gag:
– IX in
– X out

31. Extremities
 Reflexes
– Deep tendon reflexes
– Response to noxious stimuli:
 Is it a reflex or withdrawal?
 Plantar response—triple flexion

32. Glasgow Coma Scale
Eye Opening
None 1
To Pain 2
To Speech 3
Best Verbal Response
Spontaneous 4
None 1
Best Motor Response Incomprehensible sounds 2
None 1 Inappropriate words 3
Extension (at elbow) 2 Confused 4
Abnormal Flexion 3 Oriented 5
Withdrawal 4
Localizes pain (attempts to 5
remove stimulus) Total Score = 3-15
Obeys commands (simple 6
commands)

33. Case 2 (JJ)
 78 yo woman stopped talking and had right
sided weakness.
 On the way to the hospital, she vomited.
Became unresponsive.
 PMH: macular degeneration, anxiety.
 Pt was intubated in the ER. Received lasix
for HTN of 218/98.

34.  BP 180/90 P 84 afebrile
 General PE: unremarkable, except intubated.
 Neurologic: No spontaneous movements or eye
opening. Not following commands.
 Noxious stimuli:
– She localizes pain in the left UE. She has purposeful
movement in the left upper extremity (squeezing hand
sponaten.).
– On the right side, extensor posturing to pain on the
right UE and triple flexion in the right lower extremity.
 Brain stem:
– Her pupils are 2 mm and reactive. She has left gaze
preference, but has spontaneous eye movements.
Visual field is difficult to assess. She has gag reflex
intact.

35. CATEGORIZE
 Nonfocal exam with brainstem intact
– Reactive pupils, full eye movements, symmetric motor
responses.
– Suggests diffuse cerebral damage.
 Focal hemispheric signs
– Contralateral hemiparesis, gaze paresis
– Suggests structural CNS lesion
 Focal brain stem signs
– Abnormal pupil reactivity, cranial nerve signs, motor
posturing.
– Suggests brainstem lesion

37. MANAGEMENT
 In the case of a diffuse cerebral injury with
no known cause…give the coma “cocktail”:
– THIAMINE 100 mg IV
– 50% DEXTROSE 50ml IV
– NALOXONE (Narcan) 0.4-0.8 mg IV
– (FLUMAZENIL (Romazicon) 0.2-1.0 mg IV)

38. MANAGEMENT
 In the case of focal hemispheric or
brainstem signs, obtain neuroimaging..
– CT
– MRI
 And look for signs of increased intracranial
pressure

39. Case 3 (CM)
 75 yo F found down by husband.
 She has left hemiparesis, dysarthric. C/o HA.
 PMH: GERD, no HTN
 SH: Husband: she drinks and smokes as much as she can.
 PE: BP 106/90
 A+O x3. Follows commands. Speech fluent, but
dysarthric. She has left neglect.
 Pupils 63 mm. Left VF cut. Corneal and gag reflexes
present. Facial sensation is diminished on the left. Right
eyelid droop (old).
 Flaccid hemiplegia. Sensation: neglect. Deep tendon
reflexes 1 throughout. Toes going up bilaterally.

40. Right thalamic ICH & IVH
CT: on Nov 5
at 1450

41. Case 3
Day 2
 BP 169/94
 No eye opening to stimuli. Not following
commands.
 Eyes downward and to the left. Pupils 3mm
reactive. Corneal reflexes present.
 Left hemiplegic. RUE purposeful
movement. RLE withdrawal. Bilateral
upgoing toes.

42. ↑ICH & hydrocephalus
• CT: Nov 6 at
4:50 am
• Subsequently
Intubated
• Ventriculostomy

43. Case 3
Day 3
 ICP shot up early morning. Got head CT:
 Exam off propofol x 5min:
 LUE extension and RUE flexion to pain
centrally as well as peripherally.
 Triple flexion in LE bilaterally.
 Pupils 2mm reactive. Left gaze deviation
but some spontaneous roving movements.
Corneal reflex intact.

45. Case 3
Day 4
 Off propofol for 24 hours
 BP 148/68 P 120 RR 14/13
 Unresponsive to sound or pain
 Pupils fixed at 4mm, corneal reflexes
present. Absent gag reflex.
 Triple flexion in LE.
 Pt expired later that day.

46. Herniation Syndromes
 Central Transtentorial
– paratonic rigidity of lower extremities
– pinpoint pupils (sometimes)
– hyperreflexia/ spontaneous triple flexion responses
– waning level of consciousness
– sudden cardiac or respiratory arrest/ death

47. Herniation Syndromes

48. Herniation Syndromes

49. Herniation Syndromes
 Lateral Transtentorial/Uncal:
– most common in those with temporal lobe
masses (tumor, hematoma,…)
– ipsilateral dilated pupilthen bilateral
– hyperreflexia/ spasticity
– ipsilateral hemiplegia (Kernohan’s notch)
– hemianopsia (PCA infarct)
– brainstem compression/ death

50. Herniation Syndromes

51. Herniation Syndromes

52. Herniation Syndromes
 SUBFALCIAL HERNIATION
– ipsilateral and/or contralateral
paratonic rigidity
– LE paralysis (once completed)
– akinetic mutism (bilateral ACA)
 TONSILLAR HERNIATION
– downward cerebellar herniation
– nausea, vomiting, hyperreflexia
– sudden respiratory arrest

53. Herniation Syndromes

54. Herniation Syndromes

55. Herniation Syndromes
 Upward cerebellar herniation:
– nausea, vomiting, hyperreflexia
– SCA infarction syndrome
– hyperventilation
– brainstem compression/ coma/ death
 Transcranial Hernation:
– skull fracture, craniotomy
– ischemia of adjacent cortex (strangulation)

57. Herniation Syndromes

58. Case 4
 35 yo man unresponsive.
 Pt was just booked for some incident. At
police station, found with empty pill bottle.
Pt unresponsive. No known medical
history.

59. Case 4
 CT head normal
 Labs:
– Urine tox for drugs of abuse normal (opiates,
amphetamines, cocaine, tricyclics), salicylate and
acetaminophen levels undetectable.
 PE:
– Vitals normal
– General exam: shackled to stretcher
 Blood in back
– Unresponsive to voice, pain. Brainstem reflexes intact.
Extremity reflexes in tact.

60. Techniques
 Let arm drop on face
 Tickle nares
 Surprise the patient

61. Case 4
 Wouldn’t let eyes be opened
 ER residents had attempted LP without
lidocaine. (The blood in back).
 He only flinches with needle in his back.
 I further macerate his back and succeed in
getting CSF—normal
 Angry man next morning.

62. Case 5
 40 yo woman from rural Washington state
 Presents to local ER c/o “throat swelling.”
She also c/o blurred vision. The exam is
reported to be fairly unremarkable initially.
But in the ER she worsens and develops
respiratory arrest.
 No signficant past medical history. No
asthma or allergies.

63. Case 5
 She is intubated, given steroids for presumed
allergic reaction or angioedema. She is transferred
to Seattle.
 In medical ICU she is on vent. She is treated for
aspiration pneumonia, reactive airways. She
remains unresponsive. Comatose. Never wakes
up.
 Several days later neurology is consulted for post-
anoxic encephalopathy. Is she going to wake up?

64. Case 5
 Exam: Vitals normal. Riding the vent.
– Unresponsive to pain, sound.
– Pupils unreactive, absent corneals, cold calorics
absent, no gag. Areflexic in extremities
 CT of head: normal.
 Is she brain dead?

65. Brain Death:
 the complete and irreversible cessation of all
brain function
 absent pupillary responses (fixed,
midposition)
 absent oculocephalic responses
 absent corneals, gag
 absent calorics response
 absent motor response
 absent respiration (pCO2>60)

66. Brain Death:
Necessary Tests
 APNEA TEST
– preoxygenate with 100% O2
– maintain O2 through ETT with cannula etc.
– two minute duration
– pCO2 of 60mmHg or higher adequate
 COLD WATER CALORICS
– never do in a noncomatose person
– ice water 30cc to each ear
– wait 2 minutes for response before other side

67. Case 5
 Wait, she moves her toe!

68. Brain Death:
Pitfalls
 no drugs or hypothermia to explain a
precondition of diagnosis
 absent pupillary responses
– anticholinergic drugs, especially atropine in
cardiac arrest
– NM blockade
– preexisting eye disease
 absent oculocephalics
– ototoxic/ vestibular toxins

69. Brain Death:
Pitfalls
 apnea
– NM blockade
– post- hyperventilation
– phrenic nerve palsies/ diaphragm paralysis
 no motor activity
– NM blockade
– locked in syndrome
– sedatives

70. Brain Death:
Confirmatory Tests
 Confirmatory tests are NOT necessary for the
diagnosis. Tests necessary if the checklist
incomplete.
– Trauma, hemodynamic instability
 Tests:
– EEG with special array, sensitivity settings
 ICU artifact can create problems
– cerebral blood flow (Nuc Med)
– Transcranial Doppler ultrasound
– Evoked potential studies
 notlegally required to render futile care to a
dead person

71. Summary
 Get good History from surrogate
 Examine
 Is it focal or diffuse?