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Environmental Medicine: Integrating a Missing Element into Medical Education
A 67-year-old man with headache, nausea, and visual disturbance
During an afternoon visit, you see a 67-year-old man for onset of headache, nausea, and visual disturbance. The friend who accompanies him explains that both of them frequent the same senior center and that they have been preparing for a fund-raising event during the past 2 days. During this time, the patient spent between 6 and 9 hours per day reproducing fliers using a “spirit duplicator” (mimeograph machine). This activity took place in a small, unventilated room with the patient working alone most of the time.
On questioning, the patient says that he had eye irritation and lightheadedness after the first few hours of activity but considered these symptoms to be a minor annoyance. He also had nausea by the end of the first day but noted that this cleared overnight. During the second day of activity, he was again troubled by eye irritation, this time accompanied by vertigo, tinnitus, visual blurring, and photophobia. He tried to ventilate the room by placing a small fan near the door but continued to feel poorly despite a prolonged break. Late in the afternoon his friend insisted that he seek medical attention.
The patient is a widower and retired insurance salesman with a smoking history of one pack per day from age 27 to 62 (none for the last 5 years). He typically consumes a six-pack of beer per day, but he has felt poorly and has been abstinent for the past 10 days. Medical history includes coronary artery bypass surgery at age 63 with subsequent medical management of stable angina and a transurethral prostatectomy at age 65 with no recurrence of obstructive symptoms. Current medications include nitroglycerine patches used before exercise (with no patches used in the previous 4 days) and sublingual nitroglycerine, which he takes rarely. The review of symptoms is negative for other cardiopulmonary complaints. There is no family history of glaucoma, myopia, or diabetes mellitus.
On examination, the patient is alert and oriented to time, space, and person, although he appears somewhat distracted. His breath has a faint solvent-like smell. Vital signs are within normal range with the exception of a respiratory rate of 30/minute. The cardiopulmonary examination is unremarkable, but abdominal examination reveals mild tenderness in the epigastrium without rebound or guarding. Muscle tone, strength, sensation (pinprick, light touch, position sense) and reflexes are symmetrically intact. His gait is unsteady with a wide-based stance, and he shows a positive Romberg sign, heel-to-shin, and rapid alternating movements (bilaterally).
Ophthalmologic examination reveals a visual acuity of 20/200 bilaterally despite newly prescribed corrective lenses. The conjunctivae appear somewhat injected, nystagmus is present on lateral gaze, and the pupils are large and poorly reactive to light. Examination also reveals hyperemia of the optic nerve head with no hemorrhages or exudates.
(a) What is the differential diagnosis for this patient?