Charles Bonnet syndrome
From Drug Rehab Wiki
Hallucinations are known to be common when an individual engages in the recreational use of a variety of drugs. When these hallucinations occur and no drugs have been used, the problem goes deeper and may very well be related to an uncommon, yet very real problem: Charles Bonnet Syndrome (CBS).
Those who suffer from Charles Bonnet Syndrome generally experience visual loss, in addition to suffering vivid hallucinations. While this condition is described by many as very rare, research reported at the American Academy of Ophthalmology Annual Meeting suggests CBS is more common that previously reported.
One industry physician reporting on the condition highlighted that CBS can affect 10 percent to 38 percent of patients already experiencing visual impairment. Ophthalmologists continue to believe the condition is rare simply because it is an underreported and therefore under-diagnosed condition.
The doctor who authored the study conducted a retrospective study of 699 patients and found that of this group, 25 percent experienced CBS hallucinations. It is often assumed that such hallucinations occur only in those with macular degeneration. Upon further investigation, however, it has been determined that the hallucinations can also occur in other visual disorders, including optic neuropathy and anterior ischemic optic neuropathy.
The problem with CBS is that many people – especially if they are elderly – do not want to report their condition to their physician for fear of association with a mental illness. Many sufferers will avoid telling even close friends and family so that they will not be suspected of suffering mental incompetence. The condition has little to do with the mental health of the individual and is instead related to how the brain processes images.
Scientists believe that a lack of true input into the primary visual cortex allows for the spontaneous release of remembered images into the visual association area. Generally, individuals dealing with CBS experienced decreased activity in the primary visual cortex and an increased activity in visual association cortices.
In other words, there is believed to be a misfire in the brain that is similar to the neurological effects that happens in patients experiencing phantom limb syndrome. As vision deteriorates, the brain wants to interpret visual imagery in the absence of corresponding visual input. The same phenomenon occurs when the brain processes pain signals from a limb that is no longer in place.
The emergence of Charles Bonnet Syndrome in an individual is generally a clue that something else is going on with the health of the eye. Not only is there low vision, but the individual also will experience age-related macular degeneration, cataracts, diabetic retinopathy or other disorders of the eye.
There is no true treatment for CBS because medications that could make the hallucinations fade could also impact the mental state of the patient. Instead, most physicians will work under the assumption that the effects will steadily decrease. Over time, the brain will adjust to the vision loss and the hallucinations will begin to recede.
