Self-injurious behavior in frontotemporal dementia

Abstract

Frontotemporal dementia (FTD) may be one of the most common neurodegenerative dementias with onset before age 65. Investigators have only recently characterized FTD, which encompasses Pick's disease as well as non-specific degeneration of the frontal lobes. Neuropsychiatric symptoms are the main features of FTD and include disinhibition, apathy, obsessive-compulsive behavior, and the Kluver-Bucy syndrome. We report a patient with FTD who developed prominent self-injurious behavior (SIB) consisting of persistent self-biting and hair-pulling. Stereotypical, repetitive SIB usually occurs in patients with autism or mental retardation; SIB is rarely discussed in patients with dementia. This report extends the neuropsychiatric spectrum of FTD to encompass SIB and discusses the potential mechanisms for SIB in these patients. The most likely contributing source for their self-injury is the development of obsessive-compulsive behaviors in the presence of coincident self-directed behaviors. Hyperorality from anterior temporal Involvement and the release of primitive grooming behavior from frontal degeneration are self-directed behaviors that contribute to the specific manifestations of SIB among FTD patients. The pharmacological management of SIB emphasizes drugs that work through opioid, serotonergic, or dopaminergic systems.