Clinical, neuropsychological and neural correlates underlying the first symptoms in Behavioral Variant of Fronto Temporal Dementia (bvFTD)

      Introduction: The behavioural variant of frontotemporal dementia (bvFTD) is a clinical syndrome characterized by an early and progressive deterioration of personality, social comportment and cognition (Rascovsky et al, 2011). An early detection of behavioural impairments in FTD is crucial to an accurate Early behavioural changes such as disinhibition, apathy, loss of empathy among others are some symptoms used to diagnose probable bvFTD. However, it is unknown how those first behavioural symptoms influence and modify progression and course of the disease.
      Methods: We evaluated the neuropsychological, clinical and neuroanatomical correlates of a sample of forty-three FTD patients organized according to its first symptoms. We also collected neuropsychological and imaging data on thirty-four healthy seniors to control the analyses observed in patients.
      Discussion: 47% of patients debuted with apathy, 42% with disinhibition and 10% with deficits in executive functions. Patients that debuted with apathy showed worst scores in neuropsychological profile (as measured by FrSBE and Hayling test among others) compared with patients that debuted with disinhibition. Severity of apathy in apathetic-debut patients correlated with atrophy in the right dorsolateral prefrontal cortex and right insula. In contrast patients that debuted with disinhibition showed atrophy in the right mediotemporal limbic structures.
      Conclusion: First symptom in bvFTD patients is crucial to describe the course and neuropsychological impairments. Our results show that impairments in complex social behaviors represented in the prefrontal and mesolimbic structures are also involved in course and prognosis of the bvFTD.