Neuroanatomy of the self: evidence from patients with frontotemporal dementia.

OBJECTIVE: To evaluate the frequency and types of change in "self" seen in frontotemporal dementia (FTD) and to determine the relative involvement of the nondominant and dominant frontal and temporal brain regions in FTD patients with or without changes in a sense of self using neuropsychology tests and neuroimaging. BACKGROUND: The self has been defined as "the total, essential, or particular being of a person" involving "the essential qualities distinguishing one person from another." Some suggest that the frontal lobes play a dominant role in maintaining the self. FTD affects anterior frontal and temporal areas and can be associated with a loss of self. METHODS: Seventy-two consecutive FTD patients were evaluated with neuropsychiatric, neuropsychologic, and behavioral measures. Patients were imaged with MRI and SPECT. Charts were reviewed by a social psychologist to determine patients who exhibited a dramatic change in their self as defined by changes in political, social, or religious values. The brain areas with the most severe atrophy or hypoperfusion on neuroimaging were noted. RESULTS: Seven of 72 patients exhibited a dramatic change in self. In six of the seven, the selective dysfunction involved the nondominant frontal region. In contrast, only one of the other 65 patients without selective nondominant frontal dysfunction showed a change in self. CONCLUSIONS: FTD patients with asymmetric loss of function in the nondominant frontal lobe often exhibit a diminished maintenance of previously learned self-concepts despite intact memory and language. Normal nondominant frontal function is important for the maintenance of the self.

The influence of right frontotemporal dysfunction on social behavior in frontotemporal dementia.

BACKGROUND: Frontotemporal dementia (FTD) is associated with a variety of cognitive and behavioral dysfunctions. Symptoms may be influenced by the relative involvement of the right versus the left hemisphere, with left-sided FTD manifesting language changes and right-sided FTD presenting with aggressive, antisocial, and other socially undesirable behaviors. OBJECTIVE: To test the hypothesis that right-sided FTD is associated with socially undesirable behavior. METHODS: The authors assessed 41 patients with FTD diagnosed by the new research criteria for FTD(1) including behavioral, neuropsychologic, and neurologic testing as well as SPECT and MRI. Based on visual inspection of SPECT scans, 12 patients were classified as having predominantly right-sided and 19 patients were classified as having predominantly left-sided FTD. A clinician blinded to the imaging data reviewed medical records to tabulate the frequency of the following socially undesirable behaviors: criminal behavior, aggression, loss of job, alienation from family/friends, financial recklessness, sexually deviant behavior, and abnormal response to spousal crisis. RESULTS: Eleven of 12 right-sided and 2 of 19 left-sided FTD patients had socially undesirable behavior as an early presenting symptom (chi = 23.3, p < 0.001). CONCLUSION: The authors conclude that right-sided frontotemporal degeneration is associated with socially undesirable behavior. The early presence of socially undesirable behavior in FTD differentiates right-sided from left-sided degeneration. The results highlight the importance of the right hemisphere, especially frontotemporal regions, in the mediation of social behavior. The potential mechanism for these social losses with right-sided disease is discussed.

Novel applications of social-personality measures to the study of dementia.

Despite the realization that personality change is a core feature of frontotemporal dementia (FTD), little work has been performed using personality as a diagnostic tool for this disease. Likewise, personality change in Alzheimer's disease (AD) has long been recognized, but generally has not been used for diagnostic purposes. We introduce novel social-personality measures (Big Five Inventory, Interpersonal Adjectives Scale and Interpersonal Measure of Psychopathy) in the differential diagnosis of AD and temporal subtypes of FTD, and integrate these measures with traditional behavioural and neuropsychological methods commonly used in diagnosing dementia. We present four cases: an FTD patient with predominantly left temporal degeneration, an FTD patient with predominantly right temporal degeneration and two patients with Alzheimer's disease (one with mild and the other with moderate impairment). Results show the diagnostic utility of these measures in differentiating among temporal subtypes of FTD and moderate AD. Right temporal FTD, in particular, shows profound shifts in personality and interpersonal behaviour, as well as a striking lack of insight into these shifts. In addition to diagnostic purposes, we discuss how measures of personality and interpersonal behaviour can be utilized as an important component of understanding disease susceptibility and risk, as well as offering insights into the neuroanatomical underpinnings of personality and social behaviour.

Autistic savants. [correction of artistic].

OBJECTIVE: The objectives of this study were to examine common patterns in the lives and artwork of five artistic savants previously described and to report on the clinical, neuropsychological, and neuroimaging findings from one newly diagnosed artistic savant. BACKGROUND: The artistic savant syndrome has been recognized for centuries, although its neuroanatomic basis remains a mystery. METHODS: The cardinal features, strengths, and weaknesses of the work of these six savants were analyzed and compared with those of children with autism in whom artistic talent was absent. An anatomic substrate for these behaviors was considered in the context of newly emerging theories related to paradoxical functional facilitation, visual thinking, and multiple intelligences. RESULTS: The artists had features of "pervasive developmental disorder," including impairment in social interaction and communication as well as restricted repetitive and stereotyped patterns of behavior, interest, and activities. All six demonstrated a strong preference for a single art medium and showed a restricted variation in artistic themes. None understood art theory. Some autistic features contributed to their success, including attention to visual detail, a tendency toward ritualistic compulsive repetition, the ability to focus on one topic at the expense of other interests, and intact memory and visuospatial skills. CONCLUSIONS: The artistic savant syndrome remains rare and mysterious in origin. Savants exhibit extraordinary visual talents along with profound linguistic and social impairment. The intense focus on and ability to remember visual detail contributes to the artistic product of the savant. The anatomic substrate for the savant syndrome may involve loss of function in the left temporal lobe with enhanced function of the posterior neocortex.