Charles Bonnet syndrome: two case reports and review of the literature

Visual hallucinations (VHs) can be associated with a variety of clinical conditions, and are also experienced by healthy people due to visual impairment. The condition is known as Charles Bonnet Syndrome (CBS). The circumstances favoring VHs support the hypothesis that sensory deprivation enhances the ongoing activity of the visual system after sensory loss. Clinician should be aware that a significant proportion of visually impaired patients experience complex VHs, which are sometimes distressing. Herein, we report two cases of CBS. Case 1 is a 60-year-old man with visual impairment due to orbit pseudotumor in autoimmune hypothyroidism. Case 2 is an 87-year-old woman with Parkinson’s disease and a 15-year history of intermittent complex VHs due to age-related macular degeneration in both eyes. In both cases investigations for alternative pathological causes of VHs were negative and, therefore, the aetiology of hallucinations was attributed to CBS. The course and treatment of CBS patients vary according to the nature of the visual dysfunction. Drug treatments remain partially satisfactory, with individual cases successfully treated with atypical antipsychotics. Nonpharmacological interventions aimed to reduce the visual pathway deprivation. Reassurance of the benign nature of CBS is essential to support patients and reduce caregiver’s burden.