title: Palinopsia.
abstract: BACKGROUND
  Palinopsia is a visual phenomenon that has been associated with brain neoplasia, epilepsy, trauma, systemic disease, psychiatric illness, and illicit as well as prescribed drug use. Despite some resemblance to diplopia, polyopia, and physiologic afterimage formation, palinopsia is actually a distinct entity often suggestive of disease through its distinct signs and symptoms. Careful patient history, visual field testing, and neuroimaging are among the tools used to diagnose palinopsia.
  
  
  METHODS
  Four case reports of patients with palinopsia are presented. With the first patient, the palinopsia was associated with extensive lysergic acid diethylamide (LSD) use. The second patient's palinopsia was determined to be secondary to head trauma from a motor vehicle accident. The third patient began to experience palinopsia after he had been prescribed trazodone for insomnia. The fourth patient was found to have multiple potential etiologies. These 4 unique patients highlight the causes and management of palinopsia.
  
  
  CONCLUSIONS
  Optometrists should be aware of the symptoms of palinopsia to enable them to recognize this phenomenon and minimize the chance of misdiagnosis. Learning the physiologic mechanisms behind this uncommon disorder can help the clinician correctly identify its cause. Although palinopsia itself is not a disease, it is indicative of a disease, and the symptoms of palinopsia may be a manifestation of a serious underlying systemic dysfunction that could warrant treatment. In addition, identifying the symptoms of palinopsia can put patients at ease with regard to the often disturbing visual symptoms.
authors.affiliation: Vista Eye Care, Thornton, Colorado 80602, USA. brian.abert@gmail.com
authors.forename: Brian
authors.initials: B
authors.lastname: Abert
authors.forename: Pauline F
authors.initials: PF
authors.lastname: Ilsen
mesh_terms: D000328:Adult; D003941:Diagnostic Techniques, Ophthalmological; D006801:Humans; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000175:diagnosis / Q000209:etiology*; D012307:Risk Factors; D014786:Vision Disorders / Q000175:diagnosis / Q000209:etiology*; D014796:Visual Perception / Q000502:physiology*