What could be causing numbness on the left side of my neck without pain or loss of motor function (MOTOR FUNCTION)?

Isolated Neck Numbness Without Pain or Motor Deficit

This presentation of isolated sensory numbness on the left side of the neck without pain or motor dysfunction does not fit the typical pattern of cervical radiculopathy and warrants careful evaluation to exclude other causes before attributing it to nerve root compression. 1, 2

Key Clinical Distinctions

Why This Is Atypical for Cervical Radiculopathy

• Cervical radiculopathy typically presents with neck pain radiating into the arm, accompanied by varying degrees of sensory or motor deficits in a dermatomal distribution of the upper extremity—not isolated neck numbness. 1, 2, 3

• The absence of pain is unusual, as most cervical radiculopathy cases involve neck and arm pain as the predominant feature, with sensory changes being secondary. 4, 3

• Pure sensory symptoms confined to the neck itself, without upper extremity involvement, suggests a different pathophysiology than typical nerve root compression. 1, 2

Differential Considerations

Peripheral Nerve or Cutaneous Nerve Involvement

• Isolated numbness in the neck region may represent involvement of superficial cervical cutaneous nerves (C2-C3 distribution) rather than cervical radiculopathy. 1

• Peripheral nerve entrapment or irritation can cause isolated sensory changes without the dermatomal radiation pattern characteristic of radiculopathy. 5, 3

Other Neurological Causes

• Cranial neuropathy affecting sensory branches should be considered when symptoms are confined to the neck and face regions without typical radicular patterns. 1

• Plexopathy may present with atypical sensory distributions that don't follow classic dermatomal patterns. 5

Imaging Recommendations

When Imaging Is NOT Initially Indicated

• In the absence of "red flags" (trauma, malignancy risk, constitutional symptoms, progressive neurological deficits, bilateral symptoms, or myelopathy signs), immediate imaging is not recommended for isolated neck sensory changes. 1

• The American College of Radiology guidelines emphasize that imaging for acute neck symptoms without red flags rarely alters initial management, as degenerative changes are common in asymptomatic individuals over age 30. 1

When to Consider MRI

• If symptoms persist beyond 6 weeks despite conservative management, or if new neurological symptoms develop (motor weakness, upper extremity radiation, bilateral symptoms), MRI of the cervical spine without contrast becomes appropriate. 1, 2

• MRI is the most sensitive modality for detecting soft tissue abnormalities including disc herniation and nerve root compression, but should be reserved for cases where findings would change management. 1

Red Flags Requiring Urgent Evaluation

Watch for development of:

• Progressive motor weakness or neurological deficits 2
• Bilateral symptoms suggesting myelopathy 2, 5
• New bladder or bowel dysfunction 2
• Loss of perineal sensation 2
• Symptoms affecting both upper and lower extremities 5
• Constitutional symptoms (fever, weight loss, night sweats) 1

Initial Management Approach

Conservative Management First

• Most acute neck symptoms, even with radicular features, resolve spontaneously or with conservative treatment in 75-90% of cases. 2, 4

• A multimodal approach including physical therapy, activity modification, and short-term use of cervical collar (if needed) is reasonable for initial management. 4, 6

Clinical Monitoring

• Reassess at 4-6 weeks to determine if symptoms are resolving, stable, or progressing. 1

• Document any changes in sensory distribution, development of motor symptoms, or spread to the upper extremities. 2, 3

Common Pitfalls to Avoid

• Do not immediately attribute isolated neck numbness to cervical radiculopathy without considering other causes—the classic presentation includes arm pain and dermatomal sensory/motor changes. 2, 3

• Avoid ordering MRI in the acute phase (<6 weeks) without red flags, as this leads to identification of incidental degenerative findings that don't correlate with symptoms and may drive unnecessary interventions. 1

• Do not overlook non-spinal causes such as peripheral nerve involvement, which may require different diagnostic approaches. 1, 5