Organic delusional disorder in a case suggesting Huntington′s disease

Abstract

Huntington's Disease (HD) is an autosomal dominant progressive degenerative disorder of the basal ganglia characterized by motor, cognitive, and psychiatric manifestations, with an estimated prevalence of 1.75 per 100,000. It can present any time between infancy and senescence. Mood disorders, obsessive compulsive symptoms, psychosis, delirium, sexual disorders, and 'frontal' syndromes, have been reported in patients with HD. Delusions are seen in only about 5-12%. Indian data on HD has been largely through case reports. Given this background, we present an uncommon case with clinical features suggestive of HD and organic delusional disorder. This case report presents the psychiatric and neurological features of a 39-year-old male, who presented with abnormal choreiform movements since eight years, followed by a delusion of infidelity, and a family history suggestive of HD. Differential diagnosis and laboratory results, including neuroimaging and treatment, are presented. Delusions are the common manifestation of psychosis in patients with brain disorders, occurring more often than a formal thought disorder. Lesions of the temporal lobes or caudate nuclei and bilateral brain involvement are common in disorders manifesting psychosis. However, reasons for the infrequent occurrence of delusions in HD, in comparison to other neurodegenerative disorders, are unknown.