Differential Diagnosis
- Single most likely diagnosis
- c. cervical radiculopathy: This is the most likely diagnosis due to the patient's symptoms of neck and left arm pain, which radiates down the front of the left arm, especially when turning the head to the affected side. The reduced biceps reflexes on the left and restricted cervical spine range of motion also support this diagnosis. Cervical radiculopathy typically results from nerve root compression or irritation, which can be caused by a herniated disc, bone spurs, or other conditions.
- Other Likely diagnoses
- b. brachial plexus injury: Although less likely, a brachial plexus injury could also cause arm pain and weakness. However, the patient's ability to actively abduct the left shoulder beyond 90 degrees without pain and full strength with external rotation of the shoulder when the left elbow is flexed at 90 degrees makes this diagnosis less probable.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- a. cervical cord compression: This is a serious condition that requires prompt attention. Although the patient's symptoms do not strongly suggest cervical cord compression, it is essential to consider this diagnosis due to its potential severity and risk of long-term neurological damage.
- Rare diagnoses
- d. rotator cuff tear: A rotator cuff tear is unlikely in this case, as the patient's symptoms are more consistent with a cervical spine issue. The patient is able to actively abduct the left shoulder beyond 90 degrees without pain, which suggests that the rotator cuff is intact. However, it is still possible, especially if the patient has a history of shoulder trauma or overuse.