A 54-year-old man comes to the office due to aching pain in his left neck and shoulder area for the past several months. He has also had numbness and weakness of the left hand. The patient recalls no major trauma and has no prior medical problems. He tried chiropractic and massage therapies, but the symptoms persisted. Left upper extremity examination shows decreased sensation in the palm and index and middle fingers along with weakness of left wrist extension. The left biceps and brachioradialis deep tendon reflexes are normal, but the triceps reflex is diminished. Right upper extremity examination is normal. A lesion affecting which of the following labeled sections of the brachial plexus is the most likely cause of this patient's neurologic findings?

Question

A 54-year-old man comes to the office due to aching pain in his left neck and shoulder area for the past several months.  He has also had numbness and weakness of the left hand.  The patient recalls no major trauma and has no prior medical problems.  He tried chiropractic and massage therapies, but the symptoms persisted.  Left upper extremity examination shows decreased sensation in the palm and index and middle fingers along with weakness of left wrist extension.  The left biceps and brachioradialis deep tendon reflexes are normal, but the triceps reflex is diminished.  Right upper extremity examination is normal.  A lesion affecting which of the following labeled sections of the brachial plexus is the most likely cause of this patient's neurologic findings?

Quizplus · Accepted Answer

11ec160b_35ee_db4b_9249_b541945ea8a7_MD0001_00 The C5 through T1 nerve roots form the brachial plexus trunks, divisions, cords, and ultimately terminal branches, which supply sensory and motor innervation to the upper extremities. This patient has deficits involving both the radial (eg, triceps reflex, wrist extension) and median (sensation to palm and index and middle finger) nerves. This pattern of deficits across multiple peripheral nerves indicates a lesion proximal to the formation of the terminal branches. In a patient without history of trauma or malignancy, chronic shoulder and radicular arm pain with sensorimotor deficits is most likely caused by compression of a nerve root due to cervical spondylosis. The C7 root is the most frequently affected nerve root in patients with cervical radiculopathy, resulting in deficits across the median and radial nerve distributions. (Choices B and C) Damage to the superior or inferior trunk most often occurs as a result of trauma (eg, traction during delivery in infants; falls in adults). A superior trunk lesion (eg, Erb-Duchenne palsy) would result in loss of arm abduction, elbow flexion, and wrist extension (waiter's tip position: adducted arm with extended elbow and flexed wrist). An inferior trunk lesion (eg, Klumpke palsy) typically results in loss of wrist/metacarpophalangeal joint flexion and interphalangeal joint extension (claw hand position: extended wrist/metacarpophalangeal joints with flexed interphalangeal joints). (Choices D and E) Damage to one of the terminal branches of the brachial plexus would result in a pattern of deficits restricted to the sensory and/or motor function of one nerve. The radial nerve can be injured by compression against the humerus (eg, Saturday night palsy) or by a humerus fracture, causing weakness in wrist extension (eg, wrist drop). Injury to the median nerve most commonly occurs at the wrist (eg, carpal tunnel syndrome) with resulting numbness, tingling, and pain in the palm and first 3 digits. Educational objective: Motor and sensory deficits across multiple peripheral upper extremity nerves (eg, radial and median) indicate a lesion in the brachial plexus proximal to the formation of the terminal branches. In the absence of history of trauma or malignancy, the most likely cause is nerve root compression due to cervical spondylosis (cervical radiculopathy). __________ References: Diagnosis and treatment of cervical radiculopathy and myelopathy. (http://www.ncbi.nlm.nih.gov/pubmed/26231961)

A 54-Year-Old Man Comes to the Office Due to Aching