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Background: There have been previous reports of enhanced sympathoexcitation in autism spectrum disorder (ASD). However, there has been no formal investigation of autonomic dysfunction in ASD. Also, the joint hypermobile form of Ehlers-Danlos syndrome (hE-DS) that maybe overrepresented in ASD and orthostatic related autonomic dysfunction. This study examined the comorbidity of ASD, autonomic dysfunction and hE-DS in two UK autonomic national referral centers. Proven, documented and globally accepted clinical autonomic investigations were used to assess neuro-cardiovascular autonomic function in a cohort of ASD subjects and in age-matched healthy controls. Methods: Clinical data from 28 referrals with a confirmed diagnosis of ASD over a 10-year period were compared with 19 age-matched healthy controls. Autonomic function was determined using methods established in the centers previously described in detail. Results: 20/28 ASD had a diagnosed autonomic condition; 9 had the postural tachycardia syndrome (PoTS), 4 PoTS and vasovagal syncope (VVS), 3 experienced presyncope, 1 essential hyperhidrosis, 1 orthostatic hypotension, 1 VVS alone and 1 a combination of PoTS, VVS and essential hyperhidrosis. 16/20 ASD with autonomic dysfunction had hE-DS. In ASD, basal heart rate and responses to orthostatic tests of autonomic function were elevated, supporting previous findings of increased sympathoexcitation. However, sympathetic vasoconstriction was impaired in ASD. Conclusion: Intermittent neuro-cardiovascular autonomic dysfunction affecting heart rate and blood pressure was over-represented in ASD. There is a strong association with hE-DS. Autonomic dysfunction may further impair quality of life in ASD, particularly in those unable to adequately express their experience of autonomic symptoms. [ABSTRACT FROM AUTHOR]

Non-motor symptoms are now commonly recognized in Parkinson's disease (PD) and can include dysautonomia. Impairment of cardiovascular autonomic function can occur at any stage of PD but is typically prevalent in advanced stages or related to (anti-Parkinsonian) drugs and can result in atypical blood pressure (BP) readings and related symptoms such as orthostatic hypotension (OH) and supine hypertension. OH is usually diagnosed with a head-up-tilt test (HUT) or an (active) standing test (also known as Schellong test) in the laboratory, but 24 h ambulatory blood pressure monitoring (ABPM) in a home setting may have several advantages, such as providing an overview of symptoms in daily life alongside pathophysiology as well as assessment of treatment interventions. This, however, is only possible if ABPM is administrated correctly and an autonomic protocol (including a diary) is followed which will be discussed in this review. A 24-h ABPM does not only allow the detection of OH, if it is present, but also the assessment of cardiovascular autonomic dysfunction during and after various daily stimuli, such as postprandial and alcohol dependent hypotension, as well as exercise and drug induced hypotension. Furthermore, information about the circadian rhythm of BP and heart rate (HR) can be obtained and establish whether or not a patient has a fall of BP at night (i.e., "dipper" vs. non-"dipper"). The information about nocturnal BP may also allow the investigation or detection of disorders such as sleep dysfunction, nocturnal movement disorders, and obstructive sleep apnea, which are common in PD. Additionally, a 24-h ABPM should be conducted to examine the effectiveness of OH therapy. This review will outline the methodology of 24 h ABPM in PD, summarize findings of such studies in PD, and briefly consider common daily stimuli that might affect 24 h ABPM. [ABSTRACT FROM AUTHOR]

Postural tachycardia syndrome (POTS) is a poorly understood but important cause of orthostatic intolerance resulting from cardiovascular autonomic dysfunction. PoTS is distinct from the syndromes of autonomic failure usually associated with orthostatic hypotension, such as pure autonomic failure and multiple system atrophy. Individuals affected by PoTS are mainly young (aged between 15 years and 40 years) and predominantly female. The symptoms--palpitations, dizziness and occasionally syncope--mainly occur when the patient is standing upright, and are often relieved by sitting or lying flat. Common stimuli in daily life, such as modest exertion, food ingestion and heat, are now recognized to be capable of exacerbating the symptoms. Onset of the syndrome can be linked to infection, trauma, surgery or stress. PoTS can be associated with various other disorders; in particular, joint hypermobility syndrome (also known as Ehlers- Danios syndrome hypermobility type, formerly termed Ehlers-Danlos syndrome type III). This Review describes the characteristics and neuroepidemiology of POTS, and outlines possible pathophysiological mechanisms of this syndrome, as well as current and investigational treatments. [ABSTRACT FROM AUTHOR]

We present a preliminary report of the discussion of the joint committee of the American Spinal Injury Association (ASIA) and the International Spinal Cord Society concerning the development of assessment criteria for general autonomic function testing following spinal cord injury (SCI). Elements of this report were presented at the 2005 annual meeting of the ASIA. To improve the evaluation of neurological function in individuals with SCI and therefore better assess the effects of therapeutic interventions in the future, we are proposing a comprehensive set of definitions of general autonomic nervous system dysfunction following SCI that should be assessed by clinicians. Presently the committee recommends the recognition and assessment of the following conditions: neurogenic shock, cardiac dysrhythmias, orthostatic hypotension, autonomic dysreflexia, temperature dysregulation, and hyperhidrosis. [ABSTRACT FROM AUTHOR]

Patients with syndromes of generalised autonomic failure often have extreme posture-related lability of blood pressure, with both orthostatic hypotension and recumbent hypertension. Whether these changes influence intraocular pressure (IOP) is not known. Mean arterial pressure (MAP) and IOP were measured in response to variations in posture between +45° and -20° in 8 normal subjects and 9 subjects with primary generalised chronic autonomic failure (AF). With postural change normal subjects showed minimal change in MAP (p=0.6) and small but significant changes in IOP (p < 0.001). Subjects with AF showed large and significant changes in both MAP (p < 0.001) and IOP (p < 0.001). Two AF subjects had raised IOP when recumbent, despite normal IOP at +45°. There was significant covariance of MAP and IOP (p < 0.001 overall, p=0.004 in normal subjects, p=0.006 in AF subjects). However, individually, those patients with large changes in IOP could not be predicted from changes in MAP. These data show that patients with autonomic failure are subject to large posture-related changes in IOP. These appear to be related to the large posture-induced changes in systemic blood pressure which occur in these patients. [ABSTRACT FROM AUTHOR]

Continuous haemodynamic responses to head-up tilt (HUT) and its reversal were studied in 21 subjects with sympathetic denervation due to primary chronic autonomic failure; 10 had pure autonomic failure (PAF; peripheral failure) and 11 had multiple system atrophy (MSA; central failure); 8 healthy subjects (controls) also were studied. Supine systolic, diastolic and mean arterial pressure (MAP) and total peripheral resistance (TPR) were highest in PAF. The MAP response to HUT and tilt reversal were different between groups. After HUT, MAP increased in controls (12±4 mmHg), but decreased in PAF and MSA (41±4 & 19±4 mmHg respectively); the fall in PAF was greater than in MSA. With tilt reversal, MAP returned promptly, but not entirely to pretilt levels in controls, with small (insignificant) overshoots in MSA and PAF. The TPR response to HUT and tilt reversal was different between groups. After HUT, TPR increased in controls (0.31±0.04 PRU), decreased in PAF (0.23±0.1 PRU) and was unchanged in MSA. With tilt reversal, TPR remained elevated (15 %) above baseline in the controls and rose in PAF (13 %) with no change in MSA. There were no differences in supine heart rate (HR), stroke volume (SV) or cardiac output (CO) between the three groups; HR, SV or CO responses to HUT or tilt reversal also did not differ between the groups. Thus, after HUT, MAP decreased, with greater hypotension induced in PAF than MSA. Since CO did not differ between groups, the decrease in TPR appears to account for the greater fall in BP in PAF than in MSA. The elevated TPR at rest pre-tilt and after tilt reversal probably contributed to supine hypertension in PAF. These haemodynamic observations may aid therapeutic strategies to reduce orthostatic hypotension and prevent supine hypertension. [ABSTRACT FROM AUTHOR]

Offers information about postural hypotension. Definition of postural hypotension; Causes of the condition; Clinical signs of postural hypotension; Pharmacological and nonpharmacological treatment.

Abstract: The autonomic nervous system closely integrates a range of vital processes, including, cardiovascular function. Physical activity, or exercise, requires a range of integrated autonomic and cardiovascular adjustments in order to maintain homeostasis. Pathological conditions that result in dysfunction of the autonomic nervous system, such as autonomic failure, can therefore jeopardize the control of blood pressure resulting in hypotension and have serious implications for health. Exercise induced hypotension, defined as a ≥10mmHg fall in systolic blood pressure during exercise, can be a significant symptom/event for autonomic failure, as well as other autonomic disorder, patients, including, Multiple System Atrophy and Spinal Cord Injury, and can reduce physical capacity, orthostatic tolerance, result in falls, complicate management and reduce quality of life. The likely mechanisms do not appear to be an altered cardiac output or active muscle vasodilation response to exercise, but rather, a lack of and/or a blunted increase in sympathetic nerve activity during exercise and/or excessive vasodilation in the splanchnic circulation. The severity of exercise induced hypotension seems to be higher during dynamic relative to static exercise. The possible management strategies for exercise induced hypotension include both non-pharmacological, e.g., reducing risk factors, and pharmacological measures, such as sympathomimetics, but studies on other pharmacological agents are limited. [Copyright &y& Elsevier]

Abstract: Aim: A previous study on a small number of patients showed that low skin temperature of the hands, the so called “cold hands sign”, may be useful for distinguishing multiple system atrophy (MSA) from Parkinson''s disease (PD). We have further investigated skin temperature of the hand in a larger number of patients. Methods: Skin temperature on the palm was measured in 50 MSA (11 MSA-P and 39 MSA-C patients) and 50 PD patients, and 25 normal healthy subjects. Results: Palm skin temperature was significantly lower in MSA patients (32.0 ± 2.7 °C) than in controls (34.1 ± 0.9 °C, p = 0.0002), but was not different compared with the PD group (32.9 ± 1.8 °C, p = 0.06). Temperatures of <28 °C were observed in 3 MSA patients (6%) and none of the PD patients and controls. There was no significant difference in palm skin temperature between patients with and without orthostatic hypotension for each patient group, or between MSA-P and MSA-C patients. Conclusion: The cold hand (<28 °C) is a useful marker for distinguishing MSA from PD, but it is not common in MSA patients, and its sensitivity may be low for differentiating between MSA and PD. [Copyright &y& Elsevier]

Aim: To clarify the characteristics of hemodynamic responses to exercise and orthostasis in Parkinson's disease patients, especially those with autonomic failure. Methods: Clinical audit of supine cycling exercise test data (with active standing tests pre- and post-exercise) of Parkinson's patients with autonomic dysfunction. 23 patients (71 ± 7 yr, 7 females) with a confirmed diagnosis of Parkinson's were identified. Results: Group mean systolic blood pressure (SBP) fell during pre-exercise standing (−39 ± 29 mmHg, P < 0.001, 17 patients had orthostatic hypotension (OH)), while heart rate (HR) increased (+13 ± 7 beats min−1, P < 0.001). SBP (P < 0.001) increased during exercise with a wide variation in responses. SBP increased in 13 patients (INC; +30 ± 14 mmHg) and either did not change or decreased in 10 patients (DEC −12 ± 11 mmHg, P < 0.001 vs INC). The increase in HR was not different between sub-groups (30 ± 12 vs 25 ± 10 beats min−1, INC vs. DEC, P = 0.29). The size of the pre-exercise stand SBP reduction was greater in DEC vs INC (−64 ± 23 (10 out of 10 had OH) vs −19 ± 16 mmHg (7 out of 13 had OH), respectively, P < 0.001). The HR elevation was not different between sub-groups (13 ± 8 vs 13 ± 4 beats min−1, DEC vs INC, P = 0.94). Post-exercise SBP/DBP were lower for both sub-groups compared to pre-exercise and the standing SBP reduction post-exercise was not greater relative to pre-exercise in either sub-group. Conclusion: Exercise-induced hypotension can occur in Parkinson's disease patients with autonomic failure with the magnitude of the exercise response being related to the severity of autonomic dysfunction. Exercise does not appear to worsen OH in this sample of Parkinson's patients. [ABSTRACT FROM AUTHOR]

Abstract: Post-mortem studies of multiple system atrophy (MSA) patients have shown widespread subcortical neurodegeneration. In this study, we have used 18F-dopa PET, a marker of monoaminergic nerve terminal function, to explore in vivo changes in striatal and extrastriatal dopamine, noradrenaline, and serotonin transmission for a cohort of patients with MSA with predominant parkinsonism. Fourteen patients with MSA, ten patients with idiopathic Parkinson''s disease (PD) matched for disease duration, and ten healthy controls were studied with 18F-dopa PET. Regions of interest (ROIs) were placed to sample 18F-dopa uptake in thirteen structures and mean activity was compared between groups. The MSA patients showed significantly decreased 18F-dopa uptake in putamen, caudate nucleus, ventral striatum, globus pallidus externa and red nucleus compared to controls, whereas PD patients only had decreased 18F-dopa uptake in putamen, caudate nucleus, and ventral striatum. MSA cases with orthostatic hypotension had lower 18F-dopa uptake in the locus coeruleus than patients without this symptom. In conclusion, 18F-dopa PET showed more widespread basal ganglia dysfunction in MSA than in PD with similar disease duration, and extrastriatal loss of monoaminergic innervation could be detected in the red nucleus and locus coeruleus. In contrast to PD, there was no evidence of early compensatory increases in regional 18F-dopa uptake. [Copyright &y& Elsevier]

Abstract: In Parkinsons disease and multiple system atrophy (MSA), cardiovascular dysfunction may occur for a variety of reasons and may manifest itself through inappropriate changes and/or levels in blood pressure, heart rate and/or regional vascular perfusion in a range of situations. The early occurrence of orthostatic hypotension often leads to consideration of MSA, especially in the presence of other features of autonomic failure. Orthostatic hypotension, however, is increasingly recognised in PD, and especially with increasing age, severity of disease and as a result of drug therapy, sometimes for associated disorders. Investigation of cardiovascular autonomic dysfunction in Parkinsonism is therefore important for a variety of reasons, that include determining the precise diagnosis and in predicting prognosis. In Parkinsonian disorders, understanding the pathophysiological basis of the cardiovascular autonomic dysfunction aids targeting of therapy, improves management strategies and provides benefit for such patients. [Copyright &y& Elsevier]