Dysautonomia in Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease, characterized in its typical presentation by a combination of lower and upper motor neuron symptoms, with a progressive course and fatal outcome. Due to increased recognition of the non-motor symptoms, it is currently considered a multisystem disorder with great heterogeneity, regarding genetical, clinical, and neuropathological features. Often underestimated, autonomic signs and symptoms have been described in patients with ALS, and various method analyses have been used to assess autonomic nervous system involvement. The aim of this paper is to offer a narrative literature review on autonomic disturbances in ALS, based on the scarce data available to date.

Adynamic response to cold pain reflects dysautonomia in type 1 diabetes and polyneuropathy.

Cardiac autonomic neuropathy (CAN), widely assessed by heart rate variability (HRV), is a common complication of long-term diabetes. We hypothesized that HRV dynamics during tonic cold pain in individuals with type 1 diabetes mellitus (T1DM) could potentially demask CAN. Forty-eight individuals with long-term T1DM and distal symmetrical polyneuropathy and 21 healthy controls were included. HRV measures were retrieved from 24-h electrocardiograms. Moreover, ultra-short-term HRV recordings were used to assess the dynamic response to the immersion of the hand into 2 °C cold water for 120 s. Compared to healthy, the T1DM group had expectedly lower 24-h HRV measures for most components (p < 0.01), indicating dysautonomia. In the T1DM group, exposure to cold pain caused diminished sympathetic (p < 0.001) and adynamic parasympathetic (p < 0.01) HRV responses. Furthermore, compared to healthy, cold pain exposure caused lower parasympathetic (RMSSD: 4% vs. 20%; p = 0.002) and sympathetic responses (LF: 11% vs. 73%; p = 0.044) in the T1MD group. QRISK3-scores are negatively correlated with HRV measures in 24-h and ultra-short-term recordings. In T1DM, an attenuated sympathovagal response was shown as convincingly adynamic parasympathetic responses and diminished sympathetic adaptability, causing chronometric heart rhythm and rigid neurocardiac regulation threatening homeostasis. The findings associate with an increased risk of cardiovascular disease, emphasizing clinical relevance.

Vagus nerve inflammation contributes to dysautonomia in COVID-19.

Dysautonomia has substantially impacted acute COVID-19 severity as well as symptom burden after recovery from COVID-19 (long COVID), yet the underlying causes remain unknown. Here, we hypothesized that vagus nerves are affected in COVID-19 which might contribute to autonomic dysfunction. We performed a histopathological characterization of postmortem vagus nerves from COVID-19 patients and controls, and detected SARS-CoV-2 RNA together with inflammatory cell infiltration composed primarily of monocytes. Furthermore, we performed RNA sequencing which revealed a strong inflammatory response of neurons, endothelial cells, and Schwann cells which correlated with SARS-CoV-2 RNA load. Lastly, we screened a clinical cohort of 323 patients to detect a clinical phenotype of vagus nerve affection and found a decreased respiratory rate in non-survivors of critical COVID-19. Our data suggest that SARS-CoV-2 induces vagus nerve inflammation followed by autonomic dysfunction which contributes to critical disease courses and might contribute to dysautonomia observed in long COVID.

Heart Rate Variability Parameter Changes in Patients With Acute Ischemic Stroke Undergoing Intravenous Thrombolysis.

Background Autonomic dysfunction has been revealed in patients with acute ischemic stroke and is associated with poor prognosis. However, autonomic nervous system function assessed by heart rate variability (HRV) and its relationship with clinical outcomes in patients undergoing intravenous thrombolysis (IVT) remain unknown. Methods and Results Patients who did and did not undergo IVT between September 2016 and August 2021 were prospectively and consecutively recruited. HRV values were measured at 1 to 3 and 7 to 10 days after stroke to assess autonomic nervous system function. A modified Rankin scale score ≥2 at 90 days was defined as an unfavorable outcome. Finally, the analysis included 466 patients; 224 underwent IVT (48.1%), and 242 did not (51.9%). Linear regression showed a positive correlation of IVT with parasympathetic activation-related HRV parameters at 1 to 3 days (high frequency: ß=0.213, P=0.002) and with both sympathetic (low frequency: ß=0.152, P=0.015) and parasympathetic activation-related HRV parameters (high frequency: ß=0.153, P=0.036) at 7 to 10 days after stroke. Logistic regression showed HRV values and autonomic function within 1 to 3 and 7 to 10 days after stroke were independently associated with 3-month unfavorable outcomes after adjusting for confounders in patients who underwent IVT (all P<0.05). Furthermore, addition of HRV parameters to conventional risk factors significantly improved risk-predictive ability of 3-month outcome (the area under the receiver operating characteristic curve significantly improved from 0.784 [0.723-0.846] to 0.855 [0.805-0.906], P=0.002). Conclusions IVT positively affected HRV and autonomic nervous system activity, and autonomic function assessed by HRV in acute stroke phase was independently associated with unfavorable outcomes in patients undergoing IVT.

Cardiorespiratory dysautonomia in post-COVID-19 condition: Manifestations, mechanisms and management.

A significant proportion of COVID-19 patients experience debilitating symptoms for months after the acute infection. According to recent estimates, approximately 1 out of 10 COVID-19 convalescents reports persistent health issues more than 3 months after initial recovery. This 'post-COVID-19 condition' may include a large variety of symptoms from almost all domains and organs, and for some patients it may mean prolonged sick-leave, homestay and strongly limited activities of daily life. In this narrative review, we focus on the symptoms and signs of post-COVID-19 condition in adults - particularly those associated with cardiovascular and respiratory systems, such as postural orthostatic tachycardia syndrome or airway disorders - and explore the evidence for chronic autonomic dysfunction as a potential underlying mechanism. The most plausible hypotheses regarding cellular and molecular mechanisms behind the wide spectrum of observed symptoms - such as lingering viruses, persistent inflammation, impairment in oxygen sensing systems and circulating antibodies directed to blood pressure regulatory components - are discussed. In addition, an overview of currently available pharmacological and non-pharmacological treatment options is presented.

Autonomic nervous system involvement in chronic inflammatory demyelinating polyradiculoneuropathy: a literature review.

BACKGROUND AND AIMS: Although dysautonomia is a well-recognized complication of acute demyelinating polyradiculoneuropathy, it is rarely reported and evaluated in chronic demyelinating neuropathies. The purpose of this review is to search and synthesize the current literature on the prevalence and type of autonomic dysfunction (AD) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). METHODS: PubMed and Web of Science were searched for studies reporting AD in CIDP. RESULTS: Twelve studies, including 346 patients with CIDP, were found eligible for the review. Seven studies used autonomic tests only as an additional component of the comprehensive clinical evaluation, and found that dysautonomia in CIDP may indicate the presence of a comorbid disease (e.g., diabetes) and facilitate the differentiation of CIDP from other neuropathies (e.g., amyloid neuropathy). Five studies performed quantitative assessment of autonomic function in CIDP as a primary goal. Two studies have used the Composite Autonomic Severity Score (CASS) to assess severity and distribution of dysautonomia. The reported prevalence of dysautonomia in CIDP during quantitative assessment of autonomic function ranged from 25 to 89%, depending on the battery of tests used, with CASS not exceeding 4 points. The abnormalities in autonomic tests indicated both sympathetic and parasympathetic dysfunction and did not correlate with the duration, severity and variant of CIDP. CONCLUSIONS: Clinical or subclinical involvement of the ANS has been shown to be common and relatively mild in CIDP. The impact of autonomic impairment on disability and of its possible response to therapy in CIDP needs to be further investigated.

Natural History of Pediatric Cyclic Vomiting Syndrome: Progression to Dysautonomia.

BACKGROUND: The clinical features of pediatric cyclic vomiting syndrome (CVS) often evolve over time. Many patients develop a constellation of chronic symptoms that suggest autonomic nervous system (ANS) dysfunction during adolescence. We aimed to determine the proportion of children with CVS who develop chronic rather than episodic symptoms consistent with ANS dysfunction. METHODS: Retrospective chart review of children ages 0-18 years followed in an outpatient tertiary care CVS center. Patients completed standardized questionnaires at intake and follow-up visits, documenting clinical symptom pattern. Continuous variables are summarized as median [interquartile range (IQR)]. A Mann-Whitney test was used for group comparisons. RESULTS: One hundred subjects were included. A total of 40% developed symptoms of ANS dysfunction (ANS+); 20% were confirmed by comprehensive ANS testing, 11% by orthostatic vital sign abnormalities, and 9% by clinical symptoms. The median (IQR) age at onset of chronic symptoms was 14 (10.02, 15) years. The presence of another disorder of gut-brain interaction ( P = 0.018) and a greater number of comorbidities ( P = 0.031) were more common in the ANS+ group. ANS+ subjects missed more school days ( P = 0.047) and were seen less frequently in the emergency department ( P = 0.023). CONCLUSIONS: Many children with CVS (40%) develop symptoms consistent with clinical dysautonomia in adolescence. These patients experience more comorbid conditions and a greater impact on school attendance, possibly representing a worsened quality of life as their disease course transitions to daily symptoms. When symptoms of CVS change over time, therapeutic interventions may need to be adjusted and targeted accordingly.

Dysautonomia: Diagnosis and Management.

Dysautonomias are a heterogenous group of disorders that can cause variable symptoms ranging from isolated impairment of one autonomic function to multisystem failure. The causes are also diverse and can be central or peripheral and primary (owing to an intrinsic neurologic cause) or secondary (owing to a disorder that secondarily causes damage to the autonomic nervous system). This review covers common phenotypes of dysautonomias, primary and secondary causes, initial clinical workups, interpretation of common autonomic tests, and first-line treatments. A brief review of autonomic impairment associated with acute and long-COVID is also presented.

Cardiovascular Autonomic Assessment in Guillain-Barré Syndrome: A Longitudinal Study.

Background: Severe dysautonomia is typically seen during acute phase of Guillain-Barré syndrome (GBS). Objective: To investigate the relationship of cardiovascular autonomic dysfunction with motor recovery in GBS. Materials and Methods: Consecutive GBS patients presented to our hospital were recruited. Clinical assessment was evaluated with the Medical Research Council (MRC) sum score and GBS disability score (GDS). All patients had series of autonomic testing on admission and after treatment at 6 and 24 weeks. Both computation-dependent tests (heart rate variability [HRV] and baroreflex sensitivity [BRS]) and autonomic maneuvers were performed. Age- and gender-matched healthy controls (HC) were recruited. The data obtained at admission, 6 weeks and 24 weeks were compared within groups for statistical difference. Results: Six patients (4 men; mean age 39.5 ± 14.3 years) were recruited over one year. Five had GBS and one Miller Fisher syndrome. The mean MRC sum score and GDS on admission were 52.3 ± 4.3 and 3.5 ± 0.8 respectively. During admission, time-domain average RR interval (AVNN) and BRS were significantly poorer among cases compared to HC. Active standing 30:15 ratio and cold pressor test at admission were also significantly abnormal when compared with HC. All the autonomic parameters had normalized by 6 weeks and these were significant for the high frequency-HRV, BRS, and active standing 30:15 ratio. For MRC and GDS, there were significant improvements in the scoring over a period of 24 weeks. Conclusions: Dysautonomia in GBS improved gradually and in keeping with motor and disability recovery.

Severe treatment-refractory antibody positive autoimmune autonomic ganglionopathy after mRNA COVID19 vaccination.

BACKGROUND: COVID-19 vaccine-associated peripheral and central neuroimmunological disorders have been well described. We present the case of a 56 year old male who developed α3-ganglionic AChR antibody positive Autoimmune Autonomic Ganglionopathy (AAG) after completion of a two-dose course of mRNA (Comirnaty) vaccination for COVID19. RESULTS: A previously hypertensive 56 year old male presented with the subacute onset of severe constipation, urinary retention, erectile dysfunction, sudomotor failure, sicca symptoms, non-reactive pupils and severe orthostatic hypotension shortly after receiving the second dose of an mRNA vaccine against COVID19. Autonomic testing revealed severe cardiovagal, adrenergic and sudomotor impairment, and tonic 'half-mast' pupils with evidence of sympathetic and parasympathetic denervation. Pathological α3-ganglionic ACHR antibodies were positive in serum as detected by a new flow cytometric immunomodulation assay. Malignancy was excluded. The patient was diagnosed with severe, treatment-refractory acute AAG. CONCLUSIONS: While autonomic dysfunction has been previously reported post-COVID19 vaccination, to our knowledge this is the first reported case of antibody-positive AAG in this setting. The severity of this case is in marked contrast to the existing literature on idiopathic antibody-positive autoimmune pandysautonomia.

Selected autonomic signs and symptoms as risk markers for phenoconversion and functional dependence in prodromal Parkinson's disease.

PURPOSE: To determine whether dysautonomia can stratify individuals with other prodromal markers of Parkinson's disease (PD) for risk of phenoconversion and functional decline, which may help identify subpopulations appropriate for experimental studies. METHODS: Data were obtained from Parkinson's Progression Markers Initiative. Cohorts without PD but with at-risk features were included (hyposmia and/or rapid-eye-movement-sleep behavior disorder, LRRK2 gene mutation, GBA gene mutation). Dysautonomia measures included Scales-for-Outcomes-in-Parkinson's-Disease Autonomic (SCOPA-AUT), seven SCOPA-AUT subscales, and cardiovascular dysfunction (supine hypertension, low pulse pressure, neurogenic orthostatic hypotension). Outcome measures were phenoconversion and Schwab-and-England Activities-of-Daily-Living (SE-ADL) ≤ 70, which indicates functional dependence. Cox proportional-hazards regression was used to evaluate survival to phenoconversion/SE-ADL ≤ 70 for each dysautonomia measure. If a significant association was identified, a likelihood-ratio test was employed to evaluate whether a significant interaction existed between the measure and cohort. If so, regression analysis was repeated stratified by cohort. RESULTS: Median follow-up was 30 months. On multivariable analysis, gastrointestinal and female sexual dysfunction subscales were associated with increased risk of phenoconversion, while the cardiovascular subscale and neurogenic orthostatic hypotension were associated with increased risk of SE-ADL ≤ 70; respective hazard ratios (95% confidence intervals) were 1.13 (1.01-1.27), 3.26 (1.39-7.61), 1.87 (1.16-2.99), 5.45 (1.40-21.25). Only the association between the cardiovascular subscale and SE-ADL ≤ 70 was modified by cohort. CONCLUSIONS: Symptoms of gastrointestinal and female sexual dysfunction predict phenoconversion in individuals with other risk markers for PD, while signs and symptoms of cardiovascular dysfunction may be associated with functional decline.

Burden of caregiving for cardiovascular dysautonomia in Parkinson's disease.

PURPOSE: We sought to estimate the impact of cardiovascular autonomic neuropathy (cAN) on informal caregivers of patients with Parkinson's disease (PD), defined as individuals providing regular care to a friend, partner, or family member with PD, and to evaluate the mutual relationship between caregiver burden and patient health-related quality of life (HRQoL). METHODS: We enrolled 36 consecutive patients with PD and their informal caregivers. Patients underwent a detailed motor, autonomic, cognitive, and functional assessment. Caregivers were assessed using the Zarit Burden Interview (ZBI). Differences in caregiver burden, expressed by the ZBI score, and strength of association between caregiver burden, cAN, and HRQoL were assessed using analysis of covariance (ANCOVA), logistic regression, and linear regression analyses. Analyses were adjusted for patients' age, PD duration, and motor and cognitive disability, as well as caregivers' age. RESULTS: Moderate-severe caregiver burden was reported in 41.7% of PDcAN+ versus 8.7% of PDcAN- (p < 0.001). The ZBI score was increased in PDcAN+ versus PDcAN- (31.5 ± 3.4 versus 15.2 ± 2.3; p < 0.001), with tenfold higher odds (p = 0.012) of moderate-severe caregiver burden in PDcAN+, even after adjusting for potential confounders. The ZBI score correlated with cAN severity (p = 0.005), global autonomic impairment (p = 0.012), and HRQoL impairment (p < 0.001). CONCLUSION: These results highlight the significant impact of cAN on PD caregivers and the need for targeted interventions addressing this frequently overlooked and insufficiently treated source of nonmotor disability in PD.

Prevalence and patterns of symptoms of dysautonomia in patients with long-COVID syndrome: A cross-sectional study.

BACKGROUND: The association between autonomic dysfunction and long-COVID syndrome is established. However, the prevalence and patterns of symptoms of dysautonomia in long-COVID syndrome in a large population are lacking. OBJECTIVE: To evaluate the prevalence and patterns of symptoms of dysautonomia in patients with long-COVID syndrome. METHODS: We administered the Composite Autonomic Symptom Score 31 (COMPASS-31) questionnaire to a sample of post-COVID-19 patients who were referred to post-COVID clinic in Assiut University Hospitals, Egypt for symptoms concerning for long-COVID syndrome. Participants were asked to complete the COMPASS-31 questionnaire referring to the period of more than 4 weeks after acute COVID-19. RESULTS: We included 320 patients (35.92 ± 11.92 years, 73% females). The median COMPASS-31 score was 26.29 (0-76.73). The most affected domains of dysautonomia were gastrointestinal, secretomotor, and orthostatic intolerance with 91.6%, 76.4%, and 73.6%, respectively. There was a positive correlation between COMPASS-31 score and long-COVID duration (p < 0.001) and a positive correlation between orthostatic intolerance domain score and post-COVID duration (p < 0.001). There was a positive correlation between orthostatic intolerance domain score and age of participants (p = 0.004). Two hundred forty-seven patients (76.7%) had a high score of COMPASS-31 >16.4. Patients with COMPASS-31 >16.4 had a longer duration of long-COVID syndrome than those with score <16.4 (46.2 vs. 26.8 weeks, p < 0.001). CONCLUSIONS: Symptoms of dysautonomia are common in long-COVID syndrome. The most common COMPASS-31 affected domains of dysautonomia are gastrointestinal, secretomotor, and orthostatic intolerance. There is a positive correlation between orthostatic intolerance domain score and patients' age.

[Current concepts about autonomic dysfunction in patients with epilepsy]. / Sovremennye predstavleniya o vegetativnoi disfunktsii u patsientov s epilepsiei.

Autonomic dysfunction is frequently observed in people with epilepsy. Ictal and postictal dysautonomia is not only manifestation of autonomic seizures, but could be a life threatening condition in some cases and contribute to sudden unexpected death (SUDEP). Interictal decrease of autonomic activity is associated with duration and severity of epilepsy, it is the most prominent in focal and drug-resistant epilepsy. Progress in our understanding of the underlying mechanisms, development of the autonomic assessment methods, and its integration in novel technical solutions for seizure detection will improve the quality of care for people with epilepsy.

Severe Post-COVID-19 dysautonomia: a case report.

BACKGROUND: The emergence of dysautonomia as a consequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; or COVID-19) is becoming more prevalent. We have seen evidence in several post-COVID patients and in the literature of varying degrees of autonomic dysfunction. Symptoms, among others, include inappropriate tachycardia, sweating, anxiety, insomnia and blood pressure variability from the effects of excessive catecholamine, as well as cognitive impairment, fatigue, headaches and orthostatic intolerance from decreased brain perfusion. CASE PRESENTATION: We present a case of severe dysautonomia in a previously healthy 27-year-old runner. About five weeks after her initial mild COVID-19 infection, the patient began to develop weakness, which progressed into severe post-exertional fatigue, slowed cognition, headaches, blurred vision and generalized body aches. She also endorsed palpitations, especially when getting up from a seated or lying position as well as with mild exertion. She became reliant on her husband for help with her activities of daily living. Exam was significant for orthostasis; laboratory workup unremarkable. Over the following months, the patient's symptoms have improved slowly with fluid and sodium intake, compression stockings and participating in a graduated exercise program. CONCLUSIONS: Dysautonomia as a consequence of infection with COVID-19 is becoming increasingly discussed, especially as more patients recover from COVID-19. This is a case of a non-hospitalized patient with a mild initial presentation and significant, debilitating dysautonomia symptoms. More research on its pathophysiology, especially in relation to a precedent viral insult, as well as its treatment, is needed.