A 68-year-old woman comes to the office for evaluation of lower extremity weakness. The patient was hospitalized due to pneumonia and septic shock a month ago. She was intubated for respiratory failure at the time of admission and was treated in the intensive care unit for several days. After adequate improvement in her respiratory status, she was discharged to a physical rehabilitation facility. Since that time, the patient has had worsening lower extremity weakness that has failed to improve despite physical therapy. She also has had frequent occipital headaches and numbness and tingling in the hands and feet. The patient has a history of rheumatoid arthritis, hypertension, hypothyroidism, and right total knee replacement. She is a former smoker with a 20-pack-year history and does not drink alcohol. Blood pressure is 136/82 mm Hg and pulse is 72/min. Physical examination shows chronic joint deformities in both hands, clear lungs, normal heart sounds, and a nontender abdomen. Neurological examination reveals decreased lower extremity muscle strength, hyperactive knee reflexes, and decreased proprioception in the feet. Rapidly flicking the nail of the middle finger elicits flexion of the ipsilateral thumb. Which of the following is the most likely cause of this patient's current symptoms?

Question

A 68-year-old woman comes to the office for evaluation of lower extremity weakness.  The patient was hospitalized due to pneumonia and septic shock a month ago.  She was intubated for respiratory failure at the time of admission and was treated in the intensive care unit for several days.  After adequate improvement in her respiratory status, she was discharged to a physical rehabilitation facility.  Since that time, the patient has had worsening lower extremity weakness that has failed to improve despite physical therapy.  She also has had frequent occipital headaches and numbness and tingling in the hands and feet.  The patient has a history of rheumatoid arthritis, hypertension, hypothyroidism, and right total knee replacement.  She is a former smoker with a 20-pack-year history and does not drink alcohol.  Blood pressure is 136/82 mm Hg and pulse is 72/min.  Physical examination shows chronic joint deformities in both hands, clear lungs, normal heart sounds, and a nontender abdomen.  Neurological examination reveals decreased lower extremity muscle strength, hyperactive knee reflexes, and decreased proprioception in the feet.  Rapidly flicking the nail of the middle finger elicits flexion of the ipsilateral thumb.  Which of the following is the most likely cause of this patient's current symptoms?

Quizplus · Accepted Answer

11ec25c8_d5c9_296f_bc81_2b5aa30dc2a4_MD0003_00 This patient developed weakness, paresthesias, and hyperreflexia after intubation; in the setting of her known rheumatoid arthritis (RA), this presentation suggests spinal cord compression due to atlantoaxial joint instability. Although joint destruction in RA most commonly affects the small joints of the hands, the cervical spine can also be involved and may lead to subluxation (misalignment) of the atlantoaxial joints. Patients with severe RA (eg, elevated inflammatory markers, rapidly progressive erosive disease) and peripheral joint subluxation (eg, hand deformities) are at increased risk. Forced neck extension during intubation can worsen the subluxation, leading to cord compression and progressive cervical myelopathy; complete dislocation can result in paralysis and death. The earliest symptom of atlantoaxial subluxation is typically cervical pain that radiates to the occiput. Cervical myelopathy classically presents with slowly progressive, spastic paraparesis characterized by weakness involving the upper and lower extremities, hyperreflexia, and sensory changes. Upper motor neuron signs, including Babinski sign, are present. Hoffman sign (flexion and adduction of the thumb when flicking the nail of the middle finger) suggests a corticospinal tract lesion and supports the diagnosis of cervical myelopathy; however, it is nonspecific and may be seen in normal patients. Babinski sign Patients with evidence of subluxation should undergo urgent MRI of the cervical spine which demonstrates separation of C1 and C2. Management involves stiff surgical collars and neurosurgical intervention (eg, cervical fixation). (Choice A) Anterior cerebral artery stroke can result in extremity weakness with spastic paraparesis. However, stroke typically occurs acutely with maximum weakness upon presentation and the findings are unilateral; dysarthria and aphasia are also common. (Choice B) Critical illness polyneuropathy is a complication of sepsis characterized by axonal injury of the peripheral nerves. It is a common cause of weakness after a prolonged stay in an intensive care unit. However, peripheral nerve injury results in hyporeflexia; upper motor neuron signs would not occur. (Choice C) Guillain-Barré syndrome is characterized by immune-mediated nerve demyelination and typically presents as a rapidly progressive, ascending paralysis following a gastrointestinal or upper respiratory illness. Reflexes are typically decreased or absent, and Hoffman sign would be unexpected. (Choice D) Severe hypothyroidism is occasionally associated with polyneuropathy or myopathy, which can cause weakness and paresthesia. However, the reflexes are diminished, and upper motor neuron signs would be unexpected. Educational objective: Patients with rheumatoid arthritis are at risk for atlantoaxial instability; neck extension during intubation can result in subluxation with cord compression and cervical myelopathy. Symptoms of cervical myelopathy include a slowly progressive, spastic paraparesis involving the upper and lower extremities, hyperreflexia, sensory changes, and a positive Babinski sign. Hoffman sign may also be positive. References: Cervical spine disease in rheumatoid arthritis: incidence, manifestations, and therapy. (http://www.ncbi.nlm.nih.gov/pubmed/25663179)

A 68-Year-Old Woman Comes to the Office for Evaluation of Lower