There are, in truth, no specialties in medicine, since to know fully many of the most important diseases a man must be familiar with their manifestations in many organs.
Internal medicine and neurology are bound together as closely as conjoined twins. In days gone by, in academic institutions the subspecialty of neurology was commonly a division of a department of medicine. In many instances, physicians undertook neurology specialization only after additional training, beyond what is today called the program year 1 (PGY1). For a few years in the 1970s, the American Board of Internal Medicine (ABIM) permitted candidates to sit for their board examinations after 2 years of internal medicine and 1 year of subspecialty training, rather than the usual 3 years of general internal medicine. Thus, I, personally, was able to become certified in internal medicine because after 2 years of residency in internal medicine, the ABIM recognized my subsequent first year of neurology residency as subspecialty training in medicine.
The splitting of neurology from internal medicine should be regarded not as a divorce, but as an amicable separation. The recognition of the specialty of neurology should be considered as a tribute to our increasing understanding of neurologic disease, to advances in our diagnostic capability, and to the development of new therapeutic modalities. Clearly, the complexity of the nervous system and its disorders warrants a full-fledged specialty of its own. Nonetheless, the importance of a neurologist's understanding systemic disease cannot be understated, for so many of these conditions feature a panoply of neurologic manifestations. Dr Steven Lewis, the chair of this issue of CONTINUUM, clearly recognizes this and has put together an outstanding faculty to enlighten us on the neurologic complications of a number of systemic diseases. No single issue of CONTINUUM could possibly cover the entire spectrum of disorders whose primary assault lies outside the nervous system. Nonetheless, I believe that Dr Lewis has chosen wisely in his selection of eight subjects that cover a variety of often perplexing conditions for which the neurologist is consulted.
The province of gastroenterologists is visited twice in this issue of CONTINUUM. First, Dr Neeraj Kumar discusses several topics of interest, including the controversial subject of the neurology of celiac disease, nutritional deficiency, and the burgeoning area of bariatric surgery. In another chapter, Dr Karin Weissenborn focuses on the specific issues of the neurologic manifestations of liver disease, both acute and chronic. She offers an extensive discussion of the still incompletely understood, but very important, topic, hepatic encephalopathy.
The interface of cardiology and neurology, encountered routinely in neurologic practice, also receives attention in two chapters. First, Dr Shyam Prabhakaran brings us up-to-date on the diagnosis and management of neurologic complications of endocarditis, discussing both infective and noninfective etiologies. Among the most frequent calls for neurologic consultation in the hospital are those to evaluate patients who have undergone cardiac surgery. In their chapter, Drs Vivien Lee and Eelco Wijdicks help assure that you are up to speed on this important subject, which includes discussion of a variety of cardiac surgical procedures, performed both with and without cardiopulmonary bypass. The intensive care unit is another venue in the hospital that generates many neurologic consultations. Drs Jaffar Khan and Taylor Harrison discuss the neurologic manifestations of critical illness, providing a clear approach both to patients with altered mental status and to those with acquired weakness. The authors include reviews of the important subjects of critical illness polyneuropathy and myopathy.
The remaining chapters in this issue are devoted to several often bewildering multisystem disorders. First, Dr Robin Brey addresses the protean neurologic manifestations of systemic lupus erythematosus (SLE) and antiphospholipid antibody syndrome (APAS), the latter occurring in conjunction with or independent of the former. Continuing the theme of autoimmune disorders, Dr Lewis addresses the neurologic complications of Sjögren syndrome and rheumatoid arthritis. Each of these diseases has the potential to cause both central and peripheral nervous system manifestations. The CNS lesions of Sjögren syndrome, as well as those of SLE and APAS, may be confused with multiple sclerosis. Finally, Dr Allen Aksamit considers neurosarcoidosis. Again, this still poorly understood inflammatory disorder offers ample opportunity for the neurologist to be involved. This chapter will update you on the pathology, clinical and laboratory studies, and treatment of this fascinating multi-organ disease.
Complementing these thorough reviews of systemic disease subjects, Dr Joseph Kass offers an interesting ethical discussion concerning the widespread practice of off-label use of medications. Prompted by the inclusion of chapters regarding patients in several types of intensive care settings, Dr John McBurney, in the section on Practice Issues in Neurology, gives a very clear and comprehensive explanation of how to bill in the critical care setting. Finally, in order to take full advantage of this issue, be sure to reinforce your understanding of the subjects, by working through the multiple-choice questions, prepared by Drs Douglas Gelb and Joanne Lynn, as well as the Patient Management Problem, crafted by Dr Khan.
As you wander the corridors of your respective hospitals, keep this issue of under your arm for ready reference about the array of confusing systemic diseases it covers. And back in your office, don't forget that is now just a finger click away, with readily available online access for subscribers. I know that you will find this issue stimulating reading, and we are grateful to Dr Lewis and his faculty colleagues for their outstanding contributions.
-Aaron E. Miller, MD