Occult tethered cord syndrome: a survey of practice patterns

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Tethered cord syndrome (TCS) is associated with a number of congenital anomalies involving early development of the spinal cord. These include myelomeningocele, spinal cord lipoma, low-lying conus medullaris, and a fibrofatty terminal filum. Occult TCS occurs in patients when clinical features indicate a TCS but the typical anatomical abnormalities are lacking. It is controversial whether surgical release of the terminal filum leads to clinical improvement in a patient who does not have a previously identified anatomical abnormality. To assess the clinical standard used by practicing pediatric neurosurgeons, a practice survey was conducted at the 2004 Annual Meeting of the Joint Section for Pediatric Neurological Surgery of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.


The survey examined clinical decision making for a same-case scenario with differing appearance on imaging studies. There was a clear consensus regarding diagnosis and treatment in the patient with symptoms, a low-lying conus medullaris, and a fatty terminal filum. The vast majority of respondents (85%) favored surgical untethering for this patient. A majority of respondents (67%) also favored treatment for the patient having symptoms and a fatty terminal filum. There was, however, significant disagreement regarding the diagnosis and treatment of disease in one patient with symptoms and an inconclusive magnetic resonance imaging study. Some respondents clearly favored surgery, whereas others believed that this patient did not meet the diagnostic criteria for TCS.


The results of this survey support the development of a randomized clinical trial to address the benefit of surgery for occult TCS.

Abbreviations used in this paper: AANS = American Association of Neurological Surgeons; ABPNS = American Board of Pediatric Neurological Surgery; CNS = Congress of Neurological Surgeons; MR = magnetic resonance; TCS = tethered cord syndrome.

Article Information

Address reprint requests to: Nalin Gupta, M.D., Ph.D., Department of Neurosurgery, University of California at San Francisco, 505 Parnassus Avenue, Room M779, San Francisco, California 94143-0112. email: guptan@neurosurg.ucsf.edu.

© AANS, except where prohibited by US copyright law.



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    Magnetic resonance images. Case 1: A conus medullaris ending at L3–4 (upper left) and a thick, fatty terminal filum (upper center). Case 2: A conus ending normally at L-2 and a normal filum (upper right). Case 3: A normal conus ending at L-1 (lower left) and a fatty filum (lower center). Case 4: A normal conus ending at L-1 and a syrinx from T7–9 (maximum diameter 2 mm; lower right).

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    Bar graphs. Upper: The nature of the respondents. Lower: The number of years of experience of the respondents.

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    Bar graphs showing responses before and after debate and discussion about Cases 1 (upper left), 2 (upper right), 3 (lower left), and 4 (lower right).

  • View in gallery

    Bar graph showing comparison of responses from those certified and not certified by the ABPNS.


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