And now for something completely different! Neurotoxicology, the subject of this issue of CONTINUUM, does not represent a spectrum of disorders that most neurologists encounter on a regular basis. Nevertheless, the topic is of considerable importance in a variety of ways. First, we must never lose sight of the possibility that an exogenous toxin might be responsible for the relatively ordinary-appearing syndrome that we are encountering clinically. Second, with ever-increasing worldwide travel, potential exposure to toxins that we might previously have never considered becomes a possibility. Third, recognizing that toxins may cause some forms of our more common degenerative diseases, such as Alzheimer disease and Parkinson disease, helps us better understand these disorders and consider the role of other potentially more widespread exogenous “poisons” in their etiology and pathogenesis. Fourth, tragically we have already seen examples of the use of toxic substances in terrorist attacks. As neurologists we need to recognize that possibility and be prepared to intervene.
In this issue, Dr Michael Watters has assembled a knowledgeable faculty to address a panoply of toxins to which we might be exposed by land, sea, or air. The first chapter, by Drs Herbert Schaumburg and James Albers, sets the stage by helping us understand the principles involved in the recognition and identification of neurotoxic disorders. The authors also address the important phenomenon of pseudoneurotoxic disorders, critical because neurologists increasingly encounter patients who mistakenly believe that a variety of exposures are at the foundation of their neurologic symptoms. Moving into the realm of specific toxins, Dr Elijah Stommel addresses terrestrial toxins, including discussions of toxins produced by microbial organisms, those resulting from the bites of various creatures, and those acquired through a variety of exposures to botanical species.
Moving from land to sea, Dr Watters himself takes us on a fascinating journey through aspects of marine biology. From sushi lovers’ death-defying fascination with the delicacy of fugu (puffer fish) to the less serious, but much more common, ciguatera, we are educated about neurotoxic disorders that we may, indeed, encounter. The more mundane mishaps with jellyfish and an explanation of their contact neurotoxins are also reviewed in Dr Watters’s chapter. With the huge numbers of travelers to the Caribbean and Hawaiian Islands, as well as to other parts of the South Pacific, it is increasingly important that we understand these disorders in order to both educate and treat our patients.
In the next chapter, Dr Neeraj Kumar, who chaired the faculty for the June 2008 CONTINUUM issue, Spinal Cord, Root, and Plexus Disorders, demonstrates the breadth of his knowledge with a thorough review of industrial and environmental toxins. Some of these exposures are fairly common, and others warrant consideration in patients presenting, particularly, with otherwise unexplained neuropathies or encephalopathies. Dr Deborah Mash then provides a fascinating discussion of the role of cyanobacterial toxins in producing syndromes that mimic what we generally consider—perhaps out of ignorance—to be neurodegenerative disorders. Read on to learn how flying foxes contribute to the development of the ALS-parkinsonism-dementia complex of the western Pacific. In the last formal chapter of this issue, Dr Jonathan Newmark guides us through the tragic necessity of recognizing the potential terrorist use of both chemical and biological agents. In the days prior to my writing this preface, news about the detective work that led to the identification of the alleged perpetrator (who recently committed suicide) of the 2001 anthrax attacks in the United States again highlighted the importance of this subject.
Don’t stop reading after the topic-oriented chapters! Much more highly educational material awaits you. Dr Jeffrey Cohen addresses related ethical issues that should sound a ring of familiarity to neurologists. In his patient management problem, Dr Watters illustrates a “real-life” clinical problem in neurotoxicology. Finally, I encourage you to work through the multiple-choice questions, crafted for this issue by Drs Julie Hammack and Steven Lewis. They are focused particularly on clinical vignettes that will help you solidify the knowledge that you have gained from the chapters.
After reading this issue, I’m sure that you will have great appreciation for the work done by Dr Watters and his colleagues in raising your awareness and understanding of a topic sometimes neglected in neurology. The possibility of neurotoxic disease will undoubtedly loom brighter on your personal radar screen.
—Aaron E. Miller, MD