Tim Gilmer: Do you agree that many doctors are still not truly knowledgeable about untethering?

Wise Young: Yes, true. There is a saying that old ideas die with the people who hold them. In other words, few people learn new ideas or change old ideas.

TG: I see uncertainty and lack of widespread knowledge about untethering and syringomyelia among SCI survivors and many doctors. Why?

WY: A number of misleading theories concerning syringomyelic cysts dominated neurosurgery for a long time and are still being taught. Many of these theories stem from the assumption that syringomyelic cysts are solely a pressure-induced phenomena. It wasn’t until the 1990s that the first MRI flow scans showed cerebrospinal fluid flowing inside syringomyelic cysts. This suggested that the cysts resulted not only from pressure but obstructed CSF flow due to adhesions. Once this was accepted by some neurosurgeons, it became clear that this was why decompression of syringomyelic cysts alone had such high failure rates. The answer was not to relieve that pressure in the cysts but improve CSF flow in the spinal cord.

TG: What about the difficulty in identifying and differentiating symptoms?

WY: Ascending loss of function occurs only when there is sudden occlusion (and pressure) built up in the syringomyelic cysts. Most of the time, the cysts grow so slowly that there are little or no symptoms. Before the advent of widespread spinal cord MRIs on people with SCI, syringomyelic cysts were relatively rare clinical occurrences and not detected until the sudden pressure induced enlargements of cysts. Today syringomyelic cysts are often detected incidentally on MRI scans when other symptoms require MRIs of the spinal cord.

TG: What about prognosis? Many different outcomes seem possible.

WY: Prognosis depends on the nature and extent of obstruction of the cerebrospinal fluid flow. Most people, including doctors, do not realize that the choroid plexus in the fourth ventricle makes about 2 liters of CSF a day, half of which goes rostrally (towards the head) and half of which goes caudally (towards the tail of the spinal cord). I think that prognosis is quite poor when surgery only decompresses the syringomyelic cysts without removing all adhesions and restoring CSF flow in the spinal cord.

TG: Why do you think people with syringomyelic cysts sometime find it hard to choose surgery? Is it because results are not always definitive or lasting?

WY: People with syringomyelic cysts are receiving conflicting advice, some of which is wrong. As for results not always lasting, this is true of decompressive and shunt surgery by itself. However, untethering surgery that restores CSF flow by removing all adhesions is usually successful.

TG: What is needed to diminish uncertainty and promote knowledge about this field?

WY: Neurosurgical societies should form committees of experienced surgeons to recommend the best practice. It may be useful to establish a registry of syringomyelic cyst surgery and their outcomes. Currently there is no effective non-surgical treatment.