summary Cervical myelopathy is a common form of neurologic impairment caused by compression of the cervical spinal cord, most commonly due to degenerative cervical spondylosis Most commonly presents in older patients with symmetric numbness and tingling in the extremities, hand clumsiness, and gait imbalance Treatment is usually surgical decompression and stabilization, as the condition is associated with step-wise progression Etiology Pathophysiology etiology degenerative cervical spondylotic myelopathy (CSM) login to view 6 more bullets congenital stenosis login to view 1 more bullet OPLL tumor epidural abscess trauma cervical kyphosis neurologic injury mechanism of injury login to view 2 more bullets Associated conditions lumbar spinal stenosis tandem stenosis occurs in the lumbar and cervical spine in ~20% of patients Classification of Myelopathy Nurick classification based on gait and ambulatory function Nurick Classification Grade 0 Normal or root symptoms only Grade 1 Signs of cord compression, normal gait Grade 2 Gait difficulties but fully employed Grade 3 Gait difficulties prevent employment, walks unassisted Grade 4 Unable to walk without assistance Grade 5 Wheelchair or bedbound Ranawat classification Ranawat Classification Class I Pain, no neurologic deficit Class II Subjective weakness, hyperreflexia, dysesthesias Class IIIA Objective weakness, long tract signs, ambulatory Class IIIB Objective weakness, long tract signs, non-ambulatory Japanese Orthopaedic Association classification A point scoring system (17 total) based on function in the following categories: upper extremity motor function lower extremity motor function sensory function bladder function Usually a significant improvement at 1-year postoperative, even in cases of severe myelopathy Presentation of Myelopathy Symptoms neck pain and stiffness axial neck pain (often absent) occipital headache common extremity paresthesias diffuse, bilateral, nondermatomal numbness and tingling weakness and clumsiness bilateral weakness and decreased manual dexterity (dropping objects, difficulty manipulating fine objects) gait instability patient feels "unstable" on feet weakness when walking up and down stairs gait changes are the most important clinical predictor urinary retention rare and only appears late in disease progression not very useful in diagnosis due to high prevalence of concomitant urinary conditions in this patient population Physical exam motor weakness login to view 2 more bullets finger escape sign login to view 1 more bullet grip and release test login to view 1 more bullet sensory proprioception dysfunction login to view 3 more bullets decreased pain sensation login to view 2 more bullets vibratory changes are usually only found in severe case of long-standing myelopathy upper motor neuron signs (spasticity) hyperreflexia login to view 1 more bullet inverted radial reflex login to view 1 more bullet Hoffmann's sign login to view 2 more bullets sustained clonus login to view 2 more bullets Babinski test login to view 1 more bullet gait and balance toe-to-heel walk login to view 1 more bullet Romberg test login to view 2 more bullets provocative tests Lhermitte sign login to view 1 more bullet Evaluation Radiographs recommended views cervical AP, lateral, oblique, and flexion and extension views general findings degenerative changes of uncovertebral and facet joints osteophyte formation disc space narrowing decreased sagittal diameter login to view 1 more bullet lateral radiograph important to look for diameter of spinal canal login to view 1 more bullet sagittal alignment login to view 4 more bullets oblique radiograph look for foraminal stenosis, which is often caused by uncovertebral joint arthrosis flexion and extension views look for angular or translational instability look for compensatory subluxation above or below the spondylotic/stiff segment sensitivity/specificity changes often do not correlate with symptoms login to view 1 more bullet MRI indications study of choice to evaluate degree of spinal cord and nerve root compression findings effacement of CSF indicates functional stenosis spinal cord signal changes login to view 2 more bullets compression ratio of <0.4 carries poor prognosis login to view 1 more bullet sensitivity/specificity has a high rate of false positives (28% >40 y/o will have findings of HNP or foraminal stenosis) CT without contrast can provide complementary information with an MRI, and is more useful to evaluate OPLL and osteophytes CT myelography more invasive than an MRI, but gives excellent information regarding degrees of spinal cord compression useful in patients who cannot undergo MRI (e.g. pacemaker) or have artifact (local hardware) contrast is given via C1-C2 puncture and allowed to diffuse caudally, or is given via a lumbar puncture and allowed to diffuse proximally by putting patient in Trendelenburg position Nerve conduction studies high false negative rate may be useful to distinguish peripheral from central process (e.g. ALS) Differential Normal aging mild symptoms of myelopathy are often confused with a "normal aging" process Stroke Movement disorders Vitamin B12 deficiency Amyotrophic lateral sclerosis (ALS) Multiple sclerosis Treatment Nonoperative observation, NSAIDs, therapy, and lifestyle modifications indications login to view 3 more bullets modalities login to view 5 more bullets outcomes login to view 2 more bullets Operative surgical decompression, restoration of lordosis, and stabilization indications login to view 4 more bullets techniques login to view 11 more bullets outcomes login to view 2 more bullets goals login to view 1 more bullet Techniques Goals optimal surgical treatment depends on the individual. Considerations include: number of stenotic levels sagittal alignment of the spine degree of existing motion and desire to maintain medical comorbidities (e.g. dysphagia) simplified treatment algorithm Anterior cervical decompression and fusion (ACDF) alone indications mainstay of treatment in most patients with one- or two-level disease fixed cervical kyphosis of >10° login to view 1 more bullet compression arising from ≤2 disc segments pathology is anterior (OPLL, soft discs, disc-osteophyte complexes) approach Smith-Robinson anterior approach decompression corpectomy and strut graft may be required for multilevel spondylosis login to view 3 more bullets fixation anterior plating functions to increase fusion rates and preserve position of interbody cage or strut graft pros & cons advantages compared to posterior approach login to view 3 more bullets disadvantages login to view 1 more bullet Anterior cervical corpectomy and fusion (ACF) indications extensive retrovertebral disease cervical kyphosis preventing adequate posterior decompression technique anterior fixation alone login to view 2 more bullets combined anterior and posterior fixation login to view 3 more bullets Laminectomy with posterior fusion indications multilevel compression with kyphosis of <10° login to view 1 more bullet in flexible kyphotic spine, posterior decompression and fusion may be indicated if kyphotic deformity can be corrected prior to instrumentation contraindications fixed kyphosis of >10° is a contraindication to posterior decompression will not adequately decompress spinal cord due to anterior "bowstringing" pros & cons fusion may improve neck pain associated with degenerative facets not effective in patients with >10° fixed kyphosis Laminoplasty indications gaining in popularity useful when maintaining motion is desired avoids complications of fusion; may be indicated in patients at high risk of pseudoarthrosis congenital cervical stenosis contraindications cervical kyphosis login to view 2 more bullets severe axial neck pain login to view 1 more bullet technique volume of canal is expanded by hinged-door laminoplasty, followed by fusion login to view 1 more bullet open door technique login to view 2 more bullets French door technique login to view 1 more bullet pros & cons advantages login to view 8 more bullets disadvantages login to view 3 more bullets outcomes equivalent to multilevel anterior decompression and fusion Combined anterior and posterior surgery indications multilevel stenosis in a rigid kyphotic spine multilevel anterior cervical corpectomies post-laminectomy kyphosis Occipitocervical fusion indications periodontoid pannus posterior-only occipitocervical fusion is safe and effective in promoting pannus resolution transoral approaches are associated with increased morbidity, especially when surgical time exceeds 4 hours Laminectomy alone indications rarely indicated due to risk of post-laminectomy kyphosis pros & cons progressive kyphosis login to view 1 more bullet Complications Surgical infection higher rate of surgical infection with posterior approach than anterior approach Pseudoarthrosis incidence 12% for single level fusions, 30% for multilevel fusions treatment posterior wiring or plating or repeat anterior decompression and plating if patient has symptoms of radiculopathy Postoperative C5 palsy incidence occurs in ~4.6% of patients after surgery for cervical compression myelopathy login to view 1 more bullet no significant differences between patients undergoing anterior decompression and fusion and posterior laminoplasty login to view 1 more bullet occurs immediately postoperatively or within weeks following surgery mechanism controversial in laminectomy patients, thought to be caused by tethering of nerve root with dorsal migration of spinal cord following removal of posterior elements login to view 1 more bullet prognosis generally a good prognosis for functional recovery, but recovery takes time prolonged recovery associated with: login to view 3 more bullets Recurrent laryngeal nerve (RLN) injury approach in the past, has been postulated that the RLN is more vulnerable to injury on the right due to a more aberrant pathway login to view 1 more bullet prolonged retractor placement at the tracheoesophageal junction places RLN at risk for injury treatment for a postoperative RLN palsy, watch over time login to view 1 more bullet if you are performing revision anterior cervical surgery and there is any suspicion of a RLN from the first operation, obtain ENT consult to establish prior injury login to view 1 more bullet Hardware failure and migration 7-20% with two level anterior corpectomies two level corpectomies should be stabilized from behind Postlaminectomy kyphosis treat with anterior/posterior procedure Postoperative axial neck pain Airway compromise prolonged surgery (>5 hours) higher blood loss anterior exposure involving C2, C3, and C4 Vertebral artery injury Esophageal Injury Dysphagia & alteration in speech Multiple studies have demonstrated that the application of local steroid in the retropharyngeal space prior to wound closure decreases the rate of dysphagia Epidural hematoma rare complication 1/1,000 incidence associated with postoperative motor weakness and paresthesias emergent MRI and hematoma evacuation early evacuation results in better neurologic recovery MRI appearance of hematoma depends on age hyperacute (<24 hours) login to view 1 more bullet Prognosis Natural history tends to be slowly progressive and rarely improves with nonoperative modalities progression characterized by step-wise deterioration with periods of stable symptoms Prognostic variables early recognition and treatment prior to spinal cord damage is critical for good clinical outcomes