What causes neck muscle spasms?

Causes of Neck Muscle Spasms

Neck muscle spasms are primarily caused by cervical dystonia, cervical radiculopathy, cervical instability due to ligament laxity, and musculoskeletal strain, with treatment requiring proper identification of the underlying cause. 1, 2

Common Causes of Neck Muscle Spasms

Primary Neurological Causes

• Cervical dystonia: Characterized by painful dystonic spasms of the cervical muscles that can be caused by:
  • Neck dissection
  • Radiation therapy
  • Idiopathic (primary) or genetic factors
  • Secondary causes (trauma, medication side effects, neurodegenerative diseases) 1, 3

Structural/Mechanical Causes

• Cervical radiculopathy: Nerve root compression causing:

  • Neck pain with radiation to arms
  • Sensory or motor deficits
  • Muscle spasms as a protective mechanism 1, 2

• Cervical instability:

  • Capsular ligament laxity leading to excessive vertebral movement
  • Often follows whiplash injury, trauma, or degenerative changes
  • Results in protective muscle spasms to stabilize the spine 4

Musculoskeletal Causes

• Muscle strain/overuse:

  • Poor posture
  • Repetitive movements
  • Prolonged static positions
  • Physical overexertion 2, 5

• Degenerative changes:

  • Cervical spondylosis
  • Facet joint arthropathy
  • Disc degeneration 1, 5

Important Clinical Considerations

Diagnostic Approach

1. Assess for red flags that may indicate serious pathology:

   • History of cancer
   • Unexplained weight loss
   • Fever
   • Neurological deficits
   • Night pain that wakes the patient 2

2. Evaluate for neurological symptoms:

   • Numbness or tingling in arms/hands
   • Weakness
   • Sensory changes in specific dermatomes 1, 2

3. Consider imaging selectively:

   • Plain radiographs are often not helpful for diagnosis of muscle spasm
   • MRI is indicated for suspected radiculopathy or myelopathy
   • CT better visualizes bony structures but less sensitive for nerve compression 1, 2

Common Misconceptions

• Straight cervical spine on imaging: Contrary to common belief, loss of normal cervical lordosis on radiographs does not necessarily indicate muscle spasm. Research shows similar prevalence of straight cervical spines in patients with acute pain (19%), chronic pain (26%), and even in normal populations (42%) 6

Management Approach

For Cervical Dystonia

• First-line treatment: Botulinum toxin type A injections into affected muscles 1, 3
• Pharmacotherapy: Nerve-stabilizing agents such as:
  • Pregabalin
  • Gabapentin
  • Duloxetine 1
• Rehabilitation: Referral to rehabilitation specialists for comprehensive neuromusculoskeletal management 1

For Radiculopathy-Related Spasms

• Conservative management:
  • NSAIDs at lowest effective dose for shortest duration
  • Muscle relaxants for acute spasms
  • Exercise therapy including scapular resistance exercises and neck-specific exercises 2, 7
• Interventional options for refractory cases:
  • Epidural steroid injections (limited evidence)
  • Radiofrequency denervation for facet-related pain 7, 5

For Musculoskeletal Strain

• Physical interventions:
  • Exercise therapy
  • Postural correction
  • Mobilization/manipulation
  • Massage 2, 7
• Pharmacotherapy:
  • NSAIDs
  • Muscle relaxants for acute spasm 7, 5

Key Pitfalls to Avoid

1. Overreliance on imaging: MRI findings often show abnormalities in asymptomatic individuals and should be correlated with clinical findings 1, 5

2. Overlooking psychosocial factors: These can contribute to persistent muscle spasm and chronic neck pain 7

3. Prolonged use of muscle relaxants: Should be limited to acute episodes 7

4. Delayed referral: For cervical dystonia, early referral to specialists for botulinum toxin injections is recommended 1, 3

5. Missing serious underlying pathology: Always assess for red flags that may indicate infection, malignancy, or myelopathy 2