A 52-year-old man comes to the office due to upper extremity weakness and pain in his shoulders and upper back since shoveling snow 3 weeks ago. His left arm also has started to feel heavy, and he has difficulty dressing and undressing because he lacks the strength to pull clothes over his head. The patient has not had similar symptoms before and recalls no other trauma to the area. He has a history of hypertension and hypothyroidism. Vital signs are within normal limits. Physical examination of the shoulder joints shows no deformity, and passive range of motion is full with no pain. There is moderate weakness of left shoulder abduction, but strength in the other muscle groups is normal. Decreased sensation to light touch and pinprick is present on the left lateral forearm. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in evaluation of this patient's symptoms?

Question

A 52-year-old man comes to the office due to upper extremity weakness and pain in his shoulders and upper back since shoveling snow 3 weeks ago.  His left arm also has started to feel heavy, and he has difficulty dressing and undressing because he lacks the strength to pull clothes over his head.  The patient has not had similar symptoms before and recalls no other trauma to the area.  He has a history of hypertension and hypothyroidism.  Vital signs are within normal limits.  Physical examination of the shoulder joints shows no deformity, and passive range of motion is full with no pain.  There is moderate weakness of left shoulder abduction, but strength in the other muscle groups is normal.  Decreased sensation to light touch and pinprick is present on the left lateral forearm.  The remainder of the examination shows no abnormalities.  Which of the following is the most appropriate next step in evaluation of this patient's symptoms?

Quizplus · Accepted Answer

Explanation: This patient's back/shoulder pain, loss of shoulder abduction strength, and reduced sensation in the left lateral forearm raise strong suspicion for C5-6 nerve root impingement from cervical radiculopathy. Most cases arise in older individuals when physical activity such as shoveling snow, golf, or diving from a board puts stress on the neck and results in acute cervical disc herniation or nerve root compression from underlying cervical spondylosis. Cervical spondylosis is marked by cervical spine degeneration. It is generally associated with 2 clinical syndromes: Cervical radiculopathy: Degeneration and osteophyte formation in the zygapophyseal (facet) and uncovertebral joints lead to intervertebral foramen narrowing and compressive nerve root symptoms. Most patients have progressive neck, shoulder, and/or arm pain plus weakness in a myotome (eg, axillary nerve) and sensory loss in a dermatome (eg, lateral cutaneous nerve of the arm). Compressive cervical myelopathy: Degeneration and thickening of the lateral vertebral bodies and posterior longitudinal ligament lead to spinal canal narrowing and subsequent spinal cord compression. This usually presents with neck pain, lower motor neuron signs in the upper extremities, upper motor neuron signs (eg, increased reflexes, increased tone, positive Babinski sign) in the lower extremities, and bowel/bladder dysfunction. Evaluation usually begins with MRI of the cervical spine to visualize anatomy; myelography is also generally required for those with symptoms of compressive myelopathy. (Choice A) Brain lesions generally cause upper motor neuron signs in the distribution of the lesion and do not usually cause pain in the shoulders or neck. In addition, they are unlikely to be exacerbated by shoveling snow. (Choice C) Although brachial plexus injury can occasionally mimic C5-6 nerve root radiculopathy, patients generally have significant pain that is worse with passive or active motion of the arm; in addition, most such injuries occur during high-impact trauma (eg, football injury), not while shoveling snow. Although rotator cuff injury can cause shoulder pain and weakness, decreased sensation in the arm would be atypical. (Choice D) Radiculopathy can be confirmed by needle electromyography; nerve conduction studies are not sensitive for radiculopathy because sensory action potentials are usually normal when the lesion is proximal to the dorsal root ganglia. (Choice E) Hypothyroidism can be associated with carpal tunnel syndrome (eg, numbness/tingling/pain in the hand, sensory loss in third and fourth fingers) and muscle weakness with creatinine kinase elevation. Weakness and sensory loss in a C5-6 distribution after shoveling snow would be uncommon. Educational objective: Cervical radiculopathy is common in older individuals and usually arises after physical activity or trauma puts stress on the neck and leads to disc herniation or nerve root compression from underlying cervical spondylosis. Patients usually have pain in the neck radiating to the shoulder/arm, weakness in an upper extremity myotome, and sensory loss in an upper extremity dermatome. MRI of the cervical spine is the first test of choice.

A 52-Year-Old Man Comes to the Office Due to Upper