Disorders of ConsciousnessDisorders of ConsciousnessStephen Deputy, MD, FAAPStephen Deputy, MD, FAAP

ConsciousnessConsciousness

• Refers to the awareness of self and environment

• Content of Consciousness• Arousal

ConsciousnessConsciousnessLocalization

DeleriumDelerium• Clinical Signs: Agitation, confusion, poor

concentration and orientation, misperception of sensory stimuli, visual or tactile hallucinations

• Alertness intact but disturbed content of consciousness

• Generalized or multifocal process affecting both cerebral hemispheres

Depressed Levels of ConsciousnessDepressed Levels of Consciousness

• Lethargy• Stupor• Sleepy Appearing• Somnolence• Obtundation• Coma

COMACOMA

Unarousable Unresponsiveness• Consciousness: None• Eyes: Do not open to any stimulus• Vocalization: None• Motor: No purposeful movements

COMACOMA

All patients in a coma will change after 2 to 4 weeks

• Improve to a higher level of alertness• Expire• Evolve into a vegetative state

Vegetative StateVegetative State

Patients who have survived coma without gaining higher cognitive function

• Consciousness: None• Eyes: Spontaneous eye opening and closure• Vocalization: Groans and Grunts, no formed words or

purposeful communication• Motor: Postures or withdraws to noxious stimulus,

occasional nonpurposeful movement

• EEG: Preserved sleep and wake cycles

Minimally Conscious StateMinimally Conscious State

Severely altered consciousness but with definite behavioral evidence of awareness

of self and environment

Minimally Conscious StateMinimally Conscious State

• Follows simple commands• Gestural or verbal “yes/no” responses• Intelligible verbalization• Movements and affective behaviors occur

in contingent relation to relevant environment stimuli and not attributable to reflexive activity

Locked-In SyndromeLocked-In Syndrome

• Loss of voluntary motor control and vocalizations with preserved consciousness

• Bilateral injury to the cortic-spinal and cortical-bulbar tracts

• Pontine hemorrhage, tumor, demyelination

Locked-In SyndromeLocked-In Syndrome

• Consciousness: Preserved• Eyes: No lateral movements, blink and vertical

eye movements preserved, vision intact• Vocalizations: Aphonic/Anarthric• Motor: Quadriplegic• EEG: Normal awake background

Causes of ComaCauses of Coma

• Supratentorial Lesions (affecting Bilateral Cerebral Hemispheres/Thalamic Nuclei)

• Infratentorial Lesions (Affecting the Brainstem Reticular Activating System)

Causes of ComaCauses of Coma

• Toxic/Metabolic Disorders• Infectious/Post-Infectious • Trauma• Seizure/Post-Ictal State• Neoplastic/Paraneoplastic• Structural• Vascular

Herniation SyndromesHerniation Syndromes

• Subfalcine Herniation• Uncal Herniation• Central Herniation• Cerebellar Tonsillar Herniation

Regions of Brain HerniationRegions of Brain Herniation

Sub-Falcine HerniationSub-Falcine Herniation

Notching of the UncusNotching of the UncusDue to Transtentorial (Uncal) HerniationDue to Transtentorial (Uncal) Herniation

Downward Cerebellar Tonsillar Herniation Downward Cerebellar Tonsillar Herniation through the Foamen Magnumthrough the Foamen Magnum

Duret Hemorrhages of the PonsDuret Hemorrhages of the PonsFrom Brainstem HerniationFrom Brainstem Herniation

CT BrainCT Brain Subdural Hematoma Subdural Hematoma

Subfalcine and Transtentorial HerniationSubfalcine and Transtentorial Herniation

CT Brain CT Brain Intraventricular Hemorrhage,Intraventricular Hemorrhage,

Hydrocephalus, and Central HerniationHydrocephalus, and Central Herniation

Evaluation of ComaEvaluation of Coma

Patient Stabilization (ABCD’s)

History• Duration and Onset of Coma• Trauma• Past Medical History• Medications (Perscribed, OTC, Illicit, Accessable)• Family History (Others affected)

Evaluation of ComaEvaluation of Coma

Physical Examination• HEENT: Head size/Ant Fontanelle.

Nuchal rigidity. Signs of trauma. C/Spine Precautions

• Heart/Lung/Abdomen/Extremities: Look for evidence of other organ

failure/Injury

Evaluation of ComaEvaluation of Coma

Neurological Examination• Mental Status• Cranial Nerves• Motor Examination• Sensory Examination

Evaluation of ComaEvaluation of Coma

Mental Status• Describe what you see• Best Eye Opening, Vocalization, and

Motor Response to various Forms of Stimuli

• Glasgow Coma Score

Glasgow Coma ScaleGlasgow Coma ScaleEye Opening

Spontaneous 4To Verbal Command 3To Pain 2None 1

Obeys Commands 6Localizes Pain 5Withdraws to Pain 4Decorticate Postures 3Decrebrate Postures 2None 1

Oriented and Converses 5Confused Conversation 4Inappropriate Words 3Incomprehensible Sounds 2None 1

Motor Response

Verbal Response

Glasgow Coma ScaleGlasgow Coma Scale(For Infants)(For Infants)

Spontaneous 4To Speech 3To Pain 2None 1

Eye Opening

Normal Spontaneous Movements

6

Withdraws to Touch 5Withdraws to Pain 4Abnormal Flexion 3Abnormal Extension 2None 1

Motor Response

Coos Babbles 5Irritable 4Cries to Pain 3Moans to Pain 2None 1

Verbal Response

Cranial NervesCranial Nerves

II (optic Nerve)

• Fundoscopic Exam• Pupillary Light Reflex

Pupils Size Based on LocalizationPupils Size Based on Localization

Cranial NervesCranial Nerves

III, IV, VI (EOM’s)• Doll’s Eyes Maneuver• Cold Calorics

Oculocephalic ReflexOculocephalic Reflex(Doll’s Eyes and Cold Calorics)(Doll’s Eyes and Cold Calorics)

Cranial NervesCranial Nerves

V and VII(Trigeminal and Facial Nerve)

Corneal Blink Reflex• V-1 Afferent• VII Efferent

Cranial NervesCranial Nerves

IX and XThe Gag Reflex

• IX is Afferent• X is Efferent

Cranial NervesCranial Nerves

Respiration• Respiratory Patterns Based on Localization• The Apnea Test

Breathing Patterns Based on Level of Breathing Patterns Based on Level of Brainstem DysfunctionBrainstem Dysfunction

Cranial NervesCranial Nerves

The Apnea Test• No CNS Depressants or NMJ Blockade• Ventilate with 100% FiO2 for 20 minutes• Disconnect Ventilator and Continue O2• ABG until PCO2 > 60mmHg• Watch for any signs of ventilation

Motor ExaminationMotor Examination

Spontaneous MovementResponse to Noxious Painful Stimuli

• Localizes Pain• Withdraws from Pain• Decorticate Posture• Decerebrate Posture• No Movement

Decorticate PosturingDecorticate Posturing

Decerebrate PosturingDecerebrate Posturing

Motor ExaminationMotor Examination

Deep Tendon Reflexes• Segmental Spinal Reflex• Disinhibition of DTR’s When Cortical

Spinal Tract is Dysfunctional• Triple Flexion Withdrawal and the Babinski

Response

Sensory ExaminationSensory Examination

• Any motor response to painful stimuli on the right or left side of body?

• Watch for Pulse or Blood Pressure Elevations with Deep Painful Stimulation

Brain DeathBrain Death

• Accepted as death for medical, legal, and public opinion standards

• Concept developed at the same time as organ transplantation

• “Irriversible cessation of all cerebral activity, including that of the brainstem”

• “Irreversible deep coma and lack of spontaneous respiration”

Brain Death CriteriaBrain Death Criteria

• Understand the mechanism or illness that led up to brain death

• Exclude conditions which may influence examination (Hypothermia, Sedating Medications/Toxins, Paralytic Agents, Severe Peripheral Nervous System Disease)

Brain Death CriteriaBrain Death Criteria

• Determine lack of Cortical Function by examination

• Determine lack of Brainstem Function by examination (includes apnea test)

• Observation period (Varies based on age and whether mechanism of brain death is known)

• Ancillary Testing (Isoelectric EEG, Lack of cerebral blood flow, Evoked Potentials)

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