Hallucination

Hallucination is defined as the perception of an object or event (in any of the five senses) in the absence of an external stimulus. Visual hallucination is a kind of sensory misperception. Although visual hallucination is not pathognomonic of a primary psychiatric illness, it is still a primary diagnostic criterion for various psychotic disorders. People with visual hallucination usually are recommended to seek for psychiatric consultation. Three common approaches are suggested to explain the causes of visual hallucination including disturbance of brain structure, neurotransmitters and emergence of the unconcious into conciouness. The common causative mechanism are irritation of cortical centers responsible for visual processing, lesions that lead to cortical release phenomenon and that affecting the reticular activating system.
Migraines, sleep disturbance, tumors, dementia, etc, present with visual hallucinations. To accurately diagnosis, we can observe the associated symptoms, context and characteristics of visual hallucinations Features of visual hallucination includes simple patterns, unilateral distribution, associated with headache, frightening content, etc.. For example, a good insight suggests the etiologies of Charles Bonnet syndrome, migraine and peduncular hallucinosis. Doctor can also order MRI and EEG for diagnosis. EEG can detect seizure activity, delirium, delirium tremens and CJD. A rapid beta activity shown in the EEG result suggests delirium tremens. MRI of the brain help to identify tumors or infarcts that may account for Anton’s syndrome and show the characteristic ‘pulvinar sign’ associated with CJD.
The treatment of visual hallucination should be specific to the cause as it may be beneficial to one medical cause but worsen the condition of one another. Visual hallucinations due to some medical causes such as seizures can be treated with medication. However, some such as visual hallucination due to CJD do not have treatment. The good news