Review

Authors: Julia C Haston, Jennifer R Cope

PURPOSE OF REVIEW

Free-living amebae (FLA) including Naegleria fowleri , Balamuthia mandrillaris , and Acanthamoeba species can cause rare, yet severe infections that are nearly always fatal. This review describes recent developments in epidemiology, diagnosis, and treatment of amebic meningoencephalitis.

RECENT FINDINGS

Despite similarities among the three pathogenic FLA, there are notable variations in disease presentations, routes of transmission, populations at risk, and outcomes for each. Recently, molecular diagnostic tools have been used to diagnose a greater number of FLA infections. Treatment regimens for FLA have historically relied on survivor reports; more data is needed about novel treatments, including nitroxoline.

SUMMARY

Research to identify new drugs and guide treatment regimens for amebic meningoencephalitis is lacking. However, improved diagnostic capabilities may lead to earlier diagnoses, allowing earlier treatment initiation and improved outcomes. Public health practitioners should continue to prioritize increasing awareness and providing education to clinicians, laboratorians, and the public about amebic infections.

Topics: Humans; Central Nervous System Protozoal Infections; Amebiasis; Meningoencephalitis; Acanthamoeba; Infectious Encephalitis

PubMed: 37093056
DOI: 10.1097/QCO.0000000000000923

Review

Authors: Kevin Messacar, Marc Fischer, Samuel R Dominguez...

Encephalitis is an uncommon but severe disease characterized by neurologic dysfunction with central nervous system inflammation. Children with encephalitis should receive supportive care and empiric therapies for common and treatable causes while prioritizing diagnostic evaluation for common, treatable, and high-risk conditions. Even with an extensive diagnostic workup, an infectious cause is identified in less than half of cases, suggesting a role for postinfectious or noninfectious processes.

Topics: Arboviruses; Brain; Child; Diagnosis, Differential; Encephalitis; Enterovirus; Female; Herpes Simplex; Humans; Male; Meningoencephalitis; Myelitis; United States

PubMed: 29224854
DOI: 10.1016/j.idc.2017.10.007

Review

Authors: I Cornelis, L Van Ham, I Gielen...

Meningoencephalomyelitis of unknown origin (MUO) encompasses a group of idiopathic, most likely immune mediated, inflammatory central nervous system diseases that cause clinical, diagnostic and treatment challenges to veterinary neurologists. Clinical criteria for obtaining this presumptive diagnosis are currently available, and multiple treatment protocols have previously been investigated in small (prospective or retrospective) case series. As this group of diseases is considered fatal if left untreated, the identification of clinically usable prognostic indices could be of great value. This review provides an overview of recent developments in the clinical presentation, diagnostic findings, possible prognostic factors, treatment and outcome in dogs diagnosed with MUO.

Topics: Animals; Cyclosporine; Cytarabine; Dog Diseases; Dogs; Immunosuppressive Agents; Magnetic Resonance Imaging; Meningoencephalitis; Prednisolone; Prognosis; Treatment Outcome

PubMed: 30825893
DOI: 10.1016/j.tvjl.2018.12.007

Authors: M Schibler, M C Zanella, L Kaiser...

Topics: Autoimmune Diseases of the Nervous System; Central Nervous System; Clinical Laboratory Techniques; Diagnosis, Differential; Encephalitis; Humans; Meningoencephalitis

PubMed: 30703529
DOI: 10.1016/j.cmi.2019.01.013

Review

Authors: Nicholas Caffes, Katherine Hendricks, John S Bradley...

The neurological sequelae of Bacillus anthracis infection include a rapidly progressive fulminant meningoencephalitis frequently associated with intracranial hemorrhage, including subarachnoid and intracerebral hemorrhage. Higher mortality than other forms of bacterial meningitis suggests that antimicrobials and cardiopulmonary support alone may be insufficient and that strategies targeting the hemorrhage might improve outcomes. In this review, we describe the toxic role of intracranial hemorrhage in anthrax meningoencephalitis. We first examine the high incidence of intracranial hemorrhage in patients with anthrax meningoencephalitis. We then review common diseases that present with intracranial hemorrhage, including aneurysmal subarachnoid hemorrhage and spontaneous intracerebral hemorrhage, postulating applicability of established and potential neurointensive treatments to the multimodal management of hemorrhagic anthrax meningoencephalitis. Finally, we examine the therapeutic potential of minocycline, an antimicrobial that is effective against B. anthracis and that has been shown in preclinical studies to have neuroprotective properties, which thus might be repurposed for this historically fatal disease.

Topics: Anthrax; Bacillus anthracis; Cerebral Hemorrhage; Humans; Meningoencephalitis; Minocycline

PubMed: 36251558
DOI: 10.1093/cid/ciac521

Authors: Abhijeet Taori, Divya Malpani

Topics: Humans; Bacillus cereus; Meningoencephalitis

PubMed: 37635561
DOI: 10.4103/0028-3886.383861

Review

Authors: Patrick J Gavin, Kevin R Kazacos, Stanford T Shulman...

The raccoon roundworm, Baylisascaris procyonis, is the most common and widespread cause of clinical larva migrans in animals. In addition, it is increasingly recognized as a cause of devastating or fatal neural larva migrans in infants and young children and ocular larva migrans in adults. Humans become infected by accidentally ingesting infective B. procyonis eggs from raccoon latrines or articles contaminated with their feces. Two features distinguish B. procyonis from other helminthes that cause larva migrans: (i) its aggressive somatic migration and invasion of the central nervous system and (ii) the continued growth of larvae to a large size within the central nervous system. Typically, B. procyonis neural larva migrans presents as acute fulminant eosinophilic meningoencephalitis. Once invasion of the central nervous system has occurred, the prognosis is grave with or without treatment. To date, despite anthelmintic treatment of cases of B. procyonis neural larva migrans, there are no documented neurologically intact survivors. Epidemiologic study of human cases of neural larva migrans demonstrate that contact with raccoon feces or an environment contaminated by infective eggs and geophagia or pica are the most important risk factors for infection. In many regions of the United States, increasingly large populations of raccoons, with high rates of B. procyonis infection, live in close proximity to humans. Although documented cases of human baylisascariasis remain relatively uncommon, widespread contamination of the domestic environment by infected raccoons suggests that the risk of exposure and human infection is probably substantial. In the absence of early diagnosis or effective treatment, prevention of infection is the most important public health measure.

Topics: Animals; Ascaridida Infections; Ascaridoidea; Eye Diseases; Humans; Larva Migrans; Meningoencephalitis; Raccoons

PubMed: 16223954
DOI: 10.1128/CMR.18.4.703-718.2005

Authors: Rita Gonçalves, Steven De Decker, Gemma Walmsley...

BACKGROUND

Meningoencephalitis of unknown origin (MUO) comprises a group of noninfectious inflammatory diseases affecting the central nervous system of dogs. Previous studies have reported individual risk factors for survival but prognostication for MUO remains challenging.

OBJECTIVES

Identify clinical prognostic variables in dogs with MUO.

ANIMALS

A retrospective study of 447 dogs presented to 2 UK referral hospitals and diagnosed with MUO.

METHODS

Medical records of dogs diagnosed with MUO were retrospectively reviewed. Multivariable logistic regression was used for the identification of risk factors for survival and Cox proportional hazards analysis for the identification of risk factors for clinical relapse.

RESULTS

Eighty-two percent (366/447) of dogs with presumptive MUO survived to discharge and 63.5% (284/447) were alive at 6 months; 36% of the latter (103/284) had persistent neurological deficits. Breed (pugs; P = .03), epileptic seizures (P < .001), paresis (P < .001), and higher neurodisability scale (NDS) score (P < .001) at presentation were negatively associated with survival to 6 months. Dogs with persistent deficits had higher NDS scores on presentation (P = .001). Median follow-up time was 11 months (interquartile range [IQR], 1-24) and 50.6% (160/316) relapsed during treatment (median time to relapse, 7 months; IQR, 2-15). Incomplete resolution of the clinical signs during the 6 months after diagnosis (P < .001), higher NDS score (P < .001), and longer duration of the clinical signs (P < .001) were associated with relapse.

CONCLUSIONS AND CLINICAL IMPORTANCE

Knowledge of risk factors associated with survival, incomplete recovery and clinical relapse in MUO can help guide monitoring and treatment and improve owner communications regarding prognosis for this debilitating disease.

Topics: Animals; Dogs; Dog Diseases; Meningoencephalitis; Risk Factors; Retrospective Studies; Male; Female; Recurrence; Prognosis; Survival Analysis

PubMed: 38483069
DOI: 10.1111/jvim.17037

Authors: Cristiane Nascimento Soares, Abraão Iuri Medeiros Angelim, Carlos Otavio Brandão...

Neurobrucellosis is caused by bacteria of the genus Brucella and is responsible for several clinical manifestations, making diagnosis challenging. The most common route of infection is through the consumption of unpasteurized or raw dairy products such as fresh milk, butter, and cheese. As neurological complications can develop chronically, they are frequently misdiagnosed as other infections, such as tuberculosis. This report reviews the clinical manifestations, diagnostic approach, treatment, and prognosis of neurobrucellosis, illustrating a case of chronic intracranial hypertension and meningoencephalitis secondary to brucellosis. The clinical presentation of brucellosis can mimic several systemic diseases, resulting in diagnostic delays and clinical complications. A high degree of suspicion is required, and neurobrucellosis should always be considered in the differential diagnosis of chronic meningitis.

Topics: Brucella; Brucellosis; Diagnosis, Differential; Humans; Meningoencephalitis; Nervous System Diseases

PubMed: 35416876
DOI: 10.1590/0037-8682-0567-2021

Review

Authors: A Kenfak, G Eperon, M Schibler...

BACKGROUND

Encephalitis and meningoencephalitis are severe, sometime life-threatening infections of the central nervous system. Travellers may be exposed to a variety of neurotropic pathogens.

AIMS

We propose to review known infectious causes of encephalitis in adults acquired outside Europe, and how to identify them.

SOURCES

We used Pubmed and Embase, to search the most relevant publications over the last years.

CONTENT

Microbiologic tests and radiological tools to best identify the causative pathogen in travellers presenting with encephalitis and ME are presented in this narrative review, as well as a diagnostic approach tailored to the visited area and types of exposures.

IMPLICATIONS

This review highlights the diagnostic difficulties inherent to exotic causes of central nervous system infections, and attempts to guide clinicians with respect to which microbiological tests to consider, in addition to brain MRI, when approaching a returning traveller presenting with encephalitis.

Topics: Adult; Animals; Bacteria; Brain; Europe; Fungi; Humans; Magnetic Resonance Imaging; Meningoencephalitis; Parasites; Parenchymal Tissue; Travel; Travel-Related Illness; Viruses

PubMed: 30708123
DOI: 10.1016/j.cmi.2019.01.008