Autonomic involvement in extrapyramidal and cerebellar disorders

Autonomic dysfunction in progressive supranuclear palsy

BACKGROUND

The degree of involvement of the autonomic nervous system in progressive supranuclear palsy (PSP) has been investigated in several studies, often providing conflicting results. There is a need for a better characterization of autonomic dysfunction in PSP, to enhance our understanding of this highly disabling neurodegenerative disease including patients' needs and possibly be of value for clinicians in the differential diagnosis among Parkinsonian syndromes.

METHODS

We applied a systematic methodology to review existing literature on Pubmed regarding autonomic nervous system involvement in PSP.

RESULTS

PSP reported quite frequently symptoms suggestive of autonomic dysfunction in all domains. Cardiovascular autonomic testing showed in some cases a certain degree of impairment (never severe). There was some evidence suggesting bladder dysfunction particularly in the storage phase. Dysphagia and constipation were the most common gastrointestinal symptoms. Instrumental tests seemed to confirm sudomotor and pupillomotor disturbances.

CONCLUSIONS

PSP patients frequently reported visceral symptoms, however objective testing showed that not always these reflected actual autonomic impairment. Further studies are needed to better delineate autonomic profile and its prognostic role in PSP.

Autonomic failure: Clinicopathologic, physiologic, and genetic aspects

Over the past century, generations of neuroscientists, pathologists, and clinicians have elucidated the underlying causes of autonomic failure found in neurodegenerative, inherited, and antibody-mediated autoimmune disorders, each with pathognomonic clinicopathologic features. Autonomic failure affects central autonomic nervous system components in the α-synucleinopathy, multiple system atrophy, characterized clinically by levodopa-unresponsive parkinsonism or cerebellar ataxia, and pathologically by argyrophilic glial cytoplasmic inclusions (GCIs). Two other central neurodegenerative disorders, pure autonomic failure characterized clinically by deficits in norepinephrine synthesis and release from peripheral sympathetic nerve terminals; and Parkinson's disease, with early and widespread autonomic deficits independent of the loss of striatal dopamine terminals, both express Lewy pathology. The rare congenital disorder, hereditary sensory, and autonomic neuropathy type III (or Riley-Day, familial dysautonomia) causes life-threatening autonomic failure due to a genetic mutation that results in loss of functioning baroreceptors, effectively separating afferent mechanosensing neurons from the brain. Autoimmune autonomic ganglionopathy caused by autoantibodies targeting ganglionic α3-acetylcholine receptors instead presents with subacute isolated autonomic failure affecting sympathetic, parasympathetic, and enteric nervous system function in various combinations. This chapter is an overview of these major autonomic disorders with an emphasis on their historical background, neuropathological features, etiopathogenesis, diagnosis, and treatment.

Human temperature regulation under heat stress in health, disease, and injury

The human body constantly exchanges heat with the environment. Temperature regulation is a homeostatic feedback control system that ensures deep body temperature is maintained within narrow limits despite wide variations in environmental conditions and activity-related elevations in metabolic heat production. Extensive research has been performed to study the physiological regulation of deep body temperature. This review focuses on healthy and disordered human temperature regulation during heat stress. Central to this discussion is the notion that various morphological features, intrinsic factors, diseases, and injuries independently and interactively influence deep body temperature during exercise and/or exposure to hot ambient temperatures. The first sections review fundamental aspects of the human heat stress response, including the biophysical principles governing heat balance and the autonomic control of heat loss thermoeffectors. Next, we discuss the effects of different intrinsic factors (morphology, heat adaptation, biological sex, and age), diseases (neurological, cardiovascular, metabolic, and genetic), and injuries (spinal cord injury, deep burns, and heat stroke), with emphasis on the mechanisms by which these factors enhance or disturb the regulation of deep body temperature during heat stress. We conclude with key unanswered questions in this field of research.

[Thermoregulatory dysfunction in Parkinson's disease]

Thermoregulatory dysfunction is considered to be the least investigated among all the autonomic disorders in Parkinson disease. Pathophysiological mechanisms of this phenomena involve as central, as peripheric parts of nervous system. Dopamine deficiency in combination with peripheric autonomic dysfunction leads to temperature balance disturbance, which may be expressed by various clinical symptoms. Dopaminergic innervation of preoptic-anterior hypothalamus area plays a crucial role in thermoregulation function of central nervous system. Current thermoregulatory tests give possibility not only to reveal sudomotor and heat dissipation disorders in patients with Parkinson disease, but also to make differential diagnosis with other neurodegenerative disorders. Early detection and treatment of thermoregulatory dysfunction may improve quality of life in patients with Parkinson disease.

Cutaneous sensory and autonomic denervation in progressive supranuclear palsy

AIM

Progressive Supranuclear Palsy (PSP) is a progressive neurodegenerative tauopathy characterised by motor, behavioural and cognitive dysfunction. While in the last decade, sensory and autonomic disturbances as well as peripheral nerve involvement are well-recognised in Parkinson's Disease (PD), little is known in this regard for PSP. Herein, we aim to assess peripheral sensory and autonomic nerve involvement in PSP and to characterise possible differences in morpho-functional pattern compared to PD patients.

METHODS

We studied 27 PSP and 33 PD patients without electrophysiological signs of neuropathy, and 33 healthy controls (HC). In addition to motor impairment, evaluated by means of UPDRS-III and the PSP rating scale, all patients underwent clinical, functional and morphological assessment of sensory-autonomic nerves through dedicated questionnaires, sympathetic skin response, dynamic sweat test and skin biopsies. The analysis of cutaneous sensory and autonomic innervation was performed using indirect immunofluorescence and confocal microscopy.

RESULTS

PSP patients displayed a length-dependent loss of sensory and autonomic nerve fibres associated with functional impairment compared to HC and, overall, a more severe picture than in PD patients. The disease severity correlated with the loss of intraepidermal nerve fibre density in the leg of PSP patients (p < 0.05).

CONCLUSION

We demonstrated a length-dependent small fibre pathology in PSP, more severe compared to PD, and paralleling disease severity. Our findings suggest the morphological and functional study of cutaneous nerves as possible biomarkers to monitor disease progression and response to new treatments.

Sudomotor Dysfunction

Disorders of sudomotor function are common and diverse in their presentations. Hyperhidrosis or hypohidrosis in generalized or regional neuroanatomical patterns can provide clues to neurologic localization and inform neurologic diagnosis. Conditions that impair sudomotor function include small fiber peripheral neuropathy, sudomotor neuropathy, myelopathy, α-synucleinopathies, autoimmune autonomic ganglionopathy, antibody-mediated hyperexcitability syndromes, and a host of medications. Particularly relevant to neurologic practice is the detection of postganglionic sudomotor deficits as a diagnostic marker of small fiber neuropathies. Extensive anhidrosis is important to recognize, as it not only correlates with symptoms of heat intolerance but may also place the patient at risk for heat stroke when under conditions of heat stress. Methods for assessing sudomotor dysfunction include the thermoregulatory sweat test, the quantitative sudomotor axon reflex test, silicone impressions, and the sympathetic skin response.

An update on MSA: premotor and non-motor features open a window of opportunities for early diagnosis and intervention

In this review, we describe the wide clinical spectrum of features that can be seen in multiple system atrophy (MSA) with a focus on the premotor phase and the non-motor symptoms providing an up-to-date overview of the current understanding in this fast-growing field. First, we highlight the non-motor features at disease onset when MSA can be indistinguishable from pure autonomic failure or other chronic neurodegenerative conditions. We describe the progression of clinical features to aid the diagnosis of MSA early in the disease course. We go on to describe the levels of diagnostic certainty and we discuss MSA subtypes that do not fit into the current diagnostic criteria, highlighting the complexity of the disease as well as the need for revised diagnostic tools. Second, we describe the pathology, clinical description, and investigations of cardiovascular autonomic failure, urogenital and sexual dysfunction, orthostatic hypotension, and respiratory and REM-sleep behavior disorders, which may precede the motor presentation by months or years. Their presence at presentation, even in the absence of ataxia and parkinsonism, should be regarded as highly suggestive of the premotor phase of MSA. Finally, we discuss how the recognition of the broader spectrum of clinical features of MSA and especially the non-motor features at disease onset represent a window of opportunity for disease-modifying interventions.

Progressive supranuclear palsy is not associated with neurogenic orthostatic hypotension

Objective

To evaluate the pattern and severity of autonomic dysfunction in autopsy-confirmed progressive supranuclear palsy (PSP) compared to α-synuclein pathology.

Methods

Autopsy-confirmed cases of 14 patients with PSP, 18 with multiple system atrophy (MSA), and 24 with Lewy body disease (LBD) with antemortem autonomic testing were reviewed retrospectively. All patients underwent comprehensive clinical evaluations by a movement disorder specialist, formal autonomic testing, and postmortem examinations at Mayo Clinic.

Results

The absence of orthostatic hypotension (OH) was the strongest autonomic parameter that distinguished PSP from α-synucleinopathies (0% vs 69%, p < 0.0001). Tests of adrenergic failure, which distinguish neurogenic OH, also differentiated PSP from other groups. These included the pressure recovery time (p = 0.0008), adrenergic impairment score (p = 0.001), and magnitude of change of systolic (p = 0.0002) and diastolic (p = 0.0001) blood pressures (BPs) during upright tilt. In addition, REM sleep behavior disorder was seen less frequently (p = 0.006) in PSP (33%) compared to MSA (87%) and LBD (90%). Antemortem clinical diagnostic accuracy for these phenotypically variable disorders was 57% for PSP and 83% for α-synucleinopathies.

Conclusion

Our results suggest that the cardiovascular adrenergic system, which sustains BP during standing, is relatively unaffected, if not spared, in PSP. These findings increase our understanding of the clinical signature of PSP and have the potential to improve diagnostic accuracy in atypical parkinsonisms by distinguishing PSP from the α-synucleinopathies.

Quantitative autonomic function test in differentiation of multiple system atrophy from idiopathic Parkinson disease

Supplemental Digital Content is available in the text

Background:

Differential diagnosis of idiopathic Parkinson disease (IPD) and multiple system atrophy-Parkinson type (MSA-P) is challenging since they share clinical features with parkinsonism and autonomic dysfunction. To distinguish MSA-P from IPD when the symptoms are relatively mild, we investigated the usefulness of the quantitative fractionalized autonomic indexes and evaluated the correlations of autonomic test indexes and functional status.

Methods:

Thirty-six patients with parkinsonism (22 with IPD and 14 with MSA-P) in Soonchunhyang University Bucheon Hospital from February 2014 to June 2015 were prospectively enrolled in the study. We compared fractionalized autonomic indexes and composite autonomic scoring scale between patients with IPD and MSA-P with Hoehn and Yahr (H&Y) score ≤3. Parasympathetic indexes included expiratory/inspiratory ratio during deep breathing, Valsalva ratio (VR), and regression slope of systolic blood pressure (BP) in early phase II (vagal baroreflex sensitivity) during Valsalva maneuver. Sympathetic adrenergic indexes were pressure recovery time (PRT) and adrenergic baroreflex sensitivity (BRSa) (BP decrement associated with phase 3 divided by the PRT), sympathetic index 1, sympathetic index 3, early phase II mean BP drop, and pulse pressure reduction rate. Additionally, we compared the unified multiple system atrophy rating scale (UMSARS) and H&Y scores and the autonomic indexes in all patients.

Results:

PRT was significantly different between the IPD and MSA-P groups (P = 0.004) despite the similar BP drop during tilt. Cut-off value of PRT was 5.5 s (sensitivity, 71.4%; specificity, 72.7%). VR (r = −0.455, P = 0.009) and BRSa (r = −0.356, P = 0.036) demonstrated a significant correlation with UMSARS and H&Y scores.

Conclusions:

Among the cardiovascular autonomic indexes, PRT can be a useful parameter in differentiating the early stage of MSA-P from that of IPD. Moreover, VR, and BRSa may be the optimal indexes in determining functional symptom severity.

Vocal Fold "Paralysis": An Early Sign in Multiple System Atrophy

Multiple system atrophy (MSA) is a neurodegenerative disease characterized by a cerebellar syndrome, autonomic dysfunction, and extrapyramidal signs. Extrapyramidal signs may manifest as parkinsonism as well as dystonia, which is the involuntary contraction of a muscle(s) resulting in an abnormal posture. MSA belongs to a family of diseases known as α-synucleinopathies which are associated with dream enactment reflecting REM sleep behavior disorder (RBD). In patients with MSA, dystonia or paresis may involve the laryngeal muscles resulting in vocal fold hypomobility. We identified four individuals presenting with vocal complaints and subsequently diagnosed with vocal fold "paralysis." Within one year, each patient developed neurologic symptoms and upon evaluation by a movement disorders specialist was diagnosed with probable MSA. Our findings highlight the importance of screening by otolaryngologists when patients are diagnosed with vocal fold hypomobility. Specifically, patients should be assessed for RBD by questioning others if he/she acts out their dreams. The presence of RBD raises clinical suspicion for a synucleinopathy such as MSA. Untreated patients with MSA experiencing nocturnal stridor and breathing disorders have an increased risk for sudden death. Therefore, early evaluation by a movement disorders specialist to promptly diagnose MSA may have a substantial effect on morbidity and mortality in this high-risk patient population.

Autonomic dysfunction in genetic forms of synucleinopathies

The discovery of genetic links between alpha-synuclein and PD has opened unprecedented opportunities for research into a new group of diseases, now collectively known as synucleinopathies. Autonomic dysfunction, including cardiac sympathetic denervation, has been reported in familial forms of synucleinopathies that have Lewy bodies at the core of their pathogenesis. SNCA mutations and multiplications, LRRK2 disease with Lewy bodies as well as other common, sporadic forms of idiopathic PD, MSA, pure autonomic failure, and dementia with Lewy bodies have all been associated with dysautonomia. By contrast, in familial cases of parkinsonism without Lewy bodies, such as in PARK2, the autonomic profile remains normal throughout the course of the disease. The degeneration of the central and peripheral autonomic systems in genetic as well as sporadic forms of neurodegenerative synucleinopathies correlates with the accumulation of alpha-synuclein immunoreactive-containing inclusions. Given that dysautonomia has a significant impact on the quality of life of sufferers and autonomic symptoms are generally treatable, a prompt diagnostic testing and treatment should be provided. Moreover, new evidence suggests that autonomic dysfunction can be used as an outcome prediction factor in some forms of synucleinopathies or premotor diagnostic markers that could be used in the future to define further research avenues. In this review, we describe the autonomic dysfunction of genetic synucleinopathies in comparison to the dysautonomia of sporadic forms of alpha-synuclein accumulation and provide the reader with an up-to-date overview of the current understanding in this fast-growing field. © 2018 International Parkinson and Movement Disorder Society.

Small fiber neuropathy and phosphorylated alpha-synuclein in the skin of E46K-SNCA mutation carriers

BACKGROUND AND OBJECTIVE

In 2004 we described the E46K mutation in alpha-synuclein gene (E46K-SNCA), a rare point mutation causing an aggressive Lewy body disease with early prominent non-motor features and small fiber denervation of myocardium. Considering the potential interest of the skin as a target for the development of biomarkers in Parkinson's Disease (PD), in this work we aimed to evaluate structural and functional integrity of small autonomic nerve fibers and phosphorylated alpha-synuclein (p-synuclein) deposition in the skin of E46K-SNCA carriers as compared to those observed in parkin gene mutation (PARK2) carriers and healthy controls.

PATIENTS AND METHODS

We studied 7 E46K-SNCA carriers (3 dementia with Lewy bodies, 2 pure autonomic failure, 1 PD and 1 asymptomatic), 2 PARK2 carriers and 2 healthy controls to quantify intraepidermal nerve fiber density and p-synuclein deposition with cervical skin punch biopsies (immunohistochemistry against anti PGP9.5/UCHL-1, TH and p-synuclein) and sudomotor function with electrochemical skin conductance (ESC) (SudoScan).

RESULTS

All E46K-SNCA carriers had moderate to severe p-synuclein deposits and small fiber neurodegeneration in different epidermal and dermal structures including nerve fascicles and glands, especially in carriers with Pure Autonomic Failure, while p-synuclein aggregates where absent in healthy controls and in one of two PARK2 carriers. The severity of the latter skin abnormalities in E46K-SNCA were correlated with sudomotor dysfunction (lower ESC) in hands (p = 0.035).

INTERPRETATION

These results together with our previous findings support the relevance of E46K-SNCA mutation as a suitable model to study small fiber neuropathy in Lewy body diseases.

Development of a small wireless device for perspiration monitoring

A small and wireless device that can capture the temporal pattern of perspiration by a novel structure of water vapor collection combined with reusable desiccant has been developed. The novel device consists of a small cylindrical case with a temperature/relative humidity sensor, battery-driven data logger, and silica gel (desiccant). Water vapor of perspiration was detected by the change in relative humidity and then adsorbed by silica gel, allowing continuous recording of perspiration within a closed and wireless chamber, which has not been previously achieved. By comparative experiments using the commercially-available perspiration monitoring device, the developed device could measure perspiration as efficiently as the conventional one, with a normalized cross coefficient of 0.738 with 6 s delay and the interclass correlation coefficient [ICC(2, 1)] of 0.84. These results imply a good agreement between the conventional and developed devices, and thus suggest the applicability of the developed device for perspiration monitoring.

Natural history of multiple system atrophy in the USA: a prospective cohort study

Background

Multiple system atrophy (MSA) is a rare, fatal neurodegenerative disorder exhibiting a combination of parkinsonism and/or cerebellar ataxia with autonomic failure. We report the first North American prospective natural history study of MSA, and the effects of phenotype and autonomic failure on prognosis.

Methods

175 subjects with probable MSA, both MSA-P and MSA-C, were recruited and prospectively followed for 5 years with evaluations every 6 months in 12 centers. Natural history was evaluated by Kaplan-Meier survival analysis. We compared MSA-P with MSA-C and evaluated predictors of outcome. These subjects were evaluated with UMSARS I (a functional score of symptoms and ability to undertake activities of daily living), UMSARS II (neurological motor evaluation), and the Composite Autonomic Symptoms Scale (COMPASS)-select (a measure of autonomic symptoms and autonomic functional status.

Findings

Mean age of symptom onset was 63.4 (SD 8.57) years. Median survival from symptom onset by Kaplan-Meier analysis was 9.8 years (95% CI 8.8-10.7). Subjects with severe symptomatic autonomic failure (symptomatic orthostatic hypotension, urinary incontinence) at diagnosis had a worse prognosis, surviving 8.0 years (95% CI, 6.5-9.5, n=62) while remaining subjects survived a median of 10.3 years (95% CI, 9.3-11.4, n=113). At baseline MSA-P (n=126) and MSA-C (n=49) were not different in symptoms and function, UMSARS I, 25.2 (8.08) vs 24.6 (8.34), p=0.835; UMSARS II, 26.4 (8.77) vs 25.4 (10.51), p=0.7635; COMPASS_select), 43.5 (18.66) vs 42.8 (19.56), p=0.835. Progression, evaluated by change in UMSARS I, UMSARS II, COMPASS_select over the next 5 years, was not significantly different between MSA-P and MSA-C. Median time to death from enrollment baseline was 1.8 (95% CI, 0.9-2.7) years.

Interpretation

Probable MSA represents late-stage disease with short survival. Natural history of MSA-P and MSA-C are similar. Severe symptomatic autonomic failure at diagnosis is associated with worse prognosis.

Funding

National Institutes of Health (P01 NS044233), Mayo CTSA (UL1 TR000135), the Kathy Shih Memorial Foundation, and Mayo funds.

Cardiovascular autonomic testing performed with a new integrated instrumental approach is useful in differentiating MSA-P from PD at an early stage

OBJECTIVE

To evaluate whether a battery of cardiovascular autonomic tests (Ewing's battery, EB) performed with a new integrated instrumental approach is useful in differentiating multiple system atrophy with predominant parkinsonism (MSA-P) from Parkinson's disease (PD) at an early stage.

METHODS

We retrospectively analyzed EB tests of all the patients (n = 99) with a parkinsonian syndrome referred to our clinic who performed EB during the first diagnostic workup and were subsequently evaluated at least once a year until a final diagnosis of MSA-P (n = 34) or PD (n = 65). Thirty-eight controls matched for age and sex were included. EB consisted of head-up tilt test (HUTT), Valsalva manoeuvre (VM), deep breathing, and sustained handgrip whose correct execution and results were checked and obtained automatically. Results were compared between groups. Discriminant analysis was performed to identify MSA-P or PD patients.

RESULTS

Orthostatic hypotension was found in 22 MSA-P and 3 PD patients. Cardiovascular reflexes indices were significantly more affected in MSA-P compared to PD and controls. EB presented a 91% sensitivity and 94% specificity in the differentiation of MSA-P and PD. HUTT + VM presented a 91% sensitivity and 92% specificity.

CONCLUSIONS

Our results suggest that EB or HUTT + VM performed with an integrated instrumental approach and analyzed with the discriminant procedure may distinguish MSA-P from PD at an early stage and might improve the accuracy of current diagnostic criteria. However, a validation in separate samples and prospective studies is needed.

Autopsy confirmed multiple system atrophy cases: Mayo experience and role of autonomic function tests

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.

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.

The role of autonomic testing in the differentiation of Parkinson's disease from multiple system atrophy

Differentiation of idiopathic Parkinson's disease (PD) from multiple system atrophy (MSA) can be difficult. Methods devised to help distinguish the two disorders include standardized autonomic testing and cardiac imaging with iodine-123 meta-iodobenzylguanidine myocardial scintigraphy. MSA patients had more severe adrenergic and overall autonomic dysfunction when compared to control and PD patients. Area of anhidrosis on thermoregulatory sweat test was greater in MSA (67.4±12.42, p<0.001) versus PD patients (area of anhidrosis, 1.7±2.96). Postganglionic cardiac sympathetic innervation (iodine-123 meta-iodobenzylguanidine) expressed as heart to mediastinal ratio was significantly lower in Parkinson's disease patients (1.4±0.40, p=0.025) compared to controls (2.0±0.29), but not in multiple system atrophy (2.0±0.76). These findings indicate that autonomic dysfunction is generalized and predominantly preganglionic in multiple system atrophy, and postganglionic in Parkinson's disease. In our hands the thermoregulatory sweat test provides the best distinction between MSA and PD. However further confirmatory studies using larger patient numbers are required. Currently a combination of clinical judgment and autonomic testing is recommended to help differentiate MSA and PD.

Multi-organ autonomic dysfunction in Parkinson disease

Both pathologic and clinical studies of autonomic pathways have expanded the concept of Parkinson disease (PD) from a movement disorder to a multi-level widespread neurodegenerative process with non-motor features spanning several organ systems. This review integrates neuropathologic findings and autonomic physiology in PD as it relates to end organ autonomic function. Symptoms, pathology and physiology of the cardiovascular, skin/sweat gland, urinary, gastrointestinal, pupillary and neuroendocrine systems can be probed by autopsy, biopsy and non-invasive electrophysiological techniques in vivo which assess autonomic anatomy and function. There is mounting evidence that PD affects a chain of neurons in autonomic pathways. Consequently, autonomic physiology may serve as a window into non-motor PD progression and allow the development of mechanistically based treatment strategies for several non-motor features of PD. End-organ physiologic markers may be used to inform a model of PD pathophysiology and non-motor progression.

Preventing and treating orthostatic hypotension: As easy as A, B, C

Orthostatic hypotension is a chronic, debilitating illness that is difficult to treat. The therapeutic goal is to improve postural symptoms, standing time, and function rather than to achieve upright normotension, which can lead to supine hypertension. Drug therapy alone is never adequate. Because orthostatic stress varies with circumstances during the day, a patient-oriented approach that emphasizes education and nonpharmacologic strategies is critical. We provide easy-to-remember management recommendations, using a combination of drug and nondrug treatments that have proven efficacious.

[Case of Parkinson disease with heat retention due to sweating dysfunction]

A 71-year-old man was diagnosed as Parkinson disease at age 59, and levodopa therapy was started. Eleven years after the beginning of treatment, he noticed high fever (38.0 degrees C-39.0 degrees C) in July, but hyperthermia spontaneously disappeared three months later. In early July of the following year, he was re-admitted to our hospital because of continuous high fever, despite no any inflammation. Neurological examination revealed flexion posture of trunk and limbs and short step gait. He also presented limb rigidity, akinesia, and resting tremor during off period. Routine laboratory examinations and radiological examinations showed no remarkable findings. Autonomic testing revealed orthostatic hypotension and anhidrosis below trunk and lower limbs. By controlling the room temperature at 26 degrees C, hyperthermia showed a marked decline. In despite of no reports found associations between heat retention and Parkinson disease, in this case we speculate hyperthermia was caused by heat retention.

Primary Raynaud phenomenon and small-fiber neuropathy: is there a connection? A pilot neurophysiologic study

The pathophysiologic factors of primary Raynaud phenomenon (RP) are unknown. Preliminary evidence from skin biopsy suggests small-fiber neuropathy (SFN) in primary RP. We aimed to quantitatively assess SFN in participants with primary RP. Consecutive patients with an a priori diagnosis of primary RP presenting to our outpatient rheumatology clinic over a 6-month period were invited to participate. Cases of secondary RP were excluded. All participants were required to have normal results on nailfold capillary microscopy. Assessment for SFN was accomplished with autonomic reflex screening, which includes quantitative sudomotor axonal reflex test (QSART), and cardiovagal and adrenergic function testing, thermoregulatory sweat test (TST), and quantitative sensory test (QST) for vibratory, cooling, and heat-pain sensory thresholds. Nine female participants with a median age of 38 years (range 21-46 years) and a median symptom duration of 9 years (range 5 months-31 years) were assessed. Three participants had abnormal results on QSART, indicating peripheral sudomotor autonomic dysfunction. Two participants had evidence of large-fiber involvement with heat-pain thresholds on QST. Heart rate and blood pressure responses to deep breathing, Valsalva maneuver, and 70° tilt were normal for all participants. Also, all participants had normal TST results. In total, three of the nine participants had evidence of SFN. The presence of SFN raises the possibility that a subset of patients with primary RP have an underlying, subclinical small-fiber dysfunction. These data open new avenues of research and therapeutics for this common condition.

Prospective differentiation of multiple system atrophy from Parkinson disease, with and without autonomic failure

OBJECTIVE

To report preliminary results of a prospective ongoing study of multiple system atrophy (MSA) and Parkinson disease (PD), with a large subset of patients with PD with autonomic failure (25%), to evaluate autonomic indices that distinguish MSA from PD.

METHODS

We used consensus criteria, detailed autonomic studies (Composite Autonomic Symptom Scale, Composite Autonomic Scoring Scale, thermoregulatory sweat test, and plasma catecholamines), and functional scales (Unified MSA Rating Scale [UMSARS] I-IV and Hoehn-Yahr grading) on a prospective, repeated, and ongoing basis.

RESULTS

We report the results of a study on 52 patients with MSA (mean [SD], age, 61.1 [7.8] years; body mass index (calculated as weight in kilograms divided by height in meters squared), 27.2 [4.6]; Hoehn-Yahr grade, 3.2 [0.9]; UMSARS I score, 21.5 [7.4]; and UMSARS II score, 22.7 [9.0]) and 29 patients with PD, including PD with autonomic failure (mean [SD], age, 66.0 [8.1] years; body mass index, 26.6 [5.5]; Hoehn-Yahr grade, 2.2 [0.8]; UMSARS I score, 10.4 [6.1]; and UMSARS II score, 13.0 [5.9]). Autonomic indices were highly significantly more abnormal in MSA than PD (P < .001) for the Composite Autonomic Scoring Scale (5.9 [1.9] vs 3.3 [2.3], respectively), Composite Autonomic Symptom Scale (54.4 [21.8] vs 24.7 [20.5], respectively), and thermoregulatory sweat test (percentage anhidrosis, 57.4% [35.2%] vs 9.9% [17.7%], respectively). These differences were sustained and greater at 1-year follow-up, indicating a greater rate of progression of dysautonomia in MSA than PD.

CONCLUSIONS

The severity, distribution, and pattern of autonomic deficits at study entry will distinguish MSA from PD, and MSA from PD with autonomic failure. These differences continue and are increased at follow-up. Our ongoing conclusion is that autonomic function tests can separate MSA from PD. Autonomic indices support the notion that the primary lesion in PD is ganglionic and postganglionic, while MSA is preganglionic.

Effects of prior intensive insulin therapy on cardiac autonomic nervous system function in type 1 diabetes mellitus: the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications study (DCCT/EDIC)

BACKGROUND

The Epidemiology of Diabetes Interventions and Complications (EDIC) study, a prospective observational follow-up of the Diabetes Control and Complications Trial (DCCT) cohort, reported persistent benefit of prior intensive therapy on retinopathy and nephropathy in type 1 diabetes mellitus. We evaluated the effects of prior intensive insulin therapy on the prevalence and incidence of cardiac autonomic neuropathy (CAN) in former DCCT intensive and conventional therapy subjects 13 to 14 years after DCCT closeout.

METHODS AND RESULTS

DCCT autonomic measures (R-R variation with paced breathing, Valsalva ratio, postural blood pressure changes, and autonomic symptoms) were repeated in 1226 EDIC subjects in EDIC year 13/14. Logistic regression models were used to calculate the odds of incident CAN by DCCT treatment group after adjustment for DCCT baseline covariates, duration in the DCCT, and quantitative autonomic measures at DCCT closeout. In EDIC year 13/14, the prevalence of CAN using the DCCT composite definition was significantly lower in the former intensive group versus the former conventional group (28.9% versus 35.2%; P=0.018). Adjusted R-R variation was significantly greater in the former DCCT intensive versus the former conventional group (29.9 versus 25.9; P<0.001). Prior DCCT intensive therapy reduced the risks of incident CAN by 31% (odds ratio, 0.69; 95% confidence interval, 0.51 to 0.93) and of incident abnormal R-R variation by 30% (odds ratio, 0.70; 95% confidence interval, 0.51 to 0.96) in EDIC year 13/14.

CONCLUSIONS

Although CAN prevalence increased in both groups, the incidence was significantly lower in the former intensive group compared with the former conventional group. The benefits of former intensive therapy extend to measures of CAN up to 14 years after DCCT closeout.

Systemic postganglionic adrenergic studies do not distinguish Parkinson's disease from multiple system atrophy

BACKGROUND

Multiple system atrophy (MSA) affects the preganglionic adrenergic neuron and Parkinson's disease (PD) involves the postganglionic counterpart. Widespread postganglionic denervation should result in denervation supersensitivity and a failure of the axon to release norepinephrine (NE). We examined if pharmacological dissection of the adrenergic neuron can distinguish between MSA and PD.

METHOD

We measured blood pressure, heart rate, and plasma NE responses to direct (phenylephrine) and indirect (tyramine) acting adrenergic agonists in 15 patients with probable MSA, 16 patients with idiopathic PD, and 16 age- and gender-matched controls.

RESULTS

Baroreflex sensitivity was impaired in MSA and intact in PD. Pressor responses to phenylephrine (direct acting) were higher in MSA (p<0.01) and PD patients (p=0.04) than in controls. Blood pressure responses to tyramine (indirect acting) were increased in MSA only (p<0.01). Tyramine increased plasma catecholamine levels in all groups with no significant differences between groups.

CONCLUSION

There is denervation supersensitivity in PD patients that is, however, insufficient to shift the dose-response curve to the left. The excessive pressor responses to both tyramine and phenylephrine in MSA are due to baroreflex failure. We conclude that this diagnostic approach lacks sufficient sensitivity to differentiate PD and MSA.

Reduction in QSART and vasoactive intestinal polypeptide expression in the skin of Parkinson's disease patients and its relation to dyshidrosis

BACKGROUND

With regards to dyshidrosis in Parkinson's disease (PD), there is no established and consistent view on the occurrence sites, frequency and etiology, although there have been several reports on hypohidrosis of the limbs and sudoresis on the face/cervical region.

METHODS

Hydrosis in the forearms of PD patients and healthy individuals were compared by quantitative sudomotor axon reflex test (QSART). The expression of various neuropeptides and alpha-synuclein was examined with immunohistochemical staining.

RESULTS

There was a significant reduction in QSART of PD patients but not of healthy controls. Reduced expression of vasoactive intestinal polypeptide (VIP) was also detected in the sweat glands of PD patients.

CONCLUSION

Reduction in QSART and VIP expression in the sweat glands might be involved in the dyshidrosis of PD patients.

Second consensus statement on the diagnosis of multiple system atrophy

BACKGROUND

A consensus conference on multiple system atrophy (MSA) in 1998 established criteria for diagnosis that have been accepted widely. Since then, clinical, laboratory, neuropathologic, and imaging studies have advanced the field, requiring a fresh evaluation of diagnostic criteria. We held a second consensus conference in 2007 and present the results here.

METHODS

Experts in the clinical, neuropathologic, and imaging aspects of MSA were invited to participate in a 2-day consensus conference. Participants were divided into five groups, consisting of specialists in the parkinsonian, cerebellar, autonomic, neuropathologic, and imaging aspects of the disorder. Each group independently wrote diagnostic criteria for its area of expertise in advance of the meeting. These criteria were discussed and reconciled during the meeting using consensus methodology.

RESULTS

The new criteria retain the diagnostic categories of MSA with predominant parkinsonism and MSA with predominant cerebellar ataxia to designate the predominant motor features and also retain the designations of definite, probable, and possible MSA. Definite MSA requires neuropathologic demonstration of CNS alpha-synuclein-positive glial cytoplasmic inclusions with neurodegenerative changes in striatonigral or olivopontocerebellar structures. Probable MSA requires a sporadic, progressive adult-onset disorder including rigorously defined autonomic failure and poorly levodopa-responsive parkinsonism or cerebellar ataxia. Possible MSA requires a sporadic, progressive adult-onset disease including parkinsonism or cerebellar ataxia and at least one feature suggesting autonomic dysfunction plus one other feature that may be a clinical or a neuroimaging abnormality.

CONCLUSIONS

These new criteria have simplified the previous criteria, have incorporated current knowledge, and are expected to enhance future assessments of the disease.

Prevalence of orthostatic hypotension

Orthostatic hypotension (OH) is defined as a fall in blood pressure of at least 20 mmHg systolic or 10 mmHg diastolic when standing or during head-up tilt testing. The prevalence of OH increases with age, with disorders that affect autonomic nerve transmission, and with increasingly severe orthostatic stress. In normal elderly subjects, the prevalence of OH is reported to be between 5 and 30%. The actual prevalence depends on the conditions during diagnostic testing, such as the frequency of blood pressure recordings, the time of day and the degree of orthostatic stress. Elderly subjects are often taking medications, such as antihypertensives and diuretics that can cause or aggravate OH. Neurological diseases such as diabetic neuropathy, Parkinson's disease, multiple system atrophy and the autonomic neuropathies further increase the likelihood of OH. The development of OH in normal subjects is associated with an increased mortality rate. OH in diabetes is also associated with a significant increase in mortality rate.

Sweating dysfunctions in Parkinson’s disease

There is a high frequency of dyshidrosis in Parkinson's disease. Daily use of an antiparkinsonian drug does not affect sweating. Mental sweating relates to the contraction period and seriousness. However, hyperthermic sweating does not necessarily relate to the contraction period or seriousness. Abnormalities in mental sweating are not necessarily correlated with cardiovascular autonomic disturbances. As the autonomic disturbance becomes more advanced, dyshidrosis becomes more common. Hyperhidrosis may develop with dyskinesia. Hyperhidrosis may be improved by the temporally administration of levodopa. Dyshidrosis might be caused by a centrally-acting abnormality during its early stage. However, postganglional abnormalities as well as central changes may increase as the disease progresses. The presence of dyshidrosis affects the QOL and depression in patients with Parkinson's disease. The only therapy for hyperhydrotic sweating disorders is the administration of levodopa or dopaminagonist. Additional studies including therapy for sweating disorders are necessary.

Cardiovascular dysautonomia in Parkinson's disease and multiple system atrophy

OBJECTIVES

To determine whether Parkinson's disease (PD) can be distinguished from multiple system atrophy (MSA) on the basis of the assessment of iodine-123 meta-iodobenzylguanidine (123I-MIBG) radioactivity in heart and cardiovascular autonomic function.

PATIENTS AND METHODS

Seventeen patients with MSA, 39 with PD, and 25 healthy volunteers underwent 123I-MIBG scintigraphy and hemodynamic autonomic function tests using Valsalva maneuver (VM). Baroreceptor reflex sensitivity (BRS) was measured using the slope of the relation between RR interval and blood pressure during the fourth phase.

RESULTS

123I-MIBG radioactivity in heart of patients with PD was lower than that of control subjects and patients with MSA, but there was some overlap between PD and MSA. BRS in patients with PD who had a 123I-MIBG radioactivity similar to that in MSA was larger than that in patients with MSA, with no overlap in any patient.

CONCLUSION

Assessment of BRS may be useful for differentiating between MSA and PD that had a 123I-MIBG radioactivity similar to MSA.

Cardiovascular dysautonomia in de novo Parkinson's disease

BACKGROUND

Clinical symptoms of Parkinson's disease (PD) include not only motor distress, but also autonomic dysfunction.

OBJECTIVE

To clarify the progression of autonomic nervous dysfunction in PD.

METHODS

The subjects were 44 patients with de novo PD. Autonomic nervous function, including cardiac sympathetic gain, was evaluated on the basis of cardiac radioiodinated metaiodobenzylguanidine (MIBG) uptake, the response to the Valsalva maneuver, and spectral analyses of the RR interval and blood pressure.

RESULTS

Decreased cardiac MIBG uptake was found even in patients with early stage PD. MIBG uptake gradually decreased with increased disease severity. Hemodynamic studies using the Valsalva maneuver revealed that patients with early stage PD had reduced baroreceptor reflex sensitivity (BRS) in phase II, but not phase IV. Blood pressures normally rose in phases II and IV, but the increments decreased with disease progression. In early stage PD, the low frequency power of the RR interval (RR-LF) and the ratio (LF/HF) of RR-LF to the high frequency component of the RR interval (RR-HF) were significantly lower than the respective control values, despite no significant difference in RR-HF; these variables decreased with disease progression.

CONCLUSION

Our results show that latent sympathetic nervous dysfunction without parasympathetic dysfunction, especially that involving the sinus node, is already present in early stage de novo PD. It is unclear whether the responsible lesion is central or peripheral.

Cutaneous sympathetic function and cardiovascular function in patients with progressive supranuclear palsy and Parkinson's disease

Some procedures, such as deep inspiration, increase sweat output (SSwR; sympathetic sweat response) and reduce cutaneous blood flow (SVR; skin vasomotor reflex) on the palm. We investigated SSwR, SVR, and cardiovascular function in 12 patients with progressive supranuclear palsy (PSP), 13 patients with Parkinson's disease (PD), and 9 healthy subjects. In the PSP patients, SSwR was severely diminished, whereas SVR was maintained and cardiovascular function was well preserved. In the PD patients, SSwR was relatively preserved, SVR was maintained, and some patients showed cardiovascular hypofunction. A combination of skin sympathetic and cardiovascular tests may be useful for distinguishing between PD and PSP.

Efficacy of a half dose of oral pyridostigmine in the treatment of chronic fatigue syndrome: three case reports

Chronic fatigue syndrome (CFS) is characterized by persistent mental and physical fatigue for at least 6 months. Its pathophysiology is unknown and there is no proven effective treatment. We describe three cases who fulfill the criteria of CFS, in whom a defect of neuromuscular transmission and dysautonomia are present and who respond to acetylcholine-esterase inhibition. Case 1: 18-year-old female with a 3-year history of CFS. Response of compound-muscle-action potential, recorded using surface recording electrode, over left abductor pollicis brevis muscle, to repetitive nerve stimulation (RNS) at a rate of 10 Hz showed a 42% incremental response. Composite autonomic scoring system (CASS) showed mild cholinergic impairment (cardiovagal score: 1; sudomotor score: 2). Serological tests for Epstein-Barr virus (EBV) revealed positive antiviral capsid antigens (anti-VCA) immunoglobulins G (IgG). Oral pyridostigmine therapy (30 mg) resulted in marked improvement in symptoms. Case 2: 28-year-old female with 10-year history of CFS. RNS, using identical protocol, showed a 60% incremental response over the same muscle. CASS showed mild cholinergic impairment (cardiovagal score: 1; sudomotor score: 2) and this patient was also positive for EBV. This patient responded dramatically to 10-mg pyridostigmine. Case 3: 29-year-old female with a history of CFS for longer than 15 years. Repetitive stimulation, using identical paradigm to left abductor pollicis brevis muscle, showed a 42% incremental response. CASS showed mildly cholinergic impairment (cardiovagal score: 2; sudomotor score: 1). EBV antibody titers were positive. Patient responded to 30-mg pyridostigmine with an improvement in her fatigue. These three cases generate the hypothesis that the fatigue in some patients with clinical CFS might be due to a combination of mild neuromuscular transmission defect combined with cholinergic dysautonomia. Support for this thesis derives from the improvement with cholinesterase inhibition.

Are electrophysiological autonomic tests useful in the assessment of dysautonomia in Parkinson's disease?

To assess the autonomic system in Parkinson's disease (PD), the sympathetic skin response (SSR) and the R-R interval variation (RRIV) tests were studied in 26 PD patients and in 24 healthy controls. The aim of the study was to evaluate the sympathetic and parasympathetic system function in PD, to define the pattern of autonomic abnormalities found in SSR and RRIV in parkinsonian patients as well as to analyze the usefulness of both tests in paraclinical assessment of the dysautonomia, compared with clinical symptoms and signs of the autonomic nervous system involvement. The corrrelations between both autonomic tests results were also studied. In PD patients SSR test was abnormal in about 35% and RRIV was abnormal in about 54% of patients. SSR and RRIV were both abnormal in about 27% of PD patients whereas at least one of electrophysiological autonomic tests was abnormal in about 62% of PD patients. Clinical and paraclinical signs of dysautonomia occurred in a similar proportion of patients (i.e. in about 62%). A weak correlation was found between the latency of SSR from upper limbs and the value of RRIV during deep breathing (p=0.063). Our results show that SSR and RRIV are non-invasive paraclinical electrophysiological tests that confirm clinical dysautonomia in PD and can supplement the clinical differentiation of Parkinsonian syndromes.

Physiologic assessment of autonomic dysfunction in pallidopontonigral degeneration with N279K mutation in the tau gene on chromosome 17

Autonomic function was investigated in five affected and five at-risk members of a single kinship of pallidopontonigral degeneration (PPND), which is a progressive syndrome of parkinsonism and frontotemporal dementia resulting from a mutation in the N279K tau gene on chromosome 17. Affected subjects reported symptoms including hyperhidrosis, sialorrhea, urinary frequency or incontinence, thermal intolerance, male sexual dysfunction, lacrimation, and dryness of the eyes or mouth. None had orthostatic hypotension. Autonomic testing revealed mild-to-moderate abnormalities in all five affected subjects and minor abnormalities in the three oldest, asymptomatic, at-risk subjects. Findings in affected subjects consisted of preganglionic sudomotor dysfunction in all five, impaired cardiovagal function in three, and reduced or absent pupillary near responses in four. Tests of adrenergic function were normal in all subjects. The degree of autonomic dysfunction correlated significantly with disease duration and with indices of disease severity. In conclusion, there is evidence in PPND of a disturbance in the central autonomic network.

A case of chorea-acanthocytosis with dysautonomia; quantitative autonomic deficits using CASS

The purpose of this study was to quantitatively assess cardiovagal, adrenergic and postganglionic sudomotor functions in a patient with chorea-acanthocytosis. We describe a 25-year-old woman with acanthocytosis, lip and tongue biting, chorea like movements and increased levels of serum creatine phosphokinase. The patient presented with orthostatic hypotension. The heart period response to deep breathing was moderately decreased and the quantitative sudomotor axon reflex test (QSART) was mildly abnormal in the lower extremities. The composite autonomic score (CASS) for this patient was 6 points which indicates moderate autonomic failure. Although a few previous reports have described autonomic dysfunction associated with chorea-acanthocytosis and have indicated that impairment is primarily sympathetic, our case study suggests that there is also parasympathetic dysfunction. We conclude that there is widespread autonomic involvement in choreaacanthocytosis and that autonomic studies are useful in monitoring their course.