What is the differential diagnosis for neck stiffness?

Differential Diagnosis for Neck Stiffness

Neck stiffness requires immediate systematic screening for life-threatening conditions—particularly meningitis, subarachnoid hemorrhage, spinal infection, and metastatic disease—before attributing symptoms to benign mechanical causes.

Critical "Red Flag" Conditions Requiring Urgent Evaluation

Infectious Etiologies

• Bacterial meningitis presents with the classic triad of fever, neck stiffness, and altered mental status; however, the absence of all three findings effectively excludes the diagnosis, while the presence of any component mandates urgent investigation 1
• Vertebral osteomyelitis or discitis manifests with constitutional symptoms (fever, night sweats), elevated inflammatory markers (ESR, CRP, leukocytosis), and is particularly concerning in patients with IV drug use history or immunosuppression 2
• Lumbar puncture with cerebrospinal fluid examination remains the definitive diagnostic procedure for suspected meningitis, and antibiotic treatment must not be delayed while awaiting imaging 1

Vascular Emergencies

• Subarachnoid hemorrhage (SAH) can present with neck stiffness as the only neurological finding in alert patients without focal deficits 3
• The timing of examination matters critically: neck stiffness evaluated ≤6 hours after symptom onset has a positive predictive value of 90% but a negative predictive value of only 69% for SAH, meaning its absence does not rule out the diagnosis early 3
• Between 6-72 hours after symptom onset, the absence of neck stiffness becomes more reassuring (NPV 91%), but the positive predictive value drops to 76% 3
• Cervical arterial dissection presents with unilateral headache and neck pain and requires urgent vascular imaging 2

Malignant and Inflammatory Conditions

• Spinal metastases with instability cause severe, progressive neck pain worsened by axial loading, often accompanied by vertebral body tenderness and constitutional symptoms 2
• Primary spinal tumors produce progressive symptoms refractory to conservative treatment 2
• Inflammatory arthritis (rheumatoid arthritis, ankylosing spondylitis) causes persistent neck pain with elevated inflammatory markers 2
• Polymyalgia rheumatica occurs in elderly patients with pain and stiffness involving the neck, shoulder girdle, and hip girdle lasting >1 month, typically requiring low-dose corticosteroids for management 4

Neurological Emergencies

• Cervical myelopathy from spinal cord compression presents with progressive weakness, sensory changes, gait disturbance, bowel/bladder dysfunction, and hyperreflexia—requiring differentiation from radiculopathy through careful neurological examination 2
• Epidural abscess demands immediate recognition in immunocompromised patients or those with recent spinal procedures 2

Systematic Red Flag Screening Algorithm

Any single red flag mandates immediate MRI of the cervical spine without contrast 2:

Constitutional Symptoms

• Fever, unexplained weight loss, or night sweats suggest infection, malignancy, or inflammatory disease 2
• These symptoms require urgent MRI evaluation within 12-24 hours 2

Laboratory Abnormalities

• Elevated ESR, CRP, or leukocytosis warrant urgent imaging to exclude infection or malignancy 2, 5
• Coagulopathy identified on screening requires urgent MRI evaluation 2

High-Risk Patient Factors

• History of malignancy necessitates prompt MRI to assess for metastatic disease 2
• Immunosuppression (HIV, chronic steroids, chemotherapy) markedly increases infection risk 2
• Current or past IV drug use signals high risk for spinal infection or epidural abscess 2

Neurological Warning Signs

• Progressive neurological deficits (new weakness, sensory changes, gait disturbance) indicate urgent MRI for possible myelopathy 2
• Bowel or bladder dysfunction represents spinal cord compression until proven otherwise 2
• Hyperreflexia or myelopathic signs on examination mandate urgent evaluation 2

Pain Characteristics

• Intractable pain despite 6-8 weeks of appropriate conservative therapy is a red flag for serious underlying pathology 2
• Vertebral body tenderness on palpation suggests metastatic disease or infection 2
• Positional pain that worsens with axial loading may indicate spinal instability 2

Recent Trauma

• Any recent history of trauma requires urgent MRI evaluation 2

Mechanical and Benign Causes (Diagnosis of Exclusion)

These diagnoses should only be considered after systematic exclusion of red flags 6, 2:

Primary Mechanical Causes

• Cervical radiculopathy from herniated disc or osteophyte compressing nerve roots represents the primary consideration for mechanical neuropathic pain 2
• Facet joint arthropathy causes localized mechanical pain that may be unilateral 2
• Cervical osteoarthritis causes degenerative changes, though these correlate poorly with symptoms in isolation—85% of asymptomatic individuals over 30 show significant cervical degeneration 2
• Acute stiff neck in children (ages 5-14) may result from rapid strangulation of vascularized tissue in uncovertebral zones at C2-C3 or C3-C4, causing tissue edema and irritation of the posterior longitudinal ligament 7

Mimicking Conditions

• Cervicogenic headache is characterized by unilateral headache provoked by neck movement; diagnosis is clinical and imaging is not routinely indicated 2
• Muscle strain typically resolves with conservative management within 6-8 weeks 8

Imaging Strategy Based on Clinical Presentation

When Red Flags Are Present

• MRI cervical spine without contrast is mandatory within 12-24 hours when any red flag is identified 2
• MRI is superior to all other modalities for detecting spinal metastases, epidural disease, infection, and cord compression 2
• Extended full-spine MRI should be considered when metastatic disease is suspected because skip lesions are common 2
• Do not delay MRI or definitive treatment while awaiting specialist consultation 2

When No Red Flags Are Present

• For acute neck stiffness <6 weeks without red flags, initial imaging is not recommended; conservative management (reassurance, physical therapy, NSAIDs) is advised because most cases resolve spontaneously 2
• Plain radiographs rarely change management decisions and degenerative changes are present in ~85% of asymptomatic adults over 30 2
• Approximately 50% of patients experience residual or recurrent symptoms at 1 year, yet this does not alter the initial decision to defer imaging 2

Special Considerations for Suspected SAH

• CT head without contrast is the initial imaging modality for suspected SAH, not cervical spine imaging 3
• If CT is negative and clinical suspicion remains high, lumbar puncture is required 3

Critical Pitfalls to Avoid

• Never assume mechanical neck pain in the presence of fever, altered mental status, or neck stiffness without first excluding meningitis 1
• Do not rely on the absence of neck stiffness to rule out SAH when evaluated ≤6 hours after symptom onset (NPV only 69%) 3
• Avoid ordering plain radiographs alone when red flags are present—they cannot rule out metastasis, infection, or epidural disease 2
• Do not interpret degenerative changes on imaging as causative without clinical correlation—spondylotic changes are present in 85% of asymptomatic individuals over 30 2
• Never delay antibiotic treatment for suspected meningitis while awaiting CT scan—CT is only indicated in special risk situations for increased intracranial pressure 1
• Recognize that symptoms often do not correlate with physical findings in polymyalgia rheumatica—the diagnosis remains entirely clinical 4

Management Pathway After Red Flag Assessment

If Red Flags Present

• Obtain urgent MRI cervical spine without contrast within 12-24 hours 2
• Initiate empiric antibiotic therapy immediately if bacterial meningitis suspected (ceftriaxone is standard in immunocompetent adults) 1
• Neurosurgical consultation is required immediately if MRI reveals cord compression, epidural abscess, or unstable fracture 2
• Oncology referral should occur within 24-48 hours when metastatic disease is confirmed 2

If No Red Flags Present

• Pursue multimodal conservative therapy: education, activity modification, NSAIDs, and physical therapy 2
• Avoid prolonged static neck positions and overhead activities 2
• Consider MRI if symptoms persist beyond 6-8 weeks of appropriate conservative therapy 2
• Refer to spine specialist when symptoms persist beyond 6-8 weeks, progressive neurological deficits develop, or MRI reveals significant pathology 2