IINS
Letters to the editor
9 Springer-Verlag 1992 Child's Nerv Syst (1992) 8:183-184
Primary aqueduct stenosis as a cause of hydrocephalus
Ultrasonography in the management of hydrocephalus
Hazel C. Jones
Joan Venes
Department of Pharmacology and Therapeutics, The J. Hillis Miller Health Science Center, University of Florida, Box J-267, Gainesville, FL 32610-0267, USA
6A1 President Point Drive, Annapolis, MD 21403, USA Received December 13, 1991
Received November 29, 1991
Sir: The article by Yamada et al. [3] has just come to my attention. The authors have investigated the cause of hydrocephalus in the LEW/Jms rat with inherited hydrocephalus and conclude that there is a primary aqueduct stenosis. In their discussion they suggest that primary aqueduct stenosis as a cause of hydrocephalus is controversial and that it occurs rarely in animal models of hydrocephalus. They have, however, neglected to include two models studied in my laboratory, the SUMS mouse and H-Tx rat, both of which were investigated using techniques similar to those used by Yamada et al. and found to have a primary aqueduct stenosis. Indeed, I have previously argued that aqueduct stenosis occurs more frequently than generally thought. The authors' discussion would have been considerably strengthened had they been more familiar with the literature, and I append below references to the relevant papers [1, 2].
References 1. Jones HC, Bucknall RM (1988) Inherited prenatat hydrocephalus in the H-Tx rat: a morphological study. Neuropathol Appl Neurobiol 14:263-274 2. Jones HC, Dack S, Ellis C 0987) Morphological aspects of the development of hydrocephalus in a mouse mutant (SUMS/NP). Acta Neuropathol 72:286-276 3. Yamada H, Oi S, Tamaki N, Matsumoto S, Sudo K (1991) Prenatal aqueductal stenosis as a cause of congenital hydrocephalus in the inbred rat LEW/Jms. Child's Nerv Syst 7: 218-222
Sir: Drs. Huang and Chio recently reported on an interesting observation [2] which had been addressed in an earlier publication from a slightly different perspective [1]. Both papers describe a technique that will likely prove a valuable adjunct to the management of shunted hydrocephalus. However, I should like to make one cautionary note. In the United States the indiscriminate use of technology is cited as one of the critical elements in the escalating cost of health care. In the paper by Drs. Huang and Chio four of the five children in group II are characterized as being "microcephalic" in the accompanying table. We are not given information about the rate of head growth in these children, and it may well be that some of the children in group II who did not require shunting could have been identified by the simple expedient of a far less costly assessment of head circumference. In like manner, what test could this study supplant in group I and what would be the difference, if any, in resource utilization attended by this substitution? In the paper by Chadduck et al. [1], the focus is on the identification of shunt malfunction. The authors comment: "Certainly, it would be beneficial to have available a rapid, non-invasive screening test to help define those patients requiring more extensive tests. Clinical evaluations, shunt series, abdominal ultrasound, CT and MRI scanning, and isotope flow studies have all proven useful in solving the problem of shunt malfunction." Can they give us some guidance as to which patients should be screened? In the face of a positive screen, which of the tests they outlined could be avoided, or alternatively, selected? The Forum for Quality and Effectiveness in Health Care (a division of the Agency for Health Car Policy and
Letters to the editor
9 Springer-Verlag 1992 Child's Nerv Syst (1992) 8:183-184
Primary aqueduct stenosis as a cause of hydrocephalus
Ultrasonography in the management of hydrocephalus
Hazel C. Jones
Joan Venes
Department of Pharmacology and Therapeutics, The J. Hillis Miller Health Science Center, University of Florida, Box J-267, Gainesville, FL 32610-0267, USA
6A1 President Point Drive, Annapolis, MD 21403, USA Received December 13, 1991
Received November 29, 1991
Sir: The article by Yamada et al. [3] has just come to my attention. The authors have investigated the cause of hydrocephalus in the LEW/Jms rat with inherited hydrocephalus and conclude that there is a primary aqueduct stenosis. In their discussion they suggest that primary aqueduct stenosis as a cause of hydrocephalus is controversial and that it occurs rarely in animal models of hydrocephalus. They have, however, neglected to include two models studied in my laboratory, the SUMS mouse and H-Tx rat, both of which were investigated using techniques similar to those used by Yamada et al. and found to have a primary aqueduct stenosis. Indeed, I have previously argued that aqueduct stenosis occurs more frequently than generally thought. The authors' discussion would have been considerably strengthened had they been more familiar with the literature, and I append below references to the relevant papers [1, 2].
References 1. Jones HC, Bucknall RM (1988) Inherited prenatat hydrocephalus in the H-Tx rat: a morphological study. Neuropathol Appl Neurobiol 14:263-274 2. Jones HC, Dack S, Ellis C 0987) Morphological aspects of the development of hydrocephalus in a mouse mutant (SUMS/NP). Acta Neuropathol 72:286-276 3. Yamada H, Oi S, Tamaki N, Matsumoto S, Sudo K (1991) Prenatal aqueductal stenosis as a cause of congenital hydrocephalus in the inbred rat LEW/Jms. Child's Nerv Syst 7: 218-222
Sir: Drs. Huang and Chio recently reported on an interesting observation [2] which had been addressed in an earlier publication from a slightly different perspective [1]. Both papers describe a technique that will likely prove a valuable adjunct to the management of shunted hydrocephalus. However, I should like to make one cautionary note. In the United States the indiscriminate use of technology is cited as one of the critical elements in the escalating cost of health care. In the paper by Drs. Huang and Chio four of the five children in group II are characterized as being "microcephalic" in the accompanying table. We are not given information about the rate of head growth in these children, and it may well be that some of the children in group II who did not require shunting could have been identified by the simple expedient of a far less costly assessment of head circumference. In like manner, what test could this study supplant in group I and what would be the difference, if any, in resource utilization attended by this substitution? In the paper by Chadduck et al. [1], the focus is on the identification of shunt malfunction. The authors comment: "Certainly, it would be beneficial to have available a rapid, non-invasive screening test to help define those patients requiring more extensive tests. Clinical evaluations, shunt series, abdominal ultrasound, CT and MRI scanning, and isotope flow studies have all proven useful in solving the problem of shunt malfunction." Can they give us some guidance as to which patients should be screened? In the face of a positive screen, which of the tests they outlined could be avoided, or alternatively, selected? The Forum for Quality and Effectiveness in Health Care (a division of the Agency for Health Car Policy and
