What is the clinical approach to myelopathy?

Clinical Approach to Myelopathy

Myelopathy is a clinical diagnosis requiring immediate MRI of the spine to identify extrinsic cord compression, which is the most critical first step to prevent irreversible neurological damage. 1

Initial Clinical Assessment

Localization and Temporal Classification

• Localize neurological findings to the spinal cord rather than brain or peripheral nervous system, then identify the specific spinal cord segment involved through motor, sensory, and reflex examination 1
• Classify by acuity of symptom onset: acute (≤21 days to maximum deficit), subacute, or chronic/progressive, as this fundamentally determines the differential diagnosis 1, 2
• Acute presentations require emergency evaluation for extrinsic compression, vascular pathology, or infection that may need urgent intervention 1

Key Clinical Features to Identify

• Motor findings: Upper motor neuron signs including spasticity, hyperreflexia, positive Babinski sign, and weakness in a myelopathic distribution 3
• Sensory deficits: Sensory level, posterior column dysfunction (proprioception/vibration loss), or spinothalamic tract involvement (pain/temperature loss) 3
• Sphincter dysfunction: Bladder or bowel involvement indicating severe cord compromise 3
• Gait abnormalities: Spastic or ataxic gait patterns 3

Imaging Strategy

Primary Imaging Modality

MRI of the spine is the mainstay and preferred imaging modality for all myelopathy evaluations due to superior soft-tissue contrast resolution of the spinal cord. 1

• Image the entire spine even when clinical findings suggest a localized level, as multiple pathologies may coexist 1
• Brain MRI may be indicated as an adjunct when demyelinating disease or other central nervous system pathology is suspected 1
• CT myelography is reserved for patients with MRI contraindications or when MRI is non-diagnostic 1

Acute Onset Myelopathy Imaging Protocol

All patients with acute myelopathy require urgent evaluation for extrinsic spinal cord compression, which is the most common and treatable cause. 1

• Degenerative disease (spondylotic myelopathy) is the most frequent cause of extrinsic compression, particularly in the cervical spine, from osteophytes, disc herniations, and malalignment 1
• Epidural pathology including abscess or hematoma must be excluded emergently 1
• Vertebral fractures from osteoporosis or pathologic processes can cause compression even without significant trauma 1
• Neoplastic compression from extradural or intradural extramedullary tumors requires identification 1

Chronic/Progressive Myelopathy Imaging Protocol

• After excluding extrinsic compression, evaluate for intrinsic cord pathology including demyelinating diseases (multiple sclerosis, neuromyelitis optica), metabolic causes (B12/copper deficiency), infections, radiation myelopathy, and intramedullary neoplasms 1
• Vascular abnormalities such as spinal dural arteriovenous malformations/fistulas require specific imaging protocols 1

Differential Diagnosis Framework

Noninflammatory Causes

• Extrinsic compression: Degenerative disease, tumors, epidural abscess/hematoma, postoperative complications 1
• Vascular: Spinal cord ischemia (atherosclerotic disease, aortic surgery complications), arteriovenous malformations 1
• Metabolic: Vitamin B12 deficiency, copper deficiency, nitrous oxide toxicity 1

Inflammatory Causes

• Demyelinating: Multiple sclerosis, neuromyelitis optica spectrum disorders, acute disseminated encephalomyelitis 1
• Infectious: Viral myelitis, tuberculosis, schistosomiasis, HIV vacuolar myelopathy, tertiary syphilis 1
• Autoimmune: Paraneoplastic myelopathy, systemic inflammatory diseases 1

Neoplastic Causes

• Primary intramedullary tumors: Astrocytomas, ependymomas 1
• Metastatic disease: Intramedullary metastases 1

Prognostic Assessment for Surgical Candidates

Clinical Prognostic Factors

When considering surgery for cervical spondylotic myelopathy, discuss with patients that age, duration of symptoms, and preoperative neurological function commonly affect surgical outcomes. 1

• Younger age is associated with better surgical outcomes 1
• Shorter symptom duration predicts better recovery 1
• Better preoperative neurological function correlates with improved postoperative results 1

Electrophysiological Testing

Preoperative somatosensory evoked potentials should be considered for prognostic information in selected patients where clinical factors do not provide clear guidance and when results would potentially change treatment decisions. 1

Multidisciplinary Approach

Optimal myelopathy management requires integration of neurosurgery, neurology, neuroradiology, physiatry, and rehabilitation services. 4, 5

• Neurosurgical evaluation for surgical candidacy and timing of intervention 4, 5
• Neurological assessment for detailed localization and etiology determination 4, 5
• Neuroradiological expertise for advanced imaging interpretation and protocol selection 4, 5
• Rehabilitation services for preoperative optimization and postoperative recovery 5

Critical Pitfalls to Avoid

• Do not delay imaging in acute presentations, as compressive myelopathy requires urgent identification to prevent irreversible cord damage 1
• Do not assume a single level of pathology based on clinical findings alone; image the entire spine 1
• Do not rely solely on radiographs or CT for initial evaluation, as these modalities have poor sensitivity for intrinsic cord pathology and early compression 1
• Do not overlook postoperative patients who can develop delayed complications including seromas, pseudomeningoceles, hematomas, and epidural abscesses 1
• Do not miss vascular causes in acute presentations, particularly spinal cord ischemia from atherosclerotic disease or aortic pathology 1