Utility of brain biopsy in patients with acquired immunodeficiency syndrome before and after introduction of highly active antiretroviral therapy

European society of Clinical Microbiology and Infectious Diseases guidelines on diagnosis and treatment of brain abscess in children and adults

SCOPE

These European Society of Clinical Microbiology and Infectious Diseases guidelines are intended for clinicians involved in diagnosis and treatment of brain abscess in children and adults.

METHODS

Key questions were developed, and a systematic review was carried out of all studies published since 1 January 1996, using the search terms 'brain abscess' OR 'cerebral abscess' as Mesh terms or text in electronic databases of PubMed, Embase, and the Cochrane registry. The search was updated on 29 September 2022. Exclusion criteria were a sample size <10 patients or publication in non-English language. Extracted data was summarized as narrative reviews and tables. Meta-analysis was carried out using a random effects model and heterogeneity was examined by I2 tests as well as funnel and Galbraith plots. Risk of bias was assessed using Risk Of Bias in Non-randomised Studies - of Interventions (ROBINS-I) (observational studies) and Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) (diagnostic studies). The Grading of Recommendations Assessment, Development and Evaluation approach was applied to classify strength of recommendations (strong or conditional) and quality of evidence (high, moderate, low, or very low).

QUESTIONS ADDRESSED BY THE GUIDELINES AND RECOMMENDATIONS

Magnetic resonance imaging is recommended for diagnosis of brain abscess (strong and high). Antimicrobials may be withheld until aspiration or excision of brain abscess in patients without severe disease if neurosurgery can be carried out within reasonable time, preferably within 24 hours (conditional and low). Molecular-based diagnostics are recommended, if available, in patients with negative cultures (conditional and moderate). Aspiration or excision of brain abscess is recommended whenever feasible, except for cases with toxoplasmosis (strong and low). Recommended empirical antimicrobial treatment for community-acquired brain abscess in immuno-competent individuals is a 3rd-generation cephalosporin and metronidazole (strong and moderate) with the addition of trimethoprim-sulfamethoxazole and voriconazole in patients with severe immuno-compromise (conditional and low). Recommended empirical treatment of post-neurosurgical brain abscess is a carbapenem combined with vancomycin or linezolid (conditional and low). The recommended duration of antimicrobial treatment is 6-8 weeks (conditional and low). No recommendation is offered for early transition to oral antimicrobials because of a lack of data, and oral consolidation treatment after ≥6 weeks of intravenous antimicrobials is not routinely recommended (conditional and very low). Adjunctive glucocorticoid treatment is recommended for treatment of severe symptoms because of perifocal oedema or impending herniation (strong and low). Primary prophylaxis with antiepileptics is not recommended (conditional and very low). Research needs are addressed.

Evolution of gamma knife capsulotomy for intractable obsessive-compulsive disorder

For more than half a century, stereotactic neurosurgical procedures have been available to treat patients with severe, debilitating symptoms of obsessive-compulsive disorder (OCD) that have proven refractory to extensive, appropriate pharmacological, and psychological treatment. Although reliable predictors of outcome remain elusive, the establishment of narrower selection criteria for neurosurgical candidacy, together with a better understanding of the functional neuroanatomy implicated in OCD, has resulted in improved clinical efficacy for an array of ablative and non-ablative intervention techniques targeting the cingulum, internal capsule, and other limbic regions. It was against this backdrop that gamma knife capsulotomy (GKC) for OCD was developed. In this paper, we review the history of this stereotactic radiosurgical procedure, from its inception to recent advances. We perform a systematic review of the existing literature and also provide a narrative account of the evolution of the procedure, detailing how the procedure has changed over time, and has been shaped by forces of evidence and innovation. As the procedure has evolved and adverse events have decreased considerably, favorable response rates have remained attainable for approximately one-half to two-thirds of individuals treated at experienced centers. A reduction in obsessive-compulsive symptom severity may result not only from direct modulation of OCD neural pathways but also from enhanced efficacy of pharmacological and psychological therapies working in a synergistic fashion with GKC. Possible complications include frontal lobe edema and even the rare formation of delayed radionecrotic cysts. These adverse events have become much less common with new radiation dose and targeting strategies. Detailed neuropsychological assessments from recent studies suggest that cognitive function is not impaired, and in some domains may even improve following treatment. We conclude this review with discussions covering topics essential for further progress of this therapy, including suggestions for future trial design given the unique features of GKC therapy, considerations for optimizing stereotactic targeting and dose planning using biophysical models, and the use of advanced imaging techniques to understand circuitry and predict response. GKC, and in particular its modern variant, gamma ventral capsulotomy, continues to be a reliable treatment option for selected cases of otherwise highly refractory OCD.

HIV-Related Cerebral Toxoplasmosis Revisited: Current Concepts and Controversies of an Old Disease

Cerebral toxoplasmosis is the most common cause of expansive brain lesions in people living with HIV/AIDS (PLWHA) and continues to cause high morbidity and mortality. The most frequent characteristics are focal subacute neurological deficits and ring-enhancing brain lesions in the basal ganglia, but the spectrum of clinical and neuroradiological manifestations is broad. Early initiation of antitoxoplasma therapy is an important feature of the diagnostic approach of expansive brain lesions in PLWHA. Pyrimethamine-based regimens and trimethoprim-sulfamethoxazole (TMP-SMX) seem to present similar efficacy, but TMP-SMX shows potential practical advantages. The immune reconstitution inflammatory syndrome is uncommon in cerebral toxoplasmosis, and we now have more effective, safe, and friendly combined antiretroviral therapy (cART) options. As a consequence of these 2 variables, the initiation of cART can be performed within 2 weeks after initiation of antitoxoplasma therapy. Herein, we will review historical and current concepts of epidemiology, diagnosis, and treatment of HIV-related cerebral toxoplasmosis.

Equivalence of cell survival data for radiation dose and thermal dose in ablative treatments: analysis applied to essential tremor thalamotomy by focused ultrasound and gamma knife

Thermal dose and absorbed radiation dose have historically been difficult to compare because different biological mechanisms are at work. Thermal dose denatures proteins and the radiation dose causes DNA damage in order to achieve ablation. The purpose of this paper is to use the proportion of cell survival as a potential common unit by which to measure the biological effect of each procedure. Survival curves for both thermal and radiation doses have been extracted from previously published data for three different cell types. Fits of these curves were used to convert both thermal and radiation dose into the same quantified biological effect: fraction of surviving cells. They have also been used to generate and compare survival profiles from the only indication for which clinical data are available for both focused ultrasound (FUS) thermal ablation and radiation ablation: essential tremor thalamotomy. All cell types could be fitted with coefficients of determination greater than 0.992. As an illustration, survival profiles of clinical thalamotomies performed by radiosurgery and FUS are plotted on a same graph for the same metric: fraction of surviving cells. FUS and Gamma Knife have the potential to be used in combination to deliver a more effective treatment (for example, FUS may be used to debulk the main tumour mass, and radiation to treat the surrounding tumour bed). In this case, a model which compares thermal and radiation treatments is valuable in order to adjust the dose between the two.

Diagnostic Value and Safety of Stereotactic Biopsy in Acquired Immune Deficiency Syndrome Patients with Intracranial Lesions: Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the diagnostic value and safety of stereotactic biopsy in acquired immune deficiency syndrome (AIDS) patients with intracranial lesions via meta-analysis.

METHODS

Relevant cohort studies were identified through a literature search in PubMed, Embase, and Ovid from 1985 to October 1, 2016. Appropriate studies were identified per search criteria. Systematic review and meta-analysis were used to assess the diagnostic success rate, changed management rate, clinical improvement rate, mortality rate, morbidity rate, hemorrhage rate, hemorrhage in morbidity rate, and final histologic diagnosis results. Study-specific outcomes were combined per a random effects model. Outcomes were compared between the pre-highly active antiretroviral therapy (HAART) and post-HAART groups. Correlations between outcomes were assessed via meta-regression analysis.

RESULTS

A total of 19 cohort studies with 820 patients were included in this meta-analysis. The weighted proportions per the random effects model were 92.2% (95% confidence interval [CI; 89.3%-94.5%]) for diagnostic success rate, 5.1% (95% CI [2.5%-8.3%]) for morbidity, and 0.7% (95% CI [0%-1.9%]) for mortality. The most common procedure-related morbidity was hemorrhage at 3.3% (95% CI [1.1%-6.3%]). Hemorrhage in morbidity was 78.0% (95% CI [51.4%-97.4%]). Management changed and clinical improvement were 60.4% (95% CI [49.4%-71.0%]) and 34.0% (95% CI [22.2%-46.8%]), respectively. The 4 most common diagnoses were primary central nervous system lymphoma (27.8%; 95% CI [20.2%-36.1%]), progressive multifocal leukoencephalopathy (PML) (21.0%; 95% CI [14.3%-28.4%]), toxoplasma encephalitis (TE) (20.3%; 95% CI [14.3%-27.0%]), and human immunodeficiency virus (HIV) encephalitis (4.1%; 95% CI [1.4%-7.6%]). Multiple diagnoses rate was 1.2% (95% CI [0.0%-3.6%]). HIV encephalitis rate was significantly higher in the post-HAART group than the pre-HAART group (17.9% vs. 3.2%, respectively; P = 0.0024).

CONCLUSIONS

Stereotactic biopsy is a safe and effective way of diagnosing intracranial lesions in patients with AIDS. It is helpful for the differential diagnosis and for choosing a suitable therapy. The 4 most common intracranial lesions in patients with AIDS are lymphoma, PML, TE, and HIV encephalitis.

Application of stereotactic biopsy for diagnosing intracranial lesions in patients with AIDS in China: Report of 7 cases

RATIONALE

The aim of the study was to evaluate stereotactic biopsy for diagnosing intracranial lesions in patients with AIDS.

PATIENT CONCERNS

Seven AIDS patients with an intracranial lesion who underwent stereotactic biopsy were included in this retrospective study (4 males and 3 females, 15 to 49 years old). The patients' disease history ranged from 1 month to 1 year. The samples were examined by hematoxylin-eosin (HE) staining and immunohistochemical examination.

DIAGNOSES, INTERVENTIONS AND OUTCOMES

All patients were successfully sampled, and the histological results showed inflammation in 4 cases, toxoplasma gondii infection in 1 case, astrocytoma in 1 case, and abscess in 1 case. The clinical diagnosis included toxoplasma encephalitis (TE) in 2 cases, cryptococcus encephalitis in 2 cases, cytomegalovirus (CMV) encephalitis in 2 case, tubercular abscess in 1 case, astrocytoma in 1 case, and co-infection of TE with Cryptococcus infection in 1 patient. The clinical diagnosis was made according to the plasma and cerebrospinal fluid (CSF) laboratory testing, the imaging data and the histological findings. The diagnostic yield was 100%, and the post-operation morbidity was 14.3% (1/7) with an asymptomatic haemorrhage and seizure in 1 case. There was no operation-related mortality. Patients were followed up for 6 months to 6 years; 1 case fully recovered, 4 cases significantly improved in symptoms, and 2 died.

LESSONS

Stereotactic biopsy is a safe and effective way of diagnosing intracranial lesions in patient with AIDS. It is helpful for the differential diagnosis and for choosing a suitable therapy. Due to the broad spectrum of nervous system abnormalities in AIDS, histological findings are very valuable. However, histology is not a unique tool for making a definite diagnosis, whereas the combination of molecular pathology and stereotactic biopsy should play a more important role in the future.

Safety and diagnostic value of brain biopsy in HIV patients: a case series and meta-analysis of 1209 patients

Early brain biopsy may be indicated in HIV patients with focal brain lesion. This study aimed to evaluate and compare the safety and diagnostic value of brain biopsy in HIV patients in the pre-highly active antiretroviral therapy (HAART) versus post-HAART era via meta-analysis. Appropriate studies were identified per search criteria. The local database was retrospectively reviewed to select a similar patient cohort. Patient demographics, brain biopsy technique, histopathology and patient outcomes were extracted from each study. Study-specific outcomes were combined per random-effects model. Outcomes were compared between the pre-HAART and post-HAART era. Correlations between outcomes and baseline characteristics were assessed via meta-regression analysis. The proportions of histopathological diagnosis were tabulated and compared between the pre- and post-HAART era. Survival analysis was performed for patients in the post-HAART era. A total of 26 studies (including the local database) with 1209 patients were included in this meta-analysis. The most common indications for brain biopsy were diagnosis unlikely to be toxoplasmosis (n=8, 42.1%), focal brain lesion (n=5, 26.3%) or both (n=3, 15.8%). The weighted proportions for diagnostic success were 92% (95% CI 90.0% to 93.8%), change in management 57.7% (45.9% to 69.1%) and clinical improvement 36.6% (26.3% to 47.5%). Morbidity and mortality were 5.7% (3.6% to 8.3%) and 0.9% (0.3% to 1.9%), respectively. Diagnostic success rate was significantly higher in the post-HAART than the pre-HAART era (97.5% vs 91.9%, p=0.047). The odds ratio (OR) for diagnostic success in patients with contrast-enhanced lesions was 2.54 ((1.25 to 5.15), p<0.01). The median survival for HIV patients who underwent biopsy in the post-HAART era was 225 days (90-2446). Brain biopsy in HIV patients is safe with high diagnostic yield. Early brain biopsy should be considered in patients without classic presentation of toxoplasmosis encephalitis.

Technical Note: Dose gradients and prescription isodose in orthovoltage stereotactic radiosurgery

PURPOSE

The purpose of this work is to examine the trade-off between prescription isodose and dose gradients in orthovoltage stereotactic radiosurgery.

METHODS

Point energy deposition kernels (EDKs) describing photon and electron transport were calculated using Monte Carlo methods. EDKs were generated from 10  to 250 keV, in 10 keV increments. The EDKs were converted to pencil beam kernels and used to calculate dose profiles through isocenter from a 4π isotropic delivery from all angles of circularly collimated beams. Monoenergetic beams and an orthovoltage polyenergetic spectrum were analyzed. The dose gradient index (DGI) is the ratio of the 50% prescription isodose volume to the 100% prescription isodose volume and represents a metric by which dose gradients in stereotactic radiosurgery (SRS) may be evaluated.

RESULTS

Using the 4π dose profiles calculated using pencil beam kernels, the relationship between DGI and prescription isodose was examined for circular cones ranging from 4 to 18 mm in diameter and monoenergetic photon beams with energies ranging from 20 to 250 keV. Values were found to exist for prescription isodose that optimize DGI.

CONCLUSIONS

The relationship between DGI and prescription isodose was found to be dependent on both field size and energy. Examining this trade-off is an important consideration for designing optimal SRS systems.

Central nervous system EBV lymphoproliferative disorder in a patient with rhabdomyosarcoma

Epstein-Barr virus associated lymphoproliferative disorder (EBV-LPD) occurs in patients with immunodeficiency, but it has not been well described in patients who have received chemotherapy for solid tumors. We describe a child with rhabdomyosarcoma who developed isolated central nervous system (CNS) EBV-LPD during combination chemotherapy with vincristine, actinomycin D and cyclophosphamide. The patient was treated with high-dose methotrexate (HD-MTX) for CNS EBV-LPD and then treated with rituximab in addition to HD-MTX because of the emergence of LPD in the liver. I.v. rituximab combined with HD-MTX might be effective therapy for CNS EBV-LPD.

Neurosurgery and human immunodeficiency virus in the era of combination antiretroviral therapy: a review

Human immunodeficiency virus (HIV) is a global health problem. It renders the central nervous system susceptible to infectious and noninfectious diseases. HIV-positive individuals may present to neurosurgical services with brain lesions of unknown etiology. The differential diagnosis in these cases is broad, including opportunistic infections and malignancies, and investigation should be tailored accordingly. Opportunistic infections of the central nervous system can be complicated by hydrocephalus, and the management is pathogen dependent. Patients may also present to a neurosurgical service with conditions unrelated to their HIV status. This review outlines important conditions that cause brain lesions and hydrocephalus. It addresses the issues of diagnosis and intervention in HIV-positive patients in the era of combination antiretroviral therapy, while not ignoring the potential for opportunistic central nervous system infection in undiagnosed patients. The care of HIV-positive patients presenting to neurosurgical services requires a multidisciplinary approach, which is reflected in the authorship of this review, as well as in the guidance given.

Brain biopsy in AIDS patients: diagnostic yield and treatment applications

Objective

Central nervous system involvement in AIDS patients can present at any stage of the disease. Brain lesions detected in imaging studies are usually treated empirically. A brain biopsy is indicated in the absence of clinical and radiologic improvement. In the present study, 16 AIDS patients underwent brain biopsy. We evaluated the diagnostic yield of the brain biopsy and the changes in the disease course.

Materials and methods

Sixteen consecutive AIDS patients (12 men, 4 women; mean age 40.8 years) underwent a brain biopsy at Sheba Medical Center between 1997 and 2009. A retrospective analysis was performed and the clinical outcome was recorded.

Results

Median CD4 count before biopsy was 62.6. Magnetic resonance images revealed multiple lesions in 12 patients and enhancing lesions in 12 patients. A total of 19 biopsies were performed in 16 patients. In the present series, the initial procedures provided a diagnostic yield of 81.25% (13 diagnostic cases from 16 procedures in 16 patients). Two of these patients underwent repeated biopsies that were eventually diagnostic . If repeated biopsies were taken into consideration, the diagnostic yield was 93.75% (15 diagnostic cases in 16 patients). The rate of hemorrhagic complications was 10.5% (2 hemorrhages in 19 procedures).

Pathologic examination revealed parasitic and fungal infections in 6 patients (6/16; 38%), progressive multifocal leukoencephalopathy in 4 patients (4/16; 25%), AIDS encephalopathy in 4 patients (4/16; 25%), and lymphoma in 1 patient (1/16; 6%). One patient had a nonspecific inflammatory process (6%). The treatment modality was modified in 12 patients and led to clinical and radiologic improvement in 8 patients.

Conclusions

Brain biopsy should be considered when empiric treatment of central nervous system lesions in AIDS patients fails. Biopsy is diagnostic in the majority of patients. The diagnosis allows for treatment modifications, which lead to clinical and radiologic improvement in some patients.

Ring enhancing intracranial lesion responding to antituberculous treatment in an HIV-infected patient

Cerebral tuberculomas constitute a major differential diagnosis of cerebral toxoplasmosis in human immunodeficiency virus (HIV)-infected patients in developing countries. We report the case of a 34-year old woman co-infected with HIV and possible disseminated tuberculosis (hepatitis, lymphadenopathy, and pleural effusion) who presented a large and solitary intracranial mass lesion. Despite extensive diagnostic efforts, including brain, ganglionar, and liver biopsies, no definitive diagnosis was reached. However, a trial with first-line antituberculous drugs led to a significant clinical and radiological improvement. Atypical presentations of cerebral tuberculomas should always be considered in the differential diagnosis of intracranial mass lesions in HIV-infected patients and a trial with antituberculous drugs is a valuable strategy to infer the diagnosis in a subset of patients.

Primary central nervous system post-transplantation lymphoproliferative disorder: an International Primary Central Nervous System Lymphoma Collaborative Group Report

BACKGROUND

Primary central nervous system (CNS) post-transplantation lymphoproliferative disorder (PCNS-PTLD) is a rare complication of solid organ transplantation. The objectives of this study were to define the clinical, radiologic, and pathologic features of this disease and to explore the impact of treatment on patient outcomes.

METHODS

The authors reviewed the databases of participating institutions of the International Primary CNS Lymphoma Collaborative Group for cases of PCNS-PTLD. Thirty-four patients who had pathologically confirmed PCNS-PTLD without evidence of systemic PTLD were investigated retrospectively.

RESULTS

The median time from transplantation to diagnosis of PCNS-PTLD was 4.4 years. Disease usually was multifocal and involved any location of the brain but was most common in the cerebral hemispheres, usually in the subcortical white matter or basal ganglia. Radiographically, all lesions enhanced either homogenously or in a ring-enhancing pattern. Cerebral biopsy was required to establish diagnosis in most patients. Most patients had monomorphic, Epstein-Barr virus (EBV)-positive disease of B-cell origin. Response rates were high regardless of treatment type, and the median survival was 47 months. Age was the only factor predictive of survival.

CONCLUSIONS

The current study demonstrated that PCNS-PTLD is typically an EBV-induced B-cell lymphoma that is responsive to treatment with favorable survival in many patients. An aggressive approach to tissue confirmation of diagnosis and treatment with chemotherapy or radiotherapy should be strongly considered.

Solitary ring enhancing brain lesion in a patient with AIDS

Toxoplasmosis in immune competent patients usually causes asymptomatic infection or mild symptoms, while in immunocompromised and AIDS patients it can be a life threatening condition. We report a case of cerebral toxoplasmosis in a patient with AIDS and review the causes of brain ring enhancing lesions.

THE SURGICAL MANAGEMENT OF INFECTIONS INVOLVING THE CEREBRUM

OBJECTIVE

Infection involving the cerebrum is a true neurosurgical emergency that requires rapid diagnosis and appropriate surgical and medical intervention to achieve good clinical outcome.

METHODS

Because of the potential for devastating neurological sequelae, it is imperative that neurosurgeons be involved in the diagnosis and management of these serious conditions once an infection is suspected. With the advent of computed tomography and magnetic resonance imaging, it is now possible to detect an infectious process early in its course and follow the response to therapy. Although significantly more effective than in the past, antimicrobial therapy alone is insufficient to eradicate most intracranial infections, especially in the presence of compression or displacement of the cerebrum. Surgery remains an essential part of the management of intracranial infection because of its ability to provide immediate relief from pressure on neural structures and thereby result in clinical improvement.

RESULTS

The most common infections affecting the brain, namely, cranial epidural abscess, subdural empyema, brain abscess, viral infection, tuberculosis, and neurocysticercosis, can each be associated with significant mass effect on the cerebrum that is greatly reduced through surgery. This relief, in combination with newer antimicrobial agents that have an improved ability to cross the blood brain barrier, has led to a reduction in the infection-related morbidity and mortality rates associated with intracranial infections.

CONCLUSION

Combining advanced imaging and surgical techniques in the form of intraoperative magnetic resonance image-guided neurosurgery may further enhance clinical outcomes in these once uniformly fatal diseases.