Neuropsychiatric Disease and Treatment (Sep 2016)
Late life bipolar disorder evolving into frontotemporal dementia mimic
Abstract
Annemiek Dols,1 Welmoed Krudop,2 Christiane Möller,2 Kenneth Shulman,3 Martha Sajatovic,4 Yolande AL Pijnenburg2 1Department of Old Age Psychiatry, GGZInGeest, 2Alzheimer Centre and Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Centre, Amsterdam, the Netherlands; 3Department of Geriatric Psychiatry, Sunnybrook Health Science Centre, Faculty of Medicine, University of Toronto, Toronto, Canada; 4Department of Psychiatry and Neurology, Case Western Reserve University School of Medicine, University Hospitals Case Medical Center, Cleveland, OH, USA Objectives: Although bipolar disorder has been understood classically as a cyclic disease with full recovery between mood episodes, in the last decade, evidence has accumulated supporting progressive features. The clinical picture of advanced or end-stage bipolar disorder is heterogeneous with possible deficits in cognition and behavior, as illustrated by our case series.Cases: From our neuropsychiatric outpatient clinic, we describe four cases with bipolar disorder gradually developing a clinical syndrome, including apathy, disinhibition, loss of empathy, stereotypical behavior, and compulsiveness, fulfilling the criteria for possible behavioral variant frontotemporal dementia. All cases were diagnosed with bipolar 1 disorder at least 10 years before the onset of the current symptoms, which were not due to recent mood episodes or switches of medication. In all cases, 3–7 years of follow-up yielded no progression. Repeated neuroimaging was within normal limits. Cerebrospinal fluid biomarker studies were not supportive of underlying neurodegenerative pathology. C9orf72 mutation status was negative in all cases.Conclusion: Symptoms fitting the criteria for possible behavioral variant frontotemporal dementia may be present in end-stage of bipolar disorder. An alternative neurodegenerative nature seems unlikely based on repeated normal neuroimaging and the absence of clinical progression. Functional involvement of the frontal-subcortical networks might play a role. Keywords: bipolar disorder, older, staging, bvFTD, benign phenocopy syndrome
