Autonomic dysfunction: A comparative study of patients with Alzheimer’s and frontotemporal dementia – A pilot study

Abstract

Introduction:In frontotemporal dementia (FTD) and Alzheimer's disease (AD), central autonomic structures get affected early. An insight into autonomic functions in these patients is likely to be of diagnostic importance and thus help in prognosticating and also probably explain unexplained sudden death in some of these patients.Objectives:The objective of this study is to identify autonomic dysfunction prevailing in patients. Then, if there is dysfunction, is the pattern same or different in these two conditions. And if different it will serve as an additional biomarker for specific diagnosis.Patients and Methods:There were 25 patients and 25 controls and six patients and three controls in AD and FTD groups, respectively. The participants who were recruited were assessed for heart rate variability and conventional cardiac autonomic function testing. The parameters were analyzed using LabChart version 7 software and compared with control population using appropriate statistical methods using SPSS version 22 software.Results:The mean overall total power was low in the FTD group (P < 0.001), and there was significant reduction in the standard deviation of normal-to-normal intervals and root mean square of successive differences (P < 0.001) with elevated sympathovagal balance in the FTD group (P = 0.04). Patients with AD also showed sympathetic dominance, but there was in addition parasympathetic suppression unlike in the FTD group.Conclusion:This study reveals autonomic dysfunction in patients with FTD and AD. Both conditions show sympathetic dominance, probably consecutive to the involvement of central autonomic regulatory structures as a shared domain. It remains to be confirmed if these findings are the cause or effect of neurodegeneration and might open up newer territories of research based on the causal role of neurotransmitters in these regions and thus lead to novel therapeutic options such as yoga. The presence of parasympathetic suppression in AD in addition helps differentiate these two conditions.

Autonomic dysfunction in patients with Alzheimer’s disease

“…This observation correlates with neurochemical abnormality in AD which involves cholinergic depletion. The same information is supported by some of the previous studies [24,25].…”

Variability in metabolic parameters and risk of dementia: a nationwide population-based study

“…Patients with cognitive decline might have difficulties in self-care, disease management, and low compliance to medications with consequent instability in several biological parameters, increasing the possibility of reverse causation. It is also suggested that central autonomic dysfunction may accompany dementia, which could contribute to worsening of variability in BP and glucose [ 38 ]. However, our data showed a strong correlation between variability indices and dementia with a dose–response relationship, were consistent with previous data, and were coherent with laboratory findings supporting the causal relationship [ 39 , 40 ].…”

Genetic Dependency of Alzheimer’s Disease-Associated Genes across Cells and Tissue Types

“…There were 22 tissue types with data for at least 25 cell lines each from the DepMap 2020 Q2 release which were selected for further analysis (Table 1). We speci cally highlighted results from three tissue types most relevant to AD etiology: hematopoietic and lymphoid tissue (HL, given the now established role of immune response and phagocytotic pathway in AD), central nervous system (CNS), and autonomic ganglia (AG) [16][17][18].…”