Affiliations: Departments of Neurology and Psychiatry and
Biobehavioral Sciences, David Geffen School of Medicine, The University of
California at Los Angeles, V.A. Greater Los Angeles Healthcare Center, Los
Angeles, CA, USA
Note: [] Corresponding author: M.F. Mendez, MD, PhD; Neurobehavior Unit
(691/116AF), V.A. Greater Los Angeles Healthcare Center, 11301 Wilshire Blvd.,
Los Angeles, CA 90073, USA. Tel.: +1 310 478 3711, ext. 42696; Fax: +1 310 268
4181; E-mail: mmendez@UCLA.edu
Abstract: Patients with behavioral variant frontotemporal dementia (bvFTD) can
make false statements consistent with delusions or confabulations. It is
unclear whether bvFTD is primarily associated with either delusions or with
confabulations and whether they can be explained by the pathophysiology of this
disease. In order to clarify this, we retrospectively surveyed the records of
48 patients with bvFTD for the presence of any false reports and identified
four patients. Their false reports included continued interaction with a
favorite but dead relation, fictitious marriages with movie stars, and two who
claimed that their partner was having an affair. When confronted with the
falsity of their statements, the patients conveyed a lack of certainty
regarding their external or internal source but persisted in the constancy of
their reports. On functional neuroimaging, the patients had predominant frontal
involvement. This report found that patients with bvFTD can have both
fantastic, wish fulfilling confabulations and typical content-specific
delusions. We propose that both phenomena result from known disturbances of
ventromedial prefrontal cortex in bvFTD, including deficits in source
monitoring and in activating an automatic "doubt tag" for false reports.
