How is dysautonomia managed?

Management of Dysautonomia

The management of dysautonomia should focus on volume expansion, vasoconstriction, and symptom-specific treatments, with vasoconstrictive agents like midodrine being most effective for orthostatic hypotension caused by autonomic dysfunction. 1

Types of Dysautonomia and Initial Assessment

• Dysautonomia refers to dysfunction of the autonomic nervous system, manifesting in various forms with different underlying mechanisms 2
• Common types include:
  • Postural orthostatic tachycardia syndrome (POTS) - defined as heart rate increase ≥30 bpm within 10 minutes of upright posture (≥40 bpm in adolescents) 2, 3
  • Neurogenic orthostatic hypotension (nOH) - a late sign indicating greater severity 3
  • Cardiovascular autonomic neuropathy (CAN) - common in diabetes and associated with increased cardiovascular mortality 3
  • Reflex syndromes (vasovagal) - generally benign and occur in patients without intrinsic autonomic nervous system disease 3

Non-Pharmacological Management

• Volume expansion strategies:
  • Increased dietary salt/electrolyte intake with fluids such as sports drinks 1
  • Salt tablets to maintain adequate intravascular volume 1
• Physical countermeasures:
  • Moderate exercise training to improve orthostatic tolerance 1
  • Progressive tilt-training (prolonged periods of enforced upright posture) may reduce syncope recurrence in highly motivated patients 1
• Compression garments:
  • Compression stockings and abdominal straps to reduce venous pooling 3
• Postural modifications:
  • Sleeping with head elevated (20-30 cm) to manage supine hypertension 3
  • Avoiding prolonged standing and sudden position changes 3

Pharmacological Management

First-Line Medications

• Vasoconstrictive agents:
  • Midodrine - alpha-stimulating agent shown to be beneficial in severely symptomatic elderly patients with vasovagal syncope 1
  • Fludrocortisone - mineralocorticoid that increases sodium retention and plasma volume 3, 4
  • Droxidopa (not available in all countries) - synthetic amino acid converted to norepinephrine 3

Second-Line Medications

• For refractory cases:
  • Paroxetine (SSRI) - shown to be effective in one placebo-controlled trial, though confirmation from additional studies is needed 1
  • Pyridostigmine - acetylcholinesterase inhibitor that may help with POTS 5
  • Ivabradine - can help control heart rate in POTS 5

Medications to Avoid or Use with Caution

• Beta-blockers:
  • Evidence fails to support beta-blocker efficacy in neurally-mediated syncope 1
  • May be detrimental in dysautonomic syndromes by enhancing bradycardia 1
• Vasodilators:
  • Discontinuation or reduction of chronic vasodilator therapy is advisable in susceptible patients 1

Special Considerations for Specific Types of Dysautonomia

Autoimmune-Mediated Dysautonomia

• For autoimmune encephalitis with severe dysautonomia:
  • Consider combination therapy of steroids/IVIG or steroids/plasma exchange from the beginning 1
  • For refractory cases, consider second-line agents like rituximab for antibody-mediated autoimmunity or cyclophosphamide for cell-mediated autoimmunity 1
  • Plasma exchange may be particularly effective but requires caution due to volume shifts in dysautonomic patients 1

Small Fiber Neuropathy in Sarcoidosis

• Small fiber neuropathy occurs in 40-60% of sarcoidosis patients and causes neuropathic symptoms and dysautonomia 1
• Treatment includes:
  • Agents specific for the condition such as IVIg and anti-TNF therapy 1
  • Supportive care for neuropathic symptoms 1

Autonomic Dysreflexia (Emergency Condition)

• Life-threatening emergency characterized by sudden severe hypertension in patients with spinal cord injuries at or above T6 level 6
• Immediate management:
  • Terminate any ongoing procedures 6
  • Remove triggering stimulus 6
  • Monitor hemodynamics continuously 6
  • For persistent symptoms with systolic BP >150 mmHg, use rapid-acting antihypertensives 6
  • For persistent bradycardia, consider methylxanthines (theophylline or aminophylline) 6

Age-Related Considerations

• Aging is associated with significant changes in autonomic function 7
• The frailest individuals exhibit the most profound autonomic dysfunction 7
• Regular physical exercise may help prevent deleterious autonomic changes associated with aging 7
• Drugs that inhibit the renin-angiotensin system may reduce frailty scores and potentially improve autonomic function 7

Common Pitfalls and Monitoring

• Inadequate monitoring of blood pressure when initiating treatment 2
• Supine hypertension can develop in >50% of neurogenic orthostatic hypotension patients, creating a therapeutic challenge 3
• The immediate risk of orthostatic hypotension should take precedence over later risks of supine hypertension 3
• Tolerable supine blood pressure values may be higher than normal (up to 160/90 mmHg) 3
• Patients with dysautonomia are often misdiagnosed with psychiatric disorders 5