Diagnostic Approach for Cervical Dystonia
Cervical dystonia is diagnosed clinically by identifying painful dystonic spasms of the cervical muscles characterized by repetitive, patterned head/neck movements or postures that deviate from neutral position, often with a sensory trick, and importantly, without red flags suggesting alternative diagnoses. 1, 2
Clinical Diagnosis
Diagnosis is based entirely on clinical examination—there is no diagnostic test for cervical dystonia. 2 The assessment should identify these core features:
Essential Diagnostic Features
- Repetitive, patterned head/neck movements or postures that induce deviation from neutral position (torticollis being most common, but also lateroflexion, extension/retrocollis, or flexion/anterocollis) 3, 2
- Sensory trick (geste antagoniste): patients can temporarily reduce symptoms by touching their face or chin 2
- Dystonic movements that are typically spasmodic, repeated in a stereotyped pattern, often mild and intermittent at onset but becoming constant with progression 3
- Reduced voluntary neck range of motion despite the involuntary movements 3
- Pain is frequently present and distinguishes cervical dystonia from many other movement disorders 1, 3
Critical Red Flags to Exclude (Must Be Absent)
The diagnosis requires ruling out conditions that mimic dystonia. Red flags that should prompt alternative diagnoses include: 2
- Capability to voluntarily suppress spasms completely (suggests tics or functional disorder)
- Features of chorea, myasthenia, amyotrophic lateral sclerosis, or orthopedic/rheumatologic neck diseases
- Ocular torticollis (ophthalmologic cause)
- Isolated head tremor without dystonic posturing
A validated diagnostic approach achieves 96.1% sensitivity and 81% specificity when all core motor features are present AND red flags are absent. 2
Distinguish Primary vs. Secondary Cervical Dystonia
- Primary cervical dystonia has unknown cause and is most common 3
- Secondary cervical dystonia occurs due to other neurological disease, neck dissection, radiation therapy, or trauma 1, 3
- In head and neck cancer survivors, assess specifically for cervical dystonia post-neck dissection or radiation, as this represents a distinct secondary form 1
Role of Electromyography (Optional, Not Required)
While diagnosis is clinical, EMG evaluation can quantify dystonic muscle involvement and identify specific affected muscles (sternocleidomastoid, splenius capitis, trapezius/semispinalis capitis) when planning botulinum toxin therapy. 4 This is particularly useful when:
- Clinical examination reveals discrepancies in identifying dystonic muscles
- Optimizing botulinum toxin injection targeting is needed
- Distinguishing genuine dystonic coactivation from compensatory muscle activity 4
EMG is not necessary for diagnosis but may enhance treatment precision. 4
Imaging Is Not Indicated
No imaging studies (MRI, CT, radiography) are appropriate for diagnosing cervical dystonia unless red flags suggest alternative diagnoses like structural lesions, malignancy, or spinal cord pathology. 1 The diagnosis remains purely clinical.
Assessment of Impact
Once diagnosed, evaluate:
- Depression and anxiety: present in 42% and 58% of patients respectively, correlating with disability severity 5
- Quality of life impact: using validated scales like Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) or Craniocervical Dystonia Questionnaire (CDQ-24) 5
- Pain severity and functional disability in activities of daily living 5
Common Pitfalls
- Do not confuse with isolated head tremor, which lacks dystonic posturing 2
- Do not miss secondary causes in patients with history of head/neck cancer treatment 1
- Do not rely solely on head position for diagnosis—EMG may reveal different patterns than clinical examination suggests 4
- Do not overlook psychiatric comorbidity—screen for depression and anxiety at diagnosis and follow-up 5