Heart rate variability (HRV) is a useful marker for predicting mortality and cardiovascular events in cardiac diseases. Various time- and frequency-domain parameters are used for assessing HRV. The time-domain measures include standard deviation of the NN intervals (SDNN), standard deviation of the average NN interval, root mean square of the successive differences SDNN index, NN50 count, and pNN50, while the power spectrum that is used the most widely in frequency-domain analyses is divided into low frequency (LF), high frequency (HF), LF norm, HF norm, and LF/HF. The HF band is modulated by the parasympathetic nervous system, while the LF band is modulated by both the sympathetic and parasympatheticnervous systems. Altered or reduced HRV parameters have been shown to be related to cardiovascular events in patients with various neurological disorders, such as parkinsonian syndromes, dementia, cerebrovascular disorder, and epilepsy. Furthermore, analyses of HRV have attempted to distinguish different diseases and evaluate the degree of disability. This article discusses the clinical use of HRV in the neurological field.
Cerebrovascular Disorders ; Dementia ; Epilepsy ; Heart Diseases ; Heart Rate* ; Heart* ; Humans ; Mortality ; Nervous System Diseases* ; Parasympathetic Nervous System ; Parkinsonian Disorders

Background: Hypertension results from an impaired baroreceptor reflex and enhanced sympathetic activity. The prevalence of hypertension differs among ethnicities and is more frequent in South Asians than in Caucasians, suggesting that baseline autonomic nervous system functions and their regulation may also differ among ethnic groups. In most studies, the reference values for clinical autonomic function tests are obtained from heterogeneous ethnic populations, or ethnic factors are not considered in the study design. Obtaining reference data in a homogenous ethnic group and comparing them within various ethnic groups could be helpful to detect ethnic differences in autonomic functions. The aim of this study was to identify normative reference values for standard autonomic reflex measurements in a homogeneous Korean population. Methods: A total of 181 healthy Korean volunteers (age, 20–74 years) underwent standard autonomic function tests: heart rate difference during deep breathing, Valsalva maneuver, and the quantitative sudomotor axon-reflex test. Mean and 5th and 95th percentile values were obtained for each age group. We also analyzed factors (age, sex, and body mass index) that can influence autonomic functions. Results: The heart rate difference during deep breathing and expiratory-inspiratory ratio were higher in males than in females and were inversely related to age. The Valsalva ratio was inversely related to age. Males had higher sweat volumes at all body areas evaluated than those of females, and only forearm sweat volume was significantly different between the age groups. Conclusions: Cardiovagal function was affected by age and sex in Koreans. Sudomotor function was affected by sex, and only forearm sweat volume was affected by age and sex. These results represent preliminary normative clinical autonomic data in a Korean population comprised of a single ethnicity
Hypertension

No abstract available.
Aged ; Female ; Hand ; Humans ; Tremor

Heart rate variability is significantly associated with cardiovascular complications in various neurological disorders with cardiac impairment. Measures of spontaneous heart rate variability might be different from provocating tests of heart rate variability such as deep breathing and Valsava maneuver. Methods for analysis are divided into time domain methods and frequency domain methods. There are standard deviation of NN interval, standard deviation of average NN interval, root mean square of the successive differences, NN50, and pNN50 in time domain methods. Frequency domain bands can be divided into very low, low, and high frequency. Each variables are influenced by sympathetic and/or parasympathetic activity.
Autonomic Nervous System ; Cardiovascular Abnormalities ; Heart Rate* ; Nervous System Diseases ; Respiration

Objectives: White matter hyperintensities are known to influence dementia in Alzheimer’s disease. Genetic components are suggested as putative risk factors for vascular pathology and cognitive decline. This study aimed to determine whether there is an association between candidate genetic polymorphisms and the severity of white matter hyperintensities in patients with Alzheimer’s disease. Methods: Seventy-five patients diagnosed with Alzheimer’s disease underwent genetic tests for specific alleles of apolipoprotein E, angiotensin-converting enzyme, and methylenetetrahydrofolate reductase. All patients underwent brain magnetic resonance imaging scans and neuropsychological tests. The severity of white matter hyperintensities was semiquantified using the CREDOS rating scale, and patients were divided into three groups according to their rating. Results:The severity of white matter hyperintensities was related to age and hypertension. However, none of the gene polymorphisms we tested was found to be associated with the severity of white matter hyperintensities. Conclusion:The genetic polymorphisms found in apolipoprotein E, angiotensin-converting enzyme and methylenetetrahydrofolate reductase did not contribute to white matter hyperintensities in Alzheimer’s disease.Only age and hypertension factors were found to be contributory to white matter hyperintensities.
Alzheimer Disease ; Dementia

No abstract available.
Frontotemporal Dementia ; Postural Orthostatic Tachycardia Syndrome* ; Supranuclear Palsy, Progressive

No abstract available.
Adolescent ; Ataxia Telangiectasia/*genetics ; Ataxia Telangiectasia Mutated Proteins/*genetics ; Base Sequence ; Chromosome Inversion ; Chromosomes, Human, Pair 14/genetics ; Chromosomes, Human, Pair 7/genetics ; DNA Mutational Analysis ; Female ; Humans ; Karyotyping ; Magnetic Resonance Imaging ; Mutation ; RNA Splicing ; Translocation, Genetic

Anaphylaxis usually develop immediately after wasp sting, but may develop even after few days later. Neurological complications after stings are uncommon, although several cases have been reported involving central and/or peripheral nervous system. Although wasp sting-induced encephalitis has been rarely reported, all reported cases showed mental change and severe neurological deterioration. Herein, we report an atypical case who showed biphasic anaphylaxis and delayed-onset cerebellar ataxia following a wasp sting, characterized by mild cerebellar ataxia and excellent response to corticosteroids.
Adrenal Cortex Hormones ; Anaphylaxis ; Bites and Stings ; Cerebellar Ataxia ; Encephalitis ; Peripheral Nervous System ; Wasps

Objective: Although maintenance treatment for mood disorders is important, the treatment discontinuation rate is reported to be high. This study aimed to investigate the dropout rates and associated factors in mood disorders. Methods: The patients in a mood disorder clinic (n = 535) were examined. Demographic and clinical factors, scores of psychometric scales, time to dropout from initial treatment in patients with bipolar disorder (BP) (n = 288) and depressive disorder (DD) (n = 143) were evaluated based on database of the mood disorder clinic. Results: Among the studied patients with BP and DD, 50% showed dropout in 4.05 and 2.17 years, respectively. The mean survival times were 8.90 years in bipolar disorder I (BP-I), 5.19 years in bipolar II disorder, 3.22 years in bipolar disorder not otherwise specified, 4.24 years in major depressive disorder, and 4.03 years in other depressive disorders.In the multivariate Cox proportional hazards regression model in the BP group, diagnosis BP-I was found to be significantly related to the decrease in dropout rate (hazard ratio [HR] = 0.22, p = 0.001); however, increased past suicide attempt number was significantly related to the increase in dropout rate (HR = 1.13, p = 0.017). In the DD group, none of anxiety disorders as comorbidity, increased scores of openness, and extraversion personality were related to the increase in dropout rate. Conclusion Patients with BP, especially BP-I, showed a lower dropout rate as compared to patients with other mood disorders.