Hallucinations: Non-Psychiatric Causes

Category

Concerning Features *Necessitates immediate transfer to ED

Example Diagnoses

Testing to Consider

Neurologic 

HISTORY: 

• Seizures* 
• Headache +/- associated photophobia, phonophobia, diplopia, blurry vision, visual field defects, or aura
• Olfactory or gustatory hallucinations 
• Stereotyped hallucinations (simple, visual hallucinations that recur as the same perception)
• Insight to hallucinations
• Known head trauma

EXAM: 

• Altered level of consciousness* 
• Aphasia, dysarthria, or incoherent speech* 
• Cranial nerve deficit 
• Dystonia, clonus, rigidity, weakness, or choreiform movements
• Hyper/hyporeflexia 
  Ataxia, nystagmus, or dysmetria
• Kayser-Fleisher rings 

• Head trauma 
• Epilepsy 
• Delirium
• Stroke 
• Migraine
• Brain mass (tumor, arteriovenous malformation, cyst, abscess, tuberous (sclerosis)
• Multiple sclerosis
• adrenoleukodystrophy
• Wilson's disease
• Narcolepsy
• Kleine-Levin syndrome
• CNS vasculitis abscess, tuberous (sclerosis)
• Juvenile Huntington's disease 

• Neuroimaging 
• EEG

Toxicologic

HISTORY:

• Known substance abuse* 
• Association with medication (e.g., dystonia with anti-psychotics) 

EXAM: 

• Altered level of consciousness 
• Pupillary abnormalities

• Medication side effects or interactions 
• Accidental toxic ingestion
• Substance use-related disorders (e.g., intoxication or withdrawal)
• Heavy metal poisoning

• Urine drug screen
• Heavy metal panel 

Infectious

EXAM: 

• Toxic appearance
• Fever +/- abnormal vital signs 
• Lethargy 
• Meningismus

• HIV 
• Neurosyphilis
• Viral or bacterial encephalitis
• Meningitis 
• Neurocysticercosis

• Urinalysis with reflex urine culture 
• CBC with differential
• CRP 
• CSF studies
• HIV antigen/antibody
• RPR

Rheumatic/Autoimmune

HISTORY: 

• Joint pain or swelling 

EXAM: 

• Oral ulcers
• Hyperpigmentation
• Rash (malar rash, vasculitic rash, erythema nodosum)
• Nail changes
• Hair loss
• Arthritis 

• Systemic lupus erythematosus
• Sarcoidosis 
• Paraneoplastic syndrome
• Autoimmune encephalitis
• Post-infectious encephalitis or ADEM

• ANA
• Urinalysis
• SLE-specific labs
• Neuroimaging

Endocrine 

HISTORY: 

• Unexplained weight changes
• Fatigue 

EXAM: 

• Abnormal vital signs
• Abnormal thyroid exam
• Skin or hair changes
• Abnormal vital signs 

• Hyper/hypothyroidism (Hashimoto encephalitis, thyroiditis)
• Hyperparathyroidism 
• Hypoglycemia 
• Addison’s disease
• Pheochromocytoma
• Cushing disease
• Catamenial disorders

• TSH 
• Free T4
• Calcium, PTH, alkaline phosphatase 

Metabolic 

HISTORY: 

• Early age of onset 
• Developmental delay or regression
• Fatigue 
• Vomiting 

EXAM: 

• Lethargy
• Abnormal growth curve 

• Porphyria
• Urea cycle defects, fatty acid oxidation defects 
• Niemann-Pick disease
• Nutritional deficiencies (Mg, vitamin A/B1/B3/B12) 

• Complete metabolic panel 
• Urinalysis 
• Plasma amino acids
• Urine organic acids 
• Acylcarnitine profile 
• Urine protein: creatinine ratio
• Ammonia