Infectious diseases never cease to amaze. Just when you think you have figured them out, something changes. A new organism…a new syndrome…a new situation arises that brings the unexpected. In this issue of Continuum: Lifelong Learning in Neurology, Guest Editor Dr Karen Roos has recruited an expert faculty to assure that we are up-to-date with the latest information on infectious diseases of the nervous system.
The issue begins with discussions of the “bread and butter” of CNS infections—meningitis and encephalitis. First, Dr Russell Bartt brings us up to speed on acute bacterial and viral meningitis. In his article on encephalitis, Dr John Greenlee reviews both infectious and noninfectious etiologies of the syndrome. Herpes simplex remains the most common infectious cause, but varicella-zoster and the emerging pathogen enterovirus 71 are increasingly important. Several autoimmune encephalitides have been described in recent years and play an important role in the differential diagnosis.
The differential diagnosis of subacute and chronic meningitis is extensive and again includes both infectious and noninfectious causes. Drs Joseph Zunt and Kelly Baldwin review fungal pathogens, tuberculous meningitis, and neurosyphilis among infectious meningitides. They also cover the protean manifestations of neurosarcoidosis, as well as other autoimmune disorders.
Neurologic complications have been an important aspect of HIV infection since the epidemic began more than 30 years ago. However, the advent of effective antiretroviral therapy has changed the picture considerably as HIV has become a treatable chronic disease. Drs Sarah Kranick and Avindra Nath elucidate the current situation. Later in this issue, Dr Laura Powers discusses appropriate coding of HIV infections.
Lyme disease or neuroborreliosis has been the subject of considerable controversy and much misinformation regarding both diagnosis and clinical manifestations. In some endemic areas, the “diagnosis” and treatment of Lyme disease have become a cottage industry, with many patients receiving both incorrect diagnosis and unnecessary, frequently prolonged, antibiotic treatment. Dr John Halperin demystifies the diagnosis and provides much clarity about this tick-borne infection.
Infectious diseases of the CNS are not confined to the brain and leptomeninges. The spinal cord is another target of a variety of pathogens. Drs Tracy Cho and Henrikas Vaitkevicius review the subject of infectious myelopathies, in which many of the organisms previously discussed in other articles are again implicated. Additional pathogens, particularly parasites such as Schistosoma, are also discussed. Parainfectious etiologies often cause the clinical picture of acute transverse myelitis and are critical considerations in the differential diagnosis of acute myelopathies.
Progressive multifocal leukoencephalopathy (PML) was once considered a rare CNS infection. HIV changed the story as PML became a fairly common occurrence in AIDS patients with low CD4 counts. More recently PML as a complication of the treatment of multiple sclerosis with natalizumab has intensified interest in this disorder. Investigations have led to better understanding of the risks for PML in this circumstance. Dr Alan Aksamit reviews our current knowledge of this important viral disease.
Neurocysticercosis, caused by the larval form of the pork tapeworm, remains primarily a disease of the underdeveloped world. However, extensive international travel and the presence of a large immigrant population have greatly increased the likelihood that neurologists in both North America and Europe will encounter this illness and, even more frequently, need to consider it in the differential diagnosis of a variety of neurologic syndromes. Dr Oscar Del Brutto discusses the protean manifestations of neurocysticercosis in his article.
In Ethical Perspectives, issues related to HIV again come into focus as Dr James Russell and attorney Sarah Bird Nelson analyze the complex situation in which an HIV patient's right to privacy butts up against health considerations for a third party. Many patients with CNS infections are confused and sometimes combative. These conditions have important management implications, including consideration of the use of physical restraints. In his Practice article, Dr James Stevens informs us about the current rules and appropriate usage regarding restraints.
Abundant opportunities for CME accompany each issue of CONTINUUM. Herein, Drs Adam Kelly and Joseph Safdieh have crafted Multiple-Choice Questions that are both informative and challenging. Guest Editor Roos, herself, has developed a Patient Management Problem focused on meningitis that will tax your diagnostic and management skills.
This preface is also an editor's farewell as I complete a very rewarding decade as editor-in-chief of CONTINUUM. It's been not only a privilege but also tremendous fun to join you in exploring the fascinating world of neurology during the past 10 years. I am proud of the improvements and innovations we have brought to Continuum: Lifelong Learning in Neurology. Your enthusiastic reaction to the “gold journal” is reflected by your comments about each issue and by a dramatic rise in circulation at a time when the subscriber numbers of most print journals have been shrinking.
The success of CONTINUUM during my tenure as editor-in-chief could not have been achieved without the “dream team” at the AAN office in Minnesota. Andrea Weiss, executive editor, has been a true partner. Her passionate commitment to CONTINUUM, wise counsel, sound judgment, and tireless work ethic have been invaluable. Amanda Tourville, preproduction and graphics editor throughout my term, has been enormously helpful. She has calmly and competently worked through a number of changes as we adapt to an increasingly digital world so that transitions occurred seamlessly. Through most of the past decade, Cecelia Adams worked with great skill and devotion as production editor, even interrupting her retirement this past year to help us out of an editing crisis that unexpectedly occurred after her departure. The efforts of Associate Editor Steven Lewis, and Section Editors Michael Williams, Larry Goldstein, and (more recently) Laura Powers have contributed to the timely topicality of each issue. I am also indebted to the efforts of our editorial board, many of whom have been committed participants for a long time. Finally, but perhaps most importantly, I am grateful for the love and support of my wife, Ellen, who has spent countless hours watching me pound on my laptop in the corner of our living room.
I am extremely pleased that Dr Lewis will now move up to the position of editor-in-chief. He has been an important partner for the last few years, and I know that CONTINUUM will be in good hands. I am happy that I will continue to play a role on the CONTINUUM team as I serve as editor of the recently initiated Continuum Audio, a product inspired by each CONTINUUM print issue that features interviews with the authors of the articles.
Thanks for being there as faithful readers of CONTINUUM. I'm sure you will continue to do so. I know I will. “See you on the Audio.”
Aaron E. Miller MD