•A parkinsonian patient can see some familiar person or animal which are not present at that time. It is a visual hallucination; rarely they hear voices or music ( auditory hallucination)
•Visual hallucination can be distressing, in particular if the patient is seeing a relative who is dead for many years and has not the full insight of the unreality of the vision.
•Visual hallucinations can happen during the day or at night.
•Nocturnal hallucinations can be terrifying and threatening for the patient, occurring as part of a vivid nightmares in the second part of the night; it’s called REM behavior disorder (or RBD as an acronym). RBD has to be diagnosed as it required as specific therapeutic strategy (some drugs are worsening RBD and have to be stopped) and a specific treatment of the sleep disorder.has to be started. Visual hallucinations related to a RBD phenomenon. can occurred also after an afternoon nap, when the patient wakes up.
•Daytime hallucinations can be due to the high doses of antiparkinsonian drugs ( the dopaminergic psychosis). It’s usually related to the Dopaminergic agonist, the anticholinergic drugs or the Amantadine; usually the patient is also confused. Its very important to recognise this psychosis as the antiparkinsonian drugs have to be decreased very cautiously.
•Daytime visual hallucinations can also occurred very early in the disease, at the same time that the patient slow down, even without being treated;.. The patients sometimes mentioned the feeling of a presence behind or besides them ( called extra-campines hallucinations because ocurring outside the visual field, so not seen but felt). Often, in addition these patients developed nocturnal RBD. It’s often marked the onset of Lewy body dementia.
•Acute and sudden confusion and agitation with hallucinations in a advanced PD can be the sign of an infection, such as urinary tract infection or pulmonary infection, which will respond well to antibiotics.