Nervous system infections in patients with cancer

Pulmonary mass-like lesion caused by Toxoplasma gondii in a domestic shorthair cat

A 2-year-old male neutered domestic shorthair cat underwent investigations for acute onset of lethargy, hyporexia, and cough. Computed tomography of the thorax identified a large mass-like lesion in the left cranial lung lobe and bilateral pleural effusion. Thoracotomy and left cranial lung lobectomy were performed. Histopathology of the pulmonary mass was consistent with a localized Toxoplasma gondii pneumonia, confirmed by positive polymerase chain reaction on the affected lung lobe. After adjunctive medical management with a 28-day course of clindamycin (12.5 mg/kg PO q12h), clinical signs resolved and repeat thoracic radiographs documented no abnormalities. The cat remains clinically well 1 year after surgery.

Oncologic Emergencies: The Fever With Too Few Neutrophils

BACKGROUND

Cancer is associated with a variety of complications, including neutropenic fever, which can result in severe morbidity and mortality. This oncologic emergency requires ED management.

OBJECTIVE

This narrative review provides focused updates for emergency clinicians regarding neutropenic fever.

DISCUSSION

Neutropenic fever is defined by fever with oral temperature >38.3°C or temperature >38.0°C for 1 hour with an absolute neutrophil count (ANC) < 1000 cells/microL. Patients who have received chemotherapy within 6 weeks of presentation are at high risk for neutropenia. While most patients with neutropenic fever do not have an identifiable bacterial source of fever, clinicians should treat patients for bacterial infection. Rapid assessment and management are vital to improving outcomes in patients with suspected or confirmed neutropenic fever. History and examination should focus on the most common sites of infection: the gastrointestinal tract, blood, skin, lung, and urinary tract. However, physical examination and laboratory or imaging assessment may not display classic signs of infection. Blood cultures should be obtained, and broad-spectrum antibiotics are recommended. Oncology consultation is an integral component in the care of these patients. Several risk scores can assist in stratifying patients who may be appropriate for discharge home and follow-up.

CONCLUSIONS

Neutropenic fever is an oncologic emergency. Rapid diagnosis and care of patients with neutropenic fever can improve outcomes, along with oncology consultation.

Infectious Disease Emergencies in Oncology Patients

Oncology patients are a unique patient population in the emergency department (ED). Malignancy and associated surgical, chemotherapeutic, or radiation therapies put them at an increased risk for infection. The most ominous development is neutropenic fever, which happens often and may not present with signs or symptoms other than fever. A broad differential diagnosis is essential when considering infectious disease pathology in both neutropenic and non-neutropenic oncology patients in the ED.

Management of neuro-oncologic emergencies

Patients with brain tumors and systemic malignancies are subject to diverse neurologic complications that require urgent evaluation and treatment. These neurologic conditions are commonly due to the tumor's direct effects on the nervous system, such as cerebral edema, increased intracranial pressure, seizures, spinal cord compression, and leptomeningeal metastases. In addition, neurologic complications can develop as a result of thrombocytopenia, coagulopathy, hyperviscosity syndromes, infection, immune-related disorders, and adverse effects of treatment. Patients may present with typical disease syndromes. However, it is not uncommon for patients to have more subtle, nonlocalizing manifestations, such as alteration of mental status, that could be attributed to other systemic, nonneurologic complications. Furthermore, neurologic complications are at times the initial manifestations of an undiagnosed malignancy. Therefore a high index of suspicion is essential for rapid assessment and management. Timely intervention may prolong survival and improve quality of life. In this chapter, we will discuss the common neuro-oncologic emergencies, including epidemiology, pathophysiology, clinical presentation, diagnosis, and treatment.

Intracranial Toxoplasma gondii granuloma in a cat

An 8-year-old cat with recent-onset generalized seizures was diagnosed with a right forebrain mass using magnetic resonance imaging. The mass was excised and upon histologic and immunohistochemical examination shown to be a Toxoplasma gondii granuloma. Serology supported active T gondii infection. The cat was treated with phenobarbital to control seizures. After definitive diagnosis of toxoplasma granuloma, clindamycin was administered for approximately 1 month. Seizures recurred 8 months after initial presentation, and the cat was euthanased at the owner's request. This is a previously unreported manifestation of feline central nervous system toxoplasmosis. When a mass lesion is present in the brain of a cat and serologic test results support active infection with T gondii, toxoplasma granuloma must be a differential diagnosis. If the patient is suffering from clinical disease, surgical resection of the mass (if possible) can be complimented with medical treatment until definitive diagnosis is obtained. Immunocompromising factors should be identified and addressed if possible.

Neurotoxicity associated with cancer therapy

Neurologic complications can result from direct or indirect effects of cancer therapy. Treatment toxicity may affect both the central nervous system and the peripheral nervous system. Early recognition of these toxicities plays an important role in the management of patients with cancer.

Central nervous system infections in cancer patients and hematopoietic stem cell transplant recipients

Central nervous system (CNS) infections in cancer patients present a diagnostic and therapeutic challenge for clinicians. While CNS infections are not frequent complications of cancer, its therapies, or hematopoietic stem cell transplantation, the importance of CNS infections lies in their propensity to result in profound morbidity and substantial mortality in this vulnerable patient population. With an expanding population of patients with malignant disease undergoing more potent and aggressive therapies and with the advent of newer immunomodulatory agents, the incidence of CNS infectious complications is likely to rise. This chapter will summarize the clinical and diagnostic evaluation of potential infections of the CNS in these patients and will discuss particular pathogens of interest with regard to this at-risk patient population.

Neuromuscular complications

Although direct neoplastic involvement of muscle tis-sue is surprisingly rare, considering the large amount of body mass that is represented by muscle tissue, the most important and unresolved muscle effect is muscle cachexia.Other associations, such as inflammatory, paraneo-plastic, toxic, and several extremely rare associations,have been described. Drug-induced toxicity and radiation recall syndrome need to be taken into consideration when muscle symptoms appear in patients with cancer.

Neurologic emergencies in patients who have cancer: diagnosis and management

The nervous system can be significantly affected by cancer. Neurologic symptoms are present in 30% to 50% of oncologic patients presenting to the emergency department or in neurologic consultation at teaching hospitals. Evaluation and treatment require collaborative effort between specialties. The causes of neurologic emergencies in patients with cancer are mostly related to effects of cancer, toxicities of treatments, infections, and paraneoplastic syndromes. These complications cause significant morbidity and mortality and require prompt and accurate diagnostic and treatment measures. This article reviews the common neurologic emergencies affecting patients with cancer and discusses epidemiology, clinical presentation, diagnosis, and treatment modalities.

Zygomycosis in two hematologic cases

Zygomycosis are invasive mould infections, rarely diagnosed in hematologic patients. Most of the cases published are in patients with prolonged neutropenia, along with other risk factors such as the use of prior broad-spectrum antibiotics (including new antifungal agents, such as voriconazole), diabetes mellitus (with or without ketoacidosis), malnutrition, iron overload (with or without the use of deferoxamine). These infections have poor prognosis due to the involvement of vital anatomic structures and late diagnosis. Until recent years, the treatment was based on high doses of amphotericin B plus surgical debridement. Here we present two patients with hematologic diseases (one with leukemia, the second with aplastic anemia) with an impaired immune system and the diagnosis of zygomycosis. The survival of one of them was mainly due to early diagnosis and surgical debridement; unfortunately the second was misdiagnosed as an extensive ecchymosis due to thrombocytopenia and died with CNS involvement.

Construction of a Nocardia brasiliensis fluorescent plasmid to study Actinomycetoma pathogenicity

Nocardia brasiliensis, is a bacteria that lives as saprophyte in soil and causes a disease called actinomycetoma in both human and animals. Nocardia brasiliensis is an intracellular, facultative bacterium that replicates and survives within host macrophages. The mechanisms involved in the evasion of the microbicidal actions of macrophages remain unclear. The filamentous growth of N. brasiliensis is resistant to unicellular preparations, leading to inaccurate quantification of bacterial numbers by means of colony forming units (CFU). As successful survival studies with green fluorescent protein (GFP)-expressing bacterial strains have been reported, we constructed a recombinant GFP-expressing strain of N. brasiliensis. The virulence of the modified strain is maintained because it induces mycetoma in BALB/c mice. This new strain can be used for bacterial survival assays using cytometry and to elucidate the pathogenicity mechanisms in Actinomycetoma infection.

Neurotoxicity of cancer treatment

Cancer therapy--including brain-directed surgery, brain or spine irradiation, or chemotherapy--may affect the nervous system in a deleterious manner, affecting either the central or peripheral nervous systems. The causation of encephalopathy (eg, radiation, chemotherapy) is most relevant for the differential diagnosis of central nervous system (CNS) disorders, as defining a specific cause determines further treatment and outcome. Peripheral nervous system disorders (ie, steroid myopathy, spindle poison, or platinum neuropathy) are predominantly treatment related and respond best to discontinuation of the neurotoxic agent.

Nocardiosis: updated clinical review and experience at a tertiary center

Nocardiosis is a rare opportunistic disease that affects mainly patients with deficient cell-mediated immunity, such as those with acquired immunodeficiency syndrome (AIDS) or transplant recipients. Pulmonary disease is the most common presentation in immunosuppressed patients and approximately one-third have a disseminated disease. Primary cutaneous nocardiosis is more frequently observed in immunocompetent patients with direct inoculation of the organism through professional exposure. The diagnosis can be challenging, as signs and symptoms are not specific and a high index of clinical of suspicion is necessary. Although gram stain, modified acid-fast stain, and cultures remain as the standard diagnostic tools, novel molecular techniques have changed the taxonomy of these organisms and, in some instances, have facilitated their identification. The disease has a marked tendency to recur and a high morbidity and mortality rate in immunosuppressed patients. Treatment is usually prolonged and an associated antibiotic treatment is preferred for severe disease. Although sulfonamides in combination with other antibiotics are still the treatment of choice, other associations such as imipenem plus amikacin are preferred in some centers. Linezolid is a useful alternative therapeutic agent due to its oral availability and activity against most of the isolates studied. Twenty-eight cases of nocardiosis were diagnosed at our center between January 1989 and April 2009. We report the epidemiologic characteristics of Nocardia spp. observed in our institution and discuss the risk factors, clinical features, diagnosis, and management of the disease.

Diagnosis and management of infectious complications in critically ill patients with cancer

Cancer and its treatments lead to profound suppression of innate and acquired immune function. In this population, bacterial infections are common and may rapidly lead to overwhelming sepsis and death. Furthermore, infections caused by viral and fungal pathogens should be considered in patients who have specific immune defects. As cancer therapies have become more aggressive the risk for infection has increased and many patients require intensive care support. Despite improvements in long-term survival, infections remain a common complication of cancer therapy and accounts for the majority of chemotherapy-associated deaths. By understanding the host defense impairments and likely pathogens clinicians will be better able to guide diagnosis and management of this unique population.

Stroke and cancer: a review

Stroke is a disabling disease and can add to the burden of patients already suffering from cancer. Several major mechanisms of stroke exist in cancer patients, which can be directly tumour related, because of coagulation disorders, infections, and therapy related. Stroke can also occur as the first sign of cancer, or lead to its detection. The classical literature suggests that stroke occurs more frequently in cancer patients than in the average population. More recent studies report a very similar incidence between cancer and non-cancer patients. However, there are several cancer-specific types and causes of stroke in cancer patients, which need to be considered in each patient. This review classifies stroke into ischaemic, haemorrhagic, cerebral venous thrombosis and other rarer types of cerebrovascular disease. Its aim is to identify the types of stroke most frequently associated with cancer, and give a practical view on the most common and most specific types of stroke. The diagnosis of the cause of stroke in cancer patients is crucial for treatment and prevention. Management of different stroke types will be briefly discussed.

[Infection-related emergencies in oncology]

Infections in immunosuppressed patients have always to be regarded as emergencies, as they have a high rate of complications and mortality. The most important risk factor is severity and duration of granulocytopenia. Risk scores help to identify patients who, despite their immune deficiency have a low risk of complications. Diagnostic measures to identify the causative microorganism and the source of infection is necessary. However, diagnostic investigation must not delay the immediate onset of antimicrobial treatment. Patients often have to be treated empirically as the identification of the causative microorganism or the source of infection are often unknown at the beginning of clinical symptoms. Empirical treatment has to be broad to cover possible microorganisms. Especially meningitis, abdominal infections, sepsis and pneumonia can be regarded as infectiological emergencies. Patients with these infections have to be treated with intensive antimicrobial treatment, taking into account the possible causative agents.