Can C5-C7 quadriplegia cause autonomic dysfunction?

Autonomic Dysfunction in C5-C7 Quadriplegia

Yes, C5-C7 quadriplegia can cause significant autonomic dysfunction, particularly autonomic dysreflexia, which is a potentially life-threatening medical emergency occurring in approximately 85% of quadriplegic patients with injuries at or above the T6 level. 1

Pathophysiology of Autonomic Dysfunction in Cervical SCI

Cervical spinal cord injuries disrupt the normal communication between supraspinal control centers and the sympathetic nervous system, resulting in:

• Loss of tonic supraspinal autonomic control of spinal sympathetic circuits 2
• Intact parasympathetic (vagal) control 2
• Imbalance between sympathetic and parasympathetic systems
• Development of autonomic hyperreflexia below the level of injury

Clinical Manifestations

Autonomic dysfunction in C5-C7 quadriplegia commonly presents as:

Cardiovascular Dysfunction

• Orthostatic hypotension 3
• Bradycardia 3
• Autonomic dysreflexia (sudden severe hypertension, headache, sweating) 4
• Impaired heart rate variability

Respiratory Dysfunction

• Impaired respiratory control 2
• Decreased vital capacity
• Reduced respiratory reserve

Gastrointestinal Dysfunction

• Gastric dysmotility
• Constipation
• Fecal incontinence

Genitourinary Dysfunction

• Neurogenic bladder 5
• Urinary incontinence 5
• Sexual dysfunction 5

Thermoregulatory Dysfunction

• Impaired sweating below injury level 2
• Temperature dysregulation

Diagnostic Approach

Screening for autonomic dysfunction should include:

• Assessment for symptoms of orthostatic intolerance (dizziness, lightheadedness, weakness when standing) 5
• Monitoring for syncope and exercise intolerance 5
• Evaluation of bowel and bladder function 5
• Assessment of sexual function 5
• Cardiovascular autonomic testing (when indicated) 5

Autonomic Dysreflexia: A Medical Emergency

Autonomic dysreflexia is characterized by:

• Sudden, severe hypertension (>20-40 mmHg above baseline)
• Pounding headache
• Profuse sweating above the level of injury
• Cold, pale skin below the level of injury
• Nasal congestion
• Blurred vision

Common triggers include:

• Bladder distension or urinary tract infection
• Bowel impaction
• Pressure sores
• Tight clothing
• Unstable spine 4, 6

Management Approaches

Acute Management of Autonomic Dysreflexia

1. Place patient in upright position
2. Identify and remove the triggering stimulus
3. Monitor blood pressure every 2-5 minutes
4. If systolic BP remains >150 mmHg, administer antihypertensive medications:
   • First-line: short-acting agents like nifedipine or nitrates
   • For refractory cases: alpha and beta-adrenergic blocking agents (labetalol) 1

Chronic Management

• Regular bladder and bowel programs to prevent distension
• Pressure relief protocols
• For orthostatic hypotension:
  • Midodrine (alpha-agonist)
  • Fludrocortisone
  • Pseudoephedrine (may help with refractory cases) 3
  • Compression garments
  • Adequate hydration

Surgical Interventions

• Surgical stabilization may be necessary for unstable spine causing autonomic dysreflexia 4, 6
• Surgical decompression with arthrodesis and instrumentation can dramatically improve symptoms 6

Prevention Strategies

• Patient and caregiver education about triggers and symptoms
• Regular bladder and bowel programs
• Pressure relief protocols
• Regular monitoring for early signs of autonomic dysfunction
• Vigilant imaging and thorough physical examination in long-standing spinal cord injury 6

Prognosis

The prognosis depends on:

• Level and completeness of injury
• Early recognition and management
• Prevention of complications

Early recognition and timely management of autonomic dysfunctions in individuals with SCI are crucial for long-term health outcomes in this population 2.