I think the word “cure” is used far too casually in the media.

I especially find this to be the case when discussing neurological disease and cancer. Upon thinking some more about neurological disease and how it is often oversimplified and misunderstood, I thought it might be worthwhile to talk a little about how I think medicine has dealt with major challenges in the past, and how it will have to change to deal with future challenges. This is just a brisk overview with overlapping major points. I will skip over details and perhaps omit things others would consider significant, but it will convey the point that there are different challenges for which one approach alone is not necessarily appropriate.

I find that medicine can be divided into eras with the following major goals: tackling acute diseases and curing infections, managing chronic diseases and keeping degenerative processes at bay, and learning to delay the effects of aging and other (sometimes iatrogenic) byproducts  of our medical successes. Each of these challenges is further complicated for both detection and treatment must be made accessible to an ever increasing and changing populations that might be affected by a disease.

Figure 1: Change in causes of mortality throughout the 20th century.

Medicine as a science saw it’s first major reproducible successes in the era of infectious disease. The era prior to it was marked by a short average life span, a lower quality of life, and a certain inevitability that those who contract a serious illness could either get well on their own, be cured by limited means, or suffer and eventually die. Many medical treatments, especially surgeries, had very high mortality rates.  Scientific breakthroughs such as germ theory, sterilization, and public sanitization along with the discovery and application of antibiotics and vaccinations saved and lengthened innumerable lives. Medicine became established in this era,  when you were sick, you would call the doctor and he (at the time they were all he) would come to diagnose you and treat you. The diagnosis would usually consist of a physical examination where the physician searched for certain pathological signs that pointed to specific diseases. There was very little complexity in these cases, the patient had no autonomy, the physician had all the authority, and the disease was either cured or not. In a sense, very little has changed since then in the way we conceptualize (or rather, idealize) the role of the doctor in medicine.

Of course, at the time doctors were not held accountable by any real legal or professional standards (the Hippocratic Oath was perhaps the only “standard,” and it is awfully vague), thus the cultural environment treated the physician with reverence and without question, almost as if he were a deity. Eventually, the power of the physician was magnified as taking cultures of various bodily matter became common practice in cases where the physical exam was insufficient, and slowly the big picture came together and physicians along with public health professionals began to eradicate developed areas (and even the world) of certain diseases. It was during this time that medicine picked up much of its terminology, the idea of a “disease” having a “cure” came from this era, and a certain underlying assumption that there was usually only one thing wrong with each person, and that one thing could be fixed to bring them back to health also arose. This progress inevitably led to the longer lifespan and better quality of life we see today.

However, what physicians at that time could not have foreseen was the next wave of pathologies that their patients would face. I would say that we have only been in this, the era of multifactorial chronic disease, for about fifty years. A longer lifespan leads to wear and tear on the body. Lifestyle choices as well as complex genetics lead to diseases such as atherosclerosis, diabetes, and cancer. These diseases are heterogeneous, atherosclerosis can occur in multiple places and lead to heart attacks and strokes in multiple regions. Diabetes was initially thought of a Type I, insulin dependent, and Type II, insulin resistant, but even that distinction grew fuzzy and more and more people are now classified with a mix of the two and the many complications that arise from the pathology including vision loss and peripheral neuropathies are becoming better understood.

Figure 2: Improvements in cancer treatment leading to increased survival.

Cancer is perhaps the public figurehead and the greatest scientific challenge for this disease category. It can arise in almost any tissue (some cancers, such as cardiac tissue, are just very rare), and it can debilitate and eventually lead to death in many ways. Detection of the spectrum of cancers has necessitated greater scientific advances that have led to advanced imaging methods, genetic tests, enzymatic assays, and other molecular biology driven approaches for diagnoses. The treatment of these diseases is variable, as they are often not caught until they have progressed too far. Thus, a public health push has been made to diagnose earlier and treat earlier. When treatment can occur early on, these diseases can often be kept at bay, but there are no real “cures” for most varieties.

The physician faces ever greater challenges in this era with patient management. Legally, there are obligations to ensure that not only existing pathologies are treated, but reasonably predictable potential pathologies are avoided. There are complicated end-of-life issues that bring patient autonomy, religion, finances, and the allocation of scarce resources into play. The amount of information for a single physician to know has grown to the point that no single individual or series of textbooks can contain it, as hundreds of new articles are published everyday based off of new medical research. The lines between the previously concrete definitions of “disease” and “cure” are growing blurrier and blurrier.

Figure 3: Increase in prevalance of Alzheimer's with aging (from a European study).

The future holds an even greater challenge, as neurological and psychiatric diseases defy the rules that the multifactorial chronic diseases follow. It is no longer clear exactly when or where one even begins to have pathological changes, how they can be avoided, and what structures should even be targeted. Much of this is due to the general process of aging, some of it is due to environmental insults, and perhaps some of it is even due to iatrogenic insults. Thus, there is much work being done to understand how complex biological systems work and interact within themselves and with each other in order to produce the exponentially complicating phenotype of a human.

When we throw around the terms “disease” or “cure” (words which are inextricably linked to the first era of medical success), we simplify everything back to the idea of a pathogen and a drug. A doctor comes to visit you, gives you a treatment, and solves your problem. This is no longer the case in much of medicine, and until we acknowledge that as a culture, I think we will fail to properly convey what we are now actually doing for patients as physicians.

For the time I will omit developmental and genetic diseases which have their own problems and I’ll avoid world-wide health problems that could be fixed if everyone could just get along and agree to a baseline quality of life. In a sense we are facing all of the these challenges and those above simultaneously now, for none of the eras actually pass, they just compound upon each other. For instance, infections have been revived as a major problem due to resistant strains of bacteria and potentially dangerous strains of flu. Which of course brings to mind HIV/AIDS, and viruses in general. We still do not have the proper theoretical knowledge to effectively handle viral infections. Additionally the world of infectious disease has shown us that after we elucidate the scientific puzzle, we often have the daunting task of implementing solutions on a global level so that discoveries can actually be applied and save lives. The tone of this has been bleak so far, however, there has been LOTS of progress in the past couple of decades, and we are starting to see the years of medical and basic science research pay off. I will address the above complications more specifically and discuss the pending solutions as I learn more and time goes on. There will be lots and lots to post about. I will say for now that overall, I am cautiously optimistic that we will ultimately succeed in improving the quality of life for our patients.

(Click on figures for sources.)