From the Guidelines
Dysautonomia should be understood as a broad term encompassing various disorders of the autonomic nervous system, including neurogenic orthostatic hypotension, reflex syncope, and postural orthostatic tachycardia syndrome, as highlighted in the 2018 ESC guidelines 1. When considering dysautonomia, it's crucial to recognize that the term is often used beyond its specific meaning in "familial dysautonomia" (Riley–Day syndrome), to describe any abnormal function of the autonomic nervous system. This includes a range of conditions that affect involuntary bodily functions such as heart rate, blood pressure, and digestion. Key aspects of dysautonomia management include:
- Increased fluid intake to maintain blood volume
- Salt consumption to help regulate blood pressure
- Use of compression garments to prevent blood pooling
- Medications like fludrocortisone, midodrine, and beta-blockers to manage specific symptoms
- Physical therapy to improve tolerance to upright posture It's essential to approach dysautonomia with a comprehensive understanding of its various forms and to tailor treatment to the specific symptoms and underlying causes, as emphasized by the practical instructions for the 2018 ESC guidelines for the diagnosis and management of syncope 1. Given the complexity and variability of dysautonomia, a personalized treatment plan focusing on improving quality of life and reducing morbidity and mortality is paramount, considering the latest guidelines and evidence-based practices 1.
From the Research
Definition and Classification of Dysautonomia
- Dysautonomia covers a range of clinical conditions with different characteristics and prognoses, including Reflex Syndromes, Postural Orthostatic Tachycardia Syndrome (POTS), Chronic Fatigue Syndrome, Neurogenic Orthostatic Hypotension (nOH), and Carotid Sinus Hypersensitivity Syndrome 2.
- Cardiovascular Autonomic Neuropathy (CAN) is a term used to define dysautonomia with impairment of the sympathetic and/or parasympathetic cardiovascular autonomic nervous system, which can be idiopathic or secondary to systemic pathologies such as diabetes mellitus, neurodegenerative diseases, and amyloidosis 2.
Diagnosis of Dysautonomia
- The diagnostic journey for individuals affected by dysautonomia can be hindered by symptom overlap with other conditions and limited access to autonomic specialists, with an average time to diagnosis of 7.7 years 3.
- Common diagnostic tests for dysautonomia include Valsalva, Respiratory, and Orthostatic tests (30:15), which can detect initial or subclinical abnormalities and assess severity and prognosis 2.
- The Tilt Test can also be used to investigate CAN, but it is not the test of choice for early-stage diagnosis 2.
Treatment and Management of Dysautonomia
- Treatment of patients with dysautonomia is complex and often refractory, requiring specialized and multidisciplinary evaluation 2.
- Preventive measures such as postural care, good hydration, higher salt intake, and supervised physical activity are important treatment steps 2.
- Various drugs can be used for symptomatic treatment of nOH, including fludrocortisone, midodrine, and droxidopa, although the risk of exacerbation or triggering supine hypertension should be considered 2.
- Pyridostigmine, a reversible acetylcholinesterase inhibitor, has been shown to be effective in improving symptoms of orthostatic intolerance in patients with POTS, with a response rate of 43% in one study 4.
Associated Conditions and Comorbidities
- Dysautonomia can be associated with various comorbid conditions, including Ehlers-Danlos syndrome, mast cell disorders, vitamin deficiency, fibromyalgia, and myalgic encephalomyelitis, which can contribute to the symptom burden and confound the diagnostic process 3.
- Autonomic dysfunction can also be a feature of neurodegenerative diseases such as Parkinson's disease, multiple system atrophy, and dementia with Lewy bodies, as well as secondary to systemic pathologies such as diabetes mellitus and amyloidosis 5.