What could be causing stiff neck, leg pain, and arm pain in an adult with no significant medical history?

Differential Diagnosis and Urgent Evaluation Required

In an adult presenting with stiff neck combined with both leg and arm pain, you must immediately rule out cervical myelopathy from spinal cord compression, which represents a neurosurgical emergency requiring urgent MRI evaluation. 1, 2

Critical Red Flags Requiring Immediate Investigation

This symptom constellation demands urgent assessment for serious pathology:

• Cervical myelopathy from cord compression can present with neck stiffness, upper extremity radicular symptoms, AND lower extremity symptoms including leg pain, weakness, or gait disturbance 1, 2, 3
• Vertebral osteomyelitis/discitis presents with neck stiffness, fever (if present), and can cause radiating extremity pain from nerve root involvement 1, 2
• Funicular leg pain is a rare but documented presentation where cervical cord compression irritates the ascending spinothalamic tract, causing sciatica-like leg pain that mimics lumbar pathology 3
• Metastatic disease to cervical spine can cause neck pain with multilevel neurological symptoms 1, 2

Immediate Clinical Assessment

Perform focused neurological examination looking for:

• Myelopathic signs: hyperreflexia, positive Hoffman's sign, clonus, Babinski sign, gait disturbance, bowel/bladder dysfunction 1, 2
• Radiculopathy signs: dermatomal sensory loss, myotomal weakness, diminished reflexes in upper extremities 1
• Lower extremity examination: strength, sensation, reflexes, and gait assessment 1, 3
• Spurling's test: highly specific for cervical nerve root compression if positive 2, 4
• Vertebral body tenderness: palpate for point tenderness suggesting infection or malignancy 1, 2

Laboratory Evaluation

Obtain immediately:

• Two sets of blood cultures if any concern for infection 1
• ESR and CRP: elevated inflammatory markers mandate urgent investigation for osteomyelitis or inflammatory arthritis 1, 2
• Complete blood count: leukocytosis suggests infection 1, 2

Imaging Strategy

Order MRI cervical spine without contrast immediately if ANY of the following are present: 1, 2, 4

• Neurological deficits in upper OR lower extremities
• Constitutional symptoms (fever, night sweats, weight loss)
• Elevated inflammatory markers
• History of malignancy, immunosuppression, or IV drug use
• Intractable pain despite conservative therapy
• Vertebral body tenderness on examination

MRI is the most sensitive modality for detecting cord compression, disc herniation, epidural abscess, osteomyelitis, and malignancy 1, 2

Common Diagnostic Pitfall

The presence of leg pain with neck stiffness can falsely localize to lumbar pathology, leading to missed cervical cord compression. 3 This is particularly dangerous when concurrent lumbar degenerative changes exist on imaging, which are present in the majority of adults and may be incidental 1, 2. The combination of upper AND lower extremity symptoms should always prompt evaluation of the cervical spine first, as cervical myelopathy can cause symptoms throughout the entire body below the level of compression 3.

If No Red Flags Present

Only if comprehensive neurological examination is completely normal, no constitutional symptoms exist, and inflammatory markers are normal, then consider:

• Mechanical neck pain with referred symptoms: facet arthropathy or myofascial pain can cause neck stiffness and referred pain to shoulders/upper back 1, 2, 4
• Cervical radiculopathy: typically causes unilateral arm pain in dermatomal distribution, but neck stiffness alone would not explain bilateral extremity involvement 1, 2
• Conservative management trial: 6-8 weeks if no red flags, as 75-90% of cervical radiculopathy resolves without intervention 4

However, the specific combination of stiff neck WITH both arm AND leg pain is atypical for simple mechanical neck pain and warrants a lower threshold for imaging 1, 2, 3.