Profiling and Benchmarking Central Nervous System Infections in an Infectious Diseases Intensive Care Unit

BACKGROUND

There is little information comparing the performance of community acquired central nervous system infections (CNSI) treatment by intensive care units (ICUs) specialized in infectious diseases with treatment at other ICUs. Our objective was to reduce these gaps, creating bases for benchmarking and future case-mix classification.

METHODS

This is a retrospective observational cohort of 785 admissions with 82 cases of CNSI admitted to the ICU of an important Brazilian referral center for infectious diseases (INI) between January 2012 and January 2019. Comparisons were made to data retrospectively collected from the 303,500 intensive care admissions from the Brazilian state health care system included in the Epimed Monitor database. Clinical, epidemiologic, and performance indicators: the standardized mortality rate (SMR) and the standardized resource use rate per ICU surviving patient (SRU) were collected.

RESULTS

Case-mix infections profile and SMR/SRU data. SUS Mixed medical/surgical ICUs: SMR = 1.26, SRU = 1.59; SUS Neurological ICUs: SMR = 1.17, SRU = 2.23; INI ICU: SMR = 1.1, SRU = 1.1; INI ICU CNSI patients: SMR = 0.95, SRU = 1.01.

CONCLUSIONS

Severe patients with CNSI can be efficiently and effectively treated in an ICU specialized in infectious diseases when compared to mixed medical/surgical and neurological ICUs from the public health system. At the same time, we provided profiling and a case-mix that can help and encourage benchmarking by other institutions and other countries.

[Clinical analysis of 11 cases of otogenic intracranial complications treated by multidisciplinary collaboration]

Objective:To analyze the clinical diagnosis, treatment ，and surgical timing of otogenic intracranial complications. Methods:The clinical data of 11 patients with intracranial complications with ear symptoms as the first manifestation in Department of Otorhinolaryngology Head and Neck Surgery, Qilu Hospital of Shandong University（Qingdao） from December 2014 to June 2022 were collected, including 8 males and 3 females, aged from 4 to 69 years. All patients had complete otoendoscopy, audiology, imaging and etiology examination, and the diagnosis and treatment plan was jointly developed through multidisciplinary consultation according to the critical degree of clinical symptoms and imaging changes. Among the 11 patients, 5 cases were treated with intracranial lesions first in neurosurgery department and middle ear lesions later in otolaryngology, 3 cases of meningitis, were treated with middle ear surgery after intracranial infection control, 1 case was treated with middle ear lesions and intracranial infection simultaneously, and 2 cases were treated with sigmoid sinus and transverse sinus thrombosis conservatively. They were followed up for 1-6 years. Descriptive statistical methods were used for analysis. Results:All the 11 patients had ear varying symptoms, including ear pain, pus discharge and hearing loss, etc, and then fever appeared, headache, disturbance of consciousness, facial paralysis and other intracranial complication. Otoendoscopy showed perforation of the relaxation of the tympanic membrane in 5 cases, major perforation of the tension in 3 cases, neoplasia in the ear canal in 1 case, bulging of the tympanic membrane in 1 case, and turbidity of the tympanic membrane in 1 case. There were 4 cases of conductive hearing loss, 4 cases of mixed hearing loss and 3 cases of total deafness. Imaging examination showed cholesteatoma of the middle ear complicated with temporal lobe brain abscess in 4 cases, cerebellar abscess in 2 cases, cholesteatoma of the middle ear complicated with intracranial infection in 3 cases, and sigmoid sinus thrombophlebitis in 2 cases. In the etiological examination, 2 cases of Streptococcus pneumoniae were cultured in the pus of brain abscess and cerebrospinal fluid, and 1 case was cultured in streptococcus vestibularis, Bacteroides uniformis and Proteus mirabilis respectively. During the follow-up, 1 patient died of cardiovascular disease 3 years after discharge, and the remaining 10 patients survived. There was no recurrence of intracranial and middle ear lesions. Sigmoid sinus and transverse sinus thrombosis were significantly improved. Conclusion:Brain abscess, intracranial infection and thrombophlebitis are the most common otogenic intracranial complications, and cholesteatoma of middle ear is the most common primary disease. Timely diagnosis, multidisciplinary collaboration, accurate grasp of the timing in the treatment of primary focal and complications have improved the cure rate of the disease.

Severe infections in neurocritical care

PURPOSE OF REVIEW

We have highlighted the recent advances in infection in neurocritical care.

RECENT FINDINGS

Central nervous system (CNS) infections, including meningitis, encephalitis and pyogenic brain infections represent a significant cause of ICU admissions. We underwent an extensive review of the literature over the last several years in order to summarize the most important points in the diagnosis and treatment of severe infections in neurocritical care.

SUMMARY

Acute brain injury triggers an inflammatory response that involves a complex interaction between innate and adaptive immunity, and there are several factors that can be implicated, such as age, genetic predisposition, the degree and mechanism of the injury, systemic and secondary injury and therapeutic interventions. Neuroinflammation is a major contributor to secondary injury. The frequent and challenging presence of fever is a common denominator amongst all neurocritical care patients.

Consensus for prevention and management of coronavirus disease 2019 (COVID-19) for neurologists

Coronavirus disease 2019 (COVID-19) has become a pandemic disease globally. Although COVID-19 directly invades lungs, it also involves the nervous system. Therefore, patients with nervous system involvement as the presenting symptoms in the early stage of infection may easily be misdiagnosed and their treatment delayed. They become silent contagious sources or 'virus spreaders'. In order to help neurologists to better understand the occurrence, development and prognosis, we have developed this consensus of prevention and management of COVID-19. It can also assist other healthcare providers to be familiar with and recognise COVID-19 in their evaluation of patients in the clinic and hospital environment.

Bhutan's First Emergency Air Medical Retrieval Service: The First Year of Operations

OBJECTIVE

The Bhutan Emergency Aeromedical Retrieval (BEAR) Team is the only helicopter emergency medical service in Bhutan. This study was performed to review the clinical cases cared for by the BEAR Team, ascertain the types of interventions that were performed, and determine the outcomes of patients evacuated in its first year of operations.

METHODS

This is a retrospective observational study in which medical evacuations performed in the first year of operations were analyzed. The number of airlifts activated during the study period determined the sample size (171). Data were obtained from case logs and trip sheets.

RESULTS

The BEAR Team provided services to all regions of the country in its first year. The overall survival rate was 73.1%. The most common intervention required was securing a definitive airway (n = 24). The top 3 conditions requiring air medical retrieval were sepsis, acute mountain sickness, and trauma.

CONCLUSION

Helicopter emergency medical services are known to decrease the time to definitive treatment. This is particularly pertinent in Bhutan, given the scattered population distribution, long transport times, and distribution of medical resources and specialty care. This study is the first of its kind in Bhutan, and this can pave way to conduct more studies involving patients transported by air ambulance.

A systematic review of clinical guidelines on the management of acute, community-acquired CNS infections

BACKGROUND

The epidemiology of CNS infections in Europe is dynamic, requiring that clinicians have access to up-to-date clinical management guidelines (CMGs) to aid identification of emerging infections and for improving quality and a degree of standardisation in diagnostic and clinical management practices. This paper presents a systematic review of CMGs for community-acquired CNS infections in Europe.

METHODS

A systematic review. Databases were searched from October 2004 to January 2019, supplemented by an electronic survey distributed to 115 clinicians in 33 European countries through the CLIN-Net clinical network of the COMBACTE-Net Innovative Medicines Initiative. Two reviewers screened records for inclusion, extracted data and assessed the quality using the AGREE II tool.

RESULTS

Twenty-six CMGs were identified, 14 addressing bacterial, ten viral and two both bacterial and viral CNS infections. Ten CMGs were rated high quality, 12 medium and four low. Variations were identified in the definition of clinical case definitions, risk groups, recommendations for differential diagnostics and antimicrobial therapy, particularly for paediatric and elderly populations.

CONCLUSION

We identified variations in the quality and recommendations of CMGs for community-acquired CNS infections in use across Europe. A harmonised European "framework-CMG" with adaptation to local epidemiology and risks may improve access to up-to-date CMGs and the early identification and management of (re-)emerging CNS infections with epidemic potential.

Central Nervous System Infections Complicating Immunosuppression and Transplantation

PURPOSE OF REVIEW

This article reviews infections associated with cancer treatments and immunosuppressive/immunomodulatory therapies used in both neoplastic and non-neoplastic conditions, including hematopoietic cell transplantation and solid organ transplantation. It provides a clinical approach to the most commonly affected patient groups based on clinicoanatomic presentation and disease-specific risks resulting from immune deficits and drugs received.

RECENT FINDINGS

The clinical presentations, associated neuroimaging findings, and CSF abnormalities of patients with central nervous system infections who are immunocompromised may differ from those of patients with central nervous system infections who are immunocompetent and may be confused with noninfectious processes. Triggering of brain autoimmunity with emergence of neurotropic antibodies has emerged as a recognized parainfectious complication. New unbiased metagenomic assays to identify obscure pathogens help clinicians navigate the increasing range of conditions affecting the growing population of patients with altered immunity.

SUMMARY

Despite evidence-based prophylactic regimens and organism-specific antimicrobials, central nervous system infections continue to cause significant morbidity and mortality in an increasing range of patients who are immunocompromised by their conditions and therapies. Multiple new drugs put patients at risk for progressive multifocal leukoencephalopathy, which has numerous imaging and clinical manifestations; patients at risk include those with multiple sclerosis, for whom infection risk is becoming one of the most important factors in therapeutic decision making. Efficient, early diagnosis is essential to improve outcomes in these often-devastating diseases.

Other central nervous system infections: cytomegalovirus, Mycobacterium tuberculosis, and Treponema pallidum

Human immunodeficiency virus (HIV)-infected individuals are particularly susceptible to several central nervous system infections: human cytomegalovirus, which may cause encephalitis, ventriculitis, polyradiculitis, or polyradiculomyelitis; Mycobacterium tuberculosis, which can cause meningitis or space-occupying lesions; and Treponema pallidum subspecies pallidum (T. pallidum), which affects the meninges, cerebrospinal fluid, cranial nerves, and vasculature in early neurosyphilis, and additionally the brain and spinal cord parenchyma in late neurosyphilis. Central nervous system cytomegalovirus infection is seen in HIV-infected individuals with very advanced immunosuppression. Its prognosis is poor and optimal therapy has not been determined. Tuberculous meningitis has a high mortality in those also infected with HIV, especially in the developing world, and better therapies are urgently needed. As the rates of syphilis increase in the developed world, neurosyphilis and in particular ocular syphilis are increasingly reported. The likelihood of all three of these central nervous system infections is decreased in individuals who receive potent antiretroviral therapy.

The aetiologies of central nervous system infections in hospitalised Cambodian children

BACKGROUND

Central nervous system (CNS) infections are an important cause of childhood morbidity and mortality. The aetiologies of these potentially vaccine-preventable infections have not been well established in Cambodia.

METHODS

We did a one year prospective study of children hospitalised with suspected CNS infection at Angkor Hospital for Children, Siem Reap. Cerebrospinal fluid specimens (CSF) samples underwent culture, multiplex PCR and serological analysis to identify a range of bacterial and viral pathogens. Viral metagenomics was performed on a subset of pathogen negative specimens.

RESULTS

Between 1st October 2014 and 30th September 2015, 284 analysable patients were enrolled. The median patient age was 2.6 years; 62.0% were aged <5 years. CSF white blood cell count was ≥10 cells/μL in 116/272 (42.6%) cases. CNS infection was microbiologically confirmed in 55 children (19.3%). Enteroviruses (21/55), Japanese encephalitis virus (17/55), and Streptococcus pneumoniae (7/55) accounted for 45 (81.8%) of all pathogens identified. Of the pathogens detected, 74.5% (41/55) were viruses and 23.6% (13/55) were bacteria. The majority of patients were treated with ceftriaxone empirically. The case fatality rate was 2.5%.

CONCLUSIONS

Enteroviruses, JEV and S. pneumoniae are the most frequently detected causes of CNS infection in hospitalised Cambodian children.

Isolated cerebral aspergillosis in an immunocompetent woman on treatment for bacterial infected necrotizing pancreatitis: A case report

RATIONALE

Cerebral aspergillosis (CA) is a rare manifestation of invasive aspergillosis. It usually affects seriously immunocompromised hosts. Pancreatic bacterial or/and fungal infection is common in patients with severe acute pancreatitis.

PATIENT CONCERNS

We report the first case of an immunocompetent woman with infected necrotizing pancreatitis due to multidrug resistant Acinetobacter baumannii who, in the course of treatment, developed isolated CA.

DIAGNOSES

Magnetic resonance imaging, rather than computed tomography, revealed latent homolateral sinus disease-the possible source of the Aspergillus infection.

INTERVENTIONS

The pancreatic infection was controlled by open necrosectomy, and the CA was disappeared after neuronavigation-guided drainage and voriconazole antifungal therapy.

OUTCOME

The patient was discharged without complications. Our report revealed that persistent hyperglycemia, sepsisassociated immunoparalysis, and prolonged antibiotic use could impair severe patient's immunocompetence, making them more susceptible to opportunistic cerebral Aspergillus infection; the risk may be especially high in patients with paranasal sinus diseases.

LESSONS

Timely neurosurgical intervention combined with voriconazole antifungal therapy can provide a favorable outcome.

Diagnosis and Treatment of Central Nervous System Infections in the Emergency Department

Central nervous system (CNS) infections, including meningitis, encephalitis, and brain abscess, are rare but time-sensitive emergency department (ED) diagnoses. Patients with CNS infection can present to the ED with nonspecific signs and symptoms, including headache, fever, altered mental status, and behavioral changes. Neuroimaging and CSF fluid analysis can appear benign early in the course of disease. Delaying therapy negatively impacts outcomes, particularly with bacterial meningitis and herpes simplex virus encephalitis. Therefore, diagnosis of CNS infection requires vigilance and a high index of suspicion based on the history and physical examination, which must be confirmed with appropriate imaging and laboratory evaluation.

Sepsis and Other Infectious Disease Emergencies in the Elderly

Waning immunity and declining anatomic and physiologic defenses render the elder vulnerable to a wide range of infectious diseases. Clinical presentations are often atypical and muted, favoring global changes in mental status and function over febrile responses or localizing symptoms. This review encompasses early recognition, evaluation, and appropriate management of these common infections specifically in the context of elders presenting to the emergency department. With enhanced understanding and appreciation of the unique aspects of infections in the elderly, emergency physicians can play an integral part in reducing the morbidity and mortality associated with these often debilitating and life-threatening diseases.

[Psychiatric aspects of infectious diseases -- a literature review]

It is essential for the psychiatrist working in the consultation-liaison field or with comorbid patients to be familiar with the psychiatric aspects of central nervous infectious diseases or infectious diseases with psychiatric symptoms. Authors have reviewed the most important psychiatric aspects of common infectious diseases. Essential knowledge for setting up a diagnosis and starting appropriate treatment has been summarized. The most important interactions of infectological and psychiatric treatments have also been discussed.

Nocardiosis of the central nervous system: experience from a general hospital and review of 84 cases from the literature

Central nervous system (CNS) nocardiosis is a rare disease entity caused by the filamentous bacteria Nocardia species. We present a case series of 5 patients from our hospital and a review of the cases of CNS nocardiosis reported in the literature from January 2000 to December 2011. Our results indicate that CNS nocardiosis can occur in both immunocompromised and immunocompetent individuals and can be the result of prior pulmonary infection or can exist on its own. The most common predisposing factors are corticosteroid use (54% of patients) and organ transplantation (25%). Presentation of the disease is widely variable, and available diagnostic tests are far from perfect, often leading to delayed detection and initiation of treatment. The optimal therapeutic approach is still undetermined and depends on speciation, but lower mortality and relapse rates have been reported with a combination of targeted antimicrobial treatment including trimethoprim/sulfomethoxazole (TMP-SMX) for more than 6 months and neurosurgical intervention.

Intradural extramedullary primary hydatid cyst of the spine: a case report and review of literature

Primary intradural extramedullary hydatid cyst is a rare form of parasitic infection, causing focal neurological signs, commonly observed in sheep-raising areas of the world. We report a rare case of intradural, extramedullary spinal cyst, which we had misdiagnosis in the first surgery, because of rarity of the case. A 55-year-old man presented to our hospital in August 2008. He was admitted to our clinic because of lumbar pain of increasing severity and progressive difficulty with walking and stiffness of both lower limbs, which had lasted for 1 month. On the basis of imaging results, arachnoid cyst of the lumbar spine was diagnosed. Due to rapid progression of the patient's symptoms toward spastic paraplegia, he underwent an emergency surgical decompression procedure. The patient underwent exploratory surgery using a posterior approach. A L1-L2 laminectomy was performed. After opening the dura, an intradural extramedullary cystic mass was determined. The surgical specimen measured 6 × 2 cm and was described as a whitish, pearl-like, semitranslucent, cystic material, which was thought to be parasitic. Surgery has to be followed by albendazole therapy.

[Teaching curriculum about the nervous system infections for general practitioners of family practice]

Poor health-care system of Ukraine was the impetus for radical reform of the industry through the introduction of family medicine as a primary care for population. This led to the necessity for rapid training of the specialists and the development of special training programs in medical universities. Teachers have a problem to form a work model of general practitioners in severe diagnostic cases, which is especially important in the case of septic lesions of the nervous system.

Neuro-intensive care of patients with acute CNS infections

Infections in the central nervous system (CNS) are caused by a wide range of microorganisms resulting in distinct clinical syndromes including meningitis, encephalitis, and pyogenic infections, such as empyema and brain abscess. Bacterial and viral infections in the CNS can be rapidly fatal and can result in severe disability in survivors. Appropriate identification and acute management of these infections often occurs in a critical care setting and is vital to improving outcomes in this group of patients. This review of diagnosis and management of acute bacterial and viral infections in the CNS provides a general approach to patients with a suspected CNS infection and also provides a more detailed review of the diagnosis and management of patients with suspected bacterial meningitis, viral encephalitis, brain abscess, and subdural empyema.

Clinical characteristics of nosocomial infections of patients with acute central nervous system infections treated in ICU

A retrospective study was performed to evaluate the clinical characteristics of nosocomial infections in patients with acute infection of central nervous system (ACNS infections). The study included 1,686 patients admitted to the ICU. Of 1,686 patients, 936 (55.5%) had ACNS infection. Nosocomial infections was confirmed in 221 (23.6%) patients with ACNS infection. The most common risk factors for ICU-acquired nosocomial infections were consciousness disorder, mechanical ventilation and nasogastric tube. The coagulase - negative Staphylococcus aureus was the most frequent isolated pathogen (285 isolates, 56.5%). Results suggest that a persistently high level of therapeutic activity and persistently depressed consciousness after the ICU admission are associated with the occurrence of hospital-acquired infection in critically ill patients hospitalized at a medical ICU.

Tuberculosis with meningitis, myeloradiculitis, arachnoiditis and hydrocephalus: a case report

PURPOSE

Involvement of the central nervous system (CNS) by tuberculosis is rare; it can affect either immunocompromised or immunocompetent people.

CASE REPORT

Here, we report a case of tuberculosis with CNS involvement. We present the case of an immunocompetent young man who developed fever, subacute headache, disturbance of consciousness, paraparesis, sphincter dysfunction, and hypoesthesia. The final diagnosis was tuberculous meningitis, myeloradiculitis and arachnoiditis based on clinical signs, imaging studies, and cerebrospinal fluid culture. The patient received antituberculosis medication with adjunct intravenous steroid therapy. Although his clinical condition improved significantly, some neurological sequelae persisted.

CONCLUSION

Methods for detection of CNS TB and treatment protocols should be constantly re-evaluated to improve treatment outcome and reduce likelihood and severity of neurological sequelae.

[Risk factors and disposition in development of the nervous system infections]

INTRODUCTION

Although well protected, brain is not resistant to infection agents. Acute infections of our nervous system appear more often in children and in persons who have medical history data about previous disorders, especially disorders of the nervous system. It is difficult to list possible risk factors which can be responsible for the appearance of infections of CNS and the resulting conditions. It is often difficult or impossible to determine what previous neural damage was (trauma, anoxic damages etc.) from those appearing during infections of CNS. All-inclusive anamnestic research reduces the possibility of approximate judgements.

MATERIAL AND METHODS

The research was based on the retrospective analysis of medical documentation of 275 patients. All patients were divided into three groups according to the final diagnosis. The first group consisted of 125 patients who were treated for acute virus encephalitis, the second group consisted of 125 patients who were treated for acute bacterial meningoencephalitis and the third group consisted of 25 patients who were treated for cerebritis.

DISCUSSION

In our studies sample, the youngest patient was 3 years old and the oldest was 87 years old. The highest number of patients with virus infection of the CNS was in the group under 25 years of age (45.6%). The highest number of patients with bacterial infections of the CNS and cerebritis was in the group of patients over 45 years of age (64%, 37%).

CONCLUSION

Risk factors were more present in bacterial infections of the nervous system and cerebrit than in virus infection of CNS. In virus infections of the CNS, 28% of patients had some risk factor, most often-chronic ethylism, diabetes mellitus and acquired heart diseases. In bacterial infections of the CNS, 64% of patients had some predisposed factor. The most frequent factor of risk in these patients were chronic otitis (21.6%) and cranio-trauma (14.4%). In cerebritis, risk factors were present in 76% of patients and they were: sepsis (20%), chronic otitis (12%) and systemic lupus erythematosus (8%).

Central nervous system infections

Central nervous system infections have long been recognized as among the most devastating of diseases. This article describes the changing pattern and epidemiology of a variety of common central nervous system infections, including meningitis, encephalitis, and brain abscesses, and reviews pathophysiology and the most current approach to clinical diagnosis, treatment, and disposition from the emergency physician perspective.

[Infections of the central nervous system in emergency department]

Infections of the central nervous system are frequent diseases in emergency care. They can have a bacterial, parasitic or viral origin. Initial symptoms can be non-specific, which can complicate and delay diagnosis, hence the extreme importance of all the information that can be obtained through anamnesis and physical exploration, with frequent complementary explorations. In the last hundred years, with the introduction of antibiotic drugs, there has been a significant fall in mortality secondary to meningoencephalitis, but in spite of that they continue to provoke high morbidity and mortality. Other phenomena, such as vaccination campaigns, migratory movements, infection by HIV and other states of immunosuppression, have given rise to important epidemiological changes such as the virtual disappearance of some infections or the appearance of others that rarely existed previously. The list of potential infections of the central nervous system is extensive, which is why in this review we set out, from the clinical, diagnostic and therapeutic point of view, those that are most frequent in our environment and some that, although very infrequent, might require emergency attention due to their severity.

[Strokes caused by infection in the tropics]

INTRODUCTION

Almost three out of every four people in the world who suffer a fatal stroke live in developing countries. A number of different tropical diseases may appear in Europe in the coming years as a consequence of the demographic change that is being brought about by migratory flows. We review the main infectious causes of strokes in the tropics.

DEVELOPMENT

There are estimated to be 500 million cases of malaria every year. Cerebral malaria can cause cerebral oedema, diffuse or focal compromise of the subcortical white matter and cortical, cerebellar and pontine infarctions. Chagas disease is an independent risk factor for stroke in South America. At least 20 million people have the chronic form of Chagas disease. The main prognostic factors for Chagas-related stroke are the presence of apical aneurysms, arrhythmia and heart failure. Vascular complications of neurocysticercosis include transient ischemic attacks, ischemic strokes due to angiitis and intracranial haemorrhages. The frequency of cerebral infarction associated with neurocysticercosis varies between 2% and 12%. Gnathostomiasis is a cause of subarachnoid haemorrhage in south-east Asia. Other less common causes of stroke are viral haemorrhagic fevers due to arenavirus and flavivirus.

CONCLUSIONS

Several diseases that are endemic in the tropics can be responsible for up to 10% of the cases of strokes in adults.

Otogenic intracranial complications. a 7-year retrospective review

OBJECTIVES

The objectives of this study were to review our experience on intracranial complications secondary to otitis media (OM), and to compare the results to those occurring 10-15 years ago. We also reviewed the timing of both otologic and neurosurgical treatments.

MATERIAL AND METHODS

All patients with intracranial complications secondary to OM over a 7-year period were identified. A retrospective chart review was undertaken at Beaumont University Hospital, Dublin, Ireland. Clinical presentation, radiological findings, microbiology, surgical management, and antibiotic use were studied. We compare our findings to those of other international investigators.

RESULTS

Twelve cases were identified. Five had brain abscesses, 4 had lateral sinus thrombosis, and 3 had petrous apicitis. Eight of these cases were secondary to chronic OM and 4 were secondary to acute OM. Malodorous otorrhea, otalgia, headache, fever, and vertigo were the primary symptoms. Anaerobic bacteria were the most commonly isolated organisms followed by Staphylococcus aureus, Proteus mirabilis, and Pseudomonas aeruginosa. Patients with cholesteatoma underwent modified radical or radical mastoidectomy, and those who did not have cholesteatoma underwent cortical mastoidectomy. Two brain abscesses were drained before mastoid surgery; 2 were drained after mastoid surgery and 1 at the same time as otologic surgery. All patients received broad-spectrum intravenous antibiotics targeted at individual culture and sensitivity results. The mortality rate was zero.

CONCLUSION

Clinical presentation and the frequency of occurrence of intracranial complications are similar to those occurring 10 years ago. The choice of antibiotics should include adequate anaerobic cover. We recommend that otologic surgery be performed at the same time as intracranial surgery for patients with mature brain abscesses.

Mycoplasma pneumoniae central nervous system infections

PURPOSE OF REVIEW

Mycoplasma pneumoniae is associated with a wide range of central nervous system diseases, most importantly with childhood encephalitis. This review summarizes and discusses recent findings in the field of M. pneumoniae central nervous system infections in context with previously published findings, with reference to clinical spectrum, pathogenesis, diagnosis, and treatment.

RECENT FINDINGS

Further insight into the pathogenesis has been provided by studies on cytokine production and autoantibody formation. Some new manifestations have been described (e.g. Kluver-Bucy syndrome, intracranial hypertension). Anecdotal descriptions on the association of M. pneumoniae with uncommon neurologic diseases remain to be confirmed by additional reports, however, especially when aetiologic diagnosis relied exclusively on serology. New knowledge on treatment options targeting the immune system has been provided by isolated reports. Recent diagnostic advances refer to general methods (polymerase chain reaction, serology), without specific reference to neurologic disease.

SUMMARY

M. pneumoniae must be considered as causative agent of various neurologic diseases. The recent literature shows, however, that the clinical spectrum of M. pneumoniae central nervous system disease is still not well defined. In addition, the main future challenges are the investigation of the pathogenesis of M. pneumoniae central nervous system disease and the establishment of therapeutic approaches.

Central nervous system pseudallescheriasis after near-drowning

BACKGROUND

Clinical characteristics of central nervous system (CNS) pseudallescheriasis after near-drowning have not been systematically analyzed.

METHODS

Review of cases reported in the English-language literature.

RESULTS

Sixteen patients were identified. The average period between the near-drowning episode and onset of clinical manifestations was 37 days. Common manifestations included fever, altered mental status, headache, seizures, and hemiparesis. All patients developed brain abscesses; however, imaging studies were normal at presentation in 6 patients. Cerebrospinal fluid neutrophilic pleocytosis, elevated protein, and decreased glucose were commonly observed. Most patients were treated with surgical resection and systemic amphotericin B or miconazole. Voriconazole was used in 2 patients. Twelve patients (75%) died. The average time between the near-drowning episode and death was 12 weeks. Four survivors received prompt treatment.

CONCLUSIONS

CNS pseudallescheriasis after near-drowning is highly lethal. Early diagnosis and aggressive medical and surgical interventions may improve survival.

Therapeutic potential of embryonic stem cells

Nearly 20 years after murine embryonic stem cells (mESC) were isolated, the first report of the derivation of human embryonic stem cells (hESC) in 1998 spawned the field of hESC research [Evans MJ, Kaufman MH, Establishment in culture of pluripotential cells from mouse embryos. Nature 1981; 292 (5819): 154-6; Thomson JA, Itskovitz-Eldor J, Shapiro SS, et al. Embryonic stem cell lines derived from human blastocysts. Science 1998; 282 (5391): 1145-7.]. Although this field is only in its infancy, hESC represent a theoretically inexhaustible source of precursor cells that could be differentiated into any cell type to treat degenerative, malignant, or genetic diseases, or injury due to inflammation, infection, and trauma. This pluripotent, endlessly dividing cell has been hailed as a possible means for treating diabetes, Parkinson's disease, Alzheimer's, spinal cord injury, heart failure, and bone marrow failure. But the regenerative medicine applications of embryonic stem cells are only one facet of hESC therapeutic potential. Human ESC are an invaluable research tool to study development, both normal and abnormal, and can serve as a platform to develop and test new therapies. In addition to discussing the therapeutic potential of hESC, this chapter will cover limitations to using hESC for replacement cell therapy, strategies to overcome these limitations, and alternative methods of deriving hESC.

Neurologic aspects of infections in international travelers

BACKGROUND

As international travel for business and pleasure becomes part of contemporary lifestyle, the clinician today is confronted with an increasing number of travelers returning ill with unfamiliar syndromes. The physician will encounter a myriad of patients with exotic infections, emerging infectious diseases, or resurgent Old-World infections.

REVIEW SUMMARY

This review article will discuss salient points of important infectious diseases associated with overseas travel, provide a syndromic approach to the traveler who returns with neurologic manifestations, and list resources for additional diagnostic, therapeutic, and preventive information.

CONCLUSIONS

As many of infections acquired in other countries can directly or indirectly affect the nervous system, the care of the ill traveler often falls into the hands of neurologists. The contemporary neurologist should therefore be knowledgeable of the clinical manifestations, potential complications, and appropriate management of region-specific infections.

Rapid infectious killers

Central to the practice of emergency medicine is the ability to identify patients in whom immediate intervention is needed to prevent long-term morbidity and mortality. This article has highlighted some of the characteristics of several infectious diseases that may become fatal quickly if not treated quickly and appropriately by physicians. Bacterial meningitis,necrotizing soft tissue infections, invasive gram-negative disease, pneumo-coccal pneumonia, and West Nile encephalitis all require prompt recognition and treatment by emergency care providers.

Central nervous system infections due to Abiotrophia and Granulicatella species: an emerging challenge?

Although Abiotrophia and Granulicatella species, previously referred to as nutritionally variant streptococci, were initially identified over 40 years ago, isolation of these pathogens from the central nervous system (CNS) was first noted only recently. Recognition of CNS involvement with these organisms is of great concern given the association of Abiotrophia/Granulicatella infections with increased morbidity and mortality as well as greater bacteriologic failure and relapse rates. We describe A. defectiva and G. adiacens CNS infections in two patients and review the existing literature of CNS involvement with these bacteria. The clinical presentation and initial cerebrospinal fluid analysis has varied substantially across reported patients. While most infections have been characterized primarily by a localized infection (e.g., abscess), evidence of meningitis has usually also been present. Furthermore, nearly all cases have followed neurosurgical procedures suggesting possible introduction of the organism into the CNS at the time of surgery. Given the significant negative clinical impact of Abiotrophia/Granulicatella infections, elucidation of the emerging epidemiology of CNS infections with these bacteria is warranted.

Recurrent cerebral fever in the seventeenth and twenty first centuries

The development of modern neuroscience away from the concepts of Hippocrates and Galen can be traced to the writings of some 17th century clinicians, especially Thomas Willis. His exceptional skills in observation and description allow a window into the experiences of our medical forebears. His approach to the management of infection-related coma in a child is amenable to modern interpretation and comparison with modern management because of the clarity of his clinical descriptions. Modern clinicians may benefit from this historical perspective into influences on the origins of neuroscience. The different outcome for a child presenting in the 17th and 21st century encourage grateful reflection on our current privileged position.

Opportunistic infections of the CNS in patients with AIDS: diagnosis and management

The CNS is the second most commonly affected organ in patients with AIDS. Many opportunistic infections may involve the brain, but the four most frequent conditions are toxoplasmosis, progressive multifocal leukoencephalopathy (PML), cryptococcosis and cytomegalovirus infection. Although the incidence of these infections among patients with AIDS has decreased in the past years as a consequence of the introduction of highly active antiretroviral therapy (HAART), they remain a major cause of morbidity and mortality in this patient group. This article summarises the clinical manifestations, diagnostic procedures and management strategies for these four conditions. The clinical manifestations are nonspecific and depend on the type and location of the lesions. In clinical practice, the diagnosis of these entities is made with noninvasive methods. Imaging studies, especially magnetic resonance imaging, are very useful for the diagnosis of toxoplasmic encephalitis and PML, although their usefulness for the diagnosis of cryptococcal meningitis and cytomegalovirus infections is lower. The presence of multiple ring-enhancing lesions with surrounding oedema and mass effect is characteristic of toxoplasmosis. The response to antitoxoplasmic therapy, which is usually observed within the first 2 weeks, is also used for diagnostic purposes. Molecular methods applied to the CSF are essential for the diagnosis of PML and cytomegalovirus infections. In addition, the quantification of viral DNA of both JC virus (the causative agent of PML) and cytomegalovirus has prognostic implications and may serve to evaluate the response to therapy. Cryptococcosis may be easily diagnosed by CSF stains and cultures, as well as by the detection of the cryptococcal capsular polysaccharide antigen in the blood and, especially, the CSF. Effective treatments are available for toxoplasmosis and cryptococcosis, although adverse effects are common and some patients may not respond to therapy. In contrast, there is no specific treatment for PML, and the efficacy of anticytomegalovirus therapy is poor and the toxicity significant. HAART has improved the outcome of patients with AIDS who have infections of the CNS, and the initiation of this therapy is mandatory for all patients with such infections, particularly in those conditions for which effective therapy is not available. Lifelong secondary prophylaxis with agents for the opportunistic infections was necessary before the HAART era because the risk of recurrence was very high if only induction therapy was administered. However, today, the discontinuation of secondary prophylaxis in patients treated with HAART who have stably reached a certain immune reconstitution is possible.

[Septic encephalopathy. Diagnosis und therapy]

23% of all septic patients develop septic encephalopathy which is associated with an increased mortality rate. Symptoms such as agitation, confusion and disorientation ranging from stupor to coma often develop in early sepsis. Severe hypotension is significantly associated with the development of septic encephalopathy. Several other factors which may play a role are also discussed: effects of inflammatory mediators on the brain, inadequate cerebral perfusion pressure, blood-brain barrier derangements, disturbances of the cerebral microcirculation, cerebral ischemia e.g. due to hypocapnia,metabolic changes, altered amino acid levels, transmitter imbalances, liver insufficiency, multiple organ failure and infections of the CNS, respectively. Compared to patients with an isolated infection,patients in septic shock have increased levels of aromatic amino acids such as phenylalanine and tryptophan in the plasma and brain as well as decreased levels of branched chain amino acids. Patients who died had higher levels of aromatic amino acids than the survivors. The correlation between aromatic amino acids and the APACHE II score was significant. The tryptophan metabolite quinolinic acid which can be synthesized in activated macrophages could act as an excitatory transmitter on the N-methyl-D-aspartate (NMDA) -receptor. Observations from experimental models indicate that activated NMDA receptors activate the neuronal isoform of the NO-synthase and other calcium dependent enzymes. This releases free radicals which may damage the DNA and activate the nuclear enzyme Poly-ADP-ribose-synthetase (PARS), resulting in energy depletion and cell death. Sepsis is the main cause of metabolic encephalopathies in critically ill patients. The differential diagnoses include hepatic, renal,hypoxic-ischemic or cardiovascular encephalopathies as well as encephalopathies,metabolic disorders and organ dysfunctions of other origin. Therapeutic interventions are numerous,however, so far only investigated in few controlled studies. The primary therapeutic goal is to maintain an adequate perfusion pressure and to prevent hypoxia and hypocapnia. Although the infusion of branched chain amino acids is controversial, experimental investigations demonstrated improvements improvements in an animal model with septic encephalopathy. Further investigations with respect to glutamate receptor antagonists, new radical scavengers, NO- and PARS-inhibitors may show whether these substances are suitable for the prophylaxis or early therapy of septic encephalopathy.

What I have learned about infectious diseases with my sleeves rolled up

The questions most often asked of my residents and myself are the following: (1) How do you interpret the cerebrospinal fluid white blood cell count and polymerase chain reaction results when the lumbar puncture has been traumatic? (2) Does the older adult with a serum sample that tests positive by the Venereal Disease Research Laboratory test need spinal fluid analysis for neurosyphilis, and which of those syphilis tests can become nonreactive even though the patient is never treated? (3) Do you give steroids to patients with bacterial meningitis? (4) What do you do for the patient with cryptococcal meningitis who develops a spastic gait? (5) Are all cases of transverse myelitis "idiopathic"? and (6) When does the patient who has had a stroke need spinal fluid analysis to rule out an infectious etiology? This is how we answer these questions.

Central nervous system infections: a critical care approach

Central nervous system (CNS) infections are diverse. CNS infections can cause significant morbidity and mortality and are markedly different from systemic infections. The closed anatomic space of the CNS, its immunologic isolation from the rest of the body, and the often nonspecific nature of the key manifestations present a challenge to the clinician. Early recognition and aggressive management are essential to patient recovery and prevention of long-term neurologic sequelae. This review discusses the major types of CNS infections and focuses on critical care management, with emphasis on current epidemiologic trends.

Protean infectious types and frequent association with neurosurgical procedures in adult Serratia marcescens CNS infections: report of two cases and review of the literature

Serratia marcescens is a rare pathogen of adult central nervous system (CNS) infection. We report on the clinical features and therapeutic outcomes of two adult patients with such infections. The clinical characteristics of 13 other reported adult cases are also included for analysis. The 15 cases were nine males and six females, aged 19-83 years, in whom, underlying post-neurosurgical states and ear operation were noted in 93% (14/15). Fever and conscious disturbance were the most common clinical manifestations of these 15 cases, followed by hydrocephalus, seizures, and wound infections. The manifestation types were protean, including meningitis and focal suppurations such as brain abscess, cranial and spinal epidural abscess, cranial subdural abscess, and infected lumbar pseudomeningocele. One case of S. marcescens CNS infection was diagnosed postmortem; the other 14 were diagnosed by the positive culture from CSF or pus. Antibiotic therapy with or without neurosurgical intervention was the management strategy in 14/15 cases. The therapeutic results showed a high mortality rate.

Central nervous system infections in the compromised host: a diagnostic approach

The diagnostic approach to the compromised host with CNS infection depends on an analysis of the patient's clinical manifestations of CNS disease, the acuteness or subacuteness of the clinical presentation, and an analysis of the type of immune defect compromising the patient's host defenses. Most patients with CNS infections may be grouped into those with meningeal signs, or those with mass lesions. Other common manifestations of CNS infection include encephalopathy, seizures, or a stroke-like presentation. Most pathogens have a predictable clinical presentation that differs from that of the normal host. CNS Aspergillus infections present either as mass lesions (e.g., brain abscess), or as cerebral infarcts, but rarely as meningitis. Cryptococcus neoformans, in contrast, usually presents as a meningitis but not as a cerebral mass lesion even when cryptococcal elements are present. Aspergillus and Cryptococcus CNS infections are manifestations of impaired host defenses, and rarely occur in immunocompetent hosts. In contrast, the clinical presentation of Nocardia infections in the CNS is the same in normal and compromised hosts, although more frequent in compromised hosts. The acuteness of the clinical presentation coupled with the CNS symptomatology further adds to limit differential diagnostic possibilities. Excluding stroke-like presentations, CNS mass lesions tend to present subacutely or chronically. Meningitis and encephalitis tend to present more acutely, which is of some assistance in limiting differential diagnostic possibilities. The analysis of the type of immune defect predicts the range of possible pathogens likely to be responsible for the patient's CNS signs and symptoms. Patients with diseases and disorders that decrease B-lymphocyte function are particularly susceptible to meningitis caused by encapsulated bacterial pathogens. The presentation of bacterial meningitis is essentially the same in normal and compromised hosts with impaired B-lymphocyte immunity. Compromised hosts with impaired T-lymphocyte or macrophage function are prone to develop CNS infections caused by intracellular pathogens. The most common intracellular pathogens are the fungi, particularly Aspergillus, other bacteria (e.g., Nocardia), viruses (i.e., HSV, JC, CMV, HHV-6), and parasites (e.g., T. gondii). The clinical syndromic approach is most accurate when combining the rapidity of clinical presentation and the expression of CNS infection with the defect in host defenses. The presence of extra-CNS sites of involvement also may be helpful in the diagnosis. A patient with impaired cellular immunity with mass lesions in the lungs and brain that have appeared subacutely or chronically should suggest Nocardia or Aspergillus rather than cryptococcosis or toxoplasmosis. Patients with T-lymphocyte defects presenting with meningitis generally have meningitis caused by Listeria or Cryptococcus rather than toxoplasmosis or CMV infection. The disorders that impair host defenses, and the therapeutic modalities used to treat these disorders, may have CNS manifestations that mimic infections of the CNS clinically. Clinicians must be ever vigilant to rule out the mimics of CNS infections caused by noninfectious etiologies. Although the syndromic approach is useful in limiting diagnostic possibilities, a specific diagnosis still is essential in compromised hosts in order to describe effective therapy. Bacterial meningitis, cryptococcal meningitis, and tuberculosis easily are diagnosed accurately from stain, culture, or serology of the CSF. In contrast, patients with CNS mass lesions usually require a tissue biopsy to arrive at a specific etiologic diagnosis. In a compromised host with impaired cellular immunity in which the differential diagnosis of a CNS mass lesion is between TB, lymphoma, and toxoplasmosis, a trial of empiric therapy is warranted. Antitoxoplasmosis therapy may be initiated empirically and usually results in clinical improvement after 2 to 3 weeks of therapy. The nonresponse to antitoxoplasmosis therapy in such a patient would warrant an empiric trial of antituberculous therapy. Lack of response to anti-Toxoplasma and antituberculous therapy should suggest a noninfectious etiology (e.g., CNS lymphoma). Fortunately, most infections in compromised hosts are similar in their clinical presentation to those in the normal host, particularly in the case of meningitis. The compromised host is different than the normal host in the distribution of pathogens, which is determined by the nature of the host defense defect. In compromised hosts, differential diagnostic possibilities are more extensive and the likelihood of noninfectious explanations for CNS symptomatology is greater. (ABSTRACT TRUNCATED)

Controversies in neurological infectious diseases

The past several years have seen major advances in our understanding of neurological infectious diseases, their diagnosis, and their treatment. Along with these advances, however, new information about infectious agents and new therapeutic options have also introduced both uncertainty and controversy in the approach and management of patients with diseases of the central nervous system. Here, we discuss six such areas: the long-term efficacy of HAART therapy in treatment of HIV infection; the role of viral infection in chronic fatigue syndrome; Rasmussen's encephalitis as an infectious or autoimmune disease; the spectrum of neurological diseases caused by rickettsial infection; the role of Mycoplasma pneumoniae in human central nervous system disease; and the possible association of Chlamydia pneumoniae and human herpesvirus 6 with multiple sclerosis.

Infections of the nervous system: an update on recent developments

The past decade has seen major changes in the field of infectious diseases. In particular, many new infections of the nervous system have been recognised, including the lethal infections of Enterovirus 71, and the Nipah and West Nile viruses. Increased interest in prion diseases has occurred, following the recognition of animal-to-human transmission in Europe. Familiar bacteria such as the pneumococcus continue to cause problems due to increasing resistance to multiple antibiotics. Furthermore, human immunodeficiency virus-infected and other immunocompromised patients are under the constant threat of opportunistic infections, many of which are targeted towards the brain and spinal cord. This paper reviews the changing world of nervous system infections, highlighting some of the most significant recent developments.

Infections of the central nervous system in transplant recipients

Central nervous system (CNS) infections, accounting for 4-29% of CNS lesions in transplant recipients, are a significant post-transplant complication. Focal CNS infectious lesions or brain abscesses have been documented in 0.36-1% of the transplant recipients. Mycelial fungi, particularly Aspergillus, are by far the most frequent etiologies of post-transplant brain abscesses. Bacteria, with the exception of Nocardia, are rarely associated with brain abscesses in transplant recipients. Time of onset and concurrent extraneural lesions have implications relevant towards invasive diagnostic procedures in transplant recipients with brain abscesses. Meningoencephalitis in transplant recipients is predominantly due to viruses, e.g., herpesviruses, and less frequently due to Listeria monocytogenes, Toxoplasma gondii, and Cryptococcus. Despite a wide, and at times perplexing array of opportunistic pathogens that can cause CNS infections, the temporal association of the infection with the time elapsed since transplantation, risk factors, clinical manifestations, and neuroimaging characteristics of the lesion can allow a reasoned and rational approach towards the recognition, diagnosis, and appropriate management of CNS infections in transplant recipients.