Altered Mental Status
David T. Matero, M.D.
Assistant Professor
Emergency Medicine
University of Colorado Denver
Overview
 Altered mental status: It Could Be [almost] Anything!
requires a thorough work-up
 What is the differential for altered mental status?
 What is the type of problem that could cause it?
 What is the organ system(s) that could be involved?
Example
 63 yo female found down next to park bench. Bystander
called EMS who are now moving patient from gurney onto
bed.
 You ask for history: There is none
 You ask for ROS: There is none
 You ask for PMH, Meds, Anything!: There is none
WELCOME TO
EMERGENCY MEDICINE
What Could Be Wrong With Her?
Tramua: Brain laceration/injuryConcussionDepressed skull fractureHead traumaBrain, contusionBrain injury, massiveDiffuse axonal injury/Acute brain traumaShaken Baby SyndromeElectromagnetic, Physics,
trauma, Radiation CausesAsphyxia/suffocationDrowning, fresh waterDrowning, sea waterDrowning/Near- drowningHeat exhaustion/prostrationHeat strokeEncephalopathy/postanoxicHypoxiaHypoxic
environmentHypothermia, accidental/exposureElectrocution/lightning strikeHigh altitude cerebral edemaDecompression sicknessHigh altitude pulmonary edemaIatrogenic, Self Induced DisordersWater
intoxicationHypothermic anesthesiaHyponatremia correction, rapidSurgical, Procedure ComplicationAnesthesia, generalBrain surgeryInfectious Disorders (Specific Agent)Pneumonia, bacterialAIDS
MeningoencephalitisEncephalitis, herpes simplexEncephalitis, secondary viralEncephalitis, viralMeningitis BacterialMeningitis, aseptic/viralMeningitis, HemophilusMeningitis, pneumococcalMeningococcal
meningitisPneumonia/BronchopneumoniaPneumonia, acute lobarPneumonia, pneumococcalTyphoid feverMeningitis, tuberculosisAmebic (Naegleria) meningoencephalitisBacterial overwhelming
sepsisCandidiasis systemicChickenpox encephalitisEncephalitis, bacterial/cerebritisEncephalitis, Dawsons/inclusion bodyEncephalitis, Eastern equineEncephalitis, mumpsEncephalitis, Murray valleyEncephalitis,
non-viralEncephalitis, St Louis BEncephalitis, Western equineGram negative (e coli) meningitisHistoplasmosis meningitisKunjin viral encephalitisLa Crosse viral encephalitisLegionella
meningoencephalitisLeptospiral meningitisLeptospirosis/severe (Weils) typeListeria meningitisLyme meningoencephalitisMalaria, cerebralMeningitis, candidaMeningitis, Coxacki viralMeningitis, echo
viralMeningitis, staphylococcus aureusMononucleosis encephalitisPlague meningitisPost-viral/infectious encephalopathyPrimary bacterial peritonitis/ascitesRabiesReyes syndromeRussian tick-bourne
encephalitisToxic shock syndromeTrichinella meningoencephalitisTyphus, acute/epidemicWest Nile fever/encephalitisBrucellosisLegionaires diseaseListeria monocytogenes/listeriosisMeningitis, fungalRocky
mountain spotted feverToxoplasma meningoencephalitisCreutzfeld-Jakob diseaseMeningitis, cryptococcalPsittacosis/ornithosisSleeping sickness/trypanosomiasisToxoplasmosis, cerebralEncephalitis,
CaliforniaEncephalitis, equine, VenezuelanEncephalitis, Japanese BEncephalitis, powassanMalariaMeningitis, coccidioidomycosisNipah virus/encephalitisPlague, bubonicTularemia meningitisPoliomyelitis,
acuteFungus brain abscessLeptospirosis IctohemorrhagicaInfected organ, AbscessesInfectionsAbscess, intracranialBacteremia/SepticemiaBrain abscessEmbolism, septic, cerebralEndocarditis,
infectiveMeningoencephalitisPneumonia, aspirationSepsisSepsis, overwhelmingSeptic shockUrosepsis/septicemiaEncephalomyelitis, acuteEncephalopathy/secondary/toxic/sepsisNecrotizing
fasciitis/mixedBrain stem encephalitisEncephalitisMeningitisPneumoniaGranulomatous, Inflammatory DisordersHemorrhagic pancreatitis, necrotizingPancreatitis/resp distress syndromeNeoplastic
DisordersHypercalcemia of malignancyMetastatic brain diseaseBrain stem tumorBrain tumorFrontal lobe tumorMedulloblastomaMeningeal carcinomatosisParietal lobe tumorPrimary CNS lymphomaTemporal
lobe tumorBrain tumor , malignant (astrocytoma)CraniopharyngiomaGlioblastoma multiformeInsulinoma/Islet cell tumorMeningiomaPontine gliomaChoroid plexus, papillomaAllergic, Collagen, Auto-Immune
DisordersEncephalitis, hemorrhagic, acuteEncephalitis, post viralEncephalomyelitis, necrotizing hem. ac.Encephalomyelitis, post-infectiousStevens-Johnson syndromeTransfusion reaction, hemolyticLupus
cerebritisPolyarteritis nodosaBehcet's syndromeHashimotos EncephalitisMetabolic, Storage DisordersHypoglycemia, reactive diabeticDiabetic ketoacidosis/comaHyperosmolar hyperglycemic coma,
nonketNeonatal hyperbilirubinemiaMetabolic disordersMethemoglobinemia, HereditaryPorphyria, acute intermittentGlutaric aciduria/AcidemiaUrea cycle/metabolic disorderMethemoglobinemia,
acquired/toxicBiochemical DisordersEncephalopathy, hypoglycemicHypoglycemia, infantileAcid/Base derangementAcidosisHypercalcemiaHypercapnea
HypercarbiaHypernatremiaHyperosmolalityHypocalcemiaHyponatremiaLactic acidosisMetabolic encephalopathyHypoxia, systemic, chronicHypoglycemiaPontine myelinolysis, centralDeficiency
DisordersDehydration and feverDehydrationWernicke's encephalopathyMalnutrition/StarvationPellagra/niacin deficiencyMarchiafava-Bignami syndromeCongenital, Developmental DisordersNephrogenic
diabetes insipidusHereditary, Familial, Genetic DisordersMELAS EncephalopathyVan Bogaert encephalitisUsage, Degenerative, Necrosis, Age Related DisordersAlzheimer's syndromeDementia, Lewy-body
typeMultiple sclerosisRelational, Mental, Psychiatric Disorders Conversion disorderManiaHypoglycemia, factitiousCatatoniaManic deleriumAnatomic, Foreign Body, Structural DisordersAcute subdural
hematoma/hemorrhageBrain compressionEpidural hematomaIntracerebral hematomaIntraventricular brain hemorrhageSubdural hematomaTamponade, cardiacBrain stem herniation/peduncle/tonsilsFat
embolismSuperior vena cava syndromeIntracranial mass effectArteriosclerotic, Vascular, Venous DisordersCerebral vascular accidentCerebral embolismCerebral hemorrhageCerebral vein
thrombosis/phlebitisIntracerebral hemorrhageMyocardial infarction, acuteSubarachnoid hemorrhageTransient cerebral ischemia attackCerebral infarct/EncephalomalaciaBrain stem infarctCavernous sinus
thrombosisCerebral/Venous sinus thrombophlebitisSuperior sagittal sinus thrombosisVertebrobasilar artery dissectionFunctional, Physiologic Variant DisordersHyperpyrexiaSleep deprivationVegetative,
Autonomic, Endocrine DisordersCardiac arrestSyncopeSyncope, vasovagalArrhythmiasCardiogenic shockConvulsion/grand mal seizureEpilepsyHypoglycemia, functionalIncreased intracranial pressureSeizure
disorderHyperthermiaHypotensionOrthostatic hypotensionPost-ictal statusThyrotoxicosis (Graves disease)Hypothyroidism (myxedema)Encephalopathy, hypertensiveHypertension, malignantMalignant
hyperthermiaMyxedema comaMyxedema madness/psychosisStokes-Adams attacksThyrotoxic crisisComplete heart blockInappropriate ADH secretionVertebrobasilar migraine syndromeHypothyroidism,
juvenileNarcolepsyPickwick's syndromeReference to Organ SystemShockCerebral edemaDisseminated intravascular coagulopathyHepatic encephalopathyHypovolemic shockRenal Failure AcuteRespiratory
distress (adult) syndromeBrain disordersRespiratory failure/Pulmonary insufficiencyEmphysema/COPD/Chronic lung diseaseCerebral thrombotic thrombocytopeniaHepatorenal syndromeRenal Failure
ChronicUremic encephalopathyEncephalopathyHyperviscosity syndromePernicious anemiaPontine lesion/disorderThrombotic thrombocytopenic purpuraCombined system disease/pernicious an.Fever
Unknown OriginReversable Posterior Encephalopathy SyndromePathophysiologicSepsis encephalopathy/elderlyCardiac output reductionCerebral depressed functionsDrugsMedication/drugsBenzodiazepines
Administration/ToxicitySedative drugs Administration/ToxicityDigitalis toxicity/poisoningHypoglycemia, diabetic/treatmentInsulin overdose/exogenousIntoxication/overdose syndromeSalicylate
intoxication/overdoseTricyclic overdoseBarbiturate/sedative abuse/dependentDrug induced Hypoglycemia.Oral hypoglycemic Administration/Toxicity/effectInsulin (Humulin/Novulin)
Administration/ToxicityIsoniazid (INH/Nydrazid) Administration/ToxicityErgot toxicityIsoniazid hepatitisMilk-alkali syndromePoisoning (Specific Agent)Opiate overdose toxidromeKitchen gas/propane
exposureAlcohol/Ethanol ingestion/intakeAlcohol amnestic disorderAlcohol induced hypoglycemiaAlcohol intoxication, acuteAlcohol seizure (rum fits)Cholinergic crisis toxidromeDelirium
tremensInsecticide/organophosphate typeOverdose, drug/alcoholPoisoningSnakebite (neurotoxic/coral/cobra type)Snakebite (rattlesnake/pit viper type)Alcohol withdrawalHallucinogen abuseLead poisoning
in childrenSmoke inhalationHeroin/morphine usage/addictionCyanide/Hydrogen cyanide exposure/poisoningVomiting CBW agent (Dm/Da/Dc) Weapon exposureArsine gas (Hydrogen arsenide)
poisoningCarbon monoxide poisoning/exposureDiethylene Glycol poisoningEthylene glycol [Antifreeze] ingestionInsecticide/pesticide poisoningIntentional poisoningIsopropyl alcohol
ingestion/poisoningMustard gas exposure/poisoningNerve gas exposureAluminum toxicity/syndromeAmmonia exposure/inhalationHydrogen sulfide poisoning/inhalationInsecticide/chlorinated/non-ester's
inhLead poisoningLead encephalopathyNitrogen narcotic actionCarbon disulfide inhalant/poisoningChlorine gas poisoningMethane gas poisoning/asphyxiaCarbon dioxide gas inhalation/asphyxiaOrgan
Poisoning (Intoxication)Neuroleptic malignant syndrome
 From Vertebrobasilar migraine syndrome to Hyponatremia
It’s TOO MUCH
 You need a clue:
-EMS report
-Cell phone (call family members)
-Bystander account
-PMH from meds, alert bracelet, wallet, PhysEx (e.g fistula)
-Phys Exam for current physiological state of patient
-Labs
-Imaging
Physiologic Reserve Determines How
Readily the Patient Will Have AMS!
 Frail Old Patient: A simple Urinary Tract Infection can put
this patient in a coma.
 Young Healthy Patient: Likely to be something significant
that has gone wrong
 Patient With Obvious Comorbidities: Other causes (than
primary medical problem) will more readily alter this patient
(less reserve!)
You May Get Frustrated at this Patient
and Say (ddx):
 M: Metabolic—B12 or thiamine deficiency, serotonin syndrome
 O: Hypoxemia (pulmonary, cardiac, anemia); high CO2
 V: Vascular causes—hypertensive emergency, ischemic/hemorrhagic
CVA, vasculitis, MI
 E: Electrolytes and endocrine
 S: Seizures / status epilepticus, post-ictal
 T: Tumor, trauma, temperature, toxins ( lead, mercury, CO, toxidromes )
 U: Uremia. Renal or hepatic dysfuction with hepatic encephalopathy
 P: Psychiatric, porphyria
 I: Infection (inflammatory-see vasculitis above)
 D: Drugs, including withdrawal (anticholinergics, TCA;s, SSRI’s, BZD’s,
barbiturates, alcohol)
M: Metabolic—B12 or thiamine
deficiency, serotonin syndrome
 Glucose metabolism uses up even more thiamine
 Serotonin syndrome=serotonin toxicity and caused by
various drugs, medicines and combinations thereof
-increased heart rate, shivering, sweating, dilated pupils,
myoclonus, as well as overresponsive reflexes
O: Hypoxemia (pulmonary, cardiac,
anemia); high CO2
 Purely Hypoxic patient is anxious/agitated
-PE
 Purely Hypercarbic patient is sleepy
-Jet Insufflation in kids or bad COPDer
V: Vascular causes—hypertensive
emergency, ischemic/hemorrhagic
CVA, vasculitis, MI
 All of these cause poor perfusion of the brain either focally or
globally through local effects (CVA) or through loss of
forward flow to brain (MI)
E: Electrolytes and endocrine
 Electrolyte shifts can cause swelling in the brain
 High Na or Ca global depression (any electrolyte involved
in ion-channel transmission in the brain can cause a problem)
 Hypoglycemia most common cause of endocrine-related MS
depression
S: Seizures / status epilepticus, postictal
 Post-ictal state typically resolves in 20-40minutes
 Non-epileptiform seizures can be cause of depressed mental
status
-No tonic-clonic activity
-Ultimately diagnosed with EEG
-Eye movement, hx, ’trial of Ativan’ may give clue
T: Tumor, trauma, temperature, toxins
(lead, mercury, CO, toxidromes )
 Tumor causes compression or diffuse edema
 Hypothermia: Global depression of ion-channels
 Toxins: Wide range of responses depending on individual and
their reserve
 Look for Toxidromes- A symptom constellation specific to a
given toxin (e.g. Slurred speech, B lateral-gaze nystagmus,
cerebellar deficits, altered mood is the toxidrome for
Ethanol)
U: Uremia. Renal or hepatic dysfuction
with hepatic encephalopathy
 Electrolyte Abnormalities
 Uremia-Urea build-up AND electrolyte abnormalities
 Hepatic Encephalopathy- elevated Ammonia (level should be
high but poorly correlated with actual degree of AMS)
P: Psychiatric, porphyria
 Catatonia: no focal neurological deficits but unresponsive
(responds to Ativan!)
 Porphyria: A group of enzyme deficiencies in hematologic
biosynthesis pathway that results in accumulation of
Porphyrins (or precursors): Multiple s/sx including various
MS effects
I: Infection (inflammatory-see vasculitis
above)
 Meningitis (A constant concern in all patient, esp at extremes
of age)
 Cerebritis
D: Drugs, including withdrawal
(anticholinergics, TCA;s, SSRI’s, BZD’s,
barbiturates, alcohol)
 Learn and look for Toxidromes (withdrawal states are usually
essentially opposite in symptoms)
In Summary: It ALL Boils Down to One
of Two Things
 Both cerebral hemispheres are depressed
 The Reticular Activating System is not
functioning.
In Summary: It ALL Boils Down to One
of Two Things
 Both cerebral hemispheres are depressed
 The Reticular Activating System is not
functioning.
Diffuse Process– most of
the cases arise from this
In Summary: It ALL Boils Down to One
of Two Things
 Both cerebral hemispheres are depressed
 The Reticular Activating System is not
functioning.
?
Diffuse Process– most of
the cases arise from this
In Summary: It ALL Boils Down to One
of Two Things
 Both cerebral hemispheres are depressed
 The Reticular Activating System is not
functioning.
Stroke, Seizure or
Trauma to this
region
Diffuse Process– most of
the cases arise from this
Approach the Patient Covering Most
Urgent Bases First
 ABCs
 Intravenous access, oxygen therapy, cardiac
monitoring with pulse oximetry
 Accu-check / glucose / thiamine
 Cervical spine precautions
 Naloxone
Approach the Patient Covering Most
Urgent Bases First
 EKG / cardiac monitoring
 ABG with carboxyhemoglobin
 CBC, electrolytes, Ca, Mg
 Drug screen, EtOH, serum osmolarity
 Urinalysis
 Imaging
 lumbar puncture
 liver, thyroid
Approach the Patient Covering Most
Urgent Bases First
 EKG / cardiac monitoring
 ABG with carboxyhemoglobin
 CBC, electrolytes, Ca, Mg
 Drug screen, EtOH, serum osmolarity
 Urinalysis
 Imaging
 lumbar puncture
 liver, thyroid
Frail Old Patient: A
simple Urinary Tract
Infection can put this
patient in a coma.
63 yo female found down next to park
bench
 You have no information:You do a physical exam
-A: Breath sounds CTAB, +gag, trachea midline, no pooling
of secretions,
-B: Spontaneous respirations
-C: Regular rhythm , tachycardia, B femoral pulses,
diminished DP pulses (but present)
-VS:101, 88/45, T- 35.6, 92% RA
63 yo female found down next to park
bench
-HEENT: PERRL, TMs clear, MM slightly dry
-Neck: Supple, no JVD
-Chest: no crepitus, atraumatic
-GI: soft, BS present/normal; rectal no gross blood, NL tone
-Extrem: UE and LE with no clubbing, cyanosis, edema
pulses present except as noted in ABCs
-Back: Atraumatic, no step-offs
-Neuro: CN grossly intact, MAE, withdraws to pain, no gross
focal neurol deficits, reflexes symmetrical, does not answer Qs or
follow commands, moaning
-Skin: well perfused
-GU: Perineum atraumatic, no discharge or lesions
What Was Abnormal?
What Could It Mean?
What Was Abnormal?
What Could It Mean?
 You have no information:You do a Physical Exam
-A: Breath sounds CTAB, +gag, trachea midline, no pooling
of secretions,
-B: Spontaneous Respirations
-C: Regular rhythm , tachycardia, B Femoral pulses,
diminished DP pulses (but present)
-VS:101, 88/45, T- 35.6, 92% RA
63 yo female found down next to park
bench
-HEENT: PERRL, TMs clear, MM slightly dry
-Neck: Supple, no JVD
-Chest: no crepitus, atraumatic
-GI: soft, BS present/normal; rectal no gross blood, NL tone
-Extrem: UE and LE with no clubbing, cyanosis, edema, pulses
present except as noted in ABCs
-Back: Atraumatic, no step-offs
-Neuro: CN grossly intact, MAE, withdraws extrem to pain,no
gross focal neurol def, reflexes symmetrical, does not answer Qs
or follow commands, moaning
-Skin: well perfused
-GU: Perineum atraumatic, no discharge or lesions
Putting the Physical Exam Findings
Together:
 Do you think this is a Global or a Focal Process?
 How would you summarize the state of the patient based on
PEX?
 What could cause this state?
What is more likely now?
 M: Metabolic—B12 or thiamine deficiency, serotonin syndrome
 O: Hypoxemia (pulmonary, cardiac, anemia); high CO2
 V: Vascular causes—hypertensive emergency, ischemic/hemorrhagic
CVA, vasculitis, MI
 E: Electrolytes and endocrine
 S: Seizures / status epilepticus, post-ictal
 T: Tumor, trauma, temperature, toxins (lead, mercury, CO, toxidromes)
 U: Uremia. Renal or hepatic dysfuction with hepatic encephalopathy
 P: Psychiatric, porphyria
 I: Infection (inflammatory-see vasculitis above)
 D: Drugs, including withdrawal (anticholinergics, TCA;s, SSRI’s, BZD’s,
barbiturates, alcohol)
What is more likely now?
 M: Metabolic—B12 or thiamine deficiency, serotonin syndrome
 O: Hypoxemia (pulmonary, cardiac, anemia); high CO2
 V: Vascular causes—hypertensive emergency, ischemic/hemorrhagic
CVA, vasculitis, MI
 E: Electrolytes and endocrine
 S: Seizures / status epilepticus, post-ictal
 T: Tumor, trauma, temperature, toxins ( lead, mercury, CO, toxidromes )
 U: Uremia. Renal or hepatic dysfuction with hepatic encephalopathy
 P: Psychiatric, porphyria
 I: Infection (inflammatory-see vasculitis above)
 D: Drugs, including withdrawal (anticholinergics, TCA;s, SSRI’s, BZD’s,
barbiturates, alcohol)
Next Step: Diagnostic Studies
 Prioritize acute life threats first
 Get high-yield, easy items first: Glc, EKG
 Keep modifying testing as DDX changes with results
 ’Shotgun Approach’ (parallel processing)
 Is patient stable to go to imaging or to wait for lab result
before making treatment decision?
How Do I Know What to Order?
 Balance these two things to determine what
tests/priority:
-Shotgun approach (intended to move things
along quickly and cast wide net)
-What you’ve learned from your H&P
LABS
141
101
4.1
26
17
1.1
14.4
14.5
41.9
380
LFTs- Normal
ASA, APAP, Coags Normal
101
UA:
Spec grav 1.026
pH 6.0
Ketones +
Glucose –
Bile –
Blood +
Bacteria ++
WBC ++
Nitrite +
Leuk. Est +
LABS
141
101
4.1
26
17
1.1
14.4
14.5
380
41.9
LFTs- Normal
ASA, APAP, Coags Normal
101
UA:
Spec grav 1.026
pH 6.0
Ketones +
Glucose –
Bile –
Blood +
Bacteria ++
WBC ++
Nitrite +
Leuk. Est +
Do We Know What’s Going On?
 We know the patient has a UTI
 Is this enough to explain the patient’s sepsis?
 Can we stop our work-up?
 Could the UTI be a red herring?
Do We Know What’s Going On?
 We know the patient has a UTI
 Is this enough to explain the patient’s sepsis? YES
 Can we stop our work-up?
 Could the UTI be a red herring?
Do We Know What’s Going On?
 We know the patient has a UTI
 Is this enough to explain the patient’s sepsis? YES
 Can we stop our work-up? NO
 Could the UTI be a red herring?
Do We Know What’s Going On?
 We know the patient has a UTI
 Is this enough to explain the patient’s sepsis? YES
 Can we stop our work-up? NO
 Could the UTI be a red herring? YES
What Else Should We Do?
 Pt does have Sepsis and a UTI, this could be Urosepsis.
HOWEVER, it could also be something else (and there just
happens to be a UTI)
What Else Should We Do?
 EKG MI, Intervals (Toxins), Other CXR PNA (Sepsis), Edema, Trauma Head CT Bleed, Swelling, Mass  Lumbar Puncture Bleed, Infection  Urine Drug Screen Drugs of Abuse -
What Else Should We Do?
 EKG MI, Intervals (Toxins), Other- NORMAL
 CXR PNA (Sepsis), Edema, Trauma- NORMAL
 Head CT Bleed, Swelling, Mass - NORMAL
 Lumbar Puncture Bleed, Infection - NORMAL
 Urine Drug Screen Drugs of Abuse - NORMAL
We THINK We Know the Cause
 Urosepsis
We THINK We Know the Cause
 Urosepsis
 Re-Examine the patient and make sure nothing
has changed and that the exam is consistent w Dx
 Don’t become ”emotionally attached” to a Dx, as
the clinical picture can change and start looking
like something else 
“The only atypical presentation is a typical
presentation”
CONCLUSION
 Maintain a wide differential
 Get a Grip on the Diagnosis through systematic ”clue finding”
 Remember: It’s focal in the RAS, or diffuse in the Bilateral
Hemispheres
 Re-evaluate patient frequently and do frequent ”hypothesistesting” in your mind