A 60-year-old man is brought to the office due to difficulty walking. He reports being "weak" and describes occasional brief episodes of intense back pain. Review of systems is negative for constitutional, pulmonary, cardiac, genitourinary, or other neurologic symptoms, including memory concerns. He has no known medical problems except for a remote history of treated pulmonary tuberculosis. The patient recently emigrated from China to the United States to live with his daughter after his wife died. His daughter says that he is afraid of doctors and has not been evaluated for many years. He does not use tobacco, alcohol, or recreational drugs.
Blood pressure is 138/64 mm Hg and pulse is 74/min. Lung examination is normal. Cardiac auscultation reveals an early diastolic murmur in the aortic area. The abdomen is soft and nontender. Rectal examination shows an unremarkable prostate and normal rectal tone. Motor strength is normal. Bilateral lower extremity reflexes are diminished, and vibration and position sensation is decreased. The patient's gait is unsteady and broad-based.
Laboratory results are as follows:

ECG shows normal sinus rhythm. Chest x-ray reveals left upper lobe scarring, widened mediastinum, and calcifications of the ascending aorta and aortic arch.
Which of the following is most helpful in establishing the diagnosis?

Question

A 60-year-old man is brought to the office due to difficulty walking.  He reports being "weak" and describes occasional brief episodes of intense back pain.  Review of systems is negative for constitutional, pulmonary, cardiac, genitourinary, or other neurologic symptoms, including memory concerns.  He has no known medical problems except for a remote history of treated pulmonary tuberculosis.  The patient recently emigrated from China to the United States to live with his daughter after his wife died.  His daughter says that he is afraid of doctors and has not been evaluated for many years.  He does not use tobacco, alcohol, or recreational drugs.
Blood pressure is 138/64 mm Hg and pulse is 74/min.  Lung examination is normal.  Cardiac auscultation reveals an early diastolic murmur in the aortic area.  The abdomen is soft and nontender.  Rectal examination shows an unremarkable prostate and normal rectal tone.  Motor strength is normal.  Bilateral lower extremity reflexes are diminished, and vibration and position sensation is decreased.  The patient's gait is unsteady and broad-based.
Laboratory results are as follows:

ECG shows normal sinus rhythm.  Chest x-ray reveals left upper lobe scarring, widened mediastinum, and calcifications of the ascending aorta and aortic arch.
Which of the following is most helpful in establishing the diagnosis?

Quizplus · Accepted Answer

A unifying diagnosis in this patient is tertiary syphilis with tabes dorsalis and cardiovascular syphilis, which typically develop following years of untreated Treponema pallidum infection. Tabes dorsalis affects the posterior columns of the spinal cord and most commonly presents with sensory ataxia and lancinating pains. Pupillary irregularities, especially Argyll Robertson pupil, are common. Examination may demonstrate absent lower extremity reflexes and impaired vibratory and position sensation. Cardiovascular syphilis most commonly affects the ascending aorta; patients have asymptomatic aortic insufficiency or resultant left heart failure. Ascending aortic arch calcification is often noted on chest x-ray; it is usually not present with atherosclerotic disease. In tertiary syphilis, especially tabes dorsalis, nontreponemal tests (eg, rapid plasma reagin) may not be positive, but treponemal assays (eg, T pallidum enzyme immunoassay) remain almost 100% sensitive. For tertiary syphilis with evidence of neurosyphilis, treatment consists of intravenous penicillin for 10-14 days. Other forms of tertiary syphilis without neurosyphilis should be treated with intramuscular penicillin once weekly for 3 weeks. treatment (Choices A and D) Normal-pressure hydrocephalus (diagnosed with CT scan) and amyloid neuropathy from multiple myeloma (diagnosed with serum protein electrophoresis) may present with gait abnormalities; however, neither would explain the other examination findings. (Choice B) Exposure to heavy metal, especially lead, is an important consideration in patients from low-income countries. However, the neurocognitive effects of chronic lead poisoning more commonly include psychiatric abnormalities (eg, irritability) and neuropathies leading to wrist or foot drop. (Choice C) Tuberculosis of the spinal cord frequently presents with fever and signs of cord compression. Interferon-gamma release assays are not helpful for the diagnosis of active infections or in previously treated patients. Educational objective: Tabes dorsalis most commonly presents with sensory ataxia and lancinating pains, and cardiovascular syphilis most commonly presents with asymptomatic aortic insufficiency or resultant left heart failure. In both, treponemal assays remain almost 100% sensitive. __________ References: Canadian Public Health Laboratory Network laboratory guidelines for the diagnosis of neurosyphilis in Canada. (http://www.ncbi.nlm.nih.gov/pubmed/25798161) Diagnosis and management of syphilis. (http://www.ncbi.nlm.nih.gov/pubmed/12892348)

A 60-Year-Old Man Is Brought to the Office Due to Difficulty