The Thymus, Suffocation, and Sudden Infant Death Syndrome—Social Agenda or Hubris?

THE THYMUS, SUFFOCATION, AND SUDDEN INFANT DEATH SYNDROME—SOCIAL AGENDA OR HUBRIS? WARREN G. GUNTHEROTH* Beckwith, a pathologist, proposed this definition of sudden infant death syndrome (SIDS): "the sudden death of any infant or young child, which is unexpected by (medical) history, and in which a thorough postmortem examination fails to demonstrate an adequate cause for death" [1, p. 83]. Unfortunately, Beckwith's science has failed to produce a consensus on etiology after 150 years. Naeye stands almost alone among pathologists in proposing a final pathway to SIDS, hypoxia [2]; most pathologists insist that not even the final pathway can be known, let alone the immediate cause. It follows that most pathologists regard SIDS as unpreventable, a belief shared by the National SIDS Foundation. Pathologists and the National SIDS Foundation share a social agenda. The pathologists have to deal with grieving parents, and the Foundation is composed largely of parents who have lost infants to this disaster and want to minimize the grief and sense of guilt in other parents who suffer this loss. With this thought it is enlightening to review the history of attempts to explain sudden death in infants, and to evaluate the motives of the physicians, particularly pathologists, who have explored the problem. We begin with the thymus, an organ of uncertain function whose location near the trachea led to its indictment as a cause of suffocation. The Discovery of the Thymus The thymus is normally involuted in adults, and this was used to account for the delay in its description by early anatomists. That delay, however, existed only in the minds of some medical historians. The author is grateful to Keith Benson, M.D., Department of Medical History and Ethics, for his considerable help in the preparation of this paper. *Department of Pediatrics, University of Washington, RD-20, Seattle, Washington 98195.© 1993 by The University of Chicago. All rights reserved. 0031-5982/93/3701-0848101.00¿ J Warren C. Guntheroth · Sudden Infant Death Syndrome Two popular medical history texts, by Singer and Underwood [3, p. 241] and by Major [4, p. 398], erroneously asserted that the thymus was undiscovered until 1522 when reported by Jacopo Berengario [5]. The first faulty attribution is somewhat surprising given Singer's earlier translation of Galen's De Anatomías Administrationihus, where "thymos" appears more than once [6, pp. 179, 180]. However, May notes that Galen was not the first to describe the thymus; Rufus of Ephesus described the thymus in approximately 100 a.d. [7, p. 30]. The Thymus as a Cause ofDeath by Suffocation Another mistake in medical history texts was introduced by Ruhrah in his 1925 book Pediatrics of the Past [8, pp. 237-239], in which he implicated the thymus in the suffocation of an infant. He quoted a case report from seventeenth-century Swiss physician Felix Platter [9]. The case involved the sudden death of a five-month-old male who developed stridor and difficulty in breathing; the title of the report is "Suffocatio a struma interna abscondita, circa jugulum." Ruhrah translated this as "Suffocation from a Hidden Internal Struma, about the Throat." Both Dorland's and Steadman's medical dictionaries list the meaning of the Latin struma as goiter, not thymus. Confirmation of Ruhrah's error in translation may be found in a German version (Platter's native language) [10, p. 133]; struma is translated into Kropf (goiter), which was endemic in the Alps in Platter's time. When a hemorrhage occurred into his patient's gland, the infant died relatively suddenly of airway obstruction. The first actual suggestion of sudden death due to airway obstruction by the thymus was made when Kopp presented a paper on "thymic asthma" at Heidelberg in 1829, and published a monograph in 1830 [H]. Kopp's theory became widely accepted in Europe and North America. (There is still an entry in recent editions of Dorland's Medical Dictionary for "Kopp's asthma"). Charles Lee, an American, published a thorough and incisive review of "the morbid affections of the thymus gland" in 1842 [12], focusing on Kopp's claims. Lee painstakingly reviewed numerous case reports of infant deaths attributed to an enlarged thymus. He showed that most of the...