Nervous System Dysfunction In Patients Research Articles

Abnormal heart rate variability and its application in predicting treatment efficacy in patients with chronic migraine: An exploratory study.

This study aimed to investigate the extent of autonomic nervous system dysfunction in patients with chronic migraine using heart rate variability analysis. In addition, we explored the potential association between heart rate variability and treatment outcomes in patients receiving preventive treatment. In this cross-sectional and prospective study, we compared heart rate variability profiles in 81 preventive-naïve chronic migraine patients and 58 healthy controls. In addition, treatment responses of patients, who received a 12-week treatment with flunarizine, were assessed in relation to baseline heart rate variability. We observed that chronic migraine patients had a reduced heart rate variability, signifying autonomic dysfunction in comparison to healthy controls. Furthermore, patients presenting normal heart rate variability, characterized by a standard deviation exceeding 30 milliseconds in normal-to-normal RR intervals, experienced a superior response to flunarizine treatment. This improvement was exemplified by a significantly larger reduction in monthly headache days for patients with higher heart rate variability compared to those with lower heart rate variability: -9.7 (5.9) vs. -6.2 (6.0) days (p = .026). Autonomic dysfunction occurs in chronic migraine as evaluated by heart rate variability. A preserved function is associated with a better treatment outcome to flunarizine.Trial registration: Neurologic Signatures of Chronic Pain Disorders, NCT02747940. Registered 22 April 2016, https://clinicaltrials.gov/ct2/show/NCT02747940.

The effect of lifestyle change on autonomic nervous system dysfunction in patients with metabolic syndrome

Study Design: A prospective clinical cohort study. Objective: In this study, it was aimed to examine the effects of metabolic syndrome, which affects many organs, on the autonomic nervous system and to observe the changes after treatment. Materials and Methods: Heart rate variability values of 101 metabolic syndrome patients who were treated at the Kocaeli University Cardiology Outpatient Clinic included in the study. All patients were offered lifestyle change suggestions in addition to their medical treatments. At the end of three months, the heart rate variability parameters of the patients were re-evaluated. Results: Heart rate variability values were found to be significantly lower in metabolic syndrome patients compared to the control group. It was observed that the heart rate variability values improved significantly in half of the patients who applied the given treatment with lifestyle changes. A decrease in heart rate change parameters was found in the group that did not implement lifestyle changes compared to the beginning of the study. Conclusions: Autonomic nervous system functions evaluated by heart rate variability decreased in patients with metabolic syndrome, and the treatment and lifestyle changes had a positive effect on these parameters.

Nervous-mental stress and cognitive disorders as components of stress state in type 2 diabetic patients

The review focuses on the problem of nervous system dysfunction in patients with type 2 diabetes mellitus (DM), which can be manifested by neuropsychological stress (NPN), cognitive impairment and dementia, which negatively affect both metabolic processes and feelings of well-being and quality of life. The gradual development of neurovascular disorders, as well as chronic systemic inflammation associated with atherosclerosis and immune disorders are the causes of neuropsychological and neurophysiological disarrays. Cholinergic mechanisms and hyperactivation of the sympathetic-adrenal and hypothalamic-pituitary systems contribute to the secretion of stress hormones, increase mental stress against the background of chronic metabolic stress. Therefore, the assessment of the degree of NPN can be useful for characterizing the state of neuropsychological, neurophysiological processes and determining the treatment strategy for patients with type 2 DM. In general, current studies of neuropsychological parameters in patients with DM have shown that the disease adversely affects the neurocognitive characteristics of these patients. This is due to the main pathogenetic mechanisms (indicators of insulin resistance, markers of inflammation, atherogenesis and vascular dysfunction, changes in the secretion of stress hormones and neurotransmitters). Both type 2 DM and aging, can affect the development of neuropsychiatric abnormalities in patients with mental stress, memory, ability to concentrate, and cognition. Investigation of these effects and the development of methods for monitoring, prevention and pharmacotherapy of these disorders can be useful for improving the health of the elderly people, especially of patients with type 2 DM. Modern antidiabetic drugs can have a protective effect on the peripheral and central nervous system due to their hypoglycemic effects. Mechanisms of neuroprotective effect include antioxidant and anti-inflammatory action, antiapoptotic effect, enhanced neuronal differentiation. Agents for correction of intestinal microbiota also provide positive effects.

Clinical manifestations and evaluation of cardiac autonomic neuropathy in diabetes mellitus and metabolic syndrome

A serious complication of type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) is a dysfunction of the autonomic nervous system, which requires early evaluation for the effective treatment. The possibilities of pulse oximetry, which allows to assess heart rate variability in screening of autonomic nervous system dysfunction in patients with T2DM and MetS, have not yet been studied sufficiently.Objective: to evaluate the pulse oximetry effectiveness by comparing its results with the data of quantitative autonomic testing (QAT) to detect cardiac autonomic neuropathy (CAN) and clarify its degree in patients with T2DM and MetS.Patients and methods. The study included 30 patients with T2DM (mean age 63±7.9 years), 30 patients with MetS (mean age 61.5±9.1 years), 30 subjects from the control group (mean age 49.7±9.3 years). Patients underwent pulse oximetry, basic cardiovascular reflex tests, assessment of subjective sensations according to the NSC questionnaire, the severity of neurological deficit in the legs according to the NIS-LL scale and neuropathic pain syndrome according to the NTSS-9 scale.Results and discussion. In the group of patients with T2DM, severe CAN was detected in 13.3% of patients, moderate – in 40%. In the group of patients with MetS, severe CAN was detected in 10% of patients, moderate – also in 10%. In the control group, signs of moderate CAN were detected only in 3.3% of patients. The results of pulse oximetry tests with deep breathing were comparable to the QAT results (p<0.001). Conclusion. Pulse oximetry can be used to diagnose CAN.

HP07: A 24-hour heart rate variability analysis in Tunisian patients under hemodialysis is an indicator of autonomic nervous system activity

Heart rate variability (HRV) is a useful tool to evaluate autonomic nervous system activity in patients under hemodialysis (HD). The aim of the study was to evaluate the autonomic nervous system activity in Tunisian patients under HD using HRV analysis. Patients and methods: It was a prospective study including 27 patients under HD for at least 3 months. A Holter-ECG recording was realized for 48 hours. Time- and frequency-domain were analyzed. Statistical analysis were done using SPSS20. Results: The different HRV parameters were decreased. Only LF/HF ratio was increased indicating a deviation of the sympatico-vagal balance. The time-domain analysis showed a significant variation of the RR and the RMSSD during sleep-wake cycle. The latter parameters were increased during sleep. The frequency-domain analysis showed a significant increase in HF and LF during sleep. Nevertheless, LF/HF ratio decreased during sleep while the LF increased, however, without being significantly different. Conclusion: Our study showed an autonomic nervous system dysfunction in patients under HD. This dysfunction was characterized by a hyperactivation of the sympathetic system associated to a decreased parasympathetic activity. However, the physiological activation of the parasympathetic system during sleep was preserved. A HRV alteration is an independent cardiovascular risk factor.

Correction of vegetative disorders in children with irritable bowel syndrome

Introduction. The article considers the formation of irritable bowel syndrome (IBS) in children. In recent years this pathology occurs more often among the adult and children population in many countries in the world. According to the modern view of the problem, this disease is considered a biopsychological disease, in the development of which an important role is played by the connection of psychological factors, dysfunctions of the autonomic nervous system, motor and secretory disorders of various parts of the intestine, which can cause the discomfort, changes of intestinal habits. All these factors lead to a decrease in the quality of life in children. Purpose of research. The main goal of this research is to study the peculiarities of the status of the autonomic nervous system in children with irritable bowel syndrome and to evaluate the effectiveness of the proposed therapy. Materials and methods One of the main methods for assessing the condition of the autonomic system in patients is cardiointervalography. During this examination, we calculated the index of tension, which is one of the main indicators of assessing the condition of this part of the nervous system. According to this index’s indicators, the vegetative system’s state can be divided into three main variants of functioning – vagotony, eutony, and sympathicotony. All patients were divided into groups according to the main complaints and course of IBS – IBS with constipation (IBS -C), IBS with diarrhea (IBS- D), a mixed form of IBS and an unclassified form of IBS. And also another two large groups were formed – main and control. Results. We analyzed the cardiointervalogram indicators in both groups of patients with different clinical variants of IBS. In the main group, we registered a statistically significant decrease in the index of tension and an improvement in autonomic nervous system dysfunction in patients with IBS with constipation and diarrhea. Indicators in these groups were changed from the state of vagotony and sympathicotonia to eutony. This indicates the restoration of the function of the normal function of the autonomic nervous system. Patients from the control group also showed changes in the index of tension, but the indicators stayed in the borders of vagotony and sympathicotony, and didn’t reach the level of eutony. Conclusions. Аfter the evaluation of the received data, it was proved that the use of hopanthenic acid in the complex therapy of irritable bowel syndrome effectively improve the status of the autonomic nervous system in children.

Evaluation and treatment of peripheral nervous system dysfunction in patients with prediabetes

The worldwide prevalence of prediabetes is steadily increasing, with up to a third of patients already showing signs of diabetic neuropathy (DN). Prediabetes includes impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or a combination of both.Recent diagnostic criteria of prediabetes according to Russian, European, and American clinical guidelines are presented. The review covers the most common forms of DN in patients with prediabetes (distal symmetric sensory polyneuropathy, painful DN, cardiovascular autonomic neuropathy) and their prevalence. Recommended methods of DN screening are discussed: diagnostic scales, sensory testing, nerve conduction study, autonomic testing, corneal confocal microscopy. The results of studies evaluating instrumental methods for diagnosing peripheral nervous system (PNS) dysfunction in prediabetes are discussed. Management tactics in patients with prediabetes and PNS dysfunction should include non-pharmacological and pharmacological interventions. Combining a low-calorie diet and regular physical activity can delay the development of diabetes mellitus and reduce the severity of neuropathic pain. In patients with painful DN, the first-line therapy includes pregabalin, gabapentin, and duloxetine. Since there is no current data on the effect of hypoglycemic therapy on the risks of development and/or progression of DN in patients with prediabetes, antioxidants are considered pathogenetic therapy. Alpha-lipoic acid (Berlition®) in the management of patients with prediabetes is discussed.

Large animal models contribute to the development of therapies for central and peripheral nervous system dysfunction in patients with lysosomal storage diseases.

Lysosomal storage diseases (LSDs) are a group of 70 monogenic disorders characterized by the lysosomal accumulation of a substrate. As a group, LSDs affect ~1 in 5000 live births; however, each individual storage disease is rare, limiting the ability to perform natural history studies or to perform clinical trials. Perhaps in no other biomedical field have naturally occurring large animal (canine, feline, ovine, caprine, and bovine) models been so essential for understanding the fundamentals of disease pathogenesis and for developing safe and effective therapies. These models were critical for the development of hematopoietic stem cell transplantation in α- and β- mannosidosis, fucosidosis, and the mucopolysaccharidoses; enzyme replacement therapy for fucosidosis, the mucopolysaccharidoses, and neuronal ceroid lipofuscinosis; and small molecule therapy in Niemann-Pick type C disease. However, their most notable contributions to the biomedical field are in the development of gene therapy for LSDs. Adeno-associated viral vectors to treat nervous system disease have been evaluated in the large animal models of α-mannosidosis, globoid cell leukodystrophy, GM1 and GM2 gangliosidosis, the mucopolysaccharidoses, and neuronal ceroid lipofuscinosis. This review article will summarize the large animal models available for study as well as their contributions to the development of central and peripheral nervous system dysfunction in LSDs.

Autonomic Function in Insular Glioma: An Exploratory Study

Autonomic nervous system dysfunction is a known entity in strokes involving insula. It causes significant morbidity and mortality. No study to date has demonstrated autonomic nervous system dysfunction in patients with insular glioma. This is an exploratory study to identify the subclinical autonomic dysfunctions in insular glioma. A total 50 patients with newly diagnosed insular glioma in the age group of 18-60 years were evaluated with heart rate variability (HRV). All the HRV parameters in patients with insular glioma were compared with normal healthy age- and sex-matched control patients. There was a significant difference (P < 0.05) in most of the HRV parameters between patients and control patients. Patients with left insular glioma showed significantly increased heart rate (P= 0.027), low-frequency normalized units (P= 0.048), and also increased low-frequency/high-frequency ratio (P= 0.015), which indicates sympathetic dominance. Patients with seizures had significantly lower values of total power (P= 0.042). No significant difference was found in terms of the extent and size of the tumor or histopathologic grades of gliomas. Patients with insular gliomas have significant impairment of autonomic functions, with left insular glioma showing sympathetic dominance. Suppression of autonomic function is greater in those presenting with seizures.

Autonomic nerve activity indexed using 24-h heart rate variability in patients with burns

BackgroundHeart rate variability (HRV) is a noninvasive method used to quantify fluctuations in the time interval between normal heart beats. The purpose of this study was to compare the autonomic nervous system functioning of patients with burns to healthy participants after their burn scars had been re-epithelialized. Materials and methodsThe authors prospectively performed 24-h HRV monitoring in 60 patients with electrical burns, those with other major burns, those with other minor burns, and 10 healthy participants. Analysis of HRV in the time and frequency domain was performed. ResultsThe difference in sympathetic nerve measures (standard deviation of NN intervals [SDNN], total power [TP] and a low frequency [LF] band) and parasympathetic nerve measures (Root mean square successive difference [RMSSD], the number of interval differences of successive NN intervals greater than 50ms [NN50], the percentage of differences between following RR intervals greater than 50ms [pNN50] and a high frequency [HF] band) in patients with burns was significantly decreased during the daytime and the nighttime. the difference in parasympathetic nerve measures were more significantly decreased during the nighttime compared with measures of HRV in healthy participants. The groups of other burns showed significantly lower HRV than the electrical burn group indexed by a very low frequency (VLF) measure and TP during the daytime. ConclusionWe hypothesized that HRV is a surrogate for autonomic nervous system dysfunction in patients with burns. The patients with burns were observed a sympathetic predominance during daytime and a decreased parasympathetic activity during nighttime. These results of patients with other major burns were more predominant compared with the results of patients with other groups.

O163 Autonomic nervous system dysfunction in patients with high obstructive sleep apnea risk

Objectives The aim of this study was to compare autonomic nervous system (ANS) function in subjects with high OSA (obstructive sleep apnea) risk versus subjects with low OSA risk. Methods Out of 47 consecutive subjects enrolled (22 females, mean age 48.23 ± 16.09 years), 27 had high OSA risk and 20 had low OSA risk according to the Berlin Questionnaire (BQ). They all underwent standardized battery of ANS testing, including blood pressure and heart rate response to Valsalva maneuver, deep breathing test and head up tilt table test. Respiratory sinus arrhythmia (RSA), Valsalva ratio (VR) were determined and cardiovagal score of the Composite Autonomic Scoring Scale (CASS) was determined. Adrenergic score was calculated from the blood pressure response during Valslava maneuver and tilt table test. Finally heart rate variability (HRV) was determined in supine and standing positions. Results High OSA risk subjects had lower RSA compared to low OSA risk subjects (9.96 ± 5.45 vs. 15.17 ± 8.94, p = 0.022). Also VR was lower in subject with high OSA risk versus low OSA risk subjects (1.55 ± 0.34 vs. 1.83 ± 0.41, p = 0.024). There where no significant differences in CASS adrenergic score and HRV between groups. Discussion Pathogenesis of ANS dysfunction in OSA is not elucidated. Sympathetic hyperactivity leads to hypertension but can hardly explain higher cardiac morbidity and mortality. Further research is warranted to investigate the role of vagal down regulation in OSA pathogenesis. Conclusion High OSA risk is associated with vagal down regulation. Significance These findings confirms presence of vagal down regulation which might reflect central nervous system damage in OSA and also might contribute to cardiac morbidity and mortality.

Investigating the BOLD spectral power of the intrinsic connectivity networks in fibromyalgia patients: A resting-state fMRI study.

Recent advances in multivariate statistical analysis of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) have provided novel insights into the network organization of the human brain. Here, we applied group independent component analysis, a well-established approach for detecting brain intrinsic connectivity networks, to examine the spontaneous BOLD fluctuations in patients with fibromyalgia and healthy controls before and after exposure to a stressor. The BOLD spectral power characteristics of component time courses were calculated using the fast Fourier transform (FFT) algorithm, and group comparison was performed at six frequency bins between 0 and 0.24 Hz at 0.04 Hz intervals. Relative to controls, patients with fibromyalgia displayed significant BOLD spectral power differences in the default-mode, salience, and subcortical networks at the baseline level (PBon ferroni-corrected <; 0.05). Multivariate analysis of covariance (MANCOVA) further revealed significant effects of the cold water temperature, and pain rating on the spectral power of the sensorimotor, salience, and prefrontal networks, while the diagnosis of fibromyalgia influenced the BOLD spectral power of the salience and subcortical networks (PFDR-corrected <; 0.05). Since the BOLD spectral power reflects the degree of fluctuations within a network, future studies of the correlation between BOLD spectral power and pain processing can cast additional light on the nature of the central nervous system dysfunction in patients with chronic pain syndromes.

The effect of autonomic nervous system dysfunction on oxygen consumption during daily living activities in patients with spinal cord injury

Case-control study. To investigate the level of autonomic nervous system dysfunction in patients with spinal cord injury and to determine its effect on the basal metabolic rate and oxygen consumption during daily living activities. Turkish Armed Forces Rehabilitation Center, Ankara, Turkey. Thirty-six patients with chronic spinal cord injury (SCI) were allocated into two groups according to the presence of autonomic nervous system dysfunction. Autonomic nervous system dysfunction was investigated with the measurements of blood pressure and heart rate during urodynamic examination and several provocative maneuvers (standing at tilt table, forcing deep respiration and Valsalva). Groups were compared in terms of the basal metabolic rate and oxygen consumption during daily living activities. Measurement of the basal metabolic rate was determined by indirect calorimetry under standardized conditions. Total body fat mass and lean tissue mass were measured in all participants using dual-energy X-ray absorptiometry by standard methods. Telemetric intrapulmonary gas exchange analyzer was used to measure oxygen consumption during daily living activities. There was no statistically significant difference between the groups in age, time since injury, body mass lean and fat rates, or sensory and motor scores (P>0.05). Basal metabolic rates and oxygen consumption during daily living activities were not different between the groups (P>0.05). These results suggest that the presence of autonomic dysfunction does not change oxygen consumption at rest and during daily living activities.

Incidence and Predictive Factors of Central Nervous System Dysfunction in Patients Consulting for Dengue Fever in Cayenne Hospital, French Guiana.

IntroductionThe frequency, the clinical characteristics, and the prognosis of dengue is highly variable. Dengue fever is associated with a range of neurological manifestations. The objective of the present study was to determine the incidence of neurological signs and their predictive factors using data from cases of dengue seen and followed in Cayenne Hospital during the Dengue 2 epidemic in 2013.MethodsIn 2013, a longitudinal study using data from all cases of dengue seen in Cayenne hospital was collected. Medical records used a standardized form to collect demographic information, clinical signs and biological results and the date at which they were present. The analysis used Cox proportional modeling to obtain adjusted Hazard ratios.ResultsA total of 1574 patients were included 221 of whom developed central nervous system signs. These signs were spontaneously resolutive. There were 9298person days of follow-up and the overall incidence rate for central nervous system signs was 2.37 per 100 person-days. The variables independently associated with central nervous system anomalies were headache, Adjusted Hazard ratio (AHR) = 1.9(95%CI = 1.4–2.6), bleeding AHR = 2 ((95%CI = 1.3–3.1), P = 0.001, abdominal pain AHR = 1.9 ((95%CI = 1.4–2.6), P<0.001, aches AHR = 2.1 ((95%CI = 1.5–2.9), P<0.001, and fatigue AHR = 1.5 ((95%CI = 1.3–1.7), P<0.001.DiscussionOverall, the present study suggests that neurological signs of dengue are not exceptional even in patients without the most severe features of dengue. These manifestations were spontaneously resolutive. Here it was not possible to distinguish between encephalitis or encephalopathy. Further studies would require more in depth exploration of the patients.

Autonomic Nervous System Dysfunction in Patients With Parkinson Disease Having Depression.

Both depression and cardiovascular autonomic dysfunctions, such as orthostatic hypotension, supine hypertension, and the absence of normal nocturnal blood pressure (BP) fall ("nondipping"), occur relatively commonly in Parkinson disease (PD); however, the relationship between depression and cardiovascular autonomic abnormalities has not been established. In this study, we sought to determine whether the cardiovascular autonomic abnormalities found in PD are associated with depression. Among 129 nondemented, levodopa-naive patients with mild PD, 44 had depression. Orthostatic vital signs and ambulatory 24-hour BP monitoring were recorded, and geriatric depressive scales were obtained in all patients. Associations between orthostatic hypotension, supine hypertension, nocturnal hypertension, nondipping, and depression were analyzed. The ratio of the standard deviation of 24-hour heart rate to that of systolic BP (SBP) was utilized as an index of baroreflex-cardiovagal function. Depression was associated with orthostatic hypotension, and patients with depression had higher SBP change during orthostasis and attenuated cardiovagal dysfunction as observed during ambulatory BP monitoring. Across individuals, values for orthostatic changes in BP were correlated with values for geriatric depressive scale. Depression is associated with neurocirculatory abnormalities-especially orthostatic hypotension-in early PD. Although the association does not imply causation, this result suggests that depression in PD might be associated with functional impairment of the autonomic nervous system and its pathologic substrate.

Heart rate turbulence analysis in female patients with fibromyalgia

OBJECTIVE:Fibromyalgia is characterized by diffuse musculoskeletal pain and discomfort. There are several reports regarding autonomic nervous system dysfunction in patients with fibromyalgia. Heart rate turbulence is expressed as ventriculophasic sinus arrhythmia and has been considered to reflect cardiac autonomic activity. Heart rate turbulence has been shown to be an independent and powerful predictor of sudden cardiac death in various cardiac abnormalities. The aim of this study is to determine whether heart rate turbulence is changed in female patients with fibromyalgia compared with healthy controls.METHODS:Thirty-seven female patients (mean age, 40±11 years) with fibromyalgia, and 35 age- and sex-matched healthy female control subjects (mean age, 42±9 years) were included. Twenty-four hours of ambulatory electrocardiography recordings were collected for all subjects, and turbulence onset and turbulence slope values were automatically calculated.RESULTS:The baseline clinical characteristics of the two groups were similar. There were no significant differences in turbulence onset and turbulence slope measures between patients and control subjects (turbulence onset: −1.648±1.568% vs. −1.582±1.436%, p ϝ 0.853; turbulence slope: 12.933±5.693 ms/RR vs. 13.639±2.505 ms/RR, p ϝ 0.508). Although body mass index was negatively correlated with turbulence slope (r ϝ −0.258, p ϝ 0.046), no significant correlation was found between body mass index and turbulence onset (r ϝ 0.228, p ϝ 0.054).CONCLUSION:To the best of our knowledge, this is the first study to evaluate heart rate turbulence in patients with fibromyalgia. It appears that heart rate turbulence parameters reflecting cardiac autonomic activity are not changed in female patients with fibromyalgia.

Impaired circadian rhythm of blood pressure in normotensive patients with rheumatic mitral valve stenosis

The aim of the present cross-sectional study was to evaluate either non-dipper-type or dipper-type circadian rhythm of blood pressure (BP) in normotensive rheumatic mitral stenosis (MS) patients. Eighty-eight normotensive rheumatic mitral valve disease (RMVD) patients and 41 normal participants were enrolled in the study. All participants underwent ambulatory blood pressure monitoring. Nocturnal BP dipping was calculated as follows: (awake BP-asleep BP)×100/awake BP. Patients with a nocturnal reduction in average daytime systolic BP and diastolic BP of less than 10% were classified as nondippers. Patients with RMVD were divided into two groups with respect to the top and bottom 1.5 cm of the mitral valve area (MVA). There was a highly significant relationship between the two groups with control in the frequency of a nondipping status (χ=22.721; d.f.=2; P<0.001). Afterwards, the Mann-Whitney U-test was used to compare the two groups and the control group. There was no difference in the frequency of nondipping between patients with an MVA of greater than 1.5 cm and the control group (P>0.05). However, the nondipping level was higher in patients with an MVA of less than 1.5 cm than in the control group and in patients with RMVD with an MVA of greater than 1.5 cm (P<0.001 and <0.001, respectively). The circadian BP rhythm is impaired and the incidence of nondipping BP is higher in patients with MS than in normal patients. Moreover, we believe that autonomic nervous system dysfunction in patients with MS may be detected efficiently using ambulatory blood pressure monitoring.

Small fibre pathology in patients with fibromyalgia syndrome

Fibromyalgia syndrome is a clinically well-characterized chronic pain condition of high socio-economic impact. Although the pathophysiology is still unclear, there is increasing evidence for nervous system dysfunction in patients with fibromyalgia syndrome. In this case-control study we investigated function and morphology of small nerve fibres in 25 patients with fibromyalgia syndrome. Patients underwent comprehensive neurological and neurophysiological assessment. We examined small fibre function by quantitative sensory testing and pain-related evoked potentials, and quantified intraepidermal nerve fibre density and regenerating intraepidermal nerve fibres in skin punch biopsies of the lower leg and upper thigh. The results were compared with data from 10 patients with monopolar depression without pain and with healthy control subjects matched for age and gender. Neurological and standard neurophysiological examination was normal in all patients, excluding large fibre polyneuropathy. Patients with fibromyalgia syndrome had increased scores in neuropathic pain questionnaires compared with patients with depression and with control subjects (P < 0.001 each). Compared with control subjects, patients with fibromyalgia syndrome but not patients with depression had impaired small fibre function with increased cold and warm detection thresholds in quantitative sensory testing (P < 0.001). Investigation of pain-related evoked potentials revealed increased N1 latencies upon stimulation at the feet (P < 0.001) and reduced amplitudes of pain-related evoked potentials upon stimulation of face, hands and feet (P < 0.001) in patients with fibromyalgia syndrome compared to patients with depression and to control subjects, indicating abnormalities of small fibres or their central afferents. In skin biopsies total (P < 0.001) and regenerating intraepidermal nerve fibres (P < 0.01) at the lower leg and upper thigh were reduced in patients with fibromyalgia syndrome compared with control subjects. Accordingly, a reduction in dermal unmyelinated nerve fibre bundles was found in skin samples of patients with fibromyalgia syndrome compared with patients with depression and with healthy control subjects, whereas myelinated nerve fibres were spared. All three methods used support the concept of impaired small fibre function in patients with fibromyalgia syndrome, pointing towards a neuropathic nature of pain in fibromyalgia syndrome.

Exploring autonomic nervous system dysfunction in patients with cancer cachexia: A pilot study

IntroductionAbnormalities of the autonomic nervous system (ANS) have been associated with cachexia. MethodsIn nine cancer patients who had lost weight and nine age-matched healthy volunteers heart rate variability (HRV) components were determined, together with serum cortisol and urinary catecholamines/metanephrines. ResultsCompared to volunteers, patients exhibited a global reduction in HRV parameters, significantly so for high frequency, low frequency and total power (median values ms2 103 vs. 313, 62 vs. 148 and 316 vs. 736 respectively, P<0.05). Biochemical values did not differ. ConclusionOur results suggest the presence of ANS dysfunction in patients with cancer cachexia, with reduction in both sympathetic and parasympathetic components.

Autonomic Response to Periodic Leg Movements during Sleep in Narcolepsy-Cataplexy

To test the hypothesis of autonomic nervous system dysfunction in patients with narcolepsy-cataplexy (NC) by assessing the physiologic activations associated with periodic limb movements during sleep (PLMS). Sleep and heart rate (HR) were recorded during 1 night of polysomnography. Data were collected at the Sleep Disorders Center, Sacre-Coeur Hospital, Montreal, Canada. Data from 14 patients with NC (6 men, 8 women, mean age: 52.5 ± 11.9 years) were compared with data from 14 healthy control subjects matched for age and sex. NA. Analyses included sleep stages, PLMS, microarousals, RR intervals converted into beats per minute on segments lasting 25 heartbeats (10 RR intervals before PLMS and 15 after), and cardiac-activation amplitudes. A Group-by-Heartbeat interaction was noted for PLMS without microarousals; the patients had a tachycardia of lower amplitude and a delayed and lower-amplitude bradycardia, compared with normal control subjects. Similar significant HR modifications were observed for PLMS with microarousals between patients with NC and control subjects. Patients with NC had a reduced magnitude of cardiac activation associated with PLMS with and without microarousals, as compared with control subjects. A negative correlation was noted between cardiac-activation amplitude and age in patients with NC, but no correlation with PLMS index was found in either patients with NC or control subjects. A significant reduction in the amplitude of PLMS-related HR responses in both tachycardia and bradycardia was found in patients with NC. These findings favor the physiologic relevance of the action of hypocretin on autonomic function that may be of clinical significance, i.e., increasing the risk of cardiovascular diseases.