MedSchool: Ace Your OSCEsThe Medical Company
GET - On the App Store
Mental Status Exam


November 7th, 2019


Hallucinations are abnormal sensory symptoms that may manifest as visual, auditory, tactile or extraordinary disturbances. Hallucinations may be caused by organic disease or psychiatric disorders.
  • Types of Hallucinations

  • Auditory hallucinations - including commentary, insulting voices, Gedanklautwerden, echo de la pensee
  • Visual hallucinations - may be simple (such as flashes or colours) or complex (such as people, animals or objects)
  • Olfactory / gustatory hallucinationsSuggestive of frontal / temporal injury
  • Tactile hallucinationsCan occur in delerium tremens or with cocaine
  • Extracampine hallucinations: sensations that would be physically impossible, such as seeing through walls
  • Causes of Hallucinations

  • Psychiatric - schizophrenia, schizoaffective disorder, psychotic depression, delirium, Lewy body dementia
  • Neurological - space-occupying lesion, temporal lobe epilepsy, migraine
  • Metabolic - hepatic encephalopathy
  • Drugs - amphetamines, delirium tremens
Once hallucinations stop, patients with organic disease tend to recognise that they were false, while patients with functional illness tend to maintain a lack of insight.

Auditory Hallucinations

Continuous commentaryClassically a feature of schizophrenia, though may also occur in delirium or dementia
Fragmented, insulting voicesCommon in very depressed patients with delusions of guilt
Gedanklautwerden: hearing one's thoughts spoken just before they are occurring
Echo de la pensee: hearing one's thoughts spoken just after they have occurred

Visual Hallucinations

  • Interpretation

  • Simple visual hallucinations - flashes, dots, colours, patternsSuggestive of ocular pathology, seizure or migraine aura
  • Complex visual hallucinations - objects, animals, peopleSuggestive of Lewy body dementia or delirium, though can occur in severe psychosis
  • Autoscopic hallucinations: a visual hallucination of the patient's own self.
  • Anton's syndrome (cortical blindness): the patient reports that they are able to see and can describe the world around them, despite clear evidence that they are blindOccurs in the setting of bilateral occipital strokes
  • Causes of Visual Hallucinations

  • Sensory deprivation in normal people
  • Dementia with Lewy Bodies
  • Delirium
  • Severe psychosis
  • Anton's syndrome (cortical blindness)
  • Migraine aura
  • Seizure
Next Page
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now

Snapshot: Initialising...