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Purpose of review This article reviews the symptomatology, diagnosis, and treatment of neuroborreliosis. Recent findings The most recent guidelines for the diagnosis and treatment of Lyme disease were published in 2020 by the Infectious Diseases Society of America, the American Academy of Neurology, and the American College of Rheumatology. Summary The most common neurologic complications of Lyme disease are cranial neuritis (most often a unilateral or bilateral facial nerve palsy), meningitis, and radiculoneuritis/mononeuropathy multiplex. Testing for Lyme disease begins with an enzyme-linked immunosorbent assay (ELISA). If the ELISA is positive or borderline, Western blots should be performed for both IgM and IgG antibodies. As a general rule, in infectious diseases, an IgM antibody response is followed by an IgG antibody response. A central nervous system infection has either a CSF pleocytosis or pathogen-specific intrathecal antibody production. Lyme meningitis, cranial neuropathy, radiculoneuropathy, or other peripheral nervous system manifestations are treated with oral doxycycline or IV ceftriaxone, cefotaxime, or penicillin G. No additional antibiotic therapy is indicated for patients with posttreatment Lyme disease syndrome or patients with concern for chronic Lyme disease with no evidence of previous or current Lyme infection.

Acute viral meningitis refers to inflammation of the meninges of the brain in response to a viral pathogen. Viruses cause meningitis, encephalitis, myelitis, or a combination of these, meningoencephalitis or encephalomyelitis. Viral meningitis is typically a self-limited disorder with no permanent neurologic sequelae. This chapter reviews the epidemiology, etiology, diagnosis, differential diagnosis, treatment, complications, and prognosis. Tables describe Wallgren’s criteria for aseptic meningitis, important arboviral infections found in North America, herpes family viruses and meningitis, classic cerebrospinal fluid (CSF) abnormalities with viral meningitis, Centers for Disease Control and Prevention criteria for confirming arboviral meningitis, basic CSF studies for viral meningitis, and etiology of CSF pleocytosis. Figures depict common causes of viral meningitis, nuchal rigidity, examination for Kernig sign, and Brudzinski sign for meningeal irritation. This chapter contains 4 figures, 12 tables, 19 references Keywords: Meningitis, viral infection, encephalitis, enterovirus, herpesvirus, lumbar puncture, arbovirus, aseptic meningitis, Kernig sign, Brudzinski sign

Acute bacterial meningitis and spinal epidural abscess are neurological emergencies. Acute bacterial meningitis may present with symptoms as nonspecific as headache and fever, but rapid progression to an altered level of consciousness is not unusual. Spinal epidural abscess manifests initially as back pain, followed by radicular pain, then weakness, and finally paraplegia. Brain abscess may initially present only with headache, or as a new-onset seizure or with a focal neurological deficit. Bacterial infections of the central nervous system require emergent diagnosis and management. In this article, the pathogenesis, etiological organisms, diagnostic studies, differential diagnosis and management of acute bacterial meningitis, spinal epidural abscess, and brain abscess are discussed.

The central nervous system infections that are neurological emergencies are meningitis, encephalitis, focal infectious mass lesions (brain abscess and subdural empyema), and spinal epidural abscess. This chapter will review the diagnosis and management of these neuroinfectious diseases.

ObjectiveTo delineate a comprehensive curriculum for fellowship training in neuroinfectious diseases, we conducted a modified Delphi approach to reach consensus among 11 experts in the field.MethodsThe authors invited a diverse range of experts from the American Academy of Neurology Neuro-Infectious Diseases (AAN Neuro-ID) Section to participate in a consensus process using a modified Delphi technique.ResultsA comprehensive list of topics was generated with 101 initial items. Through 3 rounds of voting and discussion, a curriculum with 83 items reached consensus.ConclusionsThe modified Delphi technique provides an efficient and rigorous means to reach consensus on topics requiring expert opinion. The AAN Neuro-ID section provided the pool of diverse experts, the infrastructure, and the community through which to accomplish the consensus project successfully. This process could be applied to other subspecialties and sections at the AAN.

Bacterial infections of the central nervous system are neurologic emergencies. Prompt recognition and treatment are essential not only to prevent mortality, but also to decrease neurologic sequelae. This article focuses on the two most common central nervous system bacterial infections, bacterial meningitis and spinal epidural abscess.Two outbreaks of serogroup B meningococcal disease have occurred on US college campuses. The meningococcal vaccine given to young adults does not contain serogroup B.In bacterial meningitis and in bacterial spinal epidural abscess, the identification of and eradication of the pathogen with antimicrobial therapy is the easy part. It is the recognition of the disorder, the understanding of which diagnostic studies to obtain and their limitations, and the management of the neurologic complications that require the expertise of a neurologist.

This cohort study evaluates the rates of acute Zika virus infection among patients hospitalized with Guillain-Barré syndrome, meningoencephalitis, or transverse myelitis.

This review explores the history of serogroup B meningitis outbreaks in American universities and the rise of the monovalent serogroup B meningococcus vaccines (MenB). Serogroup B meningitis represents 30% of American meningococcal infections and had no commercially available vaccine in the USA until 2013 when the FDA made an expanded allowance for importation of the MenB-4C vaccine for outbreaks at two American universities. Infections of Neisseria meningitidis, notably meningococcal meningitis represent a continued, lethal threat to the pediatric and adolescent populations and those with primary or acquired complement component deficiencies, largely mitigated by the quadrivalent meningococcal conjugated vaccine against serogroups A, C, W, and Y (MenACWY).

Purpose of review The incidence of spinal epidural abscess is increasing, and the understanding of the pathophysiology is evolving. Better understanding of the pathophysiology, specifically the role of ischemia, warrants a change in therapy. Recent findings Paralysis in spinal epidural abscess may be the result of spinal cord compression, spinal cord arterial and/or venous ischemia and thrombophlebitis or a combination of these. Summary Recent evidence indicates the following areas of investigation and management can improve outcome in spinal epidural abscess: minimally invasive surgery early versus medical management when there are no significant neurological deficits, neuroradiologic arterial evaluation with therapies directed at vascular ischemia and thrombosis, and aggressive rehabilitation.

Objective:To review the evidence base for different treatment strategies in intraparenchymal neurocysticercosis in adults and children.Method:A literature search of Medline, EMBASE, LILACS, and the Cochrane Database from 1980 to 2008, updated in 2012, resulted in the identification of 10 Class I or Class II trials of cysticidal drugs administered with or without corticosteroids in the treatment of neurocysticercosis.Results:The available data demonstrate that albendazole therapy, administered with or without corticosteroids, is probably effective in decreasing both long-term seizure frequency and the number of cysts demonstrable radiologically in adults and children with neurocysticercosis, and is well-tolerated. There is insufficient information to assess the efficacy of praziquantel.Recommendations:Albendazole plus either dexamethasone or prednisolone should be considered for adults and children with neurocysticercosis, both to decrease the number of active lesions on brain imaging studies (Level B) and to reduce long-term seizure frequency (Level B). The evidence is insufficient to support or refute the use of steroid treatment alone in patients with intraparenchymal neurocysticercosis (Level U).

A 31-year-old man presented to his local hospital in Germany with subacute holocephalic headaches and bilateral retro-orbital pain with blurry vision and soon developed clumsiness in his right hand. Neurologic examination revealed mild upper motor neuron weakness of the right arm with impaired fine motor movements and increased muscle tendon reflexes. Examination of cranial nerves and sensation was normal. Physical examination and his past medical history were unremarkable. He smoked cigarettes, consumed alcohol infrequently, and denied any medication or drug abuse. He worked in the passenger security check at Munich airport. His family history was significant only for migraine headaches. Brain MRI showed a single tumor-like, contrast-enhancing lesion in the left paramedian midbrain (figure, A) with prominent perifocal edema and slight compression of the third ventricle. Chest radiography and abdominal ultrasound were normal. Blood tests revealed slightly elevated liver enzymes (alanine aminotransferase 55 U/L [normal

Any of a number of neuroinfectious diseases can cause a disorder of consciousness. The priority in the care of the patient is to identify an infectious disease that is treatable. This article examines disorders of consciousness that may be caused by a septic encephalopathy, bacterial meningoencephalitis, viral encephalitis, tick-borne bacterial disease, fungal meningitis, tuberculous meningitis, a focal infectious mass lesion, such as a brain abscess, or an autoimmune-mediated disorder as a complication of infection.

Purpose of review : Neurologists have a vital role in the recognition of meningitis and encephalitis, the accurate evaluation and interpretation of CSF studies, and the management and prevention of the neurologic complications of CNS infectious diseases. Recent findings ;: Although the tetravalent meningococcal glycoconjugate vaccine has decreased the incidence of meningococcal meningitis, the vaccine does not contain serogroup B, which is responsible for one-third of cases of meningococcal disease. Thus, meningitis due to Neisseria meningitidis is still a concern in a vaccinated individual. Empiric therapy for meningitis associated with sinusitis, otitis, or mastoiditis should include antibiotic therapy for anaerobes. An organism that classically causes a subacute or chronic meningitis, such as Mycobacterium tuberculosis, may on occasion present with an acute onset of symptoms. Summary ;: Unlike most other diseases, the management of patients with suspected meningitis or encephalitis begins with empiric therapy. The etiologic organism cannot always be identified. The goal is to identify those that are treatable, provide supportive care for those that are not, and, when possible, prevent the neurologic complications of these infections.

Pregnancy is associated with impaired T-cell-mediated immunity putting the woman at risk for infectious diseases not typically seen in immunocompetent individuals. When maternal infection is severe, and when a primary herpesvirus infection is acquired during pregnancy, there is a risk of fetal loss, maternal death, neonatal death, or congenital abnormalities from intrauterine infection. In this review, the authors emphasize specific neurologic infectious diseases that occur in pregnancy, the safety of the antimicrobial therapy of these diseases during pregnancy, as well as the congenital and neonatal sequelae of infection.

The vertical transmission of a prion disease from infected mothers to their offspring is believed to be one of the routes for the natural spread of animal prion diseases. Supporting this notion is the observation that prion infectivity occurs in the placenta of infected ewes. Furthermore, the prion protein (PrP), both in its cellular form (PrP(C)) and its pathological isoform (PrP(Sc)), has been observed at the fetal-maternal interface of scrapie-infected sheep. However, whether these features of prion infectivity also hold true for human prion diseases is currently unknown. To begin to address such an important question, we examined PrP in the uterus as well as gestational tissues, including the placenta and amniotic fluid, in a pregnant woman with sporadic Creutzfeldt-Jakob disease (CJD). Although the proteinase K (PK)-resistant prion protein, PrP27-30, was present in the brain tissues of the mother, the PrP detected in the uterus, placenta, and amniotic fluid was sensitive to PK digestion. Unlike PrP(C) in the brain and adjacent cerebrospinal fluid, the predominant PrP species in the reproductive and gestational tissues were N-terminally truncated, similar to urine PrP. Our study did not detect abnormal PrP in the reproductive and gestational tissues in this case of CJD. Nevertheless, examination by a highly sensitive bioassay is ongoing to ascertain possible prion infectivity from CJD in the amniotic fluid.

Editors' Note: The AAN's evidence-based guideline for the treatment of parenchymal neurocysticercosis generated several suggestions. Writ e Click contributors questioned the guideline's relevance to clinical practice, the studies included and excluded, and the outcomes measured. The authors respond that the guideline's shortcomings reflect the inadequacies found in the literature on neurocysticercosis as a whole. —Megan Alcauskas, MD, and Robert C. Griggs, MD # {#article-title-2} The success of a systematic review lies in the adequate selection of the questions that represent the daily problems encountered by treating physicians. NCC is a pleomorphic disease and the clinical behavior of patients harboring one cystic lesion is different from those with multiple intraparenchymal lesions. Confounders can also play an important role in the treatment of NCC including the patient's concomitant use of other medications (e.g., antiepileptic drugs) and stage of the lesions. These factors were not considered in the review by Baird et al.1 The authors should have performed systematic reviews in each of the following groups independently: single lesion, multiple lesions, and cysticercotic encephalitis. Furthermore, the relationship between NCC lesion and seizures is easy to assess when there is a single lesion in a case of new-onset seizures. However, it is more complicated when there are multiple lesions. Even though NCC-related epilepsy is a well-defined syndrome, there is a need to confirm the epileptogenic focus responsible for the seizures in a patient with NCC. Is it located around the lesion or lesions or other epileptogenic lesions? This needs to be ruled out. The authors did not include these …

This case series highlights our experience with use of the Fungitell assay for quantifying (1,3)-β- d -glucan in cerebrospinal fluid during the current U.S. outbreak of fungal meningitis related to contaminated methylprednisolone acetate. This test may prove a useful adjunct in diagnosis and management of exposed patients.

Neurosyphilis is caused by the spirochete Treponema pallidum. These organisms divide slowly, requiring long exposure to antibacterials for treatment success. In order for an antibacterial to be effective in the therapy of neurosyphilis, it must achieve treponemicidal concentrations in the CSF, have a long half-life and be given in a treatment regimen that favours compliance. Penicillin was first introduced for the treatment of syphilis in 1943, and despite interest in the use of amoxicillin, erythromycin, tetracycline, doxycycline, ceftriaxone and azithromycin, penicillin remains the only recommended antibacterial agent for neurosyphilis.

Stroke in children and adolescents can be a complication of a central nervous sytem infection, such as bacterial meningitis, varicella zoster virus infection, human immunodeficiency virus infection, or tuberculous meningoencephalitis, or might complicate pharyngitis, pneumonia, a systemic viral illness, or sepsis. Rarely, stroke might be a complication of the varicella zoster vaccine. The clinical presentation of stroke associated with infection is similar to stroke attributable to other causes, but the diagnostic approach is different. A review of the pathophysiology, diagnostic studies, and treatment of infectious causes of stroke in children and adolescents is presented.

Mycobacterium tuberculosis is one of the most common infectious agents in the world. It causes an insidious form of meningitis characterized by headache, low-grade fever, stiff neck and cranial nerve palsies, and an acute meningoencephalitis characterized by coma, raised intracranial pressure, seizures, and focal neurological deficits. This review focuses on the diagnosis and therapy of the insidious form of tuberculous meningitis and discusses the differential diagnosis of infectious and noninfectious etiologies of the aseptic meningitis syndrome.

Spinal epidural abscess (SEA) is an uncommon entity. We report an adolescent presenting with fever and back pain beginning 3 months after a leg abscess. This case highlights several important aspects of the diagnosis and care of patients with SEA. As illustrated by this case, plain radiographs and computed tomography of the spine can miss the diagnosis, thus when spinal epidural abscess is suspected, magnetic resonance imaging is the imaging modality of choice. Epidural abscesses most commonly arise from hematological dissemination, with Staphylococcus aureus being the most often cultured organism. Surgical intervention early combined with the administration of proper antibiotics leads to the best outcome.

Acute bacterial infections of the central nervous system include meningitis, brain abscess, subdural empyema, epidural abscess, and septic venous sinus thrombosis. The etiology, clinical presentation, diagnosis, and management of each of these infections are discussed, emphasizing recognition based on symptoms, signs, and predisposing conditions. Choosing the best available diagnostic studies and antimicrobial and adjunctive therapy minimizes possible neurologic complications.

Acute bacterial meningitis is a life-threatening infection. By definition, meningitis is an infection of the meninges and the subarachnoid space. Bacterial meningitis is associated with an inflammatory response that involves the meninges, the subarachnoid space, the brain parenchyma, and the cerebral arteries and veins. As such, bacterial meningoencephalitis is the more accurate descriptive term. This chapter discusses the epidemiology, etiology, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, complications, and prognosis of the disease. The discussion of diagnosis covers clinical manifestations, physical examination findings, laboratory tests, and imaging studies. The discussion of treatment covers empirical therapy, specific antimicrobial therapy, and dexamethasone therapy. Graphs compare causative organisms and clinical manifestations of community-acquired meningitis. Illustrations depict proper patient positioning for detecting nuchal rigidity, Kernig sign, Brudzinski sign, and lumbar puncture, as well as a sagittal view of a lumbar puncture needle as it is advanced into the subarachnoid space. An algorithm delineates the approach to the patient with symptoms and signs of bacterial meningitis. Tables outline bacterial pathogens based on predisposing and associated conditions, cerebrospinal fluid diagnostic studies for meningitis, the appearance of the organism on a Gram stain, empirical antimicrobial therapy based on predisposing and associated conditions, recommendations for specific antibiotic therapy in bacterial meningitis, and recommended doses for antibiotics commonly used in the treatment of bacterial meningitis. This chapter contains 8 figures, 13 tables, 78 references Keywords: Bacterial meningitis, antibiotics, Kernig sign, Brudzinski sign, nuchal rigidity, headache

Brain abscess is a focal, suppurative process within the brain parenchyma that begins in an area of cerebritis or devitalized brain tissue due to hypoxia, ischemia, or infarction and develops into a collection of pus surrounded by a well-vascularized capsule. A brain abscess may arise from a contiguous cranial infection, such as chronic otitis media or a frontoethmoidal sinusitis, or from hematogenous spread of infection from a remote site. The majority of brain abscesses that arise from a contiguous infection are solitary, whereas those that arise from hematogenous spread of infection tend to be multiple. Penetrating craniocerebral trauma or a neurosurgical procedure can also be the cause of a brain abscess. A brain abscess presents as an expanding intracranial mass lesion rather than as an infectious process. The most common symptom is headache, occurring in >75% of patients. Fever is present in only 50% of patients at presentation, but >60% have a focal neurological deficit. Seizures occur in 25–40% of patients. The diagnosis of a brain abscess is made by neuroimaging with magnetic resonance imaging (MRI) being more sensitive than computed tomography (CT). MRI is better able to demonstrate an abscess in the early cerebritis stage than CT. The specific etiological organism is identified by Gram's stain and the culture of brain abscess pus obtained by stereotactic CT-guided aspiration and drainage. A 6–8 week course of intravenous antimicrobial therapy is followed by a 2–3 month course of oral antimicrobial therapy.

Fungal brain abscess is a complication of immunosuppression and is rarely seen in immunocompetent patients, with the exception of Blastomyces dermatitidis . Infection with this fungus is primarily related to occupation, specifically soil-associated occupations such as mining. Cryptococcus neoformans, Histoplasma capsulatum , and Coccidioides immitis may cause brain abscess(es) in seemingly immunocompetent individuals. The fungi that cause brain abscesses, either solitary or multiple, in immunocompromised hosts are Aspergillus species, Candida species, and rare fungi. The Zygomycetes are a group of ubiquitous molds that cause fungal brain abscesses in immunocompetent diabetic patients with ketoacidosis and in diabetic transplant recipients receiving immunosuppressive therapy. In general, in immunocompromised patients, the risk of a fungal brain abscess increases when pulmonary colonization by a fungus occurs in the setting of retransplantation, hemodialysis, ventilator dependence, and/or multiple operations. Diagnosis of Aspergillus central nervous system (CNS) infection typically requires culture of brain abscess pus or culture of a surgical specimen from a brain biopsy. Aspergillus galactomannan is sensitive for invasive Aspergillus infections and should be sent as part of the routine diagnostic studies. 1,3-Beta- d -glucan is a sensitive diagnostic test for invasive fungal infections. Intracranial mass lesions in immunocompromised patients, detected on computed tomographic or magnetic resonance imaging scan, are less likely to show enhancement due to an inadequate inflammatory response than are similar lesions in nonimmunocompromised patients. Aspergillus brain abscess or abscesses require aggressive management. A combination of aspiration or excision with antifungal therapy is the standard of care. Voriconazole is the preferred antifungal agent. CNS Candida infections are treated with a combination of amphotericin B and flucytosine. Rhinocerebral mucormycosis requires aggressive surgical debridement of devitalized infected tissue in addition to amphotericin B therapy.

Encephalitis is an infectious or inflammatory disorder of the brain that presents with fever, headache, and an altered level of consciousness. There may also be focal or multifocal neurologic deficits, and focal or generalized seizure activity. Of the infectious etiologies, herpesviruses are the most common and some of the few treatable viral causative agents of encephalitis. The etiology, clinical presentation, diagnosis, and treatment of viral encephalitis is discussed in this chapter.

Encephalitis is an infectious or inflammatory disorder of the brain that presents with fever, headache, and an altered level of consciousness. There may also be focal or multifocal neurologic deficits, and focal or generalized seizure activity. Of the infectious etiologies, herpesviruses are the most common and some of the few treatable viral causative agents of encephalitis. The etiology, clinical presentation, diagnosis, and treatment of viral encephalitis is discussed in this chapter.

The inflammation in the subarachnoid space (SAS) that develops in the course of bacterial meningitis may have a role in eradicating the infection, but also, ultimately, is the cause of the neurological sequelae associated with this infection. The presence of an inflammatory exudate in the SAS leads to alterations in the blood-brain barrier, altered cerebrospinal fluid dynamics, cerebral edema and increased intracranial pressure, and loss of cerebral auto-regulation. Our increasing understanding of the pathophysiology of meningeal inflammation has led to therapeutic interventions to limit the degree of meningeal inflammation and neurologic sequelae. The inflammatory cascade that leads to alterations in central nervous system physiology will be reviewed as well as the experimental evidence and clinical trials demonstrating the efficacy of adjunctive therapy in reducing meningeal inflammation and decreasing the incidence and severity of neurological sequelae in bacterial meningitis.

Over the last several years, the therapeutic approach to bacterial meningitis has been changing. The neurological complications of bacterial meningitis result from an inflammatory process that is initiated by the lysis of bacteria in the subarachnoid space by antibiotics; to alter the pathophysiologic events initiated by this lysis, adjunctive therapy to antimicrobial therapy has been investigated in experimental and clinical trials. This article reviews our present understanding of bacterial meningitis, the efficacy of dexamethasone in treatment, and the potential use of leukocyte monoclonal antibodies, pentoxifylline, nonsteroidal antiinflammatory agents, and anticytokine antibodies.

Neurologists have a great deal of knowledge of the classic signs of central nervous system infectious diseases. After years of taking care of patients with infectious diseases, several symptoms, signs, and cerebrospinal fluid abnormalities have been identified that are helpful time and time again in determining the etiological agent. These lessons, learned at the bedside, are reviewed in this article.

Bacterial meningitis is a neurological emergency. Empiric antimicrobial and adjunctive therapy should be initiated as soon as a single set of blood cultures has been obtained. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, vomiting, photophobia, and an altered level of consciousness. The peripheral white blood cell count with a left shift, an elevated serum procalcitonin and C-reactive protein, and a cerebrospinal fluid pleocytosis with a predominance of polymorphonuclear leukocytes, and a decreased glucose concentration are predictive of bacterial meningitis. Patients with documented bacterial meningitis and those in whom the diagnosis is a strong possibility should be admitted to the intensive care unit. Timely recognition of bacterial meningitis and initiation of therapy are critical to outcome.