Spontaneous Social Behaviors Discriminate “BehavioralDementias” from Psychiatric Disorders and Other DementiasKatherine P. Rankin, Ph.D.1, Wendy Santos-Modesitt, BA1, Joel H. Kramer, Psy D1, DanijelaPavlic, BA1, Victoria Beckman, BA1, and Bruce L. Miller, MD11Department of Neurology, University of California San FranciscoAbstractObjective—Changes in social behavior are often the first symptoms of neurodegenerative disease.Patients with frontotemporal lobar degeneration (FTLD) often go undiagnosed, or are misclassifiedas psychiatric patients, because in the absence of cognitive deficits, non-experts fail to recognizethese social changes as dementia symptoms. The object of this study was to improve screening forbehavioral dementia in primary care and mental health settings by quantifying spontaneous socialbehaviors specific to FTLD.Method—In a university hospital dementia clinic, examiners blind to subject diagnosis performedone hour of cognitive testing, then completed the Interpersonal Measure of Psychopathy (IMP), an18-item checklist of observed inappropriate behaviors. Patients then underwent a multidisciplinaryevaluation to derive a neurodegenerative or psychiatric diagnosis. Data were collected from 288subjects: 45 Alzheimer's disease (AD), 40 frontotemporal dementia (FTD), 21 semantic dementia(SD), 13 progressive nonfluent aphasia (PNFA), 14 corticobasal degeneration (CBD), 21 progressivesupranuclear palsy (PSP), 37 dementia with Lewy bodies (DLB), 16 vascular dementia, 29 mixedvascular and AD, 35 primary psychiatric disorders, and 17 normal older controls.Results—Statistical item analyses demonstrated specific patterns of social behavior thatdifferentiated both FTD and SD patients from 1) non-dementing older adults, 2) non-dementingindividuals with psychiatric conditions, 3) individuals with cerebrovascular disease, and 4)individuals with other neurodegenerative disorders. SDs verbally and physically interruptedevaluations, spoke perseveratively and tangentially and resisted clinician redirection. FTDs wereapathetic or disinhibited and were unconcerned about meeting clinician expectations.Conclusions—Specific, abnormal interpersonal behaviors can alert non-experts to the need forspecialized dementia referral.INTRODUCTIONAn alarming 4.5 million people were diagnosed with Alzheimer's disease (AD) in the U.S. asof the year 20001, and the number of individuals diagnosed with the disease is predicted totriple by 2050. AD is the most common and well-known subtype of dementia; however, ittypically accounts for only 50-70% of dementia cases, while the rest can be attributed to otherneurodegenerative diseases such as vascular dementia (VascD), frontotemporal lobardegeneration (FTLD), corticobasal degeneration (CBD), progressive supranuclear palsy (PSP),Address for Correspondence and Reprint Requests: Katherine P. Rankin, Ph.D. UCSF Memory and Aging Center 350 ParnassusAvenue, Suite 706 San Francisco, CA 94143-1207 [email protected].• These data were presented as a poster at the 34thAnnual Meeting of the International Neuropsychological Society in Boston, MA, onFebruary 2, 2006, and as part of an invited platform session at the 5th International Conference on Frontotemporal Dementia in SanFrancisco, CA on September 7, 2006.NIH Public AccessAuthor ManuscriptJ Clin Psychiatry. Author manuscript; available in PMC 2009 August 31.Published in final edited form as:J Clin Psychiatry. 2008 January ; 69(1): 60–73.NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscriptand dementia with Lewy bodies (DLB). As distinct treatment regimens develop for each ofthese dementias, it becomes is increasingly imperative that they are recognized early and arereferred to dementia specialists for specialized treatment and inclusion in clinical trials.Diseases such as PSP, CBD, and DLB characteristically have early motor signs that accompanyany cognitive or behavioral symptoms, and which can serve as a red flag to primary careclinicians to initiate a neurologic referral 2-4. Similarly, variants of FTLD such as the left-temporal predominant type of semantic dementia (SD) and progressive nonfluent aphasia(PNFA) cause easily-observed speech and language deficits that can signal the need forspecialty referral 5. However, patients with two subtypes of FTLD, specifically thefrontotemporal dementia (FTD) subtype and patients with the right temporal predominantvariety of SD, can present with no appreciable motor, language, memory, or other cognitivesymptoms 6, 7, yet may already be experiencing severe frontal or temporal neurodegeneration.Because the only symptoms many of these patients display early in the disease process arealtered personality and social behavior, they are frequently misdiagnosed as having apsychiatric condition 8, 9, or the disease is missed entirely by non-experts who believe thepatient is merely difficult or odd, but neurologically normal 10. Misdiagnoses are even morelikely because SD and FTD appear at a significantly younger age than classic dementias suchas AD and VascD, with an average age of onset in the mid-60's, and cases commonly beginningas early as the 30's and 40's11. Even when a neurodegenerative condition is suspected in anFTLD patient, it is often mistaken for AD or VascD 9, 12. As a result, physicians often fail torefer the patient to a specialty clinic, and may administer incorrect treatments. For example,the current standard pharmaceutical treatment of AD and VascD is an acetylcholinesteraseinhibitor, but this treatment can often exacerbate FTLD symptoms rather than relievingthem13. Particularly in managed care settings, primary care clinicians lack the time andresources needed to provide specialized dementia examinations for their patients, and they willnot perform a separate dementia screen unless they already suspect there is a problem.14, 15Alternatively, FTLD patients may first present in a mental health setting, where neurologicaldisease may be low on the diagnostic differential.The magnitude and nature of FTLD behavior deficits, along with the fact that many of thesepatients are young and still have school-age children, combine to have a more devastatingimpact on family and caregivers than the burden caused by other dementias 16. Early, accurateeducation about disease course and typical expected symptoms, as well as FTLD-specificsupport mechanisms for the caregiver, can significantly alleviate this burden, but only if thepatient