If present, which one of the following features is of most specific value in differentiating optic neuritis from papilledema?
Correct Answer A: Papilledema is swelling of the optic disc (papilla), usually in association with increased intracranial pressure, characterized by hyperemia, blurring of the disk margins, micro-hemorrhages, blind spot enlargement, and engorgement of retinal veins. The condition usually is bilateral, the nerve head is very elevated and swollen, and pupil response typically is normal.
Vision is not affected initially (although there is an enlargement of the blind spot), and there is no pain upon eye movement. Secondary optic atrophy and permanent vision loss can occur if the primary cause of the papilledema is left untreated.
Optic neuritis is an inflammation of the optic nerve. It may affect the part of the nerve and disc within the eyeball (papillitis) or the portion behind the eyeball (retrobulbar optic neuritis, causing pain with eye movement). It also includes degeneration or demyelinization of the optic nerve. There will be no visible changes in the optic nerve head (disc) unless some optic atrophy has occurred.
The condition is unilateral rather than bilateral. If the nerve head is involved, it is slightly elevated, and pupillary response in that eye is sluggish. There usually is a marked but temporary decrease in vision for several days or weeks, and there is pain in the eye when it is moved. Single episodes generally do not result in optic atrophy nor in permanent vision loss; however, multiple episodes can result in both.
A 72-year-old patient has an acute onset of joint pain and swelling. Aspiration reveals monosodium urate crystals. Compared with younger patients, geriatric patients presenting for the first time with this condition are more likely to:
Correct Answer C: The presentation of gout in the elderly is often different from the classic presentation. It occurs more often in women, has a polyarticular onset, and often involves small joints of the hands. Older patients also tend to develop tophi early. Gout may appear in joints with Heberden’s nodes from osteoarthritis. Podagra is the classic presentation of gout in the younger population.
A strict vegan, develops symptoms of fatigue, dizziness and dyspnea. She comes in for evaluation and her CBC shows anemia with a MCV of 104 fL.
What is the most appropriate next step in diagnosis?
Correct Answer B: When vitamin B12 deficiency anemia develops, causing:
A severe deficiency may cause:
The diagnosis is based on blood tests. A CBC will show macrocytic anemia. When high doses of vitamin B12 supplements are taken, most symptoms resolve. Symptoms due to nerve damage, such as neuropathy or dementia in older people, may persist.
Vitamin B12 deficiency develops in people who do not consume any animal products (vegans) unless they take supplements. If a vegan mother breastfeeds her infant, the infant is at risk of vitamin B12 deficiency.
An iron level and Hb Electrophoresis would be useful of the anemia was microcytic (MCV < 80 fL). An RBC scan would be useful if bleeding is suspected.
A 48-year-old man complains of fatigue and shortness of breath. Peripheral blood smear reveals macrocytosis. Labs are as follows:
Which one of the following causes listed below is most unlikely?
Correct Answer B: This patient has vitamin B12 deficiency related macrocytic anemia. Pernicious anemia is a chronic illness caused by impaired absorption of vitamin B12 because of a lack of intrinsic factor (IF) in gastric secretions.
Causes include:
Which one of the following is true regarding the use of oral vitamin B12 to treat vitamin B12 deficiencies?
Correct Answer A: There is strong evidence for the existence of an alternative pathway to the usual intrinsic factor/terminal ileum pathway for vitamin B12 absorption. Studies have shown that oral vitamin B12 at daily doses of 1000 µg is effective for the treatment of vitamin B12 deficiency even in the absence of intrinsic factor (pernicious anemia), an acidic environment (gastrectomy), or terminal ileum resection (resection or damage from Crohn's disease). This high oral dose is required because doses of 500 µg or less are only variably absorbed via the alternative pathway. The Schilling test is no longer needed for determining the route of therapy for vitamin B12 deficiency, as high-dose oral therapy is effective even if the stage I Schilling test is abnormal.
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