Hallucinations, Emergency Medicine

Basics

Description

Hallucinations are a symptom or feature and not a diagnosis. They may be auditory, visual, tactile, gustatory, or olfactory. Hallucinations and similar phenomena are often defined as follows:

Hallucination:
- Sensory perception that has the compelling sense of reality of a true perception without external stimulation of the relevant sensory organ and is experienced as a sensation through that organ
- Patients may or may not have insight that they are having the hallucination
Illusion:
- Misperception or misinterpretation of a real external stimulus
Flashback:
- Recurrence of a memory, feeling, or perceptual experience from the past that may have the compelling sense of reality
Pseudohallucination:
- Hallucination that is not experienced by a sensory organ (i.e., voices inside head or "inner voice" as opposed to hearing voices)

Epidemiology

Incidence and Prevalence Estimates

Lifetime incidence of auditory hallucinations is 4-8% in general population (although some estimates are higher due to vague definitions or inclusion of pseudohallucinations)
More than 50% of elderly patients with dementia have paranoia or hallucinations

Etiology

There are numerous causes of hallucinations. The following are common: (An exhaustive list is beyond the scope of this chapter)

Psychiatric
- Schizophrenia
- Bipolar disorder, mania
- Major depression
Acute intoxications
- Ethanol
- Cannabis
  - Marijuana alternatives (i.e., K2, Spice)
- Sympathomimetics
  - Amphetamine
  - Methamphetamine
  - Cocaine
  - Synthetic cathinones (i.e., MDPV, "bath salts")
- NMDA antagonists
  - Ketamine
  - PCP
  - Dextromethorphan
- Serotonergic
  - MDMA (Ecstasy)
  - LSD
  - Peyote cactus (mescaline)
  - Mushrooms (psilocybin)
  - 2C series (i.e., 2CB, 2CT-7)
  - 5-MeO series (i.e., 5-MeO-DMT)
- Kappa opioid receptor agonist
  - Salvia divinorum (cause synesthesias - i.e., hearing colors or smelling sounds)
- Opiates
- Inhalants
  - Toluene
  - Nitrous oxide
Medications
- Anticholinergic agents
- Steroids
- Methylphenidate
Withdrawal
- Ethanol
- Benzodiazepines
- Barbiturates
- GHB
Substance-induced disorders
- Methamphetamine-associated psychosis
  - Prolonged duration of psychosis, auditory hallucinations and recurrence without relapse of using drug
- Cannabis-induced psychosis
Infectious
- Meningitis
- Encephalitis
- In patients with dementia, any infection (i.e., UTI, pneumonia) can trigger hallucinations
Metabolic
- Hypoglycemia
- Electrolyte imbalances
- Thyroid disease
- Adrenal disease
- Wilsons disease
- Thiamine deficiency
Neurologic
- Seizures
  - Partial simple or complex seizures can result in visual, auditory, olfactory, and gustatory hallucinations
- Migraines
- CNS hemorrhage or tumor
- CVA
- Tourette syndrome
- Neurodegenerative disorders
  - Parkinsons
  - Dementia (Lewy body, Alzheimer)
  - HIV
Ocular
- Glaucoma
- Macular degeneration
- Charles Bonnet syndrome
Others
- Food, sensory, sleep deprivation
- Fatigue, extreme stress
- Heat-related illness
- Religious and ritual activities
- Falling asleep and awakening from sleep

Hallucinations are relatively common in children and adolescents and are often developmentally normal. Most children with hallucinations do not have psychosis. Hallucinations can occur as part of a delirium, such as from fever. As with the adult patient, carefully conduct a search for a medical or neurologic etiology.
In the elderly patient, hallucinations are most often from an organic cause. They can commonly accompany dementia, depression, medication reactions and substance abuse, and are often associated with agitation. Atypical antipsychotic agents are effective treatment for hallucinations with agitation in the elderly.

Diagnosis

Signs and Symptoms

History

Obtaining accurate and thorough history often difficult
- Collateral history should be obtained from bystanders, EMS, police, family, physicians
Assess for changes in behavior from baseline
Explore for delusions or persecutory beliefs
Previous episodes of hallucinations
Change in medications
Substance abuse history
Alteration in cognition that rapidly develops and waxes and wanes throughout course of the day suggests delirium
Headache may suggest CNS lesion or migraine

Physical Exam

Acute psychosis
- Disorganized thought
- Responding to internal stimuli
Mania
- Excessive talking or pressured speech
Delirium
- Altered level of consciousness
- Not oriented
- Abnormal vital signs
CNS lesion
- Cranial nerve deficit
- Aphasia
- Any focal neurologic finding
- Gait abnormality
- External signs of trauma
Systemic or infectious illness
- Asterixis
- Fever
- Nuchal rigidity
- Myoclonus
- Jaundice
- Ascites
Signs of intoxication or withdrawal
- Sympathomimetic intoxication, ethanol/benzodiazepine withdrawal
  - Agitation, excited delirium
  - Mydriasis
  - Tachycardia, hypertension
  - Hyperthermia
  - Diaphoresis
- Opiate
  - Miosis
  - Bradypnea
  - Needle marks
- Serotonergic
  - Tachycardia, hypertension
  - Hyperreflexia
  - Clonus
  - Tremor
- NMDA antagonism
  - Nystagmus

Diagnosis Tests & Interpretation

Common tests:
- CBC, serum chemistries
- Ethanol, acetaminophen, salicylate serum concentrations
- Urinalysis
More focused studies depending on comorbid conditions or clinical concerns:
- Urine drug of abuse screen
  - Interpretation can be difficult as this is a test of use and not intoxication. In addition, it is not designed to detect newer drugs of abuse, although some may cross-react with this assay.
- EKG
- Thyroid function
- Liver function tests
- RPR, folate, B12, thiamine
- Specific drug concentrations

Imaging

Brain imaging (CT, MRI)
Chest x-ray

Diagnostic Procedures/Surgery

If suspicion exists for medical cause, should consider procedures such as:
- Lumbar puncture
- EEG
If hallucinations are from acute psychiatric illness or decompensation of chronic psychiatric illness
- Obtain emergent psychiatric consultation

Essential Workup

Patients with a clear psychiatric history with characteristic symptoms need minimal testing (CBC, chemistries). However, patients with undifferentiated hallucinations, especially those in high-risk groups, require extensive testing.

Differential Diagnosis

The primary goal of ED evaluation is to differentiate psychiatric from nonpsychiatric cause of hallucination. (See Psychosis, Medical vs. Psychiatric)

More likely to be from psychiatric illness:
- Auditory and command hallucination
- Hallucinations and illusions incorporated into delusional system
- Age of onset 13-40 yr old
- Flat affect
- Normal orientation
- Disorganized attention
The following groups are considered to be at higher risk for nonpsychiatric illness:
- Elderly
- History of substance abuse
- No pre-existing psychiatric history
- Presence of pre-existing medical disorders
- Lower socioeconomic level
Visual hallucinations more common:
- Delirium
- Dementia
- Migraines
- Dopamine agonist therapy (i.e., carbidopa)
- Posterior cerebral infarcts
- Narcolepsy

Treatment

Pre-Hospital

Observe details of patients environment not available to hospital care team

Disorganized living environment
Drug paraphernalia

Initial Stabilization/Therapy

Address ABCs and any abnormal vital signs (i.e., supplemental oxygen for hypoxia)
Check FSBG
Consider thiamine 100 mg IV/PO
Treat acute agitation (see Agitation)
- De-escalation techniques
- Physical restraints
- Chemical sedation

Ed Treatment/Procedures

If underlying medical cause identified
- Treat medical etiology
- These patients typically do not require antipsychotic medications
In patients with acute psychosis or decompensation of chronic psychotic illness
- Use antipsychotics and benzodiazepines (see Psychosis, Acute)
In patients with hallucinations due to intoxication with excited delirium
- General supportive care
- Benzodiazepines
If dementia with hallucinations
- Treat underlying medical etiology, if any
- Atypical antipsychotics have benefits and harm (CVA, extrapyramidal symptoms)

When treating hallucinations with an excited delirium due to acute intoxication (except for ethanol), use benzodiazepines.

Follow-Up

Disposition

Admission Criteria
Disposition determined by medical condition or psychiatric evaluation. Hallucinations from some intoxications such as methamphetamine or cannabis may persist even after drug is metabolized.
Admission Criteria

Medical condition requiring admission
Acute psychiatric illness or decompensation of chronic psychiatric illness requiring psychiatric hospitalization

Discharge Criteria

Symptoms have resolved and reversible medical cause (i.e., intoxication, UTI)
Decompensation of chronic psychiatric condition has been addressed, home environment appropriate and mental health follow-up available.

Issues for Referral
Alcohol/drug treatment as appropriate

Followup Recommendations

As appropriate for medical or chronic psychiatric condition(s)

Pearls and Pitfalls

Do not assume that auditory hallucinations are always from psychiatric illness whereas visual, tactile, olfactory, and gustatory hallucinations are nonpsychiatric - always perform thorough evaluation.
Even though 10% of cases of schizophrenia occur in patients older than 45, do not assume hallucinations are from psychiatric cause in older age group without extensive workup.
Do not treat hallucinations with excited delirium from an acute intoxication (except due to ethanol) with antipsychotic agents.

Additional Reading

El-Mallakh RS, Walker KL. Hallucinations, psuedohallucinations, and parahallucinations. Psychiatry. 2010;73(1):34-42.
Piechniczek-Buczek J. Psychiatric emergencies in the elderly population. Emerg Med Clin North Am. 2009;24(2):467-490.
Sood TR, Mcstay CM. Evaluation of the psychiatric patient. Emerg Med Clin North Am. 2009;27(4):669-683.
Sosland MD, Edelsohn GA. Hallucinations in children and adolescents. Curr Psychiatry Rep. 2005;7(3):180-188.

Codes

ICD9

291.3 Alcohol-induced psychotic disorder with hallucinations
368.16 Psychophysical visual disturbances
780.1 Hallucinations

ICD10

F10.951 Alcohol use, unsp w alcoh-induce psych disorder w hallucin
R44.1 Visual hallucinations
R44.3 Hallucinations, unspecified
R44.0 Auditory hallucinations
F12.951 Cannabis use, unsp w psychotic disorder with hallucinations
F16.151 Hallucinogen abuse w psychotic disorder w hallucinations
F19.951 Oth psychoactv sub use, unsp w psych disorder w hallucin
R44.2 Other hallucinations

SNOMED

7011001 Hallucinations (finding)
64269007 Visual hallucinations (finding)
417633001 Alcohol induced hallucinations (finding)
45150006 Auditory hallucinations (finding)
191486006 Drug-induced hallucinosis (disorder)
29139005 Gustatory hallucinations (finding)
39672001 Olfactory hallucinations (finding)

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