The association of diabetic peripheral neuropathy with cardiac autonomic neuropathy in individuals with diabetes mellitus: A systematic review.

This systematic review aimed to explore the relationship between diabetic peripheral neuropathy (DPN) and cardiac autonomic neuropathy (CAN) in individuals with type 1 and 2 diabetes mellitus (DM). METHODS: The systematic review follow the protocol registered in Prospero (CRD42020182899). Two authors independently searched the PubMed, Scopus, Embase, Cochrane, and Web of Science databases. Discrepancies were resolved by a third author. The review included observational studies investigating the relationship between CAN and DPN in individuals with DM. RESULTS: Initially, out of 1165 studies, only 16 were selected, with 42.8 % involving volunteers with one type of diabetes, 14.3 % with both types of diabetes and 14.3 % not specify the type. The total number of volunteers was 2582, mostly with type 2 DM. It was analyzed that there is a relationship between CAN and DPN. It was observed that more severe levels of DPN are associated with worse outcomes in autonomic tests. Some studies suggested that the techniques for evaluating DPN might serve as risk factors for CAN. CONCLUSION: The review presents a possible relationship between DPN and CAN, such as in their severity.

Reactive Hyperemia and Cardiovascular Autonomic Neuropathy in Type 2 Diabetic Patients: A Systematic Review of Randomized and Nonrandomized Clinical Trials.

Objective: This work aimed to determine the relationship between the autonomic nervous system and reactive hyperemia (RH) in type 2 diabetes patients with and without cardiovascular autonomic neuropathy (CAN). Methodology: A systematic review of randomized and nonrandomized clinical studies characterizing reactive hyperemia and autonomic activity in type 2 diabetes patients with and without CAN was performed. Results: Five articles showed differences in RH between healthy subjects and diabetic patients with and/or without neuropathy, while one study did not show such differences between healthy subjects and diabetic patients, but patients with diabetic ulcers had lower RH index values compared to healthy controls. Another study found no significant difference in blood flow after a muscle strain that induced reactive hyperemia between normal subjects and non-smoking diabetic patients. Four studies measured reactive hyperemia using peripheral arterial tonometry (PAT); only two found a significantly lower endothelial-function-derived measure of PAT in diabetic patients than in those without CAN. Four studies measured reactive hyperemia using flow-mediated dilation (FMD), but no significant differences were reported between diabetic patients with and without CAN. Two studies measured RH using laser Doppler techniques; one of them found significant differences in the blood flow of calf skin after stretching between diabetic non-smokers and smokers. The diabetic smokers had neurogenic activity at baseline that was significantly lower than that of the normal subjects. The greatest evidence revealed that the differences in RH between diabetic patients with and without CAN may depend on both the method used to measure hyperemia and that applied for the ANS examination as well as the type of autonomic deficit present in the patients. Conclusions: In diabetic patients, there is a deterioration in the vasodilator response to the reactive hyperemia maneuver compared to healthy subjects, which depends in part on endothelial and autonomic dysfunction. Blood flow alterations in diabetic patients during RH are mainly mediated by sympathetic dysfunction. The greatest evidence suggests a relationship between ANS and RH; however, there are no significant differences in RH between diabetic patients with and without CAN, as measured using FMD. When the flow of the microvascular territory is measured, the differences between diabetics with and without CAN become evident. Therefore, RH measured using PAT may reflect diabetic neuropathic changes with greater sensitivity compared to FMD.

Paroxysmal Sympathetic Hyperactivity in Patients Victims of Traumatic Brain Injury: Literature Review

The present literature review aims to present the physiology of paroxysmal sympathetic hyperactivity (PSH) as well as its clinical course, conceptualizing them, and establishing its diagnosis and treatment. Paroxysmal sympathetic hyperactivity is a rare syndrome, which often presents after an acute traumatic brain injury. Characterized by a hyperactivity of the sympathetic nervous system, when diagnosed in its pure form, its symptomatologic presentation is through tachycardia, tachypnea, hyperthermia, hypertension, dystonia, and sialorrhea. The treatment of PSH is basically pharmacological, using central nervous system suppressors; however, the nonmedication approach is closely associated with a reduction in external stimuli, such as visual and auditory stimuli. Mismanagement can lead to the development of serious cardiovascular and diencephalic complications, and the need for neurosurgeons and neurointensivists to know about PSH is evident in order to provide a fast and accurate treatment of this syndrome.

Distal Symmetric and Cardiovascular Autonomic Neuropathies in Brazilian Individuals with Type 2 Diabetes Followed in a Primary Health Care Unit: A Cross-Sectional Study.

The paucity of epidemiological data regarding diabetes complications in Brazil motivated us to evaluate the prevalence rates of distal symmetric polyneuropathy (DSP) and of cardiovascular autonomic neuropathy (CAN) in individuals with type 2 diabetes (T2D) followed in a primary care unit. A total of 551 individuals (59.3% women, 65 years old; diabetes duration of 10 years; HbA1c of 7.2%, medians) were included in this cross-sectional study. DSP was diagnosed by sum of the Neuropathy Symptoms Score (NSS) and Modified Neuropathy Disability Score (NDS) and by the Semmes-Weinstein monofilament. CAN was diagnosed by cardiovascular autonomic reflex tests combined with spectral analysis of heart rate variability. The prevalence rates of DSP were 6.3% and 14.3%, as evaluated by the sum of NSS and NDS and by the Semmes-Weinstein monofilament, respectively. Those with DSP diagnosed by monofilament presented longer diabetes duration, worse glycemic control and a higher stature. The prevalence rates of incipient and definitive CAN were 12.5% and 10%, respectively. Individuals with definitive CAN presented a higher frequency of hypercholesterolemia and of arterial hypertension. The higher prevalence rate of DSP with the use of the monofilament suggests that it may be a more appropriate tool to diagnose DSP in the primary care setting in Brazil.

Functional Gastrointestinal Disorders, Autonomic Nervous System Dysfunction, and Joint Hypermobility in Children: Are They Related?

OBJECTIVES: To evaluate the prevalence of orthostatic intolerance and joint hypermobility in schoolchildren with and without functional gastrointestinal disorders (FGIDs) and to assess autonomic nervous system dysfunction in children with FGIDs and joint hypermobility. STUDY DESIGN: Schoolchildren (10-18 years) attending public schools from 3 Colombian cities (Cali, Palmira, and Bucaramanga) completed validated questionnaires for FGIDs and underwent testing for hypermobility and autonomic nervous system dysfunction. Heart rate and blood pressure were assessed in recumbency and upright position at regular intervals. The differences in characteristics between schoolchildren with and without FGIDs were compared with a t-test for continuous variables and with a Fisher exact test (2 × 2 contingency tables) for categorical variables. RESULTS: In total, 155 children with FGIDs were matched with 151 healthy controls. Children with FGIDs had historically significant greater frequency of 10 of 12 symptoms of orthostatic intolerance, no significant difference in any symptoms of orthostatic intolerance during recumbency, significantly greater frequency in 6 of 12 symptoms of orthostatic intolerance during orthostasis, trend toward statistical significance for orthostatic intolerance (P = .0509), and no significant difference in prevalence of orthostatic hypotension (OH) and postural orthostatic tachycardia syndrome (POTS). There was no significant difference in prevalence of orthostatic intolerance, OH, and POTS between those with joint hypermobility and those without. CONCLUSIONS: Children with FGIDs have a greater prevalence of symptoms of orthostatic intolerance but were not more likely to have OH and POTS as compared with children without FGIDs. Children with joint hypermobility did not have a greater prevalence of orthostatic intolerance, OH, and POTS.

Modulation of Autonomic Function by Physical Exercise in Patients with Fibromyalgia Syndrome: A Systematic Review.

OBJECTIVE: To evaluate the effects of physical exercise on autonomic dysfunction in patients with fibromyalgia syndrome (FM). LITERATURE SURVEY AND METHODOLOGY: A systematic review of experimental studies published until December 2017 that analyzed the effect of physical exercise on autonomic dysfunction in patients with FM was performed using the PubMed, Pedro, Scopus, ScienceDirect, and Web of Science databases. SYNTHESIS: A total of 1105 articles were identified, 12 of which were included in the final analysis. The most analyzed exercise modalities were aerobic and resistance exercises. Overall, the studies demonstrated that aerobic exercise performed twice a week with moderate to high intensity was effective in reducing autonomic dysfunction by increasing heart rate variability. Resistance training was associated with reduced symptoms of anxiety and depression as well as increased muscle strength; however, it did not reduce autonomic dysfunction in these patients in the short or long term. CONCLUSIONS: Preliminary evidence suggests that aerobic exercise reduces autonomic dysfunction in patients with FM, whereas resistance training reduces psychological symptoms such as anxiety and depression. LEVEL OF EVIDENCE: I.

[Frequency and associated risk factors of cardiovascular autonomic neuropathy among patients with type 2 Diabetes.] / Frecuencia y factores de riesgo asociados de Neuropatía Autonómica Cardíaca en pacientes con Diabetes tipo 2.

Background: Cardiovascular autonomic neuropathy (CAN) is a common complication of diabetes and is associated with cardiovascular morbidity and mortality. Despite its prevalence, it is usually underdiagnosed. Objective to assess frequency of CAN in type 2 diabetes, treated at the Diabetology Service at Cordoba Hospital, Argentina. Method: Cross-sectional study was conducted from May 2015 to May 2016. Cardiovascular Autonomic Tests (Ewing´s battery) were performed: response to Valsalva maneuver, expiration-to-inspiration ratio (E/I ratio), standing to lying flat and postural hypotension. Results: 100 type 2 diabetes patients, 53% females. The mean age and diabetes duration 52 years old and 8.4 years, respectively. Hemoglobin A1c level of 8.7% and 47% were insulin-requiring type 2 diabetes patients. 29% had early CAN, 54% confirmed CAN (10% severe CAN) and 17% normal cardiovascular tests. Confirmed CAN was higher in those with longer duration of diabetes; longer duration of insulin therapy, older patients and severe hypoglycemia events was higher in those with confirmed CAN versus without CAN or early CAN (p 0.003). The risk factors associated were hypertension OR 2.55 (p 0.02), peripheral neuropathy OR 11.7 (p <0.0001), diabetic retinopathy OR 9.03 (p 0.001), diabetic nephropathy OR 3.12 (p 0.03) and hemoglobin A1c > 7% OR 2.57 (p 0, 03). Conclusions: frequency of CAN was high, was associated with hypertension, microvascular complications, older age, poor metabolic control, longer duration of disease and insulin therapy. Patients with a higher risk of developing CAN should be identified, in order to reduce the impact of this complication.

Introducción: La neuropatía autonómica cardíaca (NAC) es una complicación frecuente de la diabetes y aumenta la morbimortalidad cardiovascular. A pesar de su prevalencia e impacto está subdiagnosticada. Objetivo: Determinar la frecuencia de NAC y factores de riesgo asociados en pacientes con diabetes tipo 2(DM2), en el Servicio de Diabetología del Hospital Córdoba. Material y Métodos: estudio transversal, desde Mayo de 2015 a Mayo de 2016. Se realizó Test Autonómicos Cardiovasculares: Maniobra de Valsalva (MV), Respiración Profunda (RP), Razón 30/15 e Hipotensión ortostática. Resultados: Se reclutaron 100 pacientes con DM2. 53 % sexo femenino. Edad promedio 52 años, IMC 30,9; HbA1c 8,7 % y evolución de la enfermedad 8,4 años. El 17 % presentaron test normales. El 29 % tenía NAC temprana y 54% NAC confirmada (10 % NAC severa). Los pacientes con NAC confirmada tenían mayor tiempo de evolución (11 vs 5 años ), mayor duración de insulinoterapia (5 vs 1,5 años ), mayor edad ( 54 vs 49 años ) y mayor riesgo de hipoglucemias severas comparado con pacientes sin NAC o NAC temprana (p 0,003).Factores de riesgo asociados hipertensión arterial OR 2,55 (p 0,02), neuropatía periférica OR 11,7 (p<0,0001) , retinopatía OR 9,03 (p 0,001), nefropatía OR 3,12 (p 0,03) y HbA1c > 7% OR 2,57(p 0,03). Conclusiones: Hubo una alta frecuencia de NAC, se asoció con hipertensión, complicaciones microvasculares, mayor edad, duración de la enfermedad, de la insulinoterapia y mal control metabólico. Se debería identificar a pacientes con mayor riesgo, para reducir su aparición e impacto.

Autonomic Dysfunction in Neonates with Hypoxic Ischemic Encephalopathy Undergoing Therapeutic Hypothermia Impairs Physiological Responses to Routine Care Events.

OBJECTIVE: To evaluate whether infants with hypoxic-ischemic encephalopathy and evidence of autonomic dysfunction have aberrant physiological responses to care events that could contribute to evolving brain injury. STUDY DESIGN: Continuous tracings of heart rate (HR), blood pressure (BP), cerebral near infrared spectroscopy, and video electroencephalogram data were recorded from newborn infants with hypoxic-ischemic encephalopathy who were treated with hypothermia. Videos between 16 and 24 hours of age identified 99 distinct care events, including stimulating events (diaper changes, painful procedures), and vagal stimuli (endotracheal tube manipulations, pupil examinations). Pre-event HR variability was used to stratify patients into groups with impaired versus intact autonomic nervous system (ANS) function. Postevent physiological responses were compared between groups with the nearest mean classification approach. RESULTS: Infants with intact ANS had increases in HR/BP after stimulating events, whereas those with impaired ANS showed no change or decreased HR/BP. With vagal stimuli, the HR decreased in infants with intact ANS but changed minimally in those with impaired ANS. A pupil examination in infants with an intact ANS led to a stable or increased BP, whereas the BP decreased in the group with an impaired ANS. Near infrared spectroscopy measures of cerebral blood flow/blood volume increased after diaper changes in infants with an impaired ANS, but were stable or decreased in those with an intact ANS. CONCLUSION: HR variability metrics identified infants with impaired ANS function at risk for maladaptive responses to care events. These data support the potential use of HR variability as a real-time, continuous physiological biomarker to guide neuroprotective care in high-risk newborns.

Congenital Cases of Concomitant Harlequin and Horner Syndromes.

We report three pediatric cases of concomitant congenital Horner and Harlequin syndromes. This association suggests a lesion at the superior cervical ganglion or just inferior. Often, no underlying lesion is documented.

Neuropad for the detection of cardiovascular autonomic neuropathy in patients with type 2 diabetes.

BACKGROUND: Cardiovascular autonomic neuropathy (CAN) is a prevalent and neglected chronic complication of diabetes, with a large impact on morbidity and mortality. Part of the reason why it is not detected and treated opportunely is because of the complexity of the tests required for its diagnosis. We evaluated the Neuropad®, a test based on sudomotor function, as a screening tool for CAN in adult patients with type 2 diabetes in Bogotá, Colombia. METHODS: This was a cross-sectional evaluation of Neuropad® for the detection of CAN. Patients were 20-75years of age and did not suffer from any other type of neuropathy. CAN was diagnosed using the Ewing battery of tests for R-R variability during deep breathing, Valsalva and lying-to-standing maneuvers. Additionally, distal symmetric polyneuropathy (DSP) was diagnosed using a sign-based scale (Michigan Neuropathy Disability Score - NDS) and a symptom-based score (Total Symptom Score - TSS). The primary outcome was the sensitivity and specificity of the Neuropad® for the diagnosis of CAN, and secondary outcomes were the sensitivity and specificity of Neuropad® for DSP. RESULTS: We studied 154 patients (74 men and 80 women). Prevalence of CAN was extremely high (68.0% of study participants), but also DSP was prevalent, particularly according to the signs-based definition (45%). The sensitivity of the Neuropad® for any degree of CAN was 70.1%, being slightly higher for the deep breathing and Valsalva tests than for lying-to-standing. The specificity of the Neuropad® for any type of CAN was only 37.0%, as expected for a screening exam. The negative predictive value was higher for the deep breathing and Valsalva tests (69.4 and 81.6%, respectively). Neuropad showed also a good sensitivity and negative predictive value for DSP. The sensitivity and specificity of Neuropad were better among men, and among patients with diabetes duration above the group median. CONCLUSIONS: The Neuropad is a simple and inexpensive device that demonstrated an adequate performance as a screening tool for cardiovascular autonomic neuropathy in Latin American patients with DM2.

Catecholamine excess: pseudopheochromocytoma and beyond.

Symptoms of catecholamine excess or pseudopheochromocytoma can be clinically indistinguishable from pheochromocytoma. Patients usually present with paroxysmal or episodic hypertension and have a negative evaluation for pheochromocytoma. It is important to exclude other causes of catecholamine excess that can be induced by stress, autonomic dysfunction due to baroreflex failure, medications, and drugs. Patients with pseudopheochromocytoma appear to have an amplified cardiovascular responsiveness to catecholamines with enhanced sympathetic nervous stimulation. The exact mechanism is not well understood and increased secretion of dopamine, epinephrine, and norepinephrine, and their metabolites have been identified as potentiating this clinical scenario leading to differing hemodynamic presentations depending on which catecholamine is elevated. Management of this condition is often difficult and frustrating for both the physician and the patient. Most patients respond reasonably well to medications that reduce sympathetic nervous system activity. Anxiolytics, antidepressants, and psychotherapy also play an important role in managing these patients' symptoms.

Type 2 diabetes and cardiac autonomic neuropathy screening using dynamic pupillometry.

AIM: To determine if changes in pupillary response are useful as a screening tool for diabetes and to assess whether pupillometry is associated with cardiac autonomic neuropathy. METHODS: We conducted a cross-sectional study with participants drawn from two settings: a hospital and a community site. At the community site, individuals with newly diagnosed diabetes as well as a random sample of control individuals without diabetes, confirmed by oral glucose tolerance test, were selected. Participants underwent an LED light stimulus test and eight pupillometry variables were measured. Outcomes were diabetes, defined by oral glucose tolerance test, and cardiac autonomic dysfunction, determined by a positive readout on two of four diagnostic tests: heart rate response to the Valsalva manoeuvre; orthostatic hypotension; 30:15 ratio; and expiration-to-inspiration ratio. The area under the curve, best threshold, sensitivity and specificity of each pupillometry variable was calculated. RESULTS: Data from 384 people, 213 with diabetes, were analysed. The mean (±sd) age of the people with diabetes was 58.6 (±8.2) years and in the control subjects it was 56.1 (±8.6) years. When comparing individuals with and without diabetes, the amplitude of the pupil reaction had the highest area under the curve [0.69 (sensitivity: 78%; specificity: 55%)]. Cardiac autonomic neuropathy was present in 51 of the 138 people evaluated (37.0%; 95% CI 28.8-45.1). To diagnose cardiac autonomic neuropathy, two pupillometry variables had the highest area under the curve: baseline pupil radius [area under the curve: 0.71 (sensitivity: 51%; specificity: 84%)], and amplitude of the pupil reaction [area under the curve: 0.70 (sensitivity: 82%; specificity: 55%)]. CONCLUSIONS: Pupillometry is an inexpensive technique to screen for diabetes and cardiac autonomic neuropathy, but it does not have sufficient accuracy for clinical use as a screening tool.

Cardiac autonomic dysfunction in obese normotensive children and adolescents / Disfunción autonómica cardiaca en niños y adolescentes obesos normotensos / Disfunção autonômica cardíaca em crianças e adolescentes obesos normotensos

To test the hypothesis that obese normotensive children and adolescents present impaired cardiac autonomic control compared to non-obese normotensive ones. METHODS: For this cross-sectional study, 66 children and adolescents were divided into the following groups: Obese (n=31, 12±3 years old) and Non-Obese (n=35, 13±3 years old). Obesity was defined as body mass index greater than the 95th percentile for age and gender. Blood pressure was measured by oscillometric method after 15 minutes of rest in supine position. The heart rate was continuously registered during ten minutes in the supine position with spontaneous breathing. The cardiac autonomic control was assessed by heart rate variability, which was calculated from the five-minute minor variance of the signal. The derivations were the index that indicates the proportion of the number of times in which normal adjacent R-R intervals present differences >50 miliseconds (pNN50), for the time domain, and, for the spectral analysis, low (LF) and high frequency (HF) bands, besides the low and high frequencies ratio (LF/HF). The results were expressed as mean±standard deviation and compared by Student's t-test or Mann-Whitney's U-test. RESULTS: Systolic blood pressure (116±14 versus 114±13mmHg, p=0.693) and diastolic blood pressure (59±8 versus 60±11mmHg, p=0.458) were similar between the Obese and Non-Obese groups. The pNN50 index (29±21 versus 43±23, p=0.015) and HF band (54±20 versus 64±14 normalized units - n.u., p=0.023) were lower in the Obese Group. The LF band (46±20 versus 36±14 n.u., p=0.023) and LF/HF ratio (1.3±1.6 versus 0.7±0.4, p=0.044) were higher in Obese Group. CONCLUSIONS: Obese normotensive children and adolescents present impairment of cardiac autonomic control...

Probar la hipótesis de que niños y adolescentes obesos normotensos presentan disfunción autonómica cardiaca cuando comparados a individuos no obesos también normotensos. MÉTODOS: Estudio transversal con 66 niños y adolescentes, divididos en los grupos Obeso (n=31, 12±3 años) y No obesos (n=35, 13±3 años). Se definió la obesidad por el índice de masa corporal superior al percentil 95, considerándose edad y sexo. Se verificó la presión arterial clínica por oscilometría después de 15 minutos de reposo en posición supina. Se registró la frecuencia cardiaca durante 10 minutos en la posición supina, con respiración espontánea. Se evaluó el control autonómico cardiaco por la variabilidad de la frecuencia cardiaca, calculada a partir de los cinco minutos de menor variancia de la señal. Fueron derivados el índice que indica la proporción del número de veces en que los intervalos R-R normales sucesivos presentan diferencia de duración superior a 50 milisegundos (pNN50) para el dominio del tiempo y, para el análisis espectral, las bandas de baja (LF) y alta (HF) frecuencias, además de la razón entre las bandas espectrales de baja y alta frecuencia (LF/HF). Los resultados se presentaron como promedio±desviación estándar, siendo comparados por la prueba t de Student o por la prueba U de Mann-Whitney. RESULTADOS: Los niveles de presión arterial sistólica (116±14 versus 114±13mmHg, p=0,693) y diastólica (59±8 versus 60±11mmHg, p=0,458) fueron semejantes entre los grupos Obeso y No obeso, respectivamente. El índice pNN50 (29±21 versus 43±23; p=0,015) y la banda HF (54±20 versus 64±14 unidades normalizadas - u.n.; p=0,023) fueron menores en el Grupo Obeso...

Testar a hipótese de que crianças e adolescentes obesos normotensos apresentam disfunção autonômica cardíaca quando comparados a indivíduos não obesos também normotensos. MÉTODOS: Estudo transversal com 66 crianças e adolescentes, divididos nos grupos Obeso (n=31, 12±3 anos) e Não Obeso (n=35, 13±3 anos). Definiu-se a obesidade pelo índice de massa corpórea maior que o percentil 95, considerando-se idade e sexo. Aferiu-se a pressão arterial clínica por oscilometria após 15 minutos de repouso em posição supina. Registrou-se a frequência cardíaca durante dez minutos na posição supina, com respiração espontânea. Avaliou-se o controle autonômico cardíaco pela variabilidade da frequência cardíaca, calculada a partir dos cinco minutos de menor variância do sinal. Foram derivados o índice que indica a proporção do número de vezes em que os intervalos R-R normais sucessivos apresentam diferença de duração superior a 50 milisegundos (pNN50) para o domínio do tempo e, para a análise espectral, as bandas de baixa (LF) e alta (HF) frequências, além da razão entre as bandas espectrais de baixa e alta frequência (LF/HF). Os resultados apresentam-se como média±desvio padrão, sendo comparados pelo teste t de Student ou pelo teste U de Mann-Whitney. RESULTADOS: Os níveis de pressão arterial sistólica (116±14 versus 114±13mmHg, p=0,693) e diastólica (59±8 versus 60±11mmHg, p=0,458) foram semelhantes entre os grupos Obeso...

Heart rate variability in children with type 1 diabetes mellitus / Variabilidad de la frecuencia cardiaca en niños con diabetes mellitus tipo 1 / Variabilidade da frequência cardíaca em crianças com diabetes melito tipo 1

To gather current information about the effects of type 1 diabetes mellitus on children's cardiac autonomic behavior. DATA SOURCES: The search of articles was conducted on PubMed, Ibecs, Medline, Cochrane, Lilacs, SciELO and PEDro databases using the MeSH terms: "autonomic nervous system", "diabetes mellitus", "child", "type 1 diabetes mellitus", "sympathetic nervous system" and "parasympathetic nervous system", and their respective versions in Portuguese (DeCS). Articles published from January 2003 to February 2013 that enrolled children with 9-12 years old with type 1 diabetes mellitus were included in the review. DATA SYNTHESIS: The electronic search resulted in four articles that approached the heart rate variability in children with type 1 diabetes mellitus, showing that, in general, these children present decreased global heart rate variability and vagal activity. The practice of physical activity promoted benefits for these individuals. CONCLUSIONS: Children with type 1 diabetes mellitus present changes on autonomic modulation, indicating the need for early attention to avoid future complications in this group...

Reunir informaciones actuales sobre los efectos de la diabetes mellitus tipo 1 sobre el comportamiento cardiaco de niños. FUENTES DE DATOS: La búsqueda de artículos se realizó en las bases de datos PubMed, Ibecs, Medline, Cochrane, Lilacs y PEDro por medio de los descriptores del área de salud (DeCS) a continuación: "sistema nervioso autónomo", "diabetes mellitus", "niño", "diabetes mellitus tipo 1", "sistema nervioso simpático" y "sistema nervioso parasimpático" sus respectivas versiones en lengua inglesa (MeSH).Los artículos fueron publicados de enero de 2003 a febrero de 2013, implicando a niños de nueve a 12 años portadores de diabetes mellitus tipo 1. SÍNTESIS DE LOS DATOS: La búsqueda resultó en cuatro artículos que trataban la variabilidad de la frecuencia cardiaca en niños con diabetes mellitus tipo 1, demostrando que, por lo general, esos niños presentan reducción de la variabilidad de la frecuencia cardiaca global y de la actividad vagal. La práctica de actividad física promueve beneficios al organismo de niños con diabetes mellitus tipo 1. CONCLUSIONES: Niños diabéticos tipo 1 presentan modificaciones en la modulación autonómica, lo que demuestra la necesidad de atención temprana a esa población para evitar complicaciones futuras...

Reunir informações atuais acerca dos efeitos do diabetes melito tipo 1 sobre o comportamento autonômico cardíaco de crianças. FONTES DE DADOS: A busca dos artigos foi realizada nas bases de dados PubMed, Ibecs, Medline, Cochrane, Lilacs, SciELO e PEDro por meio dos seguintes descritores da área da saúde (DeCS): "sistema nervoso autônomo", "diabetes mellitus", "criança", "diabetes mellitus tipo 1", "sistema nervoso simpático" e "sistema nervoso parassimpático" e suas respectivas versões em língua inglesa (MeSH). Os artigos foram publicados de janeiro de 2003 a fevereiro de 2013, envolvendo crianças de nove a 12 anos portadoras de diabetes melito tipo 1. SÍNTESE DOS DADOS: A busca resultou em quatro artigos que abordam a variabilidade da frequência cardíaca em crianças com diabetes melito tipo 1, demonstrando que, em geral, essas crianças apresentam redução da variabilidade da frequência cardíaca global e da atividade vagal. A prática de atividade física promove benefícios no organismo de crianças com diabetes melito tipo 1. CONCLUSÕES: Crianças diabéticas tipo 1 apresentam modificações na modulação autonômica, o que demonstra a necessidade de atenção precoce a essa população para evitar complicações futuras...

Pain-autonomic interaction after work-induced sleep restriction.

BACKGROUND AND PURPOSE: Poor sleep is commonly associated with alterations in pain perception. However, there is a lack of studies that address work-associated sleep restriction (SR) and changes in non-nociceptive perception and autonomic responses after work-induced SR. METHODS: This study was performed with 19 medical students after a normal-sleep night (NS phase) and after a night shift at the local emergency room (SR phase). We performed clinical assessment, quantitative sensory testing for electrical and temperature sensation, RR interval analysis, and recorded sudomotor skin responses (SSRs). RESULTS: The total mean duration of sleep was 436 ± 18 min in the NS group and 120 ± 28 min in the SR group (P<0.001). The anxiety scores were higher following the SR phase compared with those after the NS phase (P<0.01). After SR, there was a decrease in heat-pain threshold, but neither warm nor electrical thresholds were affected. Following SR, subjects showed higher SSR amplitudes and an increased number of double responses at an interstimulus interval of 2 s. We also observed a moderate inverse correlation between heat-pain thresholds and SSR amplitude (r= -0.46; P<0.01). However, there was no correlation between anxiety scores and SSR parameters. CONCLUSIONS: The effects of SR in the context of work stress on pain are specific and appear unrelated to general changes in sensory perception. Hyperalgesia was associated with abnormal autonomic responses, but not with increased anxiety, which suggests an association between the nociceptive and autonomic nervous systems that is independent of the emotional state.

Intermittent hyperglycemia due to autonomic nervous system dysfunction: a new feature in patients with congenital central hypoventilation syndrome.

OBJECTIVE: To analyze glycemic profile in children with congenital central hypoventilation syndrome, which is characterized by autonomic nervous system dysfunction. STUDY DESIGN: We carried out a university hospital-based observational study. Participants included 14 patients assessed from 2007 to 2009 with a median age of 7.6 (25th-75th percentiles, 1.5-9.6) years at the time of the study. Glucose metabolism was assessed by calculating 24-hour plasma glucose (before and after meals) and fasting insulin concentrations and carrying out an oral glucose tolerance test (OGTT). The main outcome measure was the proportion of patients with abnormal glucose concentrations. RESULTS: Abnormal plasma glucose concentrations were found in 6 (43%) of the 14 patients with high fasting (n = 1) or postprandial (n = 5) hyperglycemia. OGTT was performed in 8 patients, of whom 3 (38%) had impaired glucose tolerance. Indices of insulin resistance and secretion were normal. No difference in clinical aspects relating to the presence of affected organs and/or systems related to central nervous system dysfunction, age, or auxology findings was found between patients with normal (43%) and abnormal (57%) glucose homeostasis over a 24-hour glycemia cycle or OGTT. CONCLUSION: This study provides new information about glucose homeostasis in congenital central hypoventilation syndrome, revealing a high incidence of hyperglycemia and expanding the spectrum of the disease. It highlights the link between autonomic nervous system dysfunction and glycemic dysregulation. Regular, long-term monitoring of glucose metabolism is recommended in these patients.

Autonomic dysfunction in presymptomatic spinocerebellar ataxia type-2.

OBJECTIVES: To explore and quantify possible abnormalities in the autonomic cardiovascular regulation in presymptomatic stage of type 2 spinocerebellar ataxia (PS-SCA2). MATERIALS & METHODS: Heart rate variability (HRV) for 5-min series of RR intervals was analyzed in 48 PS-SCA2. Autonomic testing included resting recording, standing, Valsalva maneuver, and deep breathing. The results were compared with a group of sex- and age-matched controls. RESULTS: Time-and-frequency domain HRV indices were significantly different between PS-SCA2 and control groups. Using two standard diagnostic procedures were identified 4 (8.33%) subjects with severe and 8 (16.66%) subjects with early cardiac autonomic neuropathy in PS-SCA2. CAG index significantly correlated with age (-0.35) and HR (0.31). CONCLUSIONS: Our results confirm the presence of cardiovascular autonomic dysfunction in PS-SCA2 subjects.

Effects of long-term exercise training on autonomic control in myocardial infarction patients.

Autonomic dysfunction, including baroreceptor attenuation and sympathetic activation, has been reported in patients with myocardial infarction (MI) and has been associated with increased mortality. We tested the hypotheses that exercise training (ET) in post-MI patients would normalize arterial baroreflex sensitivity (BRS) and muscle sympathetic nerve activity (MSNA), and long-term ET would maintain the benefits in BRS and MSNA. Twenty-eight patients after 1 month of uncomplicated MI were randomly assigned to 2 groups, ET (MI-ET) and untrained. A normal control group was also studied. ET consisted of three 60-minute exercise sessions per week for 6 months. We evaluated MSNA (microneurography), blood pressure (automatic oscillometric method), heart rate (ECG), and spectral analysis of RR interval, systolic arterial pressure (SAP), and MSNA. Baroreflex gain of SAP-RR interval and SAP-MSNA were calculated using the α-index. At 3 to 5 days and 1 month after MI, MSNA and low-frequency SAP were significantly higher and BRS significantly lower in MI patients when compared with the normal control group. ET significantly decreased MSNA (bursts per 100 heartbeats) and the low-frequency component of SAP and significantly increased the low-frequency component of MSNA and BRS of the RR interval and MSNA. These changes were so marked that the differences between patients with MI and the normal control group were no longer observed after ET. MSNA and BRS in the MI-untrained group did not change from baseline over the same time period. ET normalizes BRS, low-frequency SAP, and MSNA in patients with MI. These improvements in autonomic control are maintained by long-term ET. These findings highlight the clinical importance of this nonpharmacological therapy based on ET in the long-term treatment of patients with MI.

Cyclophosphamide for rapid-onset obesity, hypothalamic dysfunction, hypoventilation, and autonomic dysregulation syndrome.

Patients with rapid-onset obesity, hypothalamic dysfunction, hypoventilation, autonomic dysregulation, and neural crest tumor syndrome have poor long-term outcomes. We report a patient who was treated successfully with high-dose cyclophosphamide immunoablation. This experience offers a novel therapeutic approach and an indirect insight into the underlying pathogenesis of this syndrome.

Exercise performance in adolescents with autonomic dysfunction.

OBJECTIVE: To test the hypothesis that excessive postural tachycardia is associated with deconditioning rather than merely being an independent sign of autonomic dysfunction in patients with postural orthostatic tachycardia syndrome (POTS). STUDY DESIGN: We retrospectively analyzed records from 202 adolescents who underwent both head up-tilt and maximal exercise testing. Patients were classified as POTS if they had ≥ 30 min(-1) rise in heart rate (HR) after tilt-table test; and deconditioned if peak O(2) uptake was < 80% predicted. Changes in HR during exercise and recovery were compared between groups. RESULTS: Two-thirds of patients were deconditioned, irrespective of whether they fulfilled diagnostic criteria for POTS, but peak O(2) uptake among patients with POTS was similar to patients without POTS. HR was higher at rest and during exercise; whereas stroke volume was lower during exercise, and HR recovery was slower in patients with POTS compared with patients without POTS. CONCLUSIONS: Most patients who presented with chronic symptoms of dizziness, fatigue, or pre-syncope, were deconditioned, but, because the proportion of deconditioned patients was similar in POTS vs non-POTS groups, we conclude that HR changes in POTS are not solely because of inactivity resulting in deconditioning.