Alteration of ConsciousnessAlteration of Consciousness
Reticular activating system (RAS)
Good ConsciousnessGood Consciousness = =
Alertness + Awareness Alertness + Awareness
Diminished alertnessDiminished alertness = =
Widespread abnormalities of cerebral Widespread abnormalities of cerebral
hemispheres or reduced activity of hemispheres or reduced activity of reticular reticular
activating system (RAS)activating system (RAS)
Definition of TermsDefinition of Terms
Confusion : Confusion : – impaired attentionimpaired attention and concentration, manifest and concentration, manifest
disorientation in time, place and persondisorientation in time, place and person, impersistent , impersistent thinking, speech and performance, reduced thinking, speech and performance, reduced comprehension and capacity to reasoncomprehension and capacity to reason
– Fluctuate in severity, typically worse at night Fluctuate in severity, typically worse at night ‘sundowning’‘sundowning’
– Perceptual disturbances and misinterpret voices, Perceptual disturbances and misinterpret voices, common objects and actions of other personscommon objects and actions of other persons
Confusion is also found in dementia (progressive Confusion is also found in dementia (progressive failure of language, memory, and other intellectual failure of language, memory, and other intellectual functions)functions)
Definition of TermsDefinition of Terms
Delirium : confusion and associated Delirium : confusion and associated agitation, hallucination, convulsion and agitation, hallucination, convulsion and tremortremor
Amnesia : a loss of past memories and to Amnesia : a loss of past memories and to an ability to form new ones, despite alert an ability to form new ones, despite alert and normal attentivenessand normal attentiveness
Level of Consciousness(1)Level of Consciousness(1)
Alert : Alert : normal awake and responsive statenormal awake and responsive state Drowsiness Drowsiness :: state of apparent sleep, briefly state of apparent sleep, briefly
arousal with oral commandarousal with oral command
Lethargic Lethargic :: resembles sleepiness, but not resembles sleepiness, but not becoming fully alert, slow verbal response becoming fully alert, slow verbal response and inattentive. Unable to adequately and inattentive. Unable to adequately perform simple concentration task (such as perform simple concentration task (such as counting 20 to 1)counting 20 to 1)
Level of Consciousness (2)Level of Consciousness (2) Somnolent : easily aroused by voice or touch; aw
akens and follows commands; required stimulation to maintain arousal
Obtunded/Stuporous : arousable only with repeated and painful stimulation; verbal output is unintelligible or nil; some purposeful movement to noxious stimulation
Comatose : no arousal despite vigorous stimulation, no purposeful movement- only posturing, brainstem reflexes often absent
Dementia VS Confusional stateDementia VS Confusional state
DementiaDementia– Longstanding natureLongstanding nature
– Varies little from time to Varies little from time to timetime
– Memory problemMemory problem
Confusional stateConfusional state– AcuteAcute
– FluctuateFluctuate
– Clouding of Clouding of consciousnessconsciousness
Causes of confusional state(1)Causes of confusional state(1)
Medical or surgical diseaseMedical or surgical disease Metabolic disorders Metabolic disorders
– HepaticHepatic– UremicUremic– Hypo and hypernatremiaHypo and hypernatremia– HypercalcemiaHypercalcemia– Hypo and hyperglycemiaHypo and hyperglycemia– HypoxiaHypoxia– HypercapniaHypercapnia
Causes of confusional state(2)Causes of confusional state(2)
Infectious illnessInfectious illness– PneumoniaPneumonia– EndocarditisEndocarditis– Urinary tract infectionUrinary tract infection– PeritonitisPeritonitis
Congestive heart failureCongestive heart failure Postoperative and posttraumatic statesPostoperative and posttraumatic states
Causes of confusional state(3)Causes of confusional state(3)
Drug intoxicationDrug intoxication
OpiatesOpiates BarbituratesBarbiturates Other sedativesOther sedatives
Causes of confusional state(4)Causes of confusional state(4)
Diseases of nervous systemDiseases of nervous system Cerebrovascular disease, tumor, abscessCerebrovascular disease, tumor, abscess Subdural hematomaSubdural hematoma MeningitisMeningitis EncephalitisEncephalitis Cerebral vasculitisCerebral vasculitis Hypertensive encephalopathyHypertensive encephalopathy
ApproachApproach
HistoryHistory --- emphasizing the patient’s --- emphasizing the patient’s condition before the onset of confusioncondition before the onset of confusion
Clinical examinationClinical examination --- focus on --- focus on – signs of diminished attentiveness, signs of diminished attentiveness,
disorientation, and drowsiness and disorientation, and drowsiness and – the presence of localizing neurological signsthe presence of localizing neurological signs
Aim of careAim of care in confusion patientsin confusion patients
Control underlying medical illnessControl underlying medical illness Quiet the patient and protect him from injuryQuiet the patient and protect him from injury
- Discontinue drugs that could possibly be Discontinue drugs that could possibly be responsible for the acute confusional state : responsible for the acute confusional state : sedating, antianxiety, narcotic, anticholinergic, sedating, antianxiety, narcotic, anticholinergic, antispasticity, corticosteroid, L-dopa, antispasticity, corticosteroid, L-dopa, metoclopramide, cimetidine, antidepressant, metoclopramide, cimetidine, antidepressant, antiarrhythmic,anticonvulsant, antibiotics.antiarrhythmic,anticonvulsant, antibiotics.
Medical managementMedical management
- Haloperidol, quetiapine, risperidone are Haloperidol, quetiapine, risperidone are helpful in calming the agitated and helpful in calming the agitated and hallucinating patient, but should be used in hallucinating patient, but should be used in the lowest effective dosesthe lowest effective doses
- In alcohol or sedative withdrawal—In alcohol or sedative withdrawal—chlordiazepoxide is the drug of choice. chlordiazepoxide is the drug of choice. Chloral hydrate, lorazepam, and diazepam Chloral hydrate, lorazepam, and diazepam are equally effectiveare equally effective
COMACOMA
GLASGOW COMA SCOREGLASGOW COMA SCOREEye opening:Eye opening:
NilNil 11To pain (applied to limbs)To pain (applied to limbs) 22To voice (including command)To voice (including command) 33Spontaneous (with Spontaneous (with blinkingblinking)) 44
Motor response:Motor response:NilNil 11Arm extension to pain (nail bed pressure)Arm extension to pain (nail bed pressure) 22Arm flexion to pain (nail bed pressure)Arm flexion to pain (nail bed pressure) 33Arm withdrawal from pain (nail bed pressure)4Arm withdrawal from pain (nail bed pressure)4Hand localizes pain(supraorbital or chest pressure)5Hand localizes pain(supraorbital or chest pressure)5Obeys commandsObeys commands 66
Verbalize response:Verbalize response:NILNIL 11Groans (no re-cognizable words)Groans (no re-cognizable words) 22Inappropriate words (including expletives)Inappropriate words (including expletives) 33Confused speechConfused speech 44OrientatedOrientated 55
Glasgow Coma Scale : Eye opening (E)
Glasgow Coma Scale : Motor response (M)
Glasgow Coma Scale : Verbal response (V)
NotesNotes
1.1. scoring from the best response scoring from the best response
2.2. verbal response will not correct in the condition verbal response will not correct in the condition of aphasia, intubation andof aphasia, intubation and facial facial injuryinjury
3.3. sensory loss may interfere painful stimulation sensory loss may interfere painful stimulation
4.4. eye opening may be interfered by orbital swelling eye opening may be interfered by orbital swelling and 3and 3rdrd CN palsy CN palsy
5.5. arm movements may be impaired from local arm movements may be impaired from local trauma or cervical cord lesion trauma or cervical cord lesion
GLASGOW COMA SCOREGLASGOW COMA SCORE
Approach to the patientApproach to the patient
HistoryHistory– Circumstances and rapidity with which Circumstances and rapidity with which
neurologic symptoms developedneurologic symptoms developed– Immediately preceding medical and neurologic Immediately preceding medical and neurologic
symptomssymptoms– Use of medications, illicit drugs, or alcoholUse of medications, illicit drugs, or alcohol– Chronic liver, kidney, lung, heart, or other Chronic liver, kidney, lung, heart, or other
medical diseasemedical disease
General physical examinationGeneral physical examination
Vital signVital sign– TemperatureTemperature
FeverFever Hypothermia -- <31Hypothermia -- <31°C causes coma°C causes coma
– PulsePulse– Respiratory rate and patternRespiratory rate and pattern– Blood pressureBlood pressure
Funduscopic examinationFunduscopic examination Cutaneous lesionCutaneous lesion
Neurologic assessmentNeurologic assessment
ObserveObserve– Movement : restless, twitching, multifocal Movement : restless, twitching, multifocal
myoclonus, asterixismyoclonus, asterixis– Decorticate rigidity Decorticate rigidity
Suggest severe bilateral damage rostral to Suggest severe bilateral damage rostral to midbrainmidbrain
– Decerebrate rigidity Decerebrate rigidity
Indicate damage to motor tracts in the midbrain or Indicate damage to motor tracts in the midbrain or caudal diencephaloncaudal diencephalon
Decorticate posture results from Decorticate posture results from damage to one or both corticospinal damage to one or both corticospinal
tractstracts
Decerebrate posture results from Decerebrate posture results from damage to the upper brain stemdamage to the upper brain stem
Neurologic assessmentNeurologic assessment
Level of arousal and elicited movementsLevel of arousal and elicited movements Brainstem reflexes Brainstem reflexes
– pupilspupils– Ocular movementsOcular movements– respirationrespiration
Pupils in comatose patientsPupils in comatose patients
DESCRIPTIONSDESCRIPTIONSINTERPRETATIONINTERPRETATION
Small, reactiveSmall, reactive Metabolic causesMetabolic causesDiencephalic lesionDiencephalic lesion
Midposition, fixedMidposition, fixed Mid brain lesionMid brain lesion
large, fixedlarge, fixed Extensive brain stem lesion Extensive brain stem lesion AAnoxianoxiaSSedative overdoseedative overdose
AAnticholinergic poisoning or nticholinergic poisoning or mydriatic mydriatic eyedropseyedrops Pin pointPin point Pontine lesionPontine lesion OpiatesOpiates
Unilateral fixed dilatedUnilateral fixed dilated TThird nerve palsyhird nerve palsy
Doll’s eye Doll’s eye maneuver maneuver
(Oculocephalic (Oculocephalic reflex)reflex)
Cold caloric test Cold caloric test (Oculovestibular (Oculovestibular
reflex) reflex)
Eye movementsEye movements
ConditionCondition
AwakeAwake
Cerebral dysfunction, Cerebral dysfunction, brainstem intactbrainstem intact
Brain stem lesionBrain stem lesion
Doll’s eyesDoll’s eyes
NegativeNegative
Positive Positive
NegativeNegative
ConditionCondition
AwakeAwake
Cerebral dysfunction, Cerebral dysfunction, brainstem intactbrainstem intact
Brain stem lesionBrain stem lesion
Cold caloricsCold calorics
Nystagmus, N/V, painNystagmus, N/V, pain
Slow deviation toward Slow deviation toward waterwater
NegativeNegative
Respiratory patterns
Respiratory pattern(1)Respiratory pattern(1) Cheyne-Stokes respiration : bilateral cortical or Cheyne-Stokes respiration : bilateral cortical or
bilateral thalamic lesions, metabolic bilateral thalamic lesions, metabolic disturbances, incipient transtentorial herniationdisturbances, incipient transtentorial herniation
Hyperventilation : midbrain or pons lesionsHyperventilation : midbrain or pons lesions Apneusis : lateral tegmentum of lower half of Apneusis : lateral tegmentum of lower half of
ponspons Cluster : lower pontine or high medullary Cluster : lower pontine or high medullary
lesionslesions Ataxic : dorsomedial medulla lesion Ataxic : dorsomedial medulla lesion
Respiratory pattern(2)Respiratory pattern(2)
Least useful sign because :Least useful sign because :– Acid-base derangementsAcid-base derangements
– HypoxiaHypoxia
– Cardiac influencesCardiac influences
Conditions mimic comaConditions mimic coma
Brain deathBrain death Locked-in syndromeLocked-in syndrome Vegetative state Vegetative state Frontal lobe disease Frontal lobe disease Non-convulsive status epilepticus Non-convulsive status epilepticus Psychiatric disorder (catatonia, Psychiatric disorder (catatonia,
depression)depression)
Vegetative stateVegetative state
An An awake but unresponsive stateawake but unresponsive state Extensive damage in both cerebral Extensive damage in both cerebral
hemispherehemisphere Retained respiratory and autonomic Retained respiratory and autonomic
functionsfunctions Cardiac arrest and head injuryCardiac arrest and head injury are the most are the most
common causes.common causes.
Locked-in stateLocked-in state
AwakeAwake patient has patient has no means of no means of producing speech or volitional limb, producing speech or volitional limb, face and pharyngeal movementsface and pharyngeal movements
Vertical eye movement and lid Vertical eye movement and lid elevation remain unimpairedelevation remain unimpaired
Infarction or hemorrhage of the ventral Infarction or hemorrhage of the ventral ponspons
COMACOMA
LOCALIZING SIGN NO LOCALIZING SIGN
SUPRATENTORIAL INFRATENTORIAL
NO STIFF NECK
STIFF NECK
- CVD- TUMOUR- ABSCESS
STRUCTURAL DAMAGE FUNCTIONAL NEURONAL DEPRESSION
- HYPOXIA
- CARDIAC ARREST
- ENCEPHALITIS
- HEPATIC- URAEMIC- POST ICTAL STATE- FLUID ELECTROLYTE IMBALANCE- DRUGS
- SAH
- MENINGITIS
Blood testBlood test
CBCCBC FBSFBS BUN, CreatinineBUN, Creatinine Electrolyte, calciumElectrolyte, calcium LFTLFT Drug screen, toxicology screenDrug screen, toxicology screen
Other testsOther tests
EKGEKG CT or MRI brainCT or MRI brain CSF examCSF exam EEGEEG
Prognosis of comaPrognosis of coma
Recovery from coma depends primarily on the causes, rather than on the depth of coma
Intoxication and metabolic causes carry the best prognosis
Coma from traumatic head injury far better than those with coma from other structural causes
Coma from global hypoxic-ischemic carries least favorable prognosis
At 3rd day, no papillary light reflex or GCS < 5 is associated with poor prognosis
Brain HerniationBrain Herniation
Central Central transtentorial transtentorial herniationherniation
Uncal Uncal transtentorial transtentorial herniationherniation
Brain HerniationBrain Herniation
Management of Transtentorial Management of Transtentorial herniationherniation
Intubation andIntubation and hyperventilation (Phyperventilation (PCOCO22 25-30 25-30
mmHg)mmHg)
Mannitol (0.5-1 gm/kg body weight orMannitol (0.5-1 gm/kg body weight or 2020%%
mannitol 200 cc. infusion 10-20 minutes repeat mannitol 200 cc. infusion 10-20 minutes repeat
every 4 hours if necessary every 4 hours if necessary
Furosemide Furosemide 20-4020-40 mg IVmg IV
Dexamethasone 4-10 mg IV q 6 hours Dexamethasone 4-10 mg IV q 6 hours
decrease perilesional vasogenic cerebral decrease perilesional vasogenic cerebral
edema. Active at 24-48 hours.edema. Active at 24-48 hours.
Consult surgery Consult surgery