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BACKGROUND: Multiple system atrophy is an adult-onset, sporadic, neurodegenerative disorder with parkinsonian (MSA-P) and cerebellar (MSA-C) subtypes. OBJECTIVE: We aimed to elucidate differences in prognostic factors between MSA subtypes. METHODS: The study population comprised 45 probable MSA patients (MSA-P = 22; MSA-C = 23) and 45 healthy controls. Clinical parameters, heart rate variability (HRV), and conventional cardiac autonomic function testing (AFT) were the study tools. RESULTS: Mean age of onset of MSA was 54.7 ± 9 years for MSA-P and 51.9 ± 7 years for MSA-C subgroups. Median disease duration was 2 years in both subgroups. A greater percentage of MSA-P patients (45.5%) had beneficial response to levodopa (P < 0.01). Patients in both subgroups reported significant autonomic disturbances, such as postural symptoms, bladder disturbances, and erectile dysfunction. MSA-P patients had a trend for a greater number of falls and bladder disturbances than MSA-C patients (P = 0.05). Cardiac AFT showed that in MSA-P, 22.2% had definitive and 77.7% had severe autonomic dysfunction, whereas in MSA-C, 9.5% had early, 28.5% had definitive, and 57.1% had severe autonomic dysfunction. HRV analysis showed significant reduction in overall HRV, sympathetic activity, and parasympathetic activity in MSA patients as compared with controls (P < 0.0001). The sympathetic limb was more severely affected in MSA-P patients as compared with MSA-C patients (P < 0.05). CONCLUSION: Autonomic dysfunction and postural instability, negative prognostic markers, were relatively more common in the MSA-P than in the MSA-C patients. This implies that MSA-P patients have poorer prognosis as compared with MSA-C. Dopaminergic medications can be beneficial in MSA-P patients.
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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.
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BACKGROUND: Attention deficit/hyperactivity disorder (ADHD) is a common childhood neuropsychiatric disorder. Autonomic nervous system plays a vital role in attention, self-regulation, emotional stability and social affiliation, which are affected in ADHD. The prefrontal cortex, which is vital for attention, motor control, emotional regulation and higher order autonomic control, is hypofunctional in ADHD. In addition, catecholamine dysregulation is there. PURPOSE: We hypothesized that there is autonomic dysfunction: reduction in overall heart rate variability (HRV) and sympathovagal imbalance in children with ADHD. METHODS: Study criteria were drug-naïve ADHD children who were 7-12 years of age of either gender who fulfilled DSM-IV criteria for ADHD and did not have any associated comorbid psychiatric/neurological/medical disorders. Two hundred and seventy ADHD children were screened out of which only 12 were found eligible and 10 participated. Sample size was 20 (cases = 10, age- and gender-matched healthy controls = 10). Short-term HRV of both time and frequency domains were assessed by recording lead II electrocardiogram after using Tell-Show-Do, a behavior shaping technique. Comparison between groups was done using Mann-Whitney and Wilcoxon test. Demographic variables like age, height, weight and body mass index were similar between groups. RESULTS: Among time domain parameters, SD of all NN intervals, square root of the mean of the sum of squares of differences between adjacent NN intervals and percentage of count of number of pairs of adjacent NN intervals differing by more than 50 ms were reduced in ADHD group with p < 0.05. Among frequency domain parameters, total power was reduced in ADHD group with p < 0.05, high frequency power (HF) was reduced in ADHD group with p < 0.01 and low frequency power to HF ratio was higher in ADHD group with p < 0.01. CONCLUSION: There is autonomic dysfunction in children with ADHD - reduction in overall HRV with sympathovagal imbalance with sympathetic dominance.