Frontotemporal dementia patient with bipolar disorder: a case report

Introduction A diagnosis of frontotemporal dementia may be delayed or missed because early symptoms may develop gradually and can mimic symptoms of a variety of disorders or conditions. We aimed to write a report on a patient with frontotemporal dementia with bipolar disorder. Case report This is the case of a 63-year-old man with frontotemporal dementia whose presentation was consistent with bipolar affective disorder. With brain imaging and neurocognitive testing, frontotemporal dementia was diagnosed. Conclusion A differential diagnosis between bipolar disorder and frontotemporal dementia is difficult to establish. Frontotemporal dementia is a heterogeneous disease with a large variety of cognitive dysfunctions. Introduction Frontotemporal dementias (FTDs) are defined as the second most common cause for dementias under the age of 65 after Alzheimer’s disease and the third most common cause for neurodegenerative dementias after Alzheimer’s and Lewy body dementia1. FTD starts between the ages of 45–65 years and is seen equally in both genders2,3. The average life expectancy from onset of the disease ranges from 6–9 years2,3. FTD belongs to a group of heterogeneous diseases with different clinical and pathological findings4. FTD has three different subtypes including a behavioural variant, a semantic variant and a progressive, nonfluent aphasia5. In the behavioural variant, changes in eating habits6, loss of empathy, behavioural disinhibition, loss of social awareness, inappropriate affect, apathy and stereotypical behaviours, can be seen7. Brain imaging studies revealed—when the temporal region is affected—a significant decrease in emotional processing, disaffection in interpersonal relations, inappropriate social behaviours, jokes with sexual content, hypomanic-like behaviours and—when the frontal area is affected—apathy, reduction in social activity and tendency for criminal behaviours8,9. In FTD, mood, behaviour and speech disorders are seen before the memory impairment; thus, clinically heterogeneous symptoms may lead to misdiagnosis with psychiatric disorders. In this article, we have presented a case of a man who was misdiagnosed with late-onset bipolar disorder, but then diagnosed with FTD after neuropsychiatric examination, neuroimaging and neurocognitive testing.