When neurologists talk about a “phantom,” they mean an idea of a body part which persists in a patient’s mind even after they lose that body part. For example, there was a sailor who lost his index finger and, for the next forty years, had to deal with the phantom of the finger. Neurologists aren’t sure what causes a phantom, but it’s well-known that a sudden pathological disorder, such as a stroke, can get rid of a phantom. Sacks wonders if a “peripheral pathological disorder” would cure a phantom. In this chapter, he’ll briefly go over other characteristics of phantoms.
This chapter, unlike the others in the book, doesn’t revolve around a single patient, but rather poses a series of questions about the idea of “phantoms.”
Without phantoms, amputees wouldn’t feel comfortable with artificial limbs. Therefore, it can be important for patients to preserve a phantom. Sacks once had a patient who would “wake up” his phantom lower leg every morning by slapping his thigh.
Amputees adapt to their changing circumstances by learning how to coexist with their phantoms—indeed, some amputees have elaborate routines that preserve the “phantom” of their amputated limb.
Sacks had another patient, Charles D., who suffered from dizziness and constantly fell to the floor. After some investigation, Sacks realized that Charles could only walk steadily while looking at his feet, suggesting that Charles was suffering from tabes, which caused a “delirium of proprioceptive illusions.” The end stage of tabes is often total unawareness of the legs; however, in the disorder’s early stages, people like Charles are often intermittently unaware of their legs.
Much like Christina in the earlier chapter, Charles D. suffers from an intermittent impairment of proprioception—he finds ways to adjust to such an impairment, however, by looking at his feet; in other words, relying on his sense of sight more extensively than usual.
One of the clearest descriptions of a phantom came from a patient who told Sacks that his foot-phantom was sometimes good and sometimes bad. At best, his phantom helped him walk steadily with a prosthetic foot; at worst, it caused him pain. Sacks argues that it’s important for patients to develop physical routines for either preserving phantoms or getting rid of them.
It’s characteristic of Sacks’s approach to neurology that he stresses the importance of routine and adaptation, so that amputees can either learn how to coexist with their phantoms or rid themselves of them. In other chapters, Sacks shows how patients adapt to their neurological conditions, often with the help of some routine.
In the Postscript, Sacks notes that some people who have phantoms say that their phantoms cause them pain. Sacks learned of one patient with a phantom leg pain who said that the pain went away when doctors anaesthetized her spinous ligament, lessened when they stimulated her higher spinal cord, and intensified when they electrically stimulated the spinal roots.
Sacks alludes to a potential treatment in patients for whom phantoms are problematic; however, in the meantime, patients will have to continue replying on routine and special training to cope with their phantoms.