Musculoskeletal · Cervical Radiculopathy
The facts most likely to be tested
The C6 radiculopathy is the most common level, presenting with weakness in the biceps and wrist extensors and diminished brachioradialis reflex.
A C7 radiculopathy typically presents with triceps weakness, diminished triceps reflex, and sensory loss in the middle finger.
The Spurling test (cervical extension and lateral rotation toward the affected side) is the most specific physical exam maneuver to reproduce radicular pain.
MRI of the cervical spine is the gold standard diagnostic imaging modality for patients with persistent neurological deficits or suspected cord compression.
Cervical myelopathy is a surgical emergency characterized by gait instability, hyperreflexia, and upper motor neuron signs like the Hoffman sign.
Initial management for acute cervical radiculopathy without progressive neurological deficit is conservative therapy including NSAIDs, physical therapy, and activity modification.
The C5 radiculopathy presents with deltoid weakness, diminished biceps reflex, and sensory loss over the lateral shoulder.
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A 45-year-old male presents with a 3-week history of sharp, radiating pain down his right arm. He reports numbness in his middle finger and difficulty performing push-ups due to weakness in his triceps. On physical exam, he has a diminished triceps reflex on the right side. His Spurling test is positive on the right. He has no gait instability or hyperreflexia.
Which nerve root is most likely compressed in this patient?
C7 nerve root
The patient's clinical presentation of middle finger sensory loss, triceps weakness, and diminished triceps reflex is classic for a C7 radiculopathy, which is the second most common level of cervical disc herniation.
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High yield triage
Etiology / Epidemiology
Common in 30-50 year olds due to annulus fibrosus degeneration and repetitive neck strain.
Clinical Manifestations
Presents with radiculopathy (pain, paresthesia, weakness) in a specific dermatomal distribution.
Diagnosis
MRI is the gold standard for visualizing nerve root compression.
Treatment
Conservative management with NSAIDs and physical therapy; progressive motor deficit requires surgery.
Prognosis
Most resolve within 6-12 weeks; monitor for myelopathy.
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Epidemiology & Etiology
Peak incidence occurs in the 30-50 age group. Risk factors include smoking, heavy lifting, and repetitive neck trauma. The condition results from the extrusion of the nucleus pulposus through a tear in the annulus fibrosus.
Pertinent Anatomy
The most common levels of herniation are C6-C7 (C7 nerve root) and C5-C6 (C6 nerve root). Unlike the lumbar spine, cervical nerve roots exit above the corresponding pedicle (e.g., C6 root exits at C5-C6).
Pathophysiology
Herniation causes mechanical compression and chemical irritation of the nerve root. This triggers an inflammatory cascade leading to radicular pain. If the herniation is central, it may cause cervical myelopathy due to direct spinal cord compression.
Clinical Manifestations
Patients report neck pain radiating into the arm. C6 radiculopathy presents with weakness in the biceps and sensory loss in the thumb. C7 radiculopathy involves triceps weakness and middle finger paresthesia. Red flags include bowel/bladder dysfunction, gait instability, or progressive motor weakness.
Diagnosis
MRI is the gold standard for confirming disc herniation and nerve root impingement. Plain radiographs are used initially to rule out fracture or malignancy. Electromyography (EMG) may be used to confirm the specific nerve root level if clinical findings are ambiguous.
Treatment
Initial management is conservative with NSAIDs and activity modification. Physical therapy is indicated after the acute phase. Surgical decompression is reserved for patients with intractable pain or progressive neurological deficits.
Prognosis
Over 80-90% of patients improve with conservative therapy within 3 months. Persistent symptoms or the development of myelopathy (hyperreflexia, Hoffman's sign) necessitates urgent neurosurgical consultation.
Differential Diagnosis
Cervical Spondylosis: chronic degenerative changes rather than acute herniation
Brachial Plexitis: sudden onset severe pain followed by weakness, usually post-viral
Thoracic Outlet Syndrome: neurovascular compression at the superior thoracic aperture
Pancoast Tumor: shoulder/arm pain with Horner's syndrome
Cervical Myelopathy: bilateral symptoms and gait disturbance