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-Danlos 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.

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Parkinson's disease (PD) is a progressive neurodegenerative disorder characterised by motor dysfunction ( parkinsonism) and several non-motor features. Dysautonomia is a significant non-motor feature as well as a neuropsychiatric symptom. Autonomic dysfunction can occur even in the early stages of PD, often preceding the onset of the classic motor symptoms of PD. The patterns of autonomic features in PD are different from other parkinsonian disorders. Detection of autonomic dysfunction may therefore be helpful in diagnosing PD in the early or pre-motor stages, and/or in differentiating it from other parkinsonian disorders, such as multiple system atrophy and progressive supuranuclear palsy. The aim of this review is to describe aspects of autonomic dysfunction, including symptoms, assessment and pathophysiology, resulting from autonomic impairment in PD and other parkinsonian syndromes.

Background Neurologic and autonomic presentation in multiple system atrophy (MSA) may predict early mortality. Quantification of early autonomic failure as mortality predictor is lacking. Methods Early neurologic and autonomic clinical features were retrospectively reviewed in 49 MSA cases (median age at onset, 56.1 years; 16 women) confirmed by autopsy at Mayo Clinic. When available, the 10-point composite autonomic severity score derived from the autonomic reflex screen provided quantification of the degree of autonomic failure and thermoregulatory sweat test quantitated body surface anhidrosis. Results Symptoms at onset were autonomic in 50%, parkinsonian in 30%, and cerebellar in 20% of cases. Survival (median [95% confidence interval]) was 8.6 [6.7–10.2] years. Survival was shorter in patients with early laboratory evidence of generalized (composite autonomic severity score ≥ 6) autonomic failure (7.0 [3.9–9.8] vs. 9.8 [4.6–13.8] years; P=0.036), and early requirement of bladder catheterization (7.3 [3.1–10.2] vs. 13.7 [8.5–14.9] years; P=0.003) compared to those without these clinical features. On Cox proportional analysis, prognostic indicators of shorter survival were older age at onset (hazard ratio [95% confidence interval], 1.04 [1.01–1.08]; P=0.03), early requirement of bladder catheterization (7.9 [1.88–38.63]; P=0.004) and early generalized (composite autonomic severity score ≥ 6) autonomic failure (2.8 [1.01–9.26]; P=0.047). Gender, phenotype, and early development of gait instability, aid-requiring ambulation, orthostatic symptoms, neurogenic bladder or significant anhidrosis (thermoregulatory sweat test ≥ 40%) were not indicators of shorter survival. Conclusions Our data suggests that early development of severe generalized autonomic failure more than triples the risk of shorter survival in patients with MSA.

Background Multiple system atrophy (MSA) is a sporadic progressive neurodegenerative disorder characterised by autonomic failure, manifested as orthostatic hypotension or urogenital dysfunction, with combinations of parkinsonism that is poorly responsive to levodopa, cerebellar ataxia and corticospinal dysfunction. Published autopsy confirmed cases have provided reasonable neurological characterisation but have lacked adequate autonomic function testing. Objectives To retrospectively evaluate if the autonomic characterisation of MSA is accurate in autopsy confirmed MSA and if consensus criteria are validated by autopsy confirmation. Methods 29 autopsy confirmed cases of MSA evaluated at the Mayo Clinic who had undergone formalised autonomic testing, including adrenergic, sudomotor and cardiovagal functions and Thermoregulatory Sweat Test (TST), from which the Composite Autonomic Severity Score (CASS) was derived, were included in the study. Results Patient characteristics: 17 men, 12 women; age of onset 57±8.1 years; disease duration to death 6.5±3.3 years; first symptom autonomic in 18, parkinsonism in seven and cerebellar in two. Clinical phenotype at first visit was MSA-P (predominant parkinsonism) in 18, MSA-C (predominant cerebellar involvement) in eight, pure autonomic failure in two and Parkinson’s disease in one. Clinical diagnosis at last visit was MSA for 28 cases. Autonomic failure was severe: CASS was 7.2±2.3 (maximum 10). TST% was 65.6±33.9% and exceeded 30% in 82% of patients. The most common pattern was global anhidrosis. Norepinephrine was normal supine (203.6±112.7) but orthostatic increment of 33.5±23.2% was reduced. Four clinical features (rapid progression, early postural instability, poor levodopa responsiveness and symmetric involvement) were common. Conclusion The pattern of severe and progressive generalised autonomic failure with severe adrenergic and sudomotor failure combined with the clinical phenotype is highly predictive of MSA.

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Objective: To evaluate the efficacy of immunotherapy in the treatment of patients with seropositive and seronegative putative autoimmune autonomic ganglionopathy (AAG) using validated autonomic function tests and instruments.

Objective: To prospectively evaluate patients who met standard criteria for postural tachycardia syndrome (POTS), at baseline and 1-year follow-up, using standard clinical and laboratory methods to assess autonomic function. Methods: Fifty-eight patients met the study criteria (orthostatic symptoms and a heart rate increment of Ն30 beats/min on head-up tilt) and completed 12 months of follow-up. All patients were enrolled and completed the study from January 16, 200616, , through April 15, 2009. Patients underwent standardized autonomic testing, including head-up tilt, clinical assessment, and validated questionnaires designed to determine the severity of autonomic symptoms. Results: Patients were predominantly young females (nϭ49, 84%), with 20 patients (34%) reporting an antecedent viral infection before onset of symptoms. More than one-third (37%) no longer fulfilled tilt criteria for POTS on follow-up, although heart rate increment on head-up tilt did not differ significantly at 1 year (33.8Ϯ15.1 beats/min) compared with baseline (37.8Ϯ14.6 beats/min) for the entire cohort. Orthostatic symptoms improved in most patients. Autonomic dysfunction was mild as defined by a Composite Autonomic Severity Score of 3 or less in 55 patients (95%) at baseline and 48 patients (92%) at 1 year. Conclusion: To our knowledge, this is the first prospective study of the clinical outcomes of patients with POTS. Orthostatic symptoms improved in our patients, with more than one-third of patients no longer fulfilling tilt criteria for POTS, although the overall group change in heart rate increment was modest. Our data are in keeping with a relatively favorable prognosis in most patients with POTS. P ostural tachycardia syndrome (POTS) is defined by symptoms of orthostatic intolerance associated with heart rate increments greater than 30 beats/min on head-up tilt (HUT), with the more severe cases reaching standing heart rates of greater than 120 beats/min.1 Symptoms related to orthostatic changes most often include light-headedness, palpitations, presyncope, and symptom exacerbations caused by heat or exercise.2 The disorder begins primarily between 15 and 50 years of age (with a mean age at onset of 30 years) and is characterized by a strong female predominance. 1-5The pathophysiologic and etiologic mechanisms of POTS are heterogeneous in nature. Several important subtypes of primary POTS have been described. Neuropathic POTS describes a subgroup with length-dependent denervation of sympathetic fibers in the lower extremity. 6 In keeping with this denervation, these patients have impaired norepinephrine spillover, resulting in isolation to the legs. Approximately half of patients diagnosed as having primary POTS manifest this restricted autonomic neuropathy pattern.2,7 A second hyperadrenergic subtype has been defined by increased systolic blood pressure during HUT (Ն10 mm Hg) and an elevated plasma norepinephrine level (Ն600 pg/mL [to convert to pmol/L, multiply by 5.911]).8 These patients have episodes of tachycardia and...