You can read Dr Chopko's bio here: https://med.stanford.edu/profiles/bohdan-chopko
1) Can you share any surgical expertise that might give light to whether or not, or how common is – nerve regeneration? It’s been stated generally that peripheral nerves show a better tendency to heal than do central nerves – like the spinal cord. Do you find that this is true? And what thoughts might you offer on the subject?
Nerve regeneration can certainly occur, and is much more likely when involved with the peripheral as opposed to the central nervous system. That said, nerve regeneration, if it does occur, will occur very slowly, perhaps at best a rate of 1 mm a day. In order for a peripheral nerve to regenerate, however, certain conditions need to be met. The most important is that a continuous bridge, or conduit, composed of the critical components of the outer nerve sheath, be present across the damaged nerve site. Also, the parent cell that is contributing to the severed and regenerating nerve pathway needs to be healthy. If the parent cell is unhealthy, then the critical signaling molecules necessary for nerve regeneration will not be present. As far as the central nervous system is concerned, the hurdles to create a reparative environment are much, much higher, and hence progress has been extremely slow from the standpoint of practical applications.
2) Many people fervently wish for tumors to be treated with newer technologies like Cyber Knife. Cyber Knife seems to have only been used on a few occasions to treat members of the Schwannoma Survivors & Schwannoma Fighters group. Can you shed any light on its usage, and why it would appear that conventional surgery is still predominant?
Cyberknife is a very precise method of delivering therapeutic radiation, and is similar to other techniques (such as Gamma knife, IMRT and LINAC) that are broadly referred to as “radiosurgery.” Radiation works best on destroying rapidly growing cells, and highly vascular (or bloody) tumors. Schwannomas tend to be neither rapidly growing nor highly vascular, so radiation is not an ideal treatment approach. That said, radiation can still be useful for shrinking or stabilizing a Schwannoma. Radiation also does have side effects, some of which will not be apparent for 1 to 2 years after the treatment has been delivered. Because of these issues, most skull base surgeons, myself included, use radiation as a second choice, salvage procedure, or in patients who may be at high risk for complications from conventional open surgery.
3) Some people with schwannomas are very dismayed to wake up from surgery and find that their tumor was only partially removed. Can you share any thoughts as to why, very specifically, might a surgeon opt for a partial removal? And, do you find that patients are generally granted relief and some manner of return to health by a partial removal?
The judgments made during surgery are critical for the overall welfare of the patient. Although it is always our dream to remove every last speck of a tumor and cure a patient, this goal is not always realistic. Partial resection, or debulking, is a common and valid approach in all forms of skull base tumor surgery. If during surgery I conclude that removing a component of a tumor that is related to a vital structure will lead to destruction of that vital structure, then I will make no attempt to remove that component of the tumor. Debulking a large amount of the tumor is in essentially every case a meaningful maneuver for the patient and will typically lead to a resolution of at least some of the signs and symptoms. There are many cases where “going for broke” is pure foolishness, and destined to lead to a bad patient outcome, and a patient needs a surgeon with the wisdom to understand when to stop.
4) Many Schwannoma Survivors are interested to know, when it is a that a doctor changes their working diagnosis from schwannoma to Schwannomatosis? Is simply having a 2nd tumor of any sort considered sufficient evidence for Schwannomatosis, or does a surgeon wait for genetic testing or further scans to confirm it?
Schwannomatosis is, in my view, a diagnosis that requires genetic testing and consultation in order to firmly establish the presence of the syndrome. A precise diagnosis is especially important in patients who either have children, or are planning on having children, so the family knows what to expect.
5) Lastly, there are people who have surgery and who still have significant symptoms. Such as pain, electric feelings, pins and needles, numbness, etc. What useful advice might you share with those people, to hopefully encourage them in their recovery process and also assist them in getting the best recovery in the long run?
Persistent abnormal or painful feelings in the affected nerve after tumor resection is not unusual, and does not necessarily portend a permanent situation. A nerve can have a “memory” so to speak for pain, even after the tumor has been resected and the pressure relieved, much like a gong that has been stuck 1 minute ago remains vibrating. If such uncomfortable feelings persist beyond a few weeks, a patient should discuss this with his or her physician. Techniques for managing persistent pain include membrane stabilizing medications (such as anti-seizure medications), and functional procedures, such as direct nerve stimulation.
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** Disclaimer: Dr. Chopko and Stanford University Medical Center assume no liability whatsoever for the comments or advice offered in the content of this blog. Dr. Chopko has offered his advice generally on the issues relating to treatment of Schwannomas - however Dr Chopko and the Schwannoma Survivors & Schwannoma Fighters group always insist that a person should make all major medical decisions in consultation with one's own physician.
