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PubMed1995

[Familial amyloidotic polyneuropathy (FAP) type I and the therapies].

Since autonomic dysfunction in familial amyloidotic polyneuropathy (FAP) Type I is recognized in the early stage of FAP patients and restricts their daily life, we developed various therapies for various autonomic manifestations: Loading glucose was often effective for faintness caused by hypoglycemia and erythropoietin was also good therapy for orthostatic hypotension as well as anemia found in the end stage of FAP patients. Stoma and nasal drop of L-threo-DOPS were useful to control diarrhea and orthostatic hypotension. Duplex ultrasonography of the 4 vessels revealed that reverse flow was always recognized in FAP patients with faintness, which was effectively treated by the administration of L-threo-DOPS. Orthotopic liver transplantation revealed effective therapy for autonomic dysfunction in FAP patients. Precise analysis of protein metabolism in FAP patients revealed that among apolipoproteins, only apolipoprotein AII decreased as the progression of the disease and high density lipoprotein gained the negative charge by agarose electrophoresis study. Concerning low density lipoprotein (LDL) study, only variant transthyretin in the circulation associated with LDL in FAP patients, suggesting that LDL may play an important role in the amyloid formation of FAP.

Amyloid Neuropathies↗
PubMed1993

Autonomic function in hypertrophic cardiomyopathy.

BACKGROUND: Autonomic dysfunction has been found to be a powerful predictor of arrhythmic events and sudden death after myocardial infarction. Hypertrophic cardiomyopathy carries a risk of sudden death and this risk is increased by the occurrence of syncope. OBJECTIVES: To determine if autonomic dysfunction occurs in patients with hypertrophic cardiomyopathy and if it is associated with the occurrence of syncope. PATIENTS AND METHODS: Autonomic function was measured in 30 patients with hypertrophic cardiomyopathy, 15 with and 15 without a history of syncope, and in 28 healthy volunteers. RESULTS: Tests of parasympathetic activity showed that the mean (SD) variation in heart rate during deep breathing was reduced in patients compared with controls, 17 (9) v 22 (9) beats/min, p = 0.03, the Valsalva ratio was also reduced in patients, 1.52 (0.33) v 1.70 (0.36), p = 0.05 but the immediate heart rate response to standing, the 30:15 ratio, was similar in both groups. Tests of sympathetic activity--namely the diastolic blood pressure response to sustained handgrip and the change in systolic blood pressure on standing--did not differ between patients and controls. There was no significant difference in autonomic function between patients with and without a history of syncope. A secondary predetermined analysis showed that the degree of impairment in variation of heart rate with breathing was correlated with the severity of left ventricular hypertrophy, r = 0.39, p = 0.03. CONCLUSIONS: Patients with hypertrophic cardiomyopathy have a selective impairment of variability of heart rate with deep breathing and the Valsalva manoeuvre indicating decreased cardiac parasympathetic activity. The data suggest that the afferent limb of these reflexes is impaired and that the severity of impairment is related to the degree of left ventricular hypertrophy.

Adolescent↗
PubMed1989

Autonomic function and the sinus tachycardia of Duchenne muscular dystrophy.

The cardiovascular autonomic function of 13 boys with Duchenne muscular dystrophy was examined in order to test the hypothesis that the labile sinus tachycardia of that disorder is due to autonomic dysfunction. Five non-invasive procedures evaluated the responses of heart rate and blood pressure to postural change, the Valsalva maneuver, sustained hand grip and deep breathing. No individual had sufficient evidence of autonomic dysfunction. Most tests were normal (76%), 16% were borderline, and 8% were abnormal. None had more than one abnormal test. Although most had some difficulty with the Valsalva maneuver, the study demonstrated that simple clinical non-invasive testing of autonomic function can be carried out on a young severely handicapped population.

Adolescent↗
PubMed2000

Heart rate variability and autonomic diabetic neuropathy.

Aim of this paper is to briefly summarize available evidence about potential usefulness of heart rate variability (HRV) analysis for the clinical evaluation of autonomic diabetic neuropathy. HRV contains hidden information that can be extracted from tachogram sections of several hundred beats with spectral analysis. Subsequent normalization and the use of a paradigm including standardized stimuli (such as tilt) are commonly employed to assess autonomic cardiac regulation. In the resulting spectra, two major components of similar amplitude are usually observed (at low--LF--and high frequency--HF), their relative power is best appreciated using normalized units that provide an estimate of the balance between sympathetic and vagal modulatory activity. In states of sympathetic predominance, such as during orthostatic positions, LF increases and HF decreases. In diabetics, consistent alterations in spectral properties are a frequent early finding: initially a reduction of HRV (ie spectral power) is followed by progressive functional denervation, which is associated to severe autonomic dysfunction. The spectral methodology provides some useful potential advantages in respect to the more traditional approach employing several simple bedside tests. In conclusion, spectral analysis of HRV appears a convenient method to assess various degrees of diabetic autonomic dysfunction: it appears easy to perform, while giving results similar to traditional methods, with greater sensibility.

Autonomic Nervous System Diseases↗
PubMed1983

Congenital dysautonomia with secretory diarrhea.

A 1-year-old boy was evaluated because of failure-to-thrive and persistent diarrhea. His illness was characterized by autonomic dysfunction sharing some features of both familial dysautonomia and congenital sensory neuropathy with anhidrosis, but was consistent with neither diagnosis. The gastrointestinal tract was involved: esophageal motility was abnormal and moderate secretory diarrhea was present. This report documents an unusual case of congenital autonomic dysfunction with secretory diarrhea.

Autonomic Nervous System Diseases↗
PubMed2001

Estrogen-induced recovery of autonomic function after middle cerebral artery occlusion in male rats.

Several studies have provided evidence to suggest that estrogen results in a significant reduction (approximately 50%) in the size of the ischemic zone in the middle cerebral artery occlusion (MCAO) model of stroke in a rat. The current study was done to demonstrate whether this estrogen-induced reduction in infarct size is associated with normalization of the autonomic dysfunction observed in an acute model of stroke in male rats. Experiments were done in anesthetized (thiobutabarbitol sodium; 100 mg/kg) male Sprague-Dawley rats instrumented to record baseline and reflex changes in cardiovascular and autonomic parameters. Estrogen was intravenously administered 30 min before, immediately before, or 30 min after MCAO. Estrogen administration resulted in a recovery of autonomic function and prevented the detrimental changes in autonomic tone observed following a stroke. In addition, infarct size was significantly increased in the presence of the estrogen antagonist ICI-182,780. These results suggest that both pre- or poststroke estrogen administration prevents or reverses acute stroke-induced autonomic dysfunction and that endogenous estrogen levels in males can contribute to this neuroprotection.

Animals↗
PubMed1997

Long-term results of liver transplantation in familial amyloidotic polyneuropathy type I.

BACKGROUND: The aim of this article is to report our experience regarding the survival and the evolution of polyneuropathy of the extremities and autonomic dysfunction in 18 liver transplant patients with familial amyloidotic polyneuropathy type I after a mean follow-up of more than 2.5 years for 13 patients. METHODS: The actuarial survival rate of the 18 patients is 72.2% and 60.1%, respectively, at 12 and 58 months. RESULTS: In all the patients we noted clinical improvement of the polyneuropathy of the extremities and autonomic dysfunction during the first 6 months after transplant. The clinical data due to autonomic nervous system involvement showed an earlier improvement than those due to nervous motor involvement. CONCLUSIONS: In conclusion, our results suggest that liver transplant may be useful in the treatment of certain cases of familial amyloidotic polyneuropathy to stop the neurological deterioration of the patients and to avoid the fatal end of the disease.

Adult↗
PubMed2002

Progression and prognosis in multiple system atrophy: an analysis of 230 Japanese patients.

We investigated the disease progression and survival in 230 Japanese patients with multiple system atrophy (MSA; 131 men, 99 women; 208 probable MSA, 22 definite; mean age at onset, 55.4 years). Cerebellar dysfunction (multiple system atrophy-cerebellar; MSA-C) predominated in 155 patients, and parkinsonism (multiple system atrophy-parkinsonian; MSA-P) in 75. The median time from initial symptom to combined motor and autonomic dysfunction was 2 years (range 1-10). Median intervals from onset to aid-requiring walking, confinement to a wheelchair, a bedridden state and death were 3, 5, 8 and 9 years, respectively. Patients manifesting combined motor and autonomic involvement within 3 years of onset had a significantly increased risk of not only developing advanced disease stage but also shorter survival (P < 0.01). MSA-P patients had more rapid functional deterioration than MSA-C patients (aid-requiring walking, P = 0.03; confinement to a wheelchair, P < 0.01; bedridden state, P < 0.01), but showed similar survival. Onset in older individuals showed increased risk of confinement to a wheelchair (P < 0.05), bedridden state (P = 0.03) and death (P < 0.01). Patients initially complaining of motor symptoms had accelerated risk of aid-requiring walking (P < 0.01) and confinement to a wheelchair (P < 0.01) compared with those initially complaining of autonomic symptoms, while the time until confinement to a bedridden state and survival were no worse. Gender was not associated with differences in worsening of function or survival. On MRI, a hyperintense rim at the lateral edge of the dorsolateral putamen was seen in 34.5% of cases, and a 'hot cross bun' sign in the pontine basis (PB) in 63.3%. These putaminal and pontine abnormalities became more prominent as MSA-P and MSA-C features advanced. The atrophy of the cerebellar vermis and PB showed a significant correlation particularly with the interval following the appearance of cerebellar symptoms in MSA-C (r = 0.71, P < 0.01, r = 0.76 and P < 0.01, respectively), but the relationship between atrophy and functional status was highly variable among the individuals, suggesting that other factors influenced the functional deterioration. Atrophy of the corpus callosum was seen in a subpopulation of MSA, suggesting hemispheric involvement in a subgroup of MSA patients. The present study suggested that many factors are involved in the progression of MSA but, most importantly, the interval from initial symptom to combined motor and autonomic dysfunction can predict functional deterioration and survival in MSA.

Activities of Daily Living↗
PubMed2006

Effects of exercise training on heart rate variability after coronary angioplasty.

BACKGROUND AND PURPOSE: Cardiac autonomic dysfunction is associated with risk of restenosis and cardiovascular mortality in patients after percutaneous transluminal coronary angioplasty (PTCA). Analysis of heart rate variability (HRV) is an important, widely used method for assessing cardiac autonomic regulation. The purpose of this study was to investigate the effect of exercise training on HRV in subjects after PTCA. SUBJECTS AND METHODS: A total of 84 subjects who had undergone PTCA were recruited for this study. The subjects (age [mean+/-SD]=57.0+/-9.3 years) were randomly assigned to either an exercise group to undergo an 8-week outpatient exercise program or a control group to undergo usual care. Heart rate variability was measured for 5 minutes in the supine resting position at baseline and at the end of 8 weeks. RESULTS: The parasympathetically modulated HRV of the subjects in the exercise group increased significantly compared with the HRV of subjects in the control group. The effects of training on HRV were independent of angioplasty type (balloon or stent) and were unrelated to whether the subjects had received previous PTCA. DISCUSSION AND CONCLUSION: Exercise training can increase parasympathetic modulation of cardiac function in people after they have undergone successful PTCA. Our results suggest that analysis of HRV can be extended to assess the effect of exercise training on cardiac autonomic dysfunction in people after coronary angioplasty.

Aged↗
PubMed1992

Clinical assessment of respiratory sinus arrhythmia by computerized analysis of RR interval and respiration.

Heart rate variability (HRV) and respiratory sinus arrhythmia (RSA) are often considered as interchangeable terms. However, the application of power spectral analysis to describe spontaneous fluctuations in heart period has clearly shown that RSA is only a part of HRV, and that in specific situations their respective patterns may diverge. In order to quantify the RSA we have used a mathematical method based on combined spectral analysis of respiration and RR interval (cross-correlation function), and evaluated its performance in terms of reproducibility, sensitivity to parasympathetic withdrawal and in clinical evaluation of autonomic function. Compared to other indices of HRV the cross-correlation between RR interval and respiration showed a greater sensitivity to parasympathetic withdrawal, better reproducibility and a high sensitivity in detecting autonomic dysfunction in diabetic patients. These findings suggest that specific indices of RSA, such as the cross-correlation, can be a valid tool for the diagnostic approach to cardiac autonomic dysfunction.

Arrhythmia, Sinus↗
PubMed1999

Cardiovascular autonomic neuropathy in HIV infected patients.

OBJECTIVE: To evaluate the presence and extent of autonomic dysfunction in HIV infected individuals of one ethnic group. DESIGN: Prospective, age-sex matched study. METHODS: 25 patients (seven asymptomatic (HIV), eight AIDS related complex (ARC), 10 AIDS) and 25 controls were recruited from patients and staff at the Aga Khan Hospital, Nairobi. Autonomic function was assessed by measurement of pulse rate variability on standing, rest, deep breathing, Valsalva manoeuvre, isometric exercise, cold face test, and mental stress. Blood pressure was measured during standing, supine resting, and on Valsalva manoeuvre. CD4 count was correlated with number of abnormal test results. RESULTS: 21 patients had at least one abnormal test of autonomic function compared with one control (p < 0.0001). There were significant differences between AIDS patients and controls for supine heart rate (p < 0.001), Valsalva ratio (p = 0.05), and cold face test (p = 0.05), and almost significant results for mental stress (p = 0.051). Evidence of autonomic hypersensitivity was found in response to exercise and/or mental stress in some patients with HIV or ARC. No difference was found in blood pressure measurements. Abnormalities in autonomic function occurred at all CD4 counts and all patients with four abnormal tests of heart rate variation had a CD4 count less than 300 x 10(6)/l. CONCLUSIONS: There is evidence of substantial autonomic dysfunction in AIDS patients compared with controls and mild abnormalities in the majority of HIV infected patients studied irrespective of CD4 count. Autonomic hypersensitivity may precede loss of function in some cases.

AIDS-Related Complex↗
PubMed2006

Sudden infant death syndrome: selenium administered above dietary needs stabilizes the electrocardiograms of subjects deprived of exercise stimuli to the brain.

The human foetus begins preparation for extrauterine life in the 26th week of gestation. Victims of sudden infant death syndrome (SIDS) were described as having less-intensive reactions to environmental stimuli than their siblings. They were described as less-active physically and more breathless and exhausted during feeding. These foetal-like qualities are similar to the microgravity deconditioning of the space traveller and the autonomic dysfunction of hypokinetic humans. During quiet sleep, a group of near-miss SIDS victims displayed a faster heart-rate and a decreased movement-time, compared to controls. Another group of SIDS victims linked delayed repolarisation and sympathetic overactivity of the nervous system. The excessive Q-T wave intervals, cardiac instability and autonomic dysfunction tended to coincide with the peak incidence of SIDS which is the normal period of autonomic transformation at 2-3 months of age. Sympathetic hyperactivity transforms the subject into an energy-intensive species with an accelerated heartbeat, intensive vasoconstriction and general reactions to a hostile environment. Energy-intensive species (flight-oriented species) were sensitive to selenium (Se) deficiency. Altered mitochondrial structure and defective electron transport of heart mitochondria were features of this syndrome. Runaway excessive sympathetic autonomic activity transforms the subject into an energy-intensive species responsive to selenium. Groups of Se-deficient lambs confined for eight weeks developed abnormal electrocardiograms (ECGs). Groups exercised daily on a treadmill or Se-supplemented groups retained virtually normal ECGs. Foetuses and subjects unreactive to the environment are space travellers lacking parasympathetic stimuli to the brain. Decreased movement-time deprives the brain receptors of the stimulus induced by gravity.

Brain↗
PubMedDate not supplied

Bedside diagnosis of cardiac autonomic damage by computerized analysis of heart rate-respiration relationship.

In this study we propose a method for the analysis of the relationship between heart rate changes and respiration as a possible diagnostic tool for cardiac autonomic damage. The method consists in recording R-R intervals and respiratory amplitude by a suitably equipped personal computer, and by evaluating the cross-correlation peak between the two signals. This mathematical function appeared to be more sensitive to the degree of concordance between the two signals, rather than their absolute amplitude. The cross-correlation appeared to be lower in diabetics with autonomic dysfunction, markedly decreased after injection of atropine (only in normals), slightly increased after propranolol. Hyperpnea increased the cross-correlation peak between 3-18 breaths/min in normals, but only at lower frequencies, if at all, in diabetic subjects with various degrees of autonomic dysfunction. The cross-correlation showed the best reproducibility among R-R change tests. These preliminary results suggest that this method may provide new information on autonomic integrity and a substantial advantage in terms of reproducibility.

Adult↗
PubMed1984

Neural mechanisms in cardiac arrhythmias associated with epileptogenic activity: the effect of phenobarbital in the cat.

Sudden unexplained death accounts for 5-17% of mortality in epileptic persons; autonomic dysfunction is thought to be a contributing factor. This paper describes the effect of phenobarbital (PB) pretreatment (20 mg/kg, i.v.) one hour prior to pentylenetetrazol (PTZ) 10, 20, 50, 100, 200, and 2000 mg/kg, i.v. given at ten minute intervals on autonomic parameters in the cat. PB depressed heart rate, blood pressure, and postganglionic cardiac sympathetic neural discharge, but did not significantly alter vagal discharge. PB shifted the peak duration of interictal activity from a lower to a higher dose of PTZ without affecting the average duration across doses. PB also significantly diminished the increases in heart rate and blood pressure induced by PTZ but altered neither the occurrence of arrhythmias nor the changes in cardiac autonomic neural discharge. Thus, PB appears to prevent only some forms of autonomic dysfunction associated with epileptogenic activity in this model.

Animals↗
PubMed1995

Autonomic nerve dysfunction in patients with bolus-specific esophageal dysmotility.

The pathogenetic mechanisms causing esophageal dysmotility is not well understood. We examined 13 patients with solid bolus dysphagia in a radiologic barium study including the swallowing of a 14-mm tablet. In all 13 patients the tablet was caught in the proximal or midesophagus. In 8 patients, the entrapment was associated with symptoms (Group 1) whereas in 5 patients (Group 2), no symptoms were reported. All 13 patients together with a control group of 56 healthy, nondysphagic subjects were tested for autonomic nerve function. Autonomic nerve function tests included registration of electrocardiographic R-R interval variation during deep breathing test (E/I ratio), a test of parasympathetic, vagal, nerve function. The results showed that the E/I ratio was significantly lower in patients with symptoms of bolus-specific esophageal dysmotility (-2,19 [1.76]) (median [interquartile range]) compared with patients without symptoms (0.05 [2, 87], p = 0.0192) and controls (-0.25 [1.26], p = 0.0009). In conclusion, symptomatic bolus-specific esophageal dysmotility is associated with vagal nerve dysfunction.

Adolescent↗
PubMed2004

[Reversible MRI findings of posterior column of the spinal cord in a patient with acute autonomic and sensory neuropathy].

We report serial spinal MRI T2 findings in a patient with acute autonomic and sensory neuropathy (AASN). A 20-year-old woman was admitted to our hospital with progressive sensory disturbance in her extremities and orthostatic syncope after her symptoms of upper respiratory infection. Neurological examination demonstrated reduced tendon reflexes, hypalgesia, paresthesia, reduced position sensation in distal dominant extremities (predominant in lower legs) and wide variety of autonomic dysfunction (severe orthostatic hypotension, anhidrosis, urinary disturbance, coughing attack, constipation and appetite loss). She was diagnosed as having AASN. Although high dose intravenous immunoglobulin therapy successfully prevented the symptom progression, her sensory disturbance and autonomic dysfunction were prolonged and showed only slow improvement. Spinal MRI on acute phase was normal. On chronic phase (11 month after the onset), spinal MRI T2 weighted images demonstrated high intensity lesion in the posterior column successive from upper cervical to lower thoracic spinal cord. Those abnormal findings were attenuated in concordance with her symptom improvement and finally disappeared when she became to walk stably without assist.

Acute Disease↗
PubMed2001

Acute hypothalamic instability in traumatic brain injury: a case report.

. Acute hypothalamic instability occurs in patients with traumatic brain injury (TBI). It usually occurs in the form of autonomic dysfunction syndrome (also known as diencephalic seizures or paroxysmal sympathetic storms); however, there are other causes of acute hypothalamic instability of which the clinician must be aware. Neuroleptic malignant syndrome, malignant hyperthermia, autonomic dysfunction syndrome, and lethal catatonia are all syndromes that clinically present as signs and symptoms of acute hypothalamic instability. Because of the lethal potential of these syndromes, clinicians who care for patients with TBI must be aware of the various syndromes, their clinical presentation, and their treatment. We present a case of life-threatening acute hypothalamic instability in a patient with TBI.

Accidents, Traffic↗