Neurologic Complications of Cancer

Patients with cancer and cancer survivors are at risk for developing a wide range of neurologic problems. These complications are caused by invasion of the nervous system by tumor cells or by indirect mechanisms, in which case the pathogenesis often differs from that in the noncancer population and often requires neuro-oncological assessment. The first volume of this series on the neurologic complication of cancer was published in 2004 and while many issues faced by patients and physicians remain the same, new treatment modalities and longer patient survivals continues to lead to an evolving spectrum of disorders and, in some cases, offers new therapeutic options. As in the initial issue, this volume of Seminars in Neurology brings together an expert group of neuro-oncologists to review the neurologic complications of cancer and the side effects of oncological therapies.

In the first article, Kamar and Posner review the treatment of brain metastases and the therapeutic approaches to dealing with the problems these patients develop, such as brain edema, seizures, deep vein thrombosis, headache, and depression. Chamberlain focuses the second article in the diagnosis and treatment of leptomeningeal metastases from solid tumors. This review will help practitioners to distinguish between patients reasonably considered for treatment versus those in whom supportive care is most appropriate. Taylor and Schiff address the diagnosis and treatment of epidural spinal cord compression with an update on recent data regarding stratification of patients into those who may be better served with short versus long radiation courses. Jaeckle reviews the diagnosis and treatment of plexopathies in cancer patients, including a useful discussion of the features that assist in the differential diagnosis between radiation-induced and metastatic plexopathies. Nagpal, Glantz, and Recht review central nervous involvement by lymphoma and stress that the standard use of central nervous system prophylaxis in the acute lymphocytic leukemias has reduced the incidence of central nervous system recurrence. In the following article Dropcho discusses the neurologic complications of chemotherapy that highlights the extensive variety of neurologic complications that oncologic therapies may cause and includes a discussion of the controversial subject of “chemobrain.” Saiz and Graus have updated their chapter on neurologic complications of hematopoietic cell transplantation, a procedure that is increasingly used for both neoplastic and non-neoplastic conditions. The presentation of neurologic complications according to the stage of transplant is very useful. Infections are a common problem in cancer patients. The chapter by Pruitt reviews the variety of infectious complications according to specific immunological deficits and describes increasingly recognized syndromes such as the immune reconstitution inflammatory syndrome. Article nine by Rogers addresses cerebrovascular complications emphasizing that the pathogenic mechanisms of stroke in cancer patients frequently differ from those of the noncancer population and, therefore, the diagnostic and therapeutic approach also varies. In the last article, Rosenfeld and Dalmau provide a framework to assist in the recognition and treatment of paraneoplastic syndromes. They clarify the distinction between paraneoplastic-related onconeuronal antibodies versus cancer-related onconeuronal antibodies. The article also includes information about the recently described syndromes associated with antibodies to cell surface and synaptic proteins. Neurologic complications of cancer affect at least one in five cancer patients. These disorders can be complex and difficult to diagnose and often will require a collaborative effort between many healthcare providers. Prompt diagnosis with institution of symptomatic and, in some cases, definitive therapies can positively impact the patient's quality of life and survival. It is my pleasure to be the guest editor of this outstanding issue of Seminars in Neurology, and I thank all the authors for their contributions.