A 62-year-old woman comes to the office due to upper extremity weakness and numbness. Three days ago, the patient was involved in a motor vehicle collision in which a truck rear-ended her vehicle. The patient did not hit her head or lose consciousness but experienced a tingling and burning sensation in all extremities, which she attributed to the stress of the accident. Since then, she has had numbness in her upper extremities and clumsiness of her hands. She reports difficulty picking up objects but has had no leg weakness or bowel or bladder disturbance. The patient is upset that the other driver refused to accept fault but reports no other ongoing stressors. She has a history of hypertension and osteoarthritis. Vital signs are within normal limits. Neck and back examination show no deformity or tenderness. There is weakness of hand grip bilaterally, and the triceps reflex is decreased on both sides. Decreased pinprick sensation is present on the fingers. The remainder of the neurologic examination is normal. Cervical spine x-ray reveals no vertebral dislocation or fracture, but diffuse spondylotic changes are present. Which of the following is the most likely cause of this patient's symptoms?
This patient with cervical spine spondylosis (ie, nonspecific, degenerative cervical spine joint changes) was involved in a rear-end collision and developed subsequent upper extremity weakness, reflex loss, and sensation changes, raising strong suspicion for central cord syndrome, an incomplete acute spinal cord injury. Most cases arise when an older individual with a stenotic cervical spinal canal (eg, due to cervical spondylosis) experiences a hyperextension injury to the neck (eg, whiplash due to rear-end collision); this compresses the spinal cord between a hypertrophied ligamentum flavum posteriorly and a bulging disc/osteophyte complex anteriorly, leading to damage to the central spinal cord (grey matter).
Patients primarily develop upper extremity manifestations, including:
Due to the more central location of the lesion, the lateral spinal tracts running to the sacrum (eg, bowel, bladder) and lower limbs are generally spared.
Workup begins with spinal imaging; x-ray is often normal but may show cervical spondylosis. Cervical myelogram is generally diagnostic and often demonstrates persistent cord compression; treatment with glucocorticoids and/or surgery is usually required.
(Choice A) Acute stress disorder is common after severe motor vehicle collisions and is generally characterized by agitation, anxiety, and fear. Numbness, weakness, and loss of reflexes in the upper extremities would be atypical.
(Choice B) Brachial plexus injury (nerve roots C5-T1) is generally characterized by shoulder or arm pain, upper extremity muscle weakness, atrophy (after weeks), and sensory loss; however, most cases are unilateral. In addition, traumatic injury to the brachial plexus usually occurs when there is downward traction on the shoulder and the neck is forced to the contralateral side (not during hyperextension injury).
(Choice C) Malingering is when a patient simulates an illness to obtain obvious external benefit (eg, money, medications, work benefits). This patient's reflex, motor, and sensory abnormalities on physical examination make malingering less likely.
(Choice D) Postconcussion syndrome is generally marked by headache, dizziness, cognitive impairment (eg, loss of concentration/memory), irritability, anxiety, and noise sensitivity. Although it can occur following whiplash injury, upper extremity weakness, sensory loss, and reflex abnormalities would be atypical.
Educational objective:
Central cord syndrome is common after whiplash-type injuries in older adults with underlying cervical spondylosis. Damage to the central cervical spinal cord causes upper extremity motor, sensory, and reflex abnormalities; sacral (eg, bowel/bladder) and lower extremity function is generally preserved.