Visual release hallucinations, also known as Charles Bonnet syndrome or CBS, are a type of psychophysical visual disturbance in which a person with partial or severe blindness experiences visual hallucinations. First described by Charles Bonnet in 1760, the term Charles Bonnet syndrome was first introduced into English-speaking psychiatry in 1982. A related type of hallucination that also occurs with lack of visual input is the closed-eye hallucination. Signs and symptoms
People with significant vision loss may have vivid recurrent visual hallucinations (fictive visual percepts). One characteristic of these hallucinations is that they usually are "lilliputian" (hallucinations in which the characters or objects are smaller than normal). Depending on the content, visual hallucinations can be classified as either simple or complex. Simple visual hallucinations are commonly characterized by shapes, photopsias, and grid-like patterns. Complex visual hallucinations consist of highly detailed representations of people and objects. The most common hallucination is of faces or cartoons. Sufferers understand that the hallucinations are not real, and the hallucinations are only visual, that is, they do not occur in any other senses (such as hearing, smell or taste). Visual hallucinations generally appear when the eyes are open, fading once the visual gaze shifts. It is widely claimed that sensory deprivation is instrumental in the progression of CBS. During episodes of inactivity, hallucinations are more likely to occur.
Nelarabine, sold under the brand names Arranon (US) and Atriance (EU), is a chemotherapy medication used for the treatment of T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL). Nelarabine is a prodrug of arabinosylguanine nucleotide triphosphate (araGTP), a type of purine nucleoside analog, which causes inhibition of DNA synthesis and cytotoxicity. Pre-clinical studies suggest that T-cells are particularly sensitive to nelarabine. In October 2005, it was approved by the FDA for acute lymphoblastic leukemia and T-cell lymphoblastic lymphoma that has not responded to or has relapsed following treatment with at least two chemotherapy regimens. It was later approved in the European Union in October 2005. Complete responses have been achieved with this medication. References
External links
"Nelarabine". Drug Information Portal. U.S. National Library of Medicine. "Nelarabine". NCI Dictionary of Cancer Terms. National Cancer Institute. "Nelarabine". National Cancer Institute.