AAOS Comprehensive Orthopaedic Review 4: Print + Ebook (AAOS - American Academy of Orthopaedic Surgeons)

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15 | Degenerative Conditions of the Cervical Spine

D. Surgical treatment—outcomes a. Very high success rates

a. Subjective weakness b. Bowel and bladder symptoms c. Loss of motor strength (many patients deny having this) d. Neck pain (despite advanced degrees of spon dylosis, this may be absent) e. Radicular symptoms or signs (many patients do not have these) 4. Physical examination a. Gait instability (unable to tandem gait), dif ficulty with single leg stance, and a positive Romberg may be seen. b. Upper motor neuron signs such as an upgoing Babinski, positive Hoffman, or sustained clo nus may be present. c. Hyperreflexia, which may be present in the upper and/or lower extremities, suggests spi nal cord compression. Hyperreflexia can also be a normal finding in some. d. Patients with concomitant myelopathy and peripheral nerve disease from conditions such as diabetes, hypothyroidism, peripheral neu ropathy, or severe multilevel cervical foram inal stenosis can have diminished or absent reflexes. e. Patients with cervical myelopathy who have coexisting lumbar stenosis may exhibit brisk upper extremity reflexes consistent with upper motor neuron findings yet diminished lower extremity reflexes because of the root level compression in the lumbar spine. f. A positive jaw jerk reflex may indicate pathol ogy above the level of the pons. g. Severe weakness of the major muscle groups in the upper or lower extremities is uncommon. h. Dorsal column (proprioceptive) dysfunction occurs with advanced disease and carries a poor prognosis. C. Differential diagnosis 1. Spondylosis (ie, degenerative changes) produc ing the condition known as cervical spondylotic myelopathy (CSM) is the most common cause of cervical myelopathy in patients older than 50 years.

b. Relief of arm pain and improvements in motor and sensory function are typically in the 80% to 90% range. c. In failed nonsurgical treatment, surgery can per manently alter the natural history of symptoms arising from the involved motion segment.

IV. CERVICAL MYELOPATHY A. Overview

1. Cervical myelopathy describes a constellation of symptoms and signs arising from cervical spinal cord compression. 2. Clinical manifestations, especially early ones, can be quite subtle. 3. Cord compression can cause myelopathy by an ischemic effect secondary to compression of the anterior spinal artery or by a direct mechanical effect on cord function. 4. The natural history typically includes stable periods punctuated by unpredictable stepwise progression. 5. Early recognition and treatment, before the onset of irreversible spinal cord damage, is essential for optimal outcomes. B. Clinical presentation 1. Upper extremity symptoms a. Generalized feeling of clumsiness of the arms and hands; the patient reports dropping things b. Inability to manipulate fine objects such as coins or buttons c. Trouble with handwriting d. Diffuse (typically nondermatomal) numbness 2. Lower extremity symptoms a. Gait instability—Patients report a sense of imbalance and bumping into walls when walking. b. Patients with severe cord compression may also report Lhermitte phenomenon: elec tric shock–like sensations that radiate down the spine or into the extremities with certain offending positions of the neck (neck flexion). c. Rarely, patients may exhibit lower extremity numbness. 3. Other symptoms—The following symptoms may occur late or not at all:

2 | Spine

a. Anterior structures (such as bulging, ossified, or herniated disks) and osteophytic anterior spurs are the usual cause of cord compression in CSM. Copyright © Wolters Kluwer, Inc. Unauthorized reproduction of the content is prohibited. 2023

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AAOS Comprehensive Orthopaedic Review 4