What is the appropriate workup and imaging for a patient with a suspected myofascial trigger point (MTrP) in the left trapezius region, who is experiencing persistent pain and swelling despite treatment with Naproxen (naproxen) 375mg, and is now being considered for an increased dose of 500mg?

From the Guidelines

The patient's symptoms suggest a myofascial trigger point in the left trapezius muscle, likely due to overuse from driving with the left arm, and increasing Naproxen to 500 mg twice daily is a reasonable next step, along with a musculoskeletal ultrasound to evaluate the nodule and rule out other soft tissue abnormalities. The patient's history of driving with their left arm, despite being right-handed, and the presence of a knot/nodule that moves with the muscle, supports the diagnosis of a myofascial trigger point 1. The fact that Naproxen 375 mg is not effective suggests that the patient may require a higher dose or additional interventions.

Workup and Imaging

• A musculoskeletal ultrasound is recommended as the initial imaging study to evaluate the nodule and rule out other soft tissue abnormalities, such as tendonitis or bursitis, as it is useful for detecting moderate to full thickness tears and tendon changes of chronic tendinopathy 1.
• If symptoms persist or worsen, an MRI of the cervical spine and left shoulder would be appropriate to assess for cervical radiculopathy, rotator cuff pathology, or other structural issues that might be contributing to the discomfort, given its high sensitivity and specificity for detecting cuff tears, degeneration, and chronic tendinopathy 1.

Treatment and Management

• Physical therapy focusing on trapezius muscle release techniques, posture correction, and ergonomic driving position would be beneficial to address the underlying causes of the myofascial trigger point.
• The patient should also consider alternating driving hands and taking regular breaks during long drives to reduce the risk of overuse and repetitive strain.
• Trigger point injections with lidocaine may provide relief if conservative measures fail, as they can help to reduce pain and inflammation in the affected area.

Additional Considerations

• The patient's inability to sleep on their left side and need for a pillow between their armpit to reduce discomfort suggests that the myofascial trigger point is causing significant pain and discomfort, and addressing this issue should be a priority.
• The patient's occupation as an Uber Eats delivery person, which involves frequent driving, highlights the importance of addressing the underlying causes of the myofascial trigger point and implementing strategies to prevent further overuse and repetitive strain.

From the FDA Drug Label

The recommended dose is 250 mg, 375 mg, or 500 mg twice daily During long-term administration, the dose of naproxen may be adjusted up or down depending on the clinical response of the patient. The patient's current dose of Naproxen 375 mg is not effective, so increasing the dose to 500 mg twice daily may be considered, as it is within the recommended dosage range.

• The patient's symptoms suggest a muscular knot/myofascial trigger point from overuse, and the increased dose of Naproxen may help alleviate the pain and discomfort.
• However, it is essential to monitor the patient's response to the increased dose and adjust as needed to minimize potential adverse effects.
• As for the workup and imaging to order, there is no direct information in the provided drug label to support a specific recommendation. 2

From the Research

Patient Presentation

The patient presents with a weird discomfort along the left trapezius region, especially when the left arm rubs or presses on that muscular region. The patient is right-handed but drives with their left hand, which may contribute to the discomfort. The patient also experiences difficulty sleeping on their left side and needs a pillow between their armpit to reduce the discomfort.

Physical Examination

On exam, there is mild point tenderness on the left trapezius region, a knot/nodule that moves with the muscle, and the left trapezius region appears larger in size but not necessarily swollen. It is non-erythematous and non-pruritic.

Likely Diagnosis

The likely diagnosis is a muscular knot/myofascial trigger point from overuse, and the patient may be overcompensating in that region due to right-handed dominance.

Treatment Options

• Non-invasive measures such as spray and stretch, transcutaneous electrical stimulation, physical therapy, and massage may be effective in relieving trigger points 3.
• Invasive treatments for myofascial trigger points include injections with local anesthetics, corticosteroids, or botulism toxin or dry needling 3.
• Lidocaine injection has been shown to be effective in reducing pain and disability in patients with myofascial pain syndrome 4, 5.
• Intramuscular stimulation has also been shown to be effective in managing myofascial pain syndrome, with significant improvements in pain intensity, cervical range of motion, and depression scales 6.

Workup and Imaging

There is no clear indication for imaging in this case, as the diagnosis of myofascial trigger point is primarily clinical. However, if the patient's symptoms persist or worsen despite treatment, further evaluation with imaging studies such as MRI or ultrasound may be considered to rule out other potential causes of the patient's symptoms.

Management

The patient's current treatment with Naproxen 375 mg is not effective, and increasing the dose to 500 mg may be considered. Additionally, the patient may benefit from physical therapy, massage, or other non-invasive measures to relieve the trigger point. If the patient's symptoms persist, lidocaine injection or intramuscular stimulation may be considered as alternative treatment options 4, 5, 6.