A 64-year-old woman comes to the physician with a 10-day history of progressive difficulty walking and poor balance. Two days ago, she fell at home but did not sustain any injuries. Her chronic back pain is worse than usual and is especially bothersome at night. She has no headaches, trauma, bowel or bladder incontinence, or loss of consciousness. The patient's past medical history is significant for type 2 diabetes mellitus, hypertension, transient ischemic attack, and breast cancer status post lumpectomy followed by chemoradiation 2 years ago. Her blood pressure is 162/78 mm Hg and pulse is 73/min. Physical examination shows an unsteady gait, bilateral leg weakness, increased deep-tendon reflexes, and decreased pinprick sensation in both lower extremities up to the umbilicus. There is percussion tenderness over the lower thoracic spine. Digital rectal examination shows good sphincter tone. Mental status, memory, and cognition are intact. Which of the following is most likely responsible for this patient's clinical presentation?
Spinal cord compression | |
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This patient's presentation suggests epidural spinal cord compression (ESCC), likely from recurrent breast cancer presenting with metastasis. Other malignancies which commonly affect the spine are lung, renal, and prostate cancers and multiple myeloma. The thoracic spine is the most frequently affected level (60%), followed by the lumbar spine (30%).
Most patients present with progressively worsening back pain. Pain is usually worse in the recumbent position (due to distension of the epidural venous plexus when lying down) in contrast to back pain from degenerative joint disease, which improves with recumbency. Bilateral lower-extremity weakness is present in about 60% of patients. Sensory loss below a spinal level and gait ataxia may occur. Paraplegia and bowel or bladder dysfunctions (eg, fecal or urinary retention/incontinence) are late findings. Examination shows focal point tenderness in the spine, exaggerated deep-tendon reflexes in the legs, and upgoing plantar reflexes.
In this patient, given the T10 sensory level (umbilicus), the cord injury is likely at the T8 level. In the acute phase of spinal cord injury, patients can develop spinal shock and have absence of reflexes and flaccid paraplegia. Given that this patient has had symptoms for 10 days, the reflexes and tone generally become increased by this time.
(Choice A) Brainstem ischemic strokes typically cause focal unilateral neurologic deficits such as "crossed signs" (eg, ipsilateral cranial nerve deficit, contralateral hemiplegia). Patients often present with acute deficits that can progress over hours but not days. Pain is not a feature of stroke.
(Choice B) Diabetic polyneuropathy usually presents with symmetrical sensory loss that affects primarily the distal lower extremities. Patients have loss of pain, temperature, proprioception, and vibratory sensation; unlike in myelopathy, deep-tendon reflexes are diminished or absent. Back pain is not present.
(Choice C) Guillain-Barré syndrome presents with diminished or absent but not hyperactive reflexes.
(Choice D) The classic triad of normal-pressure hydrocephalus is cognitive dysfunction, gait difficulty (wide-based gait), and urinary incontinence. It is usually not associated with lower-extremity weakness or back pain.
(Choice F) Spinal cord infarction generally presents with abrupt symptoms such as weakness (may progress to paraplegia/quadriplegia), loss of pain and temperature sensation (anterior spinal artery infarct), and autonomic dysfunction. This patient's symptoms have evolved gradually, making acute spinal cord infarction less likely.
Educational objective:
Neoplastic epidural spinal cord compression presents with worsening focal back pain, bilateral lower-extremity weakness, sensory loss, and gait ataxia. Bowel/bladder disturbances are late findings. In the acute phase of spinal cord injury, patients can develop spinal shock with absence of reflexes and flaccid paraplegia as a result.