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.

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.

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.

Orthostatic hypotension is differentially associated with the cerebellar versus the parkinsonian variant of multiple system atrophy: a comparative study.

Orthostatic hypotension (OH) is a cardinal feature of autonomic failure in multiple system atrophy (MSA); however, there are few comparative data on OH in the motor subtypes of MSA. In the present retrospective study, postural blood pressure drop after 3 min of standing was determined in 16 patients with the cerebellar variant of MSA (MSA-C) and in 17 patients with the Parkinson variant (MSA-P). Twenty idiopathic Parkinson's disease (IPD) patients matched for age, sex, disease duration and dopaminergic therapy served as control group. OH frequency and severity were more pronounced in MSA-C followed by MSA-P and IPD. Differences in brainstem pathology are likely to account for the tight association of MSA-C and OH. A simple standing test should be obligatory in the work-up of patients with sporadic late-onset ataxias.

Modelling progressive autonomic failure in MSA: where are we now?

Multiple system atrophy (MSA) is a fatal late-onset α-synucleinopathy that presents with features of ataxia, Parkinsonism, and pyramidal dysfunction in any combination. Over the last decade, efforts have been made to develop preclinical MSA testbeds for novel interventional strategies. The main focus has been on murine analogues of MSA-linked motor features and their underlying brainstem, cerebellar and basal ganglia pathology. Although progressive autonomic failure (AF) is a prominent clinical feature of patients with MSA, reflecting a disruption of both central and peripheral autonomic networks controlling cardiovascular, respiratory, urogenital, gastrointestinal and sudomotor functions, attempts of modelling this aspect of the human disease have been limited. However, emerging evidence suggests that AF-like features may occur in transgenic MSA models reflecting α-synucleinopathy lesions in distributed autonomic networks. Further research is needed to fully characterize both autonomic and motor features in optimized preclinical MSA models.

Neurogenic orthostatic hypotension of Parkinson's disease: what exploration for what treatment?

The aim of this short review is to illustrate, using orthostatic hypotension as an example, the clinical problems related to autonomic features in Parkinson's disease. Orthostatic hypotension is frequently encountered in Parkinson's disease and its diagnosis remains manometric (a fall of at least 20 and/or 10 mmHg in standing blood pressure). It is often associated with supine hypertension to be taken into account before prescribing. To distinguish between the role of disease and of drugs (not only antiparkinsonian drugs), a simple clinical test of autonomic nervous system activity (deep breathing test and standing test with measurement of 30/15 ratio) can be used. When diagnosis with multisystem atrophy is discussed, cardiac [¹²³I]-metaiodobenzylguanidine (MIBG) scintigraphy is of value showing in Parkinson's disease a decreased uptake of the radiopharmaceutical indicating postganglionic sympathetic denervation. Concerning treatment, nonpharmacological methods have to be systematically used since no drug has been specifically evaluated for the treatment of orthostatic hypotension of Parkinson's disease.

The close relationship between life-threatening breathing disorders and urine storage dysfunction in multiple system atrophy.

Survival of multiple system atrophy (MSA) depends on whether a variety of sleep-related breathing problems as well as autonomic failure (AF) occur. Since the brainstem lesions that cause respiratory and autonomic dysfunction overlap with each other, these critical manifestations might get worse in parallel. If so, the detection of AF, which is comparatively easy, might be predictive of a latent life-threatening breathing disorder. In 15 patients with MSA, we performed autonomic function tests composed of postural challenges and administered a questionnaire on bladder condition, as well as polysomnography and laryngoscopy during wakefulness and under anesthesia. Polysomnographic variables such as the apnea-hypopnea index (AHI) and oxygen saturation (SpO(2)) and the findings of laryngoscopy were compared with the degree of cardiac and urinary autonomic dysfunction. AHI, mean SpO(2) and the lowest SpO(2) showed significant correlations with urine storage dysfunction. In addition, patients with vocal cord abductor paralysis (VCAP) or central sleep apnea (CSA) contributing to nocturnal sudden death had more severe storage disorders than those without. On the other hand, no significant relationship between polysomnographic variables and orthostatic hypotension was observed except in the case of mean SpO(2). These results indicate that life-threatening breathing disorders have a close relationship with AF, and especially urine storage dysfunction. Therefore, longitudinal assessment of deterioration of the storage function might be useful for predicting the latent progress of VCAP and CSA.

Multiple system atrophy masking multiple sclerosis.

Multiple system atrophy (MSA) and multiple sclerosis (MS) are progressive neurological disorders with overlapping clinical signs and symptoms. However, due to the course of the disease and the age of onset both disorders are rarely differential diagnosis for each other. We here report the remarkable association of the two diseases in one patient. As MSA dominated the clinical presentation, diagnosis and therapy of MS were delayed. We discuss the clinical symptoms in our patient and highlight the features that allow to differentiate both diseases.

Chiari drop attacks: surgical decompression and the role of tilt table testing.

BACKGROUND: Chiari I malformation (CM1) is characterized by impaired CSF flow through the foramen magnum. Dysfunctional autonomic cardiovascular regulation may result in syncope. Syncope may be the primary presenting symptom of CM1: a syndrome termed Chiari drop attack. It has been postulated that Chiari drop attack is secondary to dysautonomia caused by hindbrain compression. There has been recent debate regarding the association between CM1, dysautonomia and Chiari drop attack. METHODS: We selected patients with Chiari drop attacks who had negative workups for cardiac syncope, followed by tilt table testing and subsequent surgical decompression. We report test results and clinical outcomes following CM1 decompression. RESULTS: Ten patients met the inclusion criteria: 5 patients had positive and 5 negative tilt table tests. Following decompression, 7 had symptomatic improvement or resolution and 3 failed to improve. The sensitivity and specificity of the tilt table test for detecting clinical improvement with surgical decompression was 43 and 33%, respectively. Tilt table testing had 40% accuracy in predicting clinical response to decompression. CONCLUSIONS: In this short series, surgical decompression of CM1 has a high success rate (70%) for patients with Chiari drop attacks. Tilt table testing has poor predictive value in judging the clinical response to surgical decompression and is not a useful test to guide surgical decision- making.

Management of non-motor complications in Parkinson's disease.

This paper summarizes the methods we devised for the treatment of psychosis, orthostatic hypotension, and mood disorders among the various non-motor complications of Parkinson's disease. Psychosis may not manifest when a patient believes in his/her delusions. If left untreated over a prolonged period, however, the delusions progress to paranoia that is very difficult to cure. Accordingly, enquiries should be made during routine examinations to detect the presence of psychosis and facilitate early discovery. Atypical antipsychotics are used when psychosis does not improve after reducing the doses of antiparkinson drugs. We achieved favorable results by using mianserin hydrochloride prior to this step, with efficacy being observed for hallucinations and mild delusions that often manifested at night. This drug does not act as a dopamine receptor blocker, so it has the advantage of not aggravating motor symptoms. With this therapy, it is also possible to improve motor symptoms without inducing psychosis by reducing the doses of antiparkinson drugs and locally stimulating the motor loop by deep brain stimulation of the subthalamic nucleus. We previously introduced leg-holding exercises for the treatment of orthostatic hypotension, through which blood pooled in the veins is returned to the systemic circulation by holding the knees. This can be done easily and is free of adverse reactions. Mood disorders are difficult to cope with in patients with Parkinson's disease, but may be treated by selecting an appropriate dopamine agonist while giving consideration to affinity for the dopamine D3 receptor. However, treatment becomes complicated when the dopamine receptor is overstimulated. Here we report on cases of successfully treated pathological gambling and dopamine dysregulation syndrome, which are considered difficult to manage. The solution may differ depending on a patient's environment, and it is not easy to prescribe therapy based on evidence-based medicine. The best therapy should be selected by maintaining communication with the patient and developing a relationship built on trust.

Recent developments in multiple system atrophy.

Multiple system atrophy (MSA) is a rare late onset neurodegenerative disorder which presents with autonomic failure and a complicated motor syndrome including atypical parkinsonism, ataxia and pyramidal signs. MSA is a glial alpha-synucleinopathy with rapid progression and currently poor therapeutic management. This paper reviews the clinical features, natural history and novel diagnostic criteria for MSA as well as contemporary knowledge on pathogenesis based on evidence from neuropathological studies and experimental models. An outline of the rationale for managing symptomatic deterioration in MSA is provided together with a summary of novel experimental therapeutic approaches to decrease disease progression.

Orthostatic hypotension associated with an epidermoid tumor of the IV ventricle.

We report the case of a 32-year-old man with an epidermoid tumor of the fourth ventricle. About 14 years later, he showed a tumor recurrence which was removed. After this procedure the patient complained of presyncopal and syncopal crisis while attempting to stand or walk. On examination, severe orthostatic hypotension was confirmed and autonomic tests were abnormal. The brain MRI showed a tetraventricular hydrocephalus predominating in the fourth ventricle. A ventriculo-peritoneal shunt was performed, and after surgery the orthostatic intolerance improved. We believe that hydrocephalus has probably been a contributory factor to orthostatic hypotension, and suggest expanding testing for dysautonomia in patients with hydrocephalus.

Quantitative autonomic testing in the management of botulism.

Even with mild neurological signs, patients with botulism frequently complain of autonomic symptoms. This study aimed at the evaluation of sudomotor and cardiovascular reflex functions by quantitative autonomic testing (QAT), which may identify patients with autonomic involvement but otherwise benign clinical presentation. Five patients with food-borne botulism were subjected to a structured questionnaire on autonomic symptoms, cardiac and neurological examination, and QAT after a median of 2 weeks (baseline) and 12 weeks (follow-up) post intoxication. For calculation of haemodynamic and cardiovascular autonomic parameters, we used the Task Force((R)) Monitor (Version 2.1, CNSystems, Graz, Austria). Cardiovagal function was assessed by Ewing's test battery. Autonomic complaints were more pronounced than neurological symptoms. Baseline tests revealed widely abnormal sudomotor function and marked impairment of heart rate variation and blood pressure response to standing. Prominent features of cardiovascular failure were high resting heart rate, supine hypertension, orthostatic hypotension, and impaired baroreflex function. Three patients reported inability to keep up with their routine amount of physical work. Based on the baseline QAT results, these three patients were instructed to engage in physical activity but avoid physical strain until there was considerable improvement. On follow-up, fatigue was the most frequent residual complaint, sympathetic skin responses were present, and cardiovascular QAT results were significantly improved and did not differ from those of ten control subjects. QAT identified autonomic involvement in botulism patients with otherwise benign neurological presentation. Comprehensive evaluation of autonomic failure may provide useful information for the management of botulism.

Antibody titers predict clinical features of autoimmune autonomic ganglionopathy.

Autoimmune autonomic ganglionopathy is a disorder of isolated autonomic failure associated with antibodies to the nicotinic acetylcholine receptor of the autonomic ganglia resulting in severe orthostatic intolerance, syncope, constipation, gastroparesis, urinary retention, dry mouth, dry eyes, blurred vision and anhidrosis. We report the autonomic test results, antibody titers and clinical findings in 8 patients with antibodies to the nicotinic acetylcholine receptor of the autonomic ganglia. There was a sigmoidal relation between the antibody titers and the fall in systolic blood pressure (r(2)=0.84). The threshold occurred with antibody titers of approximately 1 nmol/l. Over the linear portion of the sigmoid curve, with antibody titers in the 1-3 nmol/l range, increasing antibody titers resulted in more severe orthostatic hypotension (r=0.94, P<0.001). The saturation point of the sigmoidal relation occurred at approximately 3 nmol/l with drops in systolic blood pressure of approximately 100 mmHg during upright tilt. The antibody titers correlated inversely with the Valsalva ratio (r=-0.87, P<0.001), the 30:15 ratio (r=-0.84, P<0.001) and the expiratory to inspiratory ratio (r=-0.67, P<0.01). Patients with orthostatic intolerance, anhidrosis, constipation, urinary dysfunction, sicca syndrome and pupillary dysfunction had higher antibody titers than subjects that did not (P<0.01 in all cases). Autoimmune autonomic ganglionopathy is a clinically heterogeneous disease with variable presentation, particularly in subjects with lower antibody titers. Our data suggest that patients with higher antibody titers have wide spread dysautonomia while those with lower antibody levels may present with, or evolve into, more focal or restricted presentations.

Intrathecal baclofen for autonomic instability due to spinal cord injury.

Autonomic dysreflexia may occur following spinal cord injury above mid-thoracic level, commonly developing in the early posttraumatic period. Cardiovascular dysregulation is the most prominent feature, characterized by paroxysmal high blood pressure attacks, which are precipitated by distension of urinary bladder or bowels, skin wounds, or increased spastic muscle tone. Severe drops in blood pressure may occur in orthostatic conditions. Baclofen is effective for treating spasticity. While orally administered baclofen often fails to alleviate severe spasticity adequately, intrathecal baclofen (ITB) is more effective and thus is being used increasingly. A 61-year-old male sustained a cervical spinal cord injury, subsequently developing severe spastic tetraparesis, predominantly in the legs. Some 30 years later he experienced marked spasms of the muscles of the abdominal wall, leading to extreme fluctuations of blood pressure. After positive evaluation with ITB the patient underwent implantation of a pump-catheter-system for continuous ITB application. Abdominal wall spasms ceased entirely with a daily dose of 190 microg ITB, accompanied by a sustained normotensive blood pressure profile. However, spasms reoccurred after inadvertent reduction of ITB flow when increasing the pump's ITB concentration but subsided again when the optimal antispastic dose was reestablished. Baclofen per se has the potential of lowering blood pressure. In this patient, however, ITB treatment enabled permanent stabilization of insidious blood pressure fluctuations. It would appear that suppression of abdominal spasms prevented the triggering of dysautonomic crises. This case demonstrates that ITB administration may help to stabilize autonomic dysreflexia and orthostatic hypotension in patients with spinal cord lesions.

Other autonomic neuropathies associated with ganglionic antibody.

The acetylcholine receptor ganglionic (G-AchR) antibody is a very specific serologic test for autoimmune autonomic ganglionopathy. The spectrum of autoimmune (or presumed to be autoimmune) autonomic disorders, however, is quite broad and positivity to this antibody has been reported in a variety of other conditions, albeit infrequent and with low titer. This review describes the autonomic neuropathies most frequently encountered in clinical practice in which an autoimmune etiology is suspected. They include a chronic form (pure autonomic failure) and limited autonomic neuropathies with predominant involvement of one neurotransmitter type (i.e., cholinergic vs. adrenergic) or one system (such as the gastrointestinal system) or a distal small fiber dysfunction. In each of these conditions, occasional positivity to the G-AchR antibody has been found, but the pathogenetic significance of such finding is still uncertain. Other antigens and antibodies yet to be identified are more likely to be responsible in these disorders.

Autoimmune autonomic ganglionopathy with Sjögren's syndrome: significance of ganglionic acetylcholine receptor antibody and therapeutic approach.

Autoimmune autonomic ganglionopathy (AAG) is a disorder defined by antibodies to the nicotinic acetylcholine receptor of the autonomic ganglia. We report two patients with chronically progressing dysautonomia with Sjögren's syndrome (SS). The first case showed elevated titer of ganglionic acetylcholine receptor (AChR) antibody and improved with oral intake of prednisolone. In contrast, the second case showed no elevation of ganglionic AChR antibody titer and had poor response to immunomodulatory therapy. These two cases indicate that chronic AAG may be treatable by immunomodulatory therapy, and have relevance to SS.

Assessment of autonomic dysfunction of multiple system atrophy with laryngeal abductor paralysis as an early manifestation.

Laryngeal abductor palsy (LAP) is common in the advanced stages of multiple system atrophy (MSA). However, occurrence of LAP in the early stages might make a diagnosis of MSA difficult. To search for a clue to diagnosis of MSA with LAP as an early manifestation, we assessed the clinical features of autonomic dysfunction and the central cardiovascular control circuits in two MSA patients who had LAP as a cardinal symptom in the early stages. Development of autonomic dysfunction was preceded or followed by LAP. The autonomic symptom occurring predominantly in the earliest stages was urinary disturbance rather than orthostatic hypotension. Although screening cardiovascular autonomic function tests did not conclusively indicate a diagnosis of MSA, vasopressin release in response to head-up tilt and growth hormone response to clonidine administration demonstrated inappropriate responses, suggesting that the noradrenergic neurons of the caudal ventrolateral medulla were impaired. Diagnosis of atypical MSA with LAP in the early stages might be accelerated by a detailed investigation focused on urinary symptoms and neuroendocrine approaches.