The Expanding Universe (of Neurosurgery)

摘要

From skull trephination for the release toxins or humors centuries ago, to the use of a hollowed-out chicken bone to drain a brain abscess by Macewen just over a century ago, the “what is neurosurgery” question continues to be redefined. Procedure-based manipulation of the nervous system had its roots in many applications, including the most fundamental of human needs—the relief of pain, from Nicholas Andree and trigeminal neuralgia, to peripheral nerve sections, to Mixter and Barr and discectomy. And as our understanding of the nervous system and its coverings improved over the foundations of neuropathology and later neuroimaging, neurosurgery tackled the challenges of tumors, vascular disorders, and disorders of function. The spectrum of disease that we treat, and our approaches to those problems, are what define neurosurgery. Perhaps it first required cutting into the body like all surgeries, then more refined methods of body entry. Incisions became smaller and then became punctures. Cutting or other forms of tissue manipulation was almost always mechanical in some way. The surgeon themselves did something. Later, mechanical energy was substituted for other forms of tissue manipulation, such as heat or cold (thermal probes, cryosurgery) placed via burr holes into the target. Chemical manipulation such as chymopapain injections were tried, and later other injectable biologics or agents became mainstream (glues, cements). Leksell and others worked to use targeted energy without skull access, but with rigid skull fixation and image-guidance, developing and fostering the radiosurgery idea in animals and humans. Then the concept of affecting the electrical elements of nervous system connectivity and function was followed by surgical neuromodulation for many problems, starting with pain, then movement, and then seizure and behavioral disorders. What are the limits of our expanding neurosurgical universe? I believe that our field follows, and sometimes directs, innovations in neuroscience, neuroimaging, and medicine. Neurosurgeons take things out, put things in, and direct the diagnostic processes along the way. We place the electrodes that help us learn about function, and now we can do this into the brain, along its surfaces, or within its blood vessels. While we are taking out tumors, neurosurgeons now begin their own process of tumor analysis during surgery, whether through fluorescence or spectroscopy. The expanding world of spinal neurosurgery is something to behold. Only 30 years ago, decompressions and simple fusions with wire and bone were in our purview. Now, it seems that no challenge is too great for a thoughtful surgical plan. Angles, kinetics, biologics, devices and their metallurgic principles, imaging, and so much more allow us to take the very young or very old and improve function. I have always believed that our most commonly performed functional neurosurgery is spinal neurosurgery. Are their limits to our surgical expansion? We already do surgery at the tissue level. We already do surgery at the cellular level. We are already surgical drug-deliverers using our catheters and pumps. Perhaps future applications need to be viewed from a more goal-oriented perspective. Restorative neurosurgery has been discussed for several decades, but has not yet been made mainstream.1 Cell transplantation and nervous system repair remain to be developed outside the odd clinical trial. Much has been learned to date in this area and work is ongoing. Many would argue that robotics and prosthetics technology, together with software development, has moved along faster. Neurosurgeons may become the effectors of these concepts. Cognitive neurosurgery has many potential elements beyond the discussion here, but research is moving forward. Neurosurgeons are leading much of this work and directing how and when it is performed. Organ control neurosurgery has been postulated through insights going back decades, including Peter Jannetta's work