A 44-year-old man comes to the office due to several weeks of difficulty walking and frequent falls. He has had no headache or visual impairment but reports episodes of sharp, stabbing pain in his extremities. The patient has HIV acquired from unprotected sexual contact and is nonadherent with treatments. Temperature is 37 C (98.6 F). Neurologic examination shows 5/5 motor power in all extremities. Deep-tendon reflexes are absent at the knee and ankle bilaterally. Proprioception and vibration sensation are reduced throughout the lower extremities. He has a wide-based gait and a positive Romberg sign. Which of the following diagnostic findings is most likely associated with this patient's current symptoms?

Question

A 44-year-old man comes to the office due to several weeks of difficulty walking and frequent falls.  He has had no headache or visual impairment but reports episodes of sharp, stabbing pain in his extremities.  The patient has HIV acquired from unprotected sexual contact and is nonadherent with treatments.  Temperature is 37 C (98.6 F).  Neurologic examination shows 5/5 motor power in all extremities.  Deep-tendon reflexes are absent at the knee and ankle bilaterally.  Proprioception and vibration sensation are reduced throughout the lower extremities.  He has a wide-based gait and a positive Romberg sign.  Which of the following diagnostic findings is most likely associated with this patient's current symptoms?

Quizplus · Accepted Answer

11ec160b_39de_b249_9249_07ab7fc4a74b_MD0001_00 This patient's sensory ataxia and lancinating pains raises suspicion for tabes dorsalis, a late form of neurosyphilis that usually manifests several years or decades after initial infection with Treponema pallidum. Tabes dorsalis is characterized by a slow degeneration of nerve fibers in the dorsal column of the spinal cord and dorsal nerve roots, which leads to diminished vibratory, proprioception, and discriminative touch sensation. Common manifestations include: Sensory ataxia: Wide-based gait and loss of equilibrium when the patient's eyes are closed (positive Romberg sign); due to damaged lower extremity proprioception Absent deep-tendon reflexes: Due to damaged dorsal nerve roots Lancinating pains: Sharp, stabbing pains that may last minutes or hours; the exact cause is unclear Spirochetal damage to the midbrain tectum also commonly results in Argyll Robertson pupil. This finding is marked by small, irregularly shaped pupils that fail to constrict to light but that constrict normally to accommodation (light-near dissociation). Most patients with tertiary syphilis will have a positive VDRL and mild lymphocytic pleocytosis on cerebrospinal fluid analysis. (Choice A) Central nervous system infection with Mycobacterium tuberculosis, an acid-fast bacillus, is usually characterized by headache, vomiting, cranial nerve deficits, and confusion. Lancinating pains and altered lower extremity sensation would be atypical. (Choice B) Herpes simplex encephalitis primarily affects the temporal lobe and causes fever, headache, impaired consciousness, and seizures. (Choice C) Cryptococcal meningitis can be diagnosed by examining the cerebrospinal fluid for encapsulated yeasts using India ink. However, cryptococcal meningitis usually manifests with fever, malaise, and headache. Lancinating pains, absent deep-tendon reflexes, and altered sensation would be atypical. (Choice D) JC virus is a polyomavirus that replicates in oligodendrocytes (glial cells). Reactivation of JC virus causes progressive multifocal leukoencephalopathy, which occurs primarily in severely immunocompromised patients (eg, AIDS, lymphoma, leukemia) and causes progressive dementia, motor deficits, and visual impairment. (Choice F) Patients with untreated HIV are at high risk for cerebral toxoplasmosis, which usually manifests with headache, confusion, fever, and focal neurologic deficits. MRI of the brain usually reveals ring-enhancing lesions. Educational objective: Tabes dorsalis, a late form of neurosyphilis, causes progressive degeneration of the dorsal columns and dorsal roots of the spinal cord. Manifestations include loss of proprioception and vibratory sensation, severe lancinating pains, and sensory ataxia (eg, wide-based gait, positive Romberg sign). Many patients also have Argyll Robertson pupils. __________ References: REVIEW: Neurosyphilis: a historical perspective and review. (http://www.ncbi.nlm.nih.gov/pubmed/20626434)

A 44-Year-Old Man Comes to the Office Due to Several