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Case of the month
Case of the Month Submitted by Hung-Fat Tse, MD, and Cyrus R. Kumana, MB Prepared by Lawrence M. Tierney, Jr., MD Each month, we will present a challenging Case of the Month for The Green Journal readers, who must use their clinical acumen to arrive at the correct answer. We will also post the case each month on the Journal’s web site (http://www.elsevier.com/ ajmselect). Several possible answers may be consistent with the case presentation; use your best judgment. Please send your answer (one per respondent) to The Green Journal at [email protected] or via FAX to (415) 447-2799. Indicate the case to which you are responding, and include your complete
address. The correct answer will appear in the next issue of the Journal. The first five persons who submit correct answers will receive a free one-year subscription to the Journal. Colleagues of Drs. Tse and Kumana at the University of Hong Kong are not eligible for this month’s case. If you would like to contribute a case, please submit a brief synopsis (fewer than 250 words) to the editorial office. Am J Med. 2000;109:426. 䉷2000 by Excerpta Medica, Inc.
A
ANSWER TO THE SEPTEMBER CASE OF THE MONTH
41-year-old woman was referred to the medical outpatient clinic complaining of a generalized but poorly described skin rash, paresthesias of her tongue, and vague aches in her hands for 2 months. She was otherwise well, with no chronic medical problems. Her only medication was a topical facial cream for skin depigmentation that she had obtained from a traditional Chinese practitioner. On physical examination, her blood pressure was 94/64 mm Hg, with a regular heart rate of 70 beats per minute. She was afebrile. No rash or joint abnormalities were detected. On neurologic examination, she had normal mental status; the cranial nerves were normal, and no focal motor or sensory deficits were detected. Visual fields were also normal, as was the remainder of the physical examination. Routine laboratory findings, including a complete blood count, serum aminotransferase and creatinine levels, urinalysis, 12-lead electrocardiogram, and serum antinuclear antibody and rheumatoid factor titers, were normal. Serum vitamin B12 and folate levels were also normal. Cranial magnetic resonance imaging showed multiple tiny T2 hyperintense lesions in the subcortical white matter of both occipital lobes. What is the most appropriate test? What is the most likely diagnosis?
426
䉷2000 by Excerpta Medica, Inc. All rights reserved.
Last month’s patient with the triad of episodic hypoglycemia, elevated insulin levels, and insulin autoantibodies had the insulin autoimmune syndrome due to imipenem. (For a review, see Redmon JB, Nuttall FQ. Autoimmune hypoglycemia. Endocrinol Metab Clin North Am. 1999; 28; 603-618.) After imipenem treatment was stopped, the frequency of hypoglycemic episodes lessened, and they subsided after 6 weeks. It has been proposed that sulfhydryl groups (which are present in imipenem) interact with disulfide bonds in the insulin molecule, making it more immunogenic. The mechanism of the hypoglycemia, which is usually postprandial, is uncertain but may be due to a “buffering” effect of the antibodies, leading to binding and release of secreted insulin that is asynchronous with the glucose level. Most patients with the syndrome have an underlying clinical or biochemical immune disorder; an association with HLA types Cw4 and DR4 has been reported. There were no winners with “correct” answers for the difficult July case (gastric artery aneurism), but several readers mentioned vascular involvement due to rheumatoid arthritis.
0002-9343/00/$–see front matter PII S0002-9343(00)00585-4
address. The correct answer will appear in the next issue of the Journal. The first five persons who submit correct answers will receive a free one-year subscription to the Journal. Colleagues of Drs. Tse and Kumana at the University of Hong Kong are not eligible for this month’s case. If you would like to contribute a case, please submit a brief synopsis (fewer than 250 words) to the editorial office. Am J Med. 2000;109:426. 䉷2000 by Excerpta Medica, Inc.
A
ANSWER TO THE SEPTEMBER CASE OF THE MONTH
41-year-old woman was referred to the medical outpatient clinic complaining of a generalized but poorly described skin rash, paresthesias of her tongue, and vague aches in her hands for 2 months. She was otherwise well, with no chronic medical problems. Her only medication was a topical facial cream for skin depigmentation that she had obtained from a traditional Chinese practitioner. On physical examination, her blood pressure was 94/64 mm Hg, with a regular heart rate of 70 beats per minute. She was afebrile. No rash or joint abnormalities were detected. On neurologic examination, she had normal mental status; the cranial nerves were normal, and no focal motor or sensory deficits were detected. Visual fields were also normal, as was the remainder of the physical examination. Routine laboratory findings, including a complete blood count, serum aminotransferase and creatinine levels, urinalysis, 12-lead electrocardiogram, and serum antinuclear antibody and rheumatoid factor titers, were normal. Serum vitamin B12 and folate levels were also normal. Cranial magnetic resonance imaging showed multiple tiny T2 hyperintense lesions in the subcortical white matter of both occipital lobes. What is the most appropriate test? What is the most likely diagnosis?
426
䉷2000 by Excerpta Medica, Inc. All rights reserved.
Last month’s patient with the triad of episodic hypoglycemia, elevated insulin levels, and insulin autoantibodies had the insulin autoimmune syndrome due to imipenem. (For a review, see Redmon JB, Nuttall FQ. Autoimmune hypoglycemia. Endocrinol Metab Clin North Am. 1999; 28; 603-618.) After imipenem treatment was stopped, the frequency of hypoglycemic episodes lessened, and they subsided after 6 weeks. It has been proposed that sulfhydryl groups (which are present in imipenem) interact with disulfide bonds in the insulin molecule, making it more immunogenic. The mechanism of the hypoglycemia, which is usually postprandial, is uncertain but may be due to a “buffering” effect of the antibodies, leading to binding and release of secreted insulin that is asynchronous with the glucose level. Most patients with the syndrome have an underlying clinical or biochemical immune disorder; an association with HLA types Cw4 and DR4 has been reported. There were no winners with “correct” answers for the difficult July case (gastric artery aneurism), but several readers mentioned vascular involvement due to rheumatoid arthritis.
0002-9343/00/$–see front matter PII S0002-9343(00)00585-4