Neurology · Degenerative Spine Disease
The facts most likely to be tested
Cervical spondylotic myelopathy presents with upper motor neuron signs in the lower extremities and lower motor neuron signs at the level of the lesion in the upper extremities.
The Lhermitte sign, an electric shock-like sensation radiating down the spine upon neck flexion, is a classic indicator of cervical cord pathology.
Gait instability and proprioceptive deficits are often the earliest and most sensitive clinical indicators of progressive spinal cord compression.
Hyperreflexia, clonus, and the presence of a Babinski sign are hallmark findings of long-tract involvement in the lower extremities.
MRI of the cervical spine is the gold standard diagnostic modality to visualize cord signal changes and the degree of canal stenosis.
Hoffmann sign, elicited by flicking the distal phalanx of the middle finger, indicates cervical cord compression when the thumb and index finger flex.
Surgical decompression via laminectomy or laminoplasty is the definitive treatment for patients with progressive neurological deficits or significant functional impairment.
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A 68-year-old male presents with a 6-month history of progressive difficulty walking and frequent tripping. He reports occasional numbness in his hands and difficulty with fine motor tasks like buttoning his shirt. Physical examination reveals atrophy of the intrinsic hand muscles, bilateral hyperreflexia in the lower extremities, and a positive Babinski sign on the right. He also demonstrates a positive Hoffmann sign on the left. His gait is wide-based and unsteady.
What is the most appropriate next step in the management of this patient?
MRI of the cervical spine
The patient exhibits classic signs of cervical spondylotic myelopathy (mixed UMN/LMN findings); MRI is the diagnostic test of choice to confirm cord compression and guide surgical planning.
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High yield triage
Etiology / Epidemiology
Primarily affects older adults due to degenerative disc disease and spondylosis.
Clinical Manifestations
Presents with myelopathy (gait disturbance, Lhermitte sign) and radiculopathy.
Diagnosis
MRI of the cervical spine is the gold standard; canal diameter <10 mm is diagnostic.
Treatment
Physical therapy and NSAIDs are first-line; surgical decompression for progressive deficits.
Prognosis
Early intervention prevents permanent neurological damage; monitor for gait instability.
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Epidemiology & Etiology
Most common in patients >50 years old due to chronic cervical spondylosis. Secondary causes include ossification of the posterior longitudinal ligament and congenital narrowing. It is the most common cause of spinal cord dysfunction in patients over 55.
Pertinent Anatomy
The spinal canal narrows due to osteophyte formation and ligamentum flavum hypertrophy. The cervical cord is compressed, leading to upper motor neuron signs below the level of the lesion.
Pathophysiology
Chronic compression leads to ischemia and demyelination of the spinal cord. This manifests as a combination of radiculopathy (nerve root compression) and myelopathy (cord compression). The cervical spondylotic myelopathy cascade results in progressive motor and sensory deficits.
Clinical Manifestations
Patients present with gait ataxia, Lhermitte sign (electric shock sensation with neck flexion), and hand clumsiness. Look for hyperreflexia and Babinski sign indicating upper motor neuron involvement. Red flags include bowel/bladder incontinence and rapid motor decline, which are surgical emergencies.
Diagnosis
MRI of the cervical spine is the gold standard to visualize cord compression. A sagittal canal diameter <10 mm is highly suggestive of stenosis. CT myelography is reserved for patients who cannot undergo MRI due to pacemakers or metal implants.
Treatment
Initial management includes physical therapy and activity modification. NSAIDs are the first-line pharmacologic agents for pain. Avoid cervical manipulation in patients with confirmed myelopathy. Surgical decompression (e.g., laminectomy or laminoplasty) is indicated for progressive neurological deficits or severe functional impairment.
Prognosis
Without treatment, progressive neurological deterioration is common. Surgical outcomes are best when performed before the onset of severe, irreversible cord atrophy. Patients require long-term monitoring for gait instability and fall risk.
Differential Diagnosis
Amyotrophic Lateral Sclerosis: lacks sensory deficits
Multiple Sclerosis: presence of white matter lesions on MRI
Vitamin B12 Deficiency: presents with subacute combined degeneration
Cervical Disc Herniation: acute onset rather than chronic
Syringomyelia: dissociated sensory loss (cape-like distribution)