Rosen & Barkin's 5-Minute Emergency Medicine Consult (309 page)

Patients should be considered for discharge only after consultation with neurologist

• Follow-up determined by neurologist
  
• Poor outcome associated with:
  
  • Older age
    
  • Longer time to nadir
    
  • Necessity for ventilator support
    
  • Preceding diarrheal illness,
    C. jejuni
    

• Pearls:
  
  • Check FVC and/or NIF frequently to anticipate airway compromise
    
  • Consider other etiologies if CSF WBC count >10–50
    
• Pitfalls:
  
  • Failure to obtain appropriate imaging of the brain and spinal cord to rule out other potential causes
    
  • Failure to consult neurology and admit or observe all patients with suspected GBS
    

• Brettschneider J, Petzold A, Süssmuth S, et al. Cerebrospinal fluid biomarkers in Guillain-Barré syndrome–where do we stand?
  J Neurol
  . 2009;256:3–12.
  
• Hughes RA, Swan AV, Raphaël JC, et al. Immunotherapy for Guillain-Barré syndrome: A systematic review.
  Brain
  . 2007;130:2245–2257
  .
  
• Lunn MP, Willison HJ. Diagnosis and treatment in inflammatory neuropathies.
  Postgrad Med J
  . 2009;85;437–446.
  
• Sejvar JJ, Baughman AL, Wise M, et al. Population incidence of Guillain-Barré syndrome: A systematic review and meta-analysis.
  Neuroepidemiology.
  2011;36:123–133.
  
• Yuki N, Hartung HP. Guillain-Barré syndrome.
  N Engl J Med.
  2012;366:2294–2304.
  

See Also (Topic, Algorithm, Electronic Media Element)

• Myasthenia Gravis
  
• Spinal Cord Syndromes
  
• Spine Injury
  
• Tick Bites
  

CODES

357.0 Acute infective polyneuritis

BASICS

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)
    

• 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
  

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
    
  • Wilson’s 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

• 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
  

• 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