What is the cause and treatment of tingling sensation in the left scapula (shoulder blade) when sitting forward in an adult with no previously diagnosed conditions?

Tingling Left Scapula When Sitting Forward

This symptom most likely represents cervical radiculopathy with nerve root compression, and you should obtain cervical spine MRI without contrast as the primary diagnostic test, followed by a focused physical examination to rule out scapular winging from nerve injury. 1, 2

Primary Diagnostic Considerations

Cervical Radiculopathy (Most Likely)

• Tingling in the scapular region strongly suggests referred pain from cervical spine pathology with nerve root compression, as scapular region symptoms commonly indicate referred pain from the cervical spine rather than local pathology 1
• The positional nature (occurring when sitting forward) suggests mechanical compression of a cervical nerve root that worsens with neck flexion 2
• Cervical radiculopathy most commonly results from herniated discs or osteophytes causing nerve root compression, leading to neuropathic pain and paresthesias radiating from the neck into the shoulder and scapular area 2

Scapular Nerve Injury (Important to Rule Out)

• Long thoracic nerve palsy (causing serratus anterior paralysis) or spinal accessory nerve palsy (causing trapezius paralysis) can produce scapular symptoms and are neurogenic causes in 85% of scapular dysfunction cases 3
• These conditions cause scapular winging that may be subtle initially and present with paresthesias before obvious visual deformity develops 4, 5
• Spinal accessory nerve palsy after neck surgery is the most common cause of unilateral scapular winging, while long thoracic nerve palsy from strenuous activity is the second most common 3

Scapular Dyskinesis

• Altered scapular position or motion during movement can cause periscapular symptoms and occurs frequently with shoulder dysfunction 6
• This represents a nonspecific response to shoulder injury caused by inhibition or disorganization of scapular stabilizing muscle activation patterns 6

Diagnostic Workup Algorithm

Step 1: Focused Physical Examination

• Inspect the scapula with the patient standing, arms at sides, then with forward flexion to 90 degrees - look for medial winging (serratus anterior palsy) versus lateral winging (trapezius or rhomboid palsy) 5
• Test for dermatomal sensory changes in the arm and hand to identify specific cervical nerve root involvement (C5, C6, C7, or C8 distribution) 2
• Assess for neurological symptoms including numbness, tingling, or weakness radiating down the arm in specific patterns 1, 2
• Palpate around the left scapula for continuous murmurs or palpable collaterals, which would suggest vascular causes like coarctation (though this is rare and typically presents with other cardiovascular findings) 7

Step 2: Initial Imaging

• Obtain MRI of the cervical spine without contrast as the preferred initial advanced imaging, as it directly visualizes disc herniations, osteophytes, and nerve root compression 2
• Plain radiographs of the cervical spine may be obtained first to assess for gross structural abnormalities or degenerative changes, though they cannot visualize disc herniations or nerve roots 2
• Do not assume this is simply "muscle tension" without ruling out structural cervical spine pathology 2

Step 3: Electrodiagnostic Testing

• If cervical spine imaging is negative or equivocal, obtain electrodiagnostic testing (EMG/NCS) with sensitivity over 80% and specificity of 95% for confirming nerve compression and localizing the level 2
• Electrodiagnostic examinations should be performed in patients with scapular symptoms to establish exact diagnosis and reveal coexistence of multiple causes 3

Treatment Approach Based on Diagnosis

If Cervical Radiculopathy Confirmed

• Consider pregabalin 300-600 mg daily in divided doses for neuropathic pain, as it provides therapeutic benefit for nerve-related pain 2
• Alternative nerve-stabilizing agents include gabapentin or duloxetine 2
• Refer to spine specialist if imaging shows significant nerve root compression requiring intervention 2

If Scapular Nerve Injury Confirmed

• Most cases of serratus anterior paralysis (long thoracic nerve) spontaneously resolve within 24 months 5
• Recommend 6-24 months of conservative treatment to allow time for spontaneous recovery before considering surgical intervention 5
• Conservative treatment includes exercises to strengthen involved musculature, which may take 12-18 months to achieve adequate results 8
• If no recovery after conservative period, patients become candidates for nerve surgery (neurolysis, nerve transfers, nerve grafts) or tendon transfers for chronic cases 4, 5

If Scapular Dyskinesis Confirmed

• Treatment focuses on restoring normal scapular muscle activation patterns through kinetic chain-based rehabilitation protocols 6
• Address underlying shoulder dysfunction that may be causing the dyskinesis 6

Critical Pitfalls to Avoid

• Do not dismiss positional paresthesias as benign without imaging, as they may represent significant cervical spine pathology requiring intervention 2
• Do not overlook trapezius palsy, which is easy to miss but represents an important differential diagnosis for scapular symptoms 4
• Patients with scapular nerve injuries should be referred to specialized centers for surgery if recovery is not spontaneous, as appropriate management can yield excellent results 4