What causes muscle twitching, trembling, shaking, and clenching in Postural Orthostatic Tachycardia Syndrome (POTS)?

From the Guidelines

Muscle twitching, trembling, shaking, and clenching in POTS are primarily caused by autonomic nervous system dysfunction and the body's compensatory mechanisms, leading to excessive sympathetic nervous system activation and increased adrenaline and noradrenaline levels. These symptoms typically result from the body's attempt to maintain blood pressure when changing positions, and can be exacerbated by electrolyte imbalances, particularly low potassium, magnesium, or calcium levels, as well as dehydration 1.

Causes of Muscle Symptoms in POTS

• Autonomic nervous system dysfunction
• Excessive sympathetic nervous system activation
• Increased adrenaline and noradrenaline levels
• Electrolyte imbalances (low potassium, magnesium, or calcium levels)
• Dehydration

Management of Muscle Symptoms in POTS

• Staying well-hydrated with electrolyte-rich fluids (2-3 liters daily) 1
• Increasing salt intake (3-10g daily) 1
• Considering supplements like magnesium glycinate (300-400mg daily) or potassium if levels are low
• Medications such as beta-blockers (propranolol 10-40mg) to reduce adrenaline effects 1
• Gentle stretching, warm baths, and compression garments for symptomatic relief

It is essential to note that while these management strategies can help alleviate muscle symptoms, medical evaluation is crucial to rule out other neurological conditions or adjust POTS treatment, especially if muscle symptoms are severe or persistent 1.

From the Research

Pathophysiology of POTS

The pathophysiology of Postural Orthostatic Tachycardia Syndrome (POTS) is complex and multifaceted, involving various mechanisms that contribute to the development of symptoms such as muscle twitching, trembling, shaking, and clenching. Some of the key mechanisms include:

• Impaired sympathetically mediated vasoconstriction 2
• Excessive sympathetic drive 2, 3
• Volume dysregulation 2, 3
• Deconditioning 2
• Partial autonomic neuropathy 3
• Hypovolemia 3
• Hyperadrenergic state 3, 4

Symptoms and Clinical Presentation

Patients with POTS often experience a range of symptoms, including:

• Palpitations 5, 4
• Dizziness 5
• Lightheadedness 4
• Tremor 4
• Near-syncope 4
• Fatigue 6
• Exercise intolerance 6
• Gastrointestinal distress 6
• Muscle twitching, trembling, shaking, and clenching (although not explicitly mentioned in the studies, these symptoms can be related to the hyperadrenergic state and autonomic dysfunction characteristic of POTS) 3, 4

Treatment and Management

Treatment of POTS typically involves a combination of non-pharmacologic and pharmacologic interventions, including:

• Patient education 6
• Non-pharmacologic treatment options such as volume expansion, exercise training, and physical countermaneuvers 2, 3
• Medications such as beta-blockers, fludrocortisone, and midodrine to address specific symptoms 2, 3, 4