News potpourri (*). (SPECIAL FEATURE).

SMOKING AND BREAST CANCER SPREAD TO LUNGS ARE LINKED

Source: Lancet 2001; 357:2031

Breast cancer is more likely to spread to the lungs in women who smoke than in non-smokers. Researchers from the University of California-Davis Medical Center say women are more likely to survive breast cancer if they don't smoke. Case-control studies compared 87 patients with invasive breast cancer that had spread to the lungs with 174 patients whose breast cancer had not spread. The women whose breast cancer had metastasized were twice as likely (odds ratio: 1.96) to be smokers when compared with women without pulmonary metastatic disease.

GENE THERAPY SHOWS PROMISE FOR HAEMOPHILIA

Source: BMJ 2001; 322:1442

A new type of gene therapy boosts levels of the clotting factor VIII in some people with hemophilia. Researchers from Beth Israel Deaconess Medical Center in Boston, MA used a non-viral somatic cell, gene therapy system, (transkaryotic implantation) in six patients with severe hemophilia. The procedure consisted of isolating dermal fibroblasts from a full thickness skin biopsy. These were transfected by electroporation with a plasmid containing the gene for factor VIII. The cells that expressed factor VIII were cloned, propagated, and laparoscopically implanted into the omentum of these patients. No significant adverse effects related to the procedure were observed, and none of the patients developed antibodies against factor VIII or a cellular immune response to the implanted transfected fibroblasts. The results do not yet lend the proof needed to bring the treatment to the market.

PAEDIATRIC HEART SOUNDS ASSESSED BY COMPUTER

Source: Lancet 2001; 357:1856

An electronic stethoscope and a computer program can accurately distinguish innocent heart murmurs from pathologic murmurs in children. Researchers from the University of Colorado Health Sciences Center, Denver, CO say this technology has potential as a low-cost, high-volume screening tool; however, it would assist, not replace the clinician's assessment. It could help in decision-making about the utility of additional, and often costly tests. Thirty-seven children with abnormal heart murmurs and 32 with innocent heart murmurs were tested with the stethoscope to record heart sounds. The sounds were fed into the computer program to discriminate between the different types of murmurs. Eventually, it achieved 100% sensitivity (ability to identify an abnormal murmur) and 100% specificity (ability to identify an innocent murmur).

AIR POLLUTION CAN TRIGGER A MYOCARDIAL INFARCTION

Source: Lancet 2001; 357:1952

Exposure to air pollution for as little as two hours increases the risk of a myocardial infarction in people at risk of cardiovascular disease. Researchers at Beth Israel Deaconess Medical Center, Boston, Massachusetts say high levels of fine particles have been linked to higher mortality, primarily from respiratory and cardiovascular causes. Data on the time of onset of symptoms were obtained through detailed interviews with 772 patients in the Boston area a median of four days after their myocardial infarction. The time of symptom onset was compared with air-quality data that were collected during the study period. Air pollutants measured included fine particulate matter ([less than]2.5 mm diameter; PM 2-5), black carbon, ozone, carbon monoxide, sulphur dioxide, and nitrogen dioxide. Relative humidity and temperature were also measured. The risk of a myocardial infarction was greater in the two hours following exposure to high levels of PM 2-5. The risk was approximately 40% greater on the worst 5% of days compared with the 5% of days with the lowest concentration of particles.

RELATION BETWEEN HEADACHE IN CHILDHOOD AND PHYSICAL AND PSYCHIATRIC SYMPTOMS IN ADULTHOOD: NATIONAL BIRTH COHORT STUDY

Source: BMJ 2001; 322:1145

Children who experience headaches are at an increased risk of recurring headaches in adulthood as well as other physical and psychiatric symptoms. This population-based cohort study included people participating in the national child development study established in 1958. Headaches, multiple physical symptoms, and psychiatric morbidity at age 33 years were used as main outcome measures. Headaches in childhood were associated with several psychosocial factors. Prospectively, those with frequent headaches had an increased risk of headaches in adulthood (odds ratio 2.22, 95% confidence interval, 1.62-3.06), multiple physical symptoms (1.75, 1.46-2.10), and psychiatric morbidity (1.41, 1.20-1.66). The outcomes of headaches and multiple physical symptoms were not accounted for by psychiatric morbidity.

FREQUENCY AND PREVENTION OF SYMPTOM-LESS DEEP-VEIN THROMBOSIS IN LONG-HAUL FLIGHTS: A RANDOMISED TRIAL

Source: Lancet 2001; 357:1485-1489

Elastic compression stockings worn during long-haul air travel reduce symptomless deepvein thrombosis (DVT). Eighty-nine male and 142 female passengers over 50 years of age with no history of thromboembolic problems were included in this study at the Vascular Institute at the Stamford Hospital, London, UK. Passengers were randomly allocated to one of two groups. One group wore class-1 below-knee graduated elastic compression stockings, while the other group did not. All of the passengers made journeys lasting more than eight hours per flight (median total duration 24 hours), and returned to the United Kingdom within six weeks. Duplex ultrasonography assessed the deep veins before and after travel. Twelve of 116 passengers (10%; 95% CI 4.8%-16.0%) developed symptomless DVT in the calf (5 men and 7 women). None of these passengers wore elastic compression stockings, and 2 were heterozygous for factor V Leiden. Four other patients, who wore elastic compression stockings, had varicose veins and developed superfic ial thrombophlebitis. Not any of the passengers who wore Class 1 compression stockings developed DVT (95% CI, 0-3.2%). [A related article, "Venous thromboembolism after long flights: are airlines to blame?" appears in the same issue, pp 1461-1462.]

HEALTH INFORMATION ON THE INTERNET

Source: JAMA 2001; 285:2612-2621

Web-based health information requires high reading levels for comprehension. Three studies were performed from July 2000 through December 2000. Accessibility of 14 search engines was assessed with a structured search experiment. The quality of 25 health Web sites and content provided by one search engine was evaluated by 35 physicians using structured implicit review (interrater reliability was greater than 0.90). The Fry Readability Graph method was used to establish the reading grade level of text selected for structured implicit review. Less than one quarter of the search engines' first pages of links led to applicable content (20% of English, and 12% of Spanish). On average, 45% of the clinical elements on English and 22% on Spanish Web sites were more than minimally covered and completely accurate. Twenty-four percent of the clinical elements on English and 53% on Spanish Web sites were not covered at all. All English and 85% of the Spanish Web sites required a high school level or greater reading abilit y.

CORRESPONDENCE

(Letters to the Editor are welcomed. They may report new clinical or laboratory observations and new developments in medical care or may contain comments on recent contents of the Journal. They will be published, if found suitable, as space permits. Like other material submitted for publication, letters must be typewritten, double-spaced, and submitted in duplicate. They must not exceed two typewritten pages in length. No more than five references and one figure or table may be used. See "Information for Authors" for format of references, tables, and figures. Editing, possible abridgment, and acceptance remain the prerogative of the Editors.)

Amaurosis Fugax From Metastatic Prostate Cancer to the Tuberculum Sellae

To the Editor: Amaurosis fugax is a term frequently used to describe transient monocular blindness. Although it is usually attributed to an embolus occluding the central retinal artery, there are other important causes to consider. We describe a patient who experienced an episode of amaurosis fugax from epidural spread of prostate cancer to the tuberculum sellae region.

Case Report. A 65-year-old man presented with blurring of vision in his left eye. His past history included prostate cancer diagnosed at age 59 treated with bilateral orchiectomy and flutamide therapy. Eleven years earlier, he had had right carotid endarterectomy for a TIA manifested by transient left-sided hemiparesis. He also had a history of subclavian stenosis. He stated his vision slowly faded over the course of several minutes until he was completely blind in his left eye. Over a 24-hour period, his vision slowly resolved back to normal. He experienced no eye pain. His review of systems was normal and he had had no neurologic symptoms or TIAs since his carotid endarterectomy.

Two weeks after complete resolution of his left eye blindness, he experienced slowly decreasing visual acuity in the left eye again over 24 hours. Four weeks after the second episode, examination showed light perception only in the left eye. Again, he experienced no pain. General physical examination and vital signs were normal. There were no carotid or ophthalmic bruits. Neurologic examination revealed a left afferent pupillary defect and a normal funduscopic examination. Visual acuity was 20/25 OD and the patient had no vision in the left eye. Goldman visual fields were full in the right eye and absent in the left eye. Mental status, cranial nerves, sensory, motor, cerebellar, and gait examinations were normal. T1 MRI image of the head showed a gadolinium contrast-enhancing tuberculum sella mass lesion compressing the left optic nerve (Figure) just anterior to the optic chiasm. The lesion was isodense to brain on TI and T2 images without contrast. A gross total resection was done. At operation, the lesion w as found to be epidural. Pathologic examination showed metastatic carcinoma of the prostate. The patient's vision returned to near baseline in the left eye several weeks postoperatively.

Discussion. Prostate cancer most commonly affects the central nervous system through epidural spread and spinal cord or cauda equina compression. (1) Prostate cancer has also been reported intracranially to involve the optic canal and orbits, resulting in amaurosis or blindness. This case is the first report of prostate cancer causing amaurosis from an epidural lesion of the tuberculum sellae region. An actual etiology for amaurosis is not identified in as many as two thirds of cases. Embolic disease, vasospasm, migraine, hypotension, hypercoagulability, glaucoma, optic disk edema, vasculitis, or Uhthoff's phenomenon (due to exercise) all have been reported. There have also been reports of other CNS tumors causing amaurosis fugax, possibly by causing a temporary swelling of the optic disk or nerve by a mass effect. (2) Other lesions reported to cause amaurosis symptomatology include craniopharyngioma, nasopharyngeal carcinoma, meningioma, optic nerve glioma, Rathe's cleft cyst, metastatic breast carcinoma, ca rcinomatosis, leukemia, orbital or optic canal metastasis of prostate cancer, leukemia, pituitary mass or apoplexy, acute extradural hematoma, or cavernous angioma. It is important to recognize these lesions as potentially reversible causes of visual loss. Decompression of axons by surgery or radiation therapy may lead to a gradual reorganization and remyelination of visual fibers leading to improvement in symptoms. (3)

Amaurosis fugax is another term for transient monocular blindness. The usual cause is embolus from the heart or carotid artery. The attacks are classically brief and last no more than 15 minutes. They usually are not accompanied by eye pain. The atypical feature that distinguished our case on initial presentation was that the transient attack of visual loss lasted 24 hours. Amaurosis for greater than a few moments should prompt immediate investigation for tumor especially if there is a history of underlying carcinoma. Tuberculum sellae durally-based prostate cancer should be added to the list of potential causes of amaurosis fugax.

Joseph E. Robison, BS

Michael S. Okun, MD

Emory University

Wesley Wood Health Center Building

Third Floor Neurology

1841 Clifton Rd NE

Atlanta, GA 30329

(*) Originally prepared for presentation on Southern Medical Association's Web site (http://www.sma.org) by Elaine McClellan-Holm.

References

(1.) Schaller B, Merlo A, Kirsch E, et al: Prostate-specific antigen in the cerebrospinal fluid leads to diagnosis of solitary cauda equina metastasis. Br J Cancer 1998; 77:2386-2389

(2.) Izumi Y, Udaka F, Nakamizo T, et al: A case of giant meningioma that induced visual changes similar to those observed in amaurosis fugax in an early stage of disease. Rinsho-Shinkeigaku 1999; 39:577-580

(3.) Stark KL, Kaufman B, Lee BC, et al: Visual recovery after a year of craniopharyngioma-related amaurosis: report of a nine year old child and a review of pathophysiologic mechanisms. JAAPOS 1999; 3:366-371

Firearm Ownership Among Female Physicians

To the Editor: In an article that appeared in the Journal in late 1999, Frank and Kellerman (1) concluded that their observations may have implications for physicians' counseling patients on the benefits and risks of firearm ownership. I agree, and would suggest two such implications.

First, assuming that medical organizations and medical journal editors are going to continue to urge physicians to counsel patients on firearms, perhaps they should take their cue from the emergency physicians (EPs) cited by the authors. The EPs, we are told, "reported the highest prevalence of household gun ownership. ... EPs also often work odd hours in high-crime neighborhoods ... and have frequent contact with perpetrators of crime." (1) These sound to me like good reasons to exercise the Second Amendment right to keep arms. That 33% of EPs own a firearm evinces an intuitive understanding on their part that decisions regarding the risks and benefits of gun ownership need to be individualized. Calls to urge patients across the board to remove guns from their homes do not serve the best interests of individual patients and may not on balance save lives. (2)

Second, regarding gun-owning physicians, let me suggest that they would need to be especially careful about advising patients against gun ownership. The reason for this has to do with the so-called "best judgment rule." Thus, generally a "physician is under an obligation to exercise the same degree of knowledge, skill, diligence and care that the ordinary competent practitioner would exercise under the same or similar circumstances." (3) However, the "physician is under the further obligation to use his best judgment in exercising his skill and applying his knowledge." (3) In other words, a physician who knows that what is medically customary is problematic will not be permitted to argue that he has met the standard of care by doing what was customary. Thus, the conduct of a physician whose best judgment it was in 1953 that prolonged exposure of neonates to oxygen caused retrolental fibroplasia but who nevertheless employed such treatment for research purposes was found to have fallen below the standard of ca re. (4)

Analogously, even if one assumes that physicians owe their patients a duty to discuss gun ownership with them (which they do not), and that advising them against gun ownership is something the "ordinary competent practitioner" would do (which is arguable), the gun-owning physician who counsels her comparably situated patient against gun ownership would be vulnerable to a charge that she had violated the best judgment rule.

Frederick Paola, MD, JD

Department of Medicine

Division of Medical Ethics & Humanities

University of South Florida College of Medicine 

MDC Box 19

12901 Bruce B. Downs Blvd

Tampa, FL 33612-4799

References

(1.) Frank E, Kellerman A: Firearm ownership among female physicians in the United States. South Med J 1999; 92:1083-1088.

(2.) Kleck G: Targeting Guns: Firearms and Their Control. New York, Aldine de Gruyter, 1997, pp 147-190

(3.) Pike v. Honsiger, 155 NY 20l (1898)

(4.) Burton v. Brooklyn Doctors Hospital, 452 NYS2d 875 (1982)