Autonomic dysfunction following COVID-19 infection: an early experience.

PURPOSE: Post-COVID-19 syndrome is a poorly understood aspect of the current pandemic, with clinical features that overlap with symptoms of autonomic/small fiber dysfunction. An early systematic analysis of autonomic dysfunction following COVID-19 is lacking and may provide initial insights into the spectrum of this condition. METHODS: We conducted a retrospective review of all patients with confirmed history of COVID-19 infection referred for autonomic testing for symptoms concerning for para-/postinfectious autonomic dysfunction at Mayo Clinic Rochester or Jacksonville between March 2020 and January 2021. RESULTS: We identified 27 patients fulfilling the search criteria. Symptoms developed between 0 and 122 days following the acute infection and included lightheadedness (93%), orthostatic headache (22%), syncope (11%), hyperhidrosis (11%), and burning pain (11%). Sudomotor function was abnormal in 36%, cardiovagal function in 27%, and cardiovascular adrenergic function in 7%. The most common clinical scenario was orthostatic symptoms without tachycardia or hypotension (41%); 22% of patients fulfilled the criteria for postural tachycardia syndrome (POTS), and 11% had borderline findings to support orthostatic intolerance. One patient each was diagnosed with autoimmune autonomic ganglionopathy, inappropriate sinus tachycardia, vasodepressor syncope, cough/vasovagal syncope, exacerbation of preexisting orthostatic hypotension, exacerbation of sensory and autonomic neuropathy, and exacerbation of small fiber neuropathy. CONCLUSION: Abnormalities on autonomic testing were seen in the majority of patients but were mild in most cases. The most common finding was orthostatic intolerance, often without objective hemodynamic abnormalities on testing. Unmasking/exacerbation of preexisting conditions was seen. The temporal association between infection and autonomic symptoms implies a causal relationship, which however cannot be proven by this study.

Association of innervation-adjusted alpha-synuclein in arrector pili muscles with cardiac noradrenergic deficiency in autonomic synucleinopathies.

BACKGROUND: Autonomic synucleinopathies feature deposition of the protein alpha-synuclein (AS) in neurons [e.g., Lewy body neurogenic orthostatic hypotension (nOH)] or glial cells (multiple system atrophy, MSA). AS in skin biopsies might provide biomarkers of these diseases; however, this approach would be complicated or invalidated if there were substantial loss of AS-containing nerves. We report AS content in arrector pili muscles in skin biopsies after adjustment for local innervation in patients with Lewy body nOH or MSA. Cardiac sympathetic neuroimaging by myocardial 18F-dopamine positron emission tomography (PET) was done to examine pathophysiological correlates of innervation-adjusted AS. METHODS: Thirty-one patients (19 Lewy body nOH, 12 MSA) underwent thoracic 18F-dopamine PET and skin biopsies. AS signal intensity analyzed by immunofluorescence microscopy was adjusted for innervation by the ratio of AS to protein gene product (PGP) 9.5, a pan-axonal marker (Harvard lab site), or the ratio of AS to tyrosine hydroxylase (TH), an indicator of catecholaminergic neurons (NIH lab site). RESULTS: The Lewy body nOH group had higher ratios of AS/PGP 9.5 or log AS/TH than did the MSA group (0.89 ± 0.05 vs. 0.66 ± 0.04, -0.13 ± 0.05 vs. -1.60 ± 0.33; p < 0.00001 each). All 19 Lewy body patients had AS/PGP 9.5 > 0.8 or log AS/TH > 1.2 and had myocardial 18F-dopamine-derived radioactivity < 6000 nCi-kg/cc-mCi, the lower limit of normal. Two MSA patients (17%) had increased AS/PGP or log AS/TH, and two (17%) had low 18F-dopamine-derived radioactivity. CONCLUSIONS: Lewy body forms of nOH are associated with increased innervation-adjusted AS in arrector pili muscles and neuroimaging evidence of myocardial noradrenergic deficiency.

Multiple system atrophy: Building a global community - 30years of advocacy efforts.

Multiple system atrophy (MSA) is a rare, progressive and ultimately fatal neurodegenerative disease with no known cause and no available disease modifying treatment. Known previously by various names including Shy-Drager Syndrome, olivopontocerebellar atrophy (OPCA) and striatonigral degeneration, MSA can be classified simultaneously as a movement disorder, an autonomic disorder, a cerebellar ataxia and an atypical parkinsonian disorder. Despite scholarly attempts to better describe the disease, awareness among medical practitioners about multiple system atrophy as a diagnostic possibility has been slow to catch on. As a result, patients often go undiagnosed for many years or are largely misdiagnosed as Parkinson's disease. The non-homogeneous clinical presentation of MSA and years of confusing nomenclature have all contributed to a lack of awareness of the disease among healthcare professionals as well as the public. This lack of awareness has amplified the unmet needs of MSA patients and other stakeholders. Since the 1980s there has been a growing advocacy effort directed at this rare disease from advocacy groups, grassroots supporters, healthcare professionals and research networks. These stakeholders are beginning to unite their efforts and attack the disease from a global perspective in the hopes of improving outcomes for MSA patients in the future.

A Japanese familial ALS patient with autonomic failure and a p.Cys146Arg mutation in the gene for SOD1 (SOD1).

We describe a Japanese man with familial amyotrophic lateral sclerosis (ALS) associated with a p.Cys146Arg mutation in the copper/zinc superoxide dismutase gene (SOD1). The patient developed bulbar signs followed by rapidly progressive limb muscle weakness. The prominent clinical feature was orthostatic hypotension due to autonomic failure, which occurred after he underwent tracheostomy 1 year and 3 months after the onset. Thereafter, he required mechanical ventilation and progressed to communication stage V (totally locked-in state) 7 years after the onset. Neuropathology showed ALS with posterior column degeneration and multiple system degeneration. Severe neuronal loss in the intermediolateral nucleus was also observed. Two previously reported cases of ALS patients with autonomic failure showed severe neuronal loss in the intermediolateral nucleus in addition to degeneration of the motor neurons. Thus, autonomic failure due to neuronal loss in the intermediolateral nucleus could present in patients with ALS associated with certain mutations in SOD1.

Effect of orthostatic hypotension on sustained attention in patients with autonomic failure.

INTRODUCTION: Orthostatic hypotension has been associated with impaired cognitive function, but cognitive function during orthostatic hypotension has hardly been studied. We studied the effect of orthostatic hypotension, induced by head-up tilt (HUT), on sustained attention in patients with autonomic failure. METHODS: We studied the sustained attention to response task (SART) in the supine position and during HUT in 10 patients with autonomic failure and 10 age-matched and sex-matched controls. To avoid syncope, the tilting angle was tailored to patients to reach a stable systolic blood pressure below 100 mm Hg. Controls were all tilted at an angle of 60°. Cerebral blood flow velocity, blood pressure and heart rate were measured continuously. RESULTS: In patients, systolic blood pressure was 61.4 mm Hg lower during HUT than in the supine position (p<0.001). Patients did not make more SART errors during HUT than in the supine position (-1.3 errors, p=0.3). Controls made 2.3 fewer errors during SART in the HUT position compared to the supine position (p=0.020). SART performance led to an increase in systolic blood pressure (+11.8 mm Hg, p=0.018) and diastolic blood pressure (+5.8 mm Hg, p=0.017) during SART in the HUT position, as well as to a trend towards increased cerebral blood flow velocity (+3.8 m/s, p=0.101). DISCUSSION: Orthostatic hypotension in patients with autonomic failure was not associated with impaired sustained attention. This might partly be explained by the observation that SART performance led to a blood pressure increase. Moreover, the upright position was associated with better performance in controls and, to a lesser extent, also in patients.

Neuropathology of multiple system atrophy: new thoughts about pathogenesis.

Multiple system atrophy (MSA) is a fatal adult-onset neurodegenerative disorder of uncertain etiology, clinically manifesting with autonomic failure associated with parkinsonism, cerebellar dysfunction, and pyramidal signs in variable combination. The pathological process affects central autonomic, striatonigral, and olivopontocerebellar systems. These show varying degrees of neurodegeneration and underlie the stratification of the heterogenous disorder into MSA-P and MSA-C clinical variants, which correlate to the morphologic phenotypes of striatonigral degeneration and olivopontocerebellar atrophy (MSA-C). The lesions are not limited to these most consistently and severely affected systems but may involve many other parts of the central, peripheral, and autonomic nervous systems, underpinning the multisystem character of MSA. The histological core feature are glial cytoplasmic inclusions (GCIs, Papp-Lantos bodies) in all types of oligodendroglia that contain aggregates of misfolded α-Synuclein (α-Syn). In addition to the ectopic appearance of α-Syn in oligodendrocytes and other cells, oxidative stress, proteasomal and mitochondrial dysfunction, excitotoxiciy, neuroinflammation, metabolic changes, and energy failure are important contributors to the pathogenesis of MSA, as shown by various neurotoxic and transgenic animal models. Although the basic mechanisms of α-Syn-triggered neurodegeneration are not completely understood, neuron-to-oligodendrocyte transfer of α-Syn by prion-like spreading, inducing oligodendroglial and myelin dysfunction associated with chronic neuroinflammation, are suggested finally to lead to a system-specific pattern of neurodegeneration.

Prevention of supine hypotensive syndrome in pregnant women treated with transcranial magnetic stimulation.

In our studies of transcranial magnetic stimulation in pregnant women with major depressive disorder, two subjects had an episode of supine hypotensive syndrome and one subject had an episode of dizziness without hypotension. Prevention of the supine hypotensive syndrome in pregnant women receiving transcranial magnetic stimulation is described.

[Sudden death occurring after anti-Hu associated paraneoplastic cerebellar degeneration and dysautonomia revealing a small cell lung carcinoma]. / Mort subite au cours d'une dégénérescence cérébelleuse subaiguë paranéoplasique avec dysautonomie associée aux anticorps anti-Hu révélant un cancer bronchique à petites cellules.

INTRODUCTION: Paraneoplastic syndromes are a rare cancer complication with a frequent subacute evolution. OBSERVATION: A 62-year-old man was admitted presenting with a cerebellar syndrome and orthostatic hypotension with dysautonomia. Anti-Hu antibody research was positive. A subcarinal adenopathy biopsy found out a small cell lung carcinoma. Despite a treatment with immunoglobulin and chemotherapy, the patient died suddenly, after a raise of dysautonomia symptoms. CONCLUSION: Sudden death observations represent exceptional complications of paraneoplastic syndrome. They might be secondary to arrhythmias, ictal asystol or laryngospasm. Systematic research of paroxystic heart arrhythmias with holter-ECG in paraneoplastic syndrome may prevent sudden deaths.

[Evaluation of autonomic nervous function by assessing baroreceptor reflex].

The autonomic nervous functional tests assessing baroreceptor reflex (BR) were described. I. Head-up tilt test: Sympathetic nervous function is activated and alginine-vasopressin is secreted through the BR. Orthostatic hypotension is induced by BR dysfunction. II. Spectral analysis of heart and blood pressure: High-frequency power in R-R interval variability indicates parasympathetic function and low-frequency power may reflect BR function. Low-frequency power in blood pressure may indicate sympathetic nervous function. However, spectral analysis of them can not detect a sympathetic nervous hyperfunction. III. Baroreceptor sensitivity during the Valsalva maneuver: Baroreceptor sensitivity is obtained from the correlation of systolic blood pressure and RR interval. It decreases in early stage of Parkinson's disease. IV. Correlation of heart rate and blood pressure: The correlation of them may reflect qualitative differences in the central autonomic dysfunction.

Skin sympathetic fiber α-synuclein deposits: a potential biomarker for pure autonomic failure.

OBJECTIVE: This study aimed to test whether peripheral α-synuclein staining might be useful for pure autonomic failure (PAF) diagnosis, helping to differentiate degenerative from acquired peripheral autonomic neuropathy. METHODS: We studied 21 patients with chronic peripheral autonomic neuropathy showing sympathetic and parasympathetic involvement as confirmed by cardiovascular reflexes and microneurography from the peroneal nerve. Twelve patients showed a specific cause of neuropathy (acquired autonomic neuropathy) whereas 9 had no specific acquired causes fulfilling the diagnostic criteria for PAF. Fifteen matched healthy subjects served as controls. Subjects underwent skin biopsy from thigh and leg to study skin innervation and phosphorylated α-synuclein deposits in the peripheral axons. RESULTS: Somatic and autonomic skin innervations were significantly decreased in patients with peripheral autonomic neuropathy compared to controls. No differences were found between acquired autonomic neuropathy and PAF. The deposits of α-synuclein were not found in controls but served to distinguish acquired from degenerative autonomic peripheral neuropathy: all patients with PAF showed α-synuclein deposits, which were absent in patients with acquired autonomic neuropathy. Colocalization study disclosed α-synuclein neuritic inclusions in the postganglionic sympathetic adrenergic and cholinergic nerve fibers. CONCLUSIONS: Our study demonstrated that a search for neuritic inclusions of phosphorylated α-synuclein in the skin sympathetic nerve fibers could provide a sensitive in vivo biomarker for degenerative peripheral autonomic neuropathy and may shed more light on the pathogenesis of PAF.

Confounders of vasovagal syncope: orthostatic hypotension.

A syncope evaluation should start by identifying potentially life-threatening causes, including valvular heart disease, cardiomyopathies, and arrhythmias. Most patients who present with syncope, however, have the more benign vasovagal (reflex) syncope. A busy syncope practice often also sees patients with neurogenic orthostatic hypotension presenting with syncope or severe recurrent presyncope. Recognition of these potential confounders of syncope might be difficult without adequate knowledge of their presentation, and this can adversely affect optimal management. This article reviews the presentation of the vasovagal syncope confounder and the putative pathophysiology of orthostatic hypotension, and suggests options for nonpharmacologic and pharmacologic management.

Effect of laser arytenoidectomy on respiratory stridor caused by multiple system atrophy.

Respiratory stridor in patients with multiple system atrophy is a complication that occasionally causes nocturnal sudden death. Continuous positive airway pressure (CPAP) therapy has been proposed as an alternative to tracheostomy to treat nocturnal stridor associated with multiple system atrophy. However, some patients cannot tolerate CPAP therapy and experience sleep disturbances, even if the pressure is controlled; also, CPAP therapy can be less effective in patients with a narrow glottic opening during sleep. This report describes the effect of laser arytenoidectomy on respiratory stridor caused by multiple system atrophy.

The impact of autonomic dysfunction on survival in patients with dementia with Lewy bodies and Parkinson's disease with dementia.

INTRODUCTION: Autonomic dysfunction is a well-known feature in neurodegenerative dementias, especially common in α-synucleinopathies like dementia with Lewy bodies and Parkinson's disease with dementia. The most common symptoms are orthostatic hypotension, incontinence and constipation, but its relevance in clinical practice is poorly understood. There are no earlier studies addressing the influence of autonomic dysfunction on clinical course and survival. The aim of this study was to investigate the frequency of the three most common features of autonomic dysfunction and analyze how it affects survival. METHODS: Thirty patients with dementia with Lewy bodies and Parkinson's disease with dementia were included in this prospective, longitudinal follow-up study. Presence of incontinence and constipation was recorded at baseline. Blood pressure was measured at baseline, after 3 months and after 6 months according to standardized procedures, with 5 measurements during 10 minutes after rising. Orthostatic hypotension was defined using consensus definitions and persistent orthostatic hypotension was defined as 5 or more measurements with orthostatic hypotension. Difference in survival was analyzed 36 months after baseline. RESULTS: There was a high frequency of persistent orthostatic blood pressure (50%), constipation (30%) and incontinence (30%). Patients with persistent orthostatic hypotension had a significantly shorter survival compared to those with no or non-persistent orthostatic hypotension (Log rank x(2) = 4.47, p = 0.034). Patients with constipation and/or urinary incontinence, in addition to persistent orthostatic hypotension, had a poorer prognosis compared to those with isolated persistent orthostatic hypotension or no orthostatic hypotension (Log rank x(2) = 6.370, p = 0.041). DISCUSSION: According to our findings, the identification of autonomic dysfunction seems to be of great importance in clinical practice, not only to avoid falls and other complications, but also as a possible predictor of survival.

Neurogenic orthostatic hypotension as the initial feature of Parkinson disease.

Autonomic failure is a common finding in patients with Parkinson disease (PD). Here we describe a patient with PD in whom autonomic symptoms began 3 years before motor deficits.

Synergistic effect of norepinephrine transporter blockade and α-2 antagonism on blood pressure in autonomic failure.

Patients with autonomic failure have disabling orthostatic hypotension because of impaired sympathetic activity. Norepinephrine transporter blockade with atomoxetine raises blood pressure in autonomic failure by increasing synaptic norepinephrine concentrations in postganglionic sympathetic neurons. This effect requires tonic release of norepinephrine, which is decreased in patients with low sympathetic tone. We hypothesized that increasing residual sympathetic outflow with the α-2 antagonist yohimbine would potentiate the pressor effect of norepinephrine transporter blockade with atomoxetine and improve orthostatic tolerance in peripheral autonomic failure. Seventeen patients received a single oral dose of either placebo, yohimbine 5.4 mg or atomoxetine 18.0 mg, and the combination yohimbine and atomoxetine in a single blind, crossover study. Blood pressure was assessed while patients were seated and standing for ≤10 minutes before and 1 hour postdrug. Neither yohimbine nor atomoxetine significantly increased seated systolic blood pressure or orthostatic tolerance compared with placebo. The combination, however, significantly increased seated systolic blood pressure and orthostatic tolerance (P<0.001 and P=0.016, respectively) in a synergistic manner. The maximal increase in seated systolic blood pressure seen with the combination was 31±33 mm Hg at 60 minutes postdrug. Only the combination showed a significant improvement in orthostatic symptoms. In conclusion, the combination of yohimbine and atomoxetine had a synergistic effect on blood pressure and orthostatic tolerance in peripheral autonomic failure, which may be explained by an increased release of norepinephrine in peripheral sympathetic neurons by α-2 antagonism combined with a reduced norepinephrine clearance by norepinephrine transporter blockade. Safety studies are required to address the clinical usefulness of this pharmacological approach.