The Relationship between Usher's Syndrome and Psychosis with Capgras Syndrome

Abstract

Usher's syndrome is a genetic disorder that causes congenital sensorineural hearing loss, visual impairment due to progressive pigmentary retinopathy, and, often, vestibular dysfunction. The aim of this article is to illustrate a case that clearly demonstrates psychotic symptoms in Usher's syndrome Type III and serves to increase clinical awareness of this disorder and its possible link to psychotic symptoms. There is some evidence in the literature of concurrent psychiatric symptoms, particularly psychotic symptoms, associated with Usher's syndrome, and several theories around this association have been proposed. These theories of associations include a genetic link between the genes responsible for schizophrenia and the genes for Usher's syndrome; a neuropathological explanation as radiologic studies have revealed that patients with Usher's syndrome have CNS abnormalities in multiple brain structures; and a sensory deficit model which proposes that the stressors associated with sensory impairment and the brain's adaptation to changes in sensory inputs place an individual at increased risk for psychopathology.

Translation into British Sign Language and validation of the Strengths and Difficulties Questionnaire

“…Some have suggested increased risk of psychosis in deaf people 33 and there have been case reports of psychosis in Usher syndrome. 34,35 However, there is no clear systematic evidence for an increased likelihood of psychotic disorders in deaf people. 36 Although many deaf children (especially those with no neurological deficits or neurological damage, and with healthy cultural and linguistic experiences) have an IQ similar to hearing counterparts, 37,38 many deaf children with neurological damage have learning disabilities 32,39,40 and there is ample research to show that children with learning disabilities have higher rates of mental health problems than those without.…”

Base rates, blindness, and schizophrenia

“…In addition to these points, we noted in our original paper that other congenital sensory impairments have not been associated with absence of schizophrenia, that congenital deafness and later blindness, such as found in Usher Syndrome, whose prevalence has been estimated at 0.005% (Rosenberg et al, 1997) has been associated with psychotic disorders at rates between 4–24% (Waldeck et al, 2001), and that non-psychotic psychiatric disorders are observed in C/E blindness. These data suggest a unique relationship between C/E blindness and schizophrenia.…”

Genetic Analysis for Two Italian Siblings with Usher Syndrome and Schizophrenia

“…This theory is supported by the fact that visual or auditory impairment is associated with higher rate of depression, suicidal behavior, psychological stress, and social handicap. In addition as occurs in Charles Bonnet syndrome, characterized by visual loss and complex visual hallucinations, it may be related to abnormal central processing [9, 15]. Sufficiently prolonged isolation from society or deprivation of sensory stimuli can produce mental abnormalities in the form of hallucinations, anxiety states, depression, and paranoid symptoms, as discussed by Ziskind [16], who reported the higher prevalence of psychotic manifestations after extraction of the cataract.…”