[Differential diagnosis between Bipolar Disorder and behavioral variant Frontotemporal Dementia: the role of longitudinal neuropsychological assessment. A Case Report.].

INTRODUCTION: Bipolar Disorder (BD) and the behavioral variant of Frontotemporal Dementia (bvFTD) can present overlapping clinical features in their early stages, characterized by disinhibition, euphoria, and executive function deficits. Differential diagnosis is particularly challenging when behavioral symptoms are accompanied by evidence of cortical atrophy on neuroimaging.

CASE PRESENTATION: We describe the case of a 48-year-old woman diagnosed with Type I BD since age 25, referred for suspected bvFTD due to a progressive decline in memory functions and sleep disturbances. At the time of evaluation (T0), the patient had been on long-term treatment with aripiprazole, paroxetine, chlorpromazine, and clonazepam. A brain MRI was performed, and a second-level neuropsychological battery was administered to assess memory, attention, executive functions, language, and praxic functions. The entire protocol was repeated after two years (T1). At T0, analysis revealed marked deficits in executive functions, complex attention, and episodic memory; MRI showed moderate bilateral frontoparietal cortical atrophy. At follow-up (T1), despite the structural finding of atrophy, a complete normalization of the cognitive profile was observed, with performance returning to within normal limits for age and education.

CONCLUSIONS: The longitudinal improvement confirms that the deficits detected at T0 were an expression of the clinical state of BD rather than a progressive neurodegenerative process. This case emphasizes the fundamental importance of longitudinal neuropsychological assessment and a multidisciplinary approach to avoid misdiagnosis and to optimize the pharmacological treatment of affective and psychotic symptoms.