Can Cervical Lesions Cause Weakness, Urgency, and Spasticity?
Yes, cervical lesions absolutely cause weakness, urgency, and spasticity through compression of the cervical spinal cord, producing a classic myelopathy syndrome with upper motor neuron signs below the level of the lesion.
Mechanism and Clinical Presentation
Cervical myelopathy results from external compression of the cervical medulla, producing a characteristic clinical picture of unsteady gait with long-tract signs including hyperreflexia, spasticity, and extensor plantar responses 1. The clinical course can progress acutely (secondary to trauma), subacutely (weeks to months), or chronically (months to years) 1.
The neurological manifestations occur because the compressed spinal cord disrupts descending motor pathways (causing weakness and spasticity) and ascending sensory pathways, while also affecting autonomic control (causing urgency). 2
Key Clinical Features to Assess:
- Motor symptoms: Progressive bilateral leg weakness, hand clumsiness, wide-based gait 2
- Spasticity: Increased muscle tone with hyperreflexia and extensor plantar responses 1
- Autonomic dysfunction: Bowel and bladder incontinence or urgency 2
- Sensory changes: Numbness, tingling, loss of sensation 3
Critical Diagnostic Considerations
Cervical lesions can present with isolated lower extremity symptoms without upper extremity involvement, which is a common diagnostic pitfall. 2 A 2023 case report demonstrated severe C6-C7 spinal stenosis presenting exclusively with progressive bilateral leg weakness and neurogenic urinary incontinence, with no upper extremity signs 2. This emphasizes the importance of conducting cervical spine workup even when symptoms appear confined to the lower extremities 2.
Atypical Presentations:
- Cervical spondylotic amyotrophy can present as isolated lower motor neuron weakness of the upper limbs 4
- Compressive thoracic cord lesions at T11/12 can cause isolated lower motor neuron weakness of lower limbs (thoracic spondylotic amyotrophy) 4
- Developmental spinal stenosis increases risk of transient quadriplegia with minor trauma 3
Risk Factors and Complications
Patients with cervical spondylotic myelopathy and cervical instability face significantly higher risk of neurologic deterioration after even minor trauma. 5 The incidence of neurologic deterioration after low-energy trauma is significantly higher in patients with lower cervical instability compared to those without (p<0.05) 5.
Consequences of Missed or Delayed Diagnosis:
- A missed or delayed diagnosis produces 10 times higher rates of secondary neurological injury (10.5% vs. 1.4%) 6
- Up to 4.3% of cervical fractures may be missed, with 67% of these patients suffering neurological deterioration 6
- 29.4% of cases with delayed diagnosis develop permanent neurological deficits 6
- Before widespread adoption of Advanced Trauma Life Support guidelines, up to 10% of initially neurologically intact patients developed deficits during emergency care 6
Imaging and Evaluation
MRI of the cervical spine is essential when evaluating patients with weakness, spasticity, or urgency, as these symptoms indicate potential cord compression requiring urgent assessment. 2 The ACR Appropriateness Criteria recommend that if the underlying pathology involves the cord, there may be weakness, hyperreflexia, spasticity, and sensory loss in addition to ataxia 6.
Imaging Approach:
- Cervical MRI is most sensitive for detecting soft tissue injuries and cord compression 7
- CT scan has 98% sensitivity for fractures when clinically suspected 7
- Plain radiographs have limited sensitivity (36%) for cervical injuries 7
- Do not rely solely on lumbar imaging when lower extremity symptoms are present—always consider cervical pathology 2
Management Implications
Eliminating local instability through surgical or non-surgical methods is necessary before decompression and fusion surgery in patients with cervical instability. 5 Patients with cervical instability have lower preoperative functional scores and experience less post-surgery improvement in neurologic function compared to those without instability (p<0.01) 5.
Treatment Considerations:
- Anterior approach is preferred as first-line because osteophytic spurs are typically more dominant anteriorly 1
- Extended spondylectomy is favored over multilevel decompression for bisegmental or multisegmental stenosis 1
- Even minor neck trauma can lead to irreversible spinal cord injury in patients with cervical spondylotic myelopathy and instability 5
Common Pitfalls
The most critical error is failing to obtain cervical spine imaging in patients presenting with isolated lower extremity weakness, spasticity, or urgency. 2 Always maintain high clinical suspicion for cervical pathology regardless of symptom distribution, as the absence of upper extremity signs does not exclude cervical cord compression 2.