Stereotactic biopsy of cerebral lesions in AIDS

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Two for the Price of One: A Case of Methicillin-Resistant Staphylococcus aureus (MRSA) Brain Abscess With Atypical Lymphoplasmacytic Infiltrate With Underlying Clonal Lymphoproliferative Process in a Patient Infected With HIV

Multiple etiologies can coexist and trigger CNS symptoms in individuals infected with HIV. This article reviews a case of a cerebellar mass in an HIV patient who, on biopsy, grew methicillin-resistant Staphylococcus aureus (MRSA) and by pathology, showed an atypical lymphoplasmacytic infiltrate concerning a clonal lymphoproliferative process, which may be a precursor of CNS lymphoma. The patient, a 36-year-old male with multiple comorbidities including HIV Infection, presented to the hospital for evaluation of a one-week course of headache and photophobia. Remarkable physical examination findings included dilated pupils and anisocoria. Initial CT brain imaging revealed vasogenic edema seen throughout the left cerebellar hemisphere provoking mass effect on the fourth ventricle and pontocerebellar cistern resulting in mild hydrocephalus, new findings compared to prior. MRI brain displayed a T1 isointense, T2 hypointense ring-enhancing lesion in the left cerebellar hemisphere, with restricted diffusion, and surrounding vasogenic edema resulting in mass effect over the fourth ventricle, left cerebellar peduncle, and pontocerebellar cistern causing mild hydrocephalus. The patient underwent left suboccipital craniotomy with evacuation of the cerebellar lesion by neurosurgery. Tissue cultures grew MRSA. Pathology was sent to New York-Presbyterian Columbia University Irving Medical Center due to the presence of atypical lymphoplasmacytic infiltrates. The final diagnosis was polyclonal B-cell population in the sample; however, prominent peaks were also seen above the polyclonal background, possibly representing a clonal proliferation. Therefore, the lymphoplasmacytic infiltrates remained atypical and the possibility of the underlying clonal lymphoproliferative process could not be entirely ruled out.

MRI imaging features of HIV-related central nervous system diseases: diagnosis by pattern recognition in daily practice

With the advent of antiretroviral therapy (ART), the prognosis of people infected with human immunodeficiency virus (HIV) has improved, and the frequency of HIV-related central nervous system (CNS) diseases has decreased. Nevertheless, mortality from HIV-related CNS diseases, including those associated with ART (e.g., immune reconstitution inflammatory syndrome) remains significant. Magnetic resonance imaging (MRI) can improve the outlook for people with HIV through early diagnosis and prompt treatment. For example, HIV encephalopathy shows a diffuse bilateral pattern, whereas progressive multifocal leukoencephalopathy, HIV-related primary CNS lymphoma, and CNS toxoplasmosis show focal patterns on MRI. Among the other diseases caused by opportunistic infections, CNS cryptococcosis and CNS tuberculosis have extremely poor prognoses unless diagnosed early. Immune reconstitution inflammatory syndrome shows distinct MRI findings from the offending opportunistic infections. Although distinguishing between HIV-related CNS diseases based on imaging alone is difficult, in this review, we discuss how pattern recognition approaches can contribute to their early differentiation.

Intracranial Mass Lesions in Human Immunodeficiency Virus Patients in the Philippines: A Retrospective Cohort Study

BACKGROUND

Central nervous system involvement is commonly seen in patients with human immunodeficiency virus (HIV) infection, with up to 2%-10% of patients presenting with intracranial mass lesions. The management of these lesions depends largely on their etiology and their relative frequency in the local population.

METHODS

We performed a retrospective chart review of patients with HIV and evidence of intracranial mass lesions on cranial magnetic resonance imaging or computed tomography from 2007 to 2018. Demographic data, clinical features, etiology, surgical management, and outcomes were collected.

RESULTS

The prevalence of intracranial mass lesions in our cohort was 2.2% (45/2032). Patients were predominantly male (98%), with a mean age at diagnosis of 28 years. The most common clinical manifestations were headache (75%), focal weakness (49%), and seizures (32%). The most common diagnoses were toxoplasmic encephalitis (51%) and tuberculosis (24%). Biopsy or excision was performed in 10% of cases, leading to a definitive diagnosis in 60% of these cases. A favorable outcome was observed in 58% of all patients at 46 months median follow-up, with adequate disease-specific treatment.

CONCLUSIONS

The prevalence of intracranial mass lesions in Filipino patients with HIV is 2.2%. The most common etiology was toxoplasmic encephalitis followed by tuberculosis. These findings are substantially different from other findings reported in the literature and should be considered in formulating guidelines for the Filipino population.

AIDS-related Cryptococcus neoformans choroiditis

We describe a case of Cryptococcal choroiditis in a person with advanced HIV/AIDS. A 29-year-old male with AIDS presented with fever, photophobia, and ataxia secondary to cryptococcal and toxoplasma meningoencephalitis. Dilated fundoscopic examination revealed bilateral and multifocal posterior infiltrates consistent with cryptococcal choroiditis. Treatment with parenteral and intravitreal liposomal amphotericin B, oral flucytosine, and oral trimethoprim-sulfamethoxazole led to resolution of his symptoms and improvement in his vision. Our case documents a rare, intraocular opportunistic infection and highlights the importance of ophthalmologic examination in immunocompromised hosts with visual symptoms and invasive fungal infection. We discuss diagnostic and treatment considerations in cryptococcal choroiditis.

Indian Antimicrobial Prescription Guidelines in Critically Ill Immunocompromised Patients

How to cite this article: Kulkarni AP, Sengar M, Chinnaswamy G, Hegde A, Rodrigues C, Soman R, Khilnani GC, Ramasubban S, Desai M, Pandit R, Khasne R, Shetty A, Gilada T, Bhosale S, Kothekar A, Dixit S, Zirpe K, Mehta Y, Pulinilkunnathil JG, Bhagat V, Khan MS, Narkhede AM, Baliga N, Ammapalli S, Bamne S, Turkar S, Bhat KV, Choudhary J, Kumar R, Divatia JV. Indian Journal of Critical Care Medicine 2019;23(Suppl 1): S64-S96.

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.

Dual infection of the central nervous system caused by Cryptococcus and Toxoplasma in a patient with AIDS: a case report and literature review

Dual infection of the central nervous system secondary to Cryptococcus and Toxoplasma is very uncommon, even in the setting of acquired immunodeficiency syndrome (AIDS). We report the case of a 52-year-old patient who was admitted with multiple cranial nerve deficits. Magnetic resonance imaging showed supratentorial and infratentorial enhancing lesions. He was newly diagnosed with HIV infection with a CD4 count of 59 cells/uL and HIV viral load of 299,619 copies/mL. Diagnosis of Cryptococcus meningitis was made by Cryptococcal antigen in cerebrospinal fluid (CSF). The high clinical suspicion for Toxoplasmosis prompted an early empiric treatment for this condition. The diagnosis of Toxoplasmosis was later confirmed by PCR in CSF. Despite an adequate treatment for these two pathologies, his condition deteriorated and eventually expired. We reviewed the English language literature for cases of Cryptococcus and Toxoplasma co-infection of the central nervous system in patients with AIDS. To our knowledge, our patient is the third case of simultaneous infection described in the literature. Clinicians must be aware that focal brain lesions in patients with cryptococcal meningitis should prompt a full evaluation to search for concomitant pathologies of which Toxoplasmosis is the most important. Our case illustrates the utility of PCR in CSF for an early diagnosis of toxoplasmosis, reserving brain biopsy for cases of anti-toxoplasma therapy failure.

Neurosyphilis with Concomitant Cryptococcal and Tuberculous Meningitis in a Patient with AIDS: Report of a Unique Case

Meningitis in individuals living with acquired immunodeficiency syndrome (AIDS) is most frequently infectious in origin and usually due to opportunistic infections. The most common pathogens are Cryptococcus neoformans and Mycobacterium tuberculosis. Treponema pallidum causes neurosyphilis and can complicate HIV infections at any time after the initial infection. Simultaneous infections of the central nervous system caused by these pathogens are very uncommon even in the setting of severe immunosuppression. We report the case of a newly diagnosed HIV/AIDS young man who was found to have neurosyphilis with Cryptococcus meningitis. After a few weeks of treatment and initiation of antiretroviral therapy, he was also diagnosed with tuberculous meningitis, which was probably unmasked by the development of immune reconstitution inflammatory syndrome (IRIS). To the best of our knowledge, this is the only case of reported neurosyphilis and meningitis caused concomitantly by Cryptococcus and Mycobacterium tuberculosis.

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.

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 ABSCESS DUE TO Staphylococcus aureus OF CRYPTOGENIC SOURCE IN AN HIV-1 INFECTED PATIENT IN USE OF ANTIRETROVIRAL THERAPY

The spectrum of neurological complications associated with human immunodeficiency virus type 1 (HIV-1) infection is broad. The most frequent etiologies include primary diseases (caused by HIV itself) or secondary diseases (opportunistic infections or neoplasms). Despite these conditions, HIV-infected patients are susceptible to other infections observed in patients without HIV infection. Here we report a rare case of a brain abscess caused by Staphylococcus aureus in an HIV-infected patient. After drainage of the abscess and treatment with oxacilin, the patient had a favorable outcome. This case reinforces the importance of a timely neurosurgical procedure that supported adequate management of an unusual cause of expansive brain lesions in HIV-1 infected patients.

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.

Meningeal Hemangiopericytoma with Intracranial Metastases in an HIV-Positive Male: Case Report and Review of the Literature

Background

Meningeal hemangiopericytoma is a rare, aggressive CNS tumor that tends to invade locally, metastasize, and has a high rate of recurrence. HIV classically increases the risk of 3 AIDS-defining malignancies: Kaposi's sarcoma, non-Hodgkin's lymphoma and invasive cervical cancer. More recently, considerable interest has been paid to the link between HIV and a wider range of non-AIDS-defining cancers. An HIV-positive patient with meningeal hemangiopericytoma is described.

Case Description

A 36-year-old HIV-positive male presented with worsening headache and ataxia. The patient had experienced similar neurologic symptoms 4 months prior and MRI at that time had showed an extra-axial left cerebellar mass most consistent with benign meningioma. Repeat MRI showed the tumor had increased in size by a factor of greater than 20 in this 4-month period, with 4 small additional foci of similar enhancement. Subtotal resection was performed on the mass and final pathological diagnosis was meningeal hemangiopericytoma.

Conclusions

This represents the first reported case of meningeal hemangiopericytoma in an HIV-positive patient. This is also the shortest time to intracranial metastasis ever reported for a meningeal hemangiopericytoma. Although the increased risk in the HIV-positive population of non-AIDS-defining cancers that has been observed in recent years can largely be attributed to cancers with a known viral pathogenesis, it is speculated that HIV infection in this patient may have contributed to the occurrence or unique behavior of this rare tumor.

Whipple disease of the central nervous system: an unusual occurrence in association with acquired immune deficiency syndrome

Whipple disease is a multisystem infectious disease caused by Tropheryma whippleii. It commonly affects the CNS and produces neurological symptoms in 10–20% of cases. Central nervous system Whipple disease occurring in patients with AIDS is extremely rare. The authors present a case of a newly diagnosed AIDS patient in whom intracranial Whipple disease was diagnosed by stereotactic brain biopsy.

Stereotactic biopsies of brain lesions

OBJECTIVE

In the majority of cases, the correct treatment of brain lesions is possible only when the histopathological diagnosis is made. Several deep-seated lesions near eloquent areas are not safely approached by the classical neurosurgical procedures. These patients can get benefit by a minimally invasive procedure.

METHOD

We present a series of 176 consecutive patients submitted to stereotactic biopsies due to a great variety of brain lesions.

RESULTS

Histological diagnosis found in this series: glioma in 40.1% of the patients, other neoplasms in 12.2% and infectious or inflammatory diseases in 29.1 %. The result was inconclusive in 5.2% of the procedures. One patient died (0.6%) and two (1.2%) presented operative complications. The criteria, advantages and risks of the stereotactic biopsies are discussed.

CONCLUSION

The efficacy of the method is adequate and morbid-mortality rates were low.

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.

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

OBJECTIVE

This study investigates the changing indications, results, and practice patterns of brain biopsy in patients with acquired immunodeficiency syndrome (AIDS) as treatment evolved with the development of highly active antiretroviral therapy (HAART).

METHODS

We collected data on 246 patients with AIDS who were undergoing brain biopsy of intracranial lesions. Patients were managed in accordance with a uniform protocol. Patients were divided into two groups of those biopsied in the era before (1992-1996) or after (1997-2001) the use of HAART.

RESULTS

The introduction of HAART led to a steep decrease in the number of biopsies performed annually. The protocol functioned well. Diagnoses were obtained for 92.3% of patients. Lymphoma was the most frequent diagnosis (52.9% of patients), followed by progressive multifocal leukoencephalopathy (18.9% of patients) and toxoplasmosis (8.1% of patients). No patient who underwent lesion biopsy for reasons of negative toxoplasmosis titers or atypical radiology evaluation was diagnosed with toxoplasmosis. Nineteen patients who experienced failed toxoplasmosis treatment were diagnosed with toxoplasmosis. Toxoplasmosis titers had a high specificity and a negative predictive value. Patients with progressive multifocal leukoencephalopathy or nondiagnostic biopsies were more likely to have solitary lesions. The average Karnofsky performance score at the time of biopsy was 72.4, which is still within the range of independent functioning. Significant intracerebral hemorrhages were only observed in patients with lymphoma who also had low platelet counts.

CONCLUSION

Although the number of patients with AIDS who require brain biopsy has decreased, the procedure still has merits. The paradigm we developed was useful for selecting patients for early biopsy. Patients with AIDS who also have intracerebral lesions should have toxoplasmosis titers performed, and those whose titers are negative for toxoplasmosis should undergo early brain biopsy.

Nocardia abscess during treatment of brain toxoplasmosis in a patient with aids, utility of proton MR spectroscopy and diffusion-weighted imaging in diagnosis

We report the case of a 30-year-old man with known HIV-positive status who developed, 4 months prior to admission, recurrent left partial motor seizures followed by left hemiparesis. At another hospital, contrasted CT scan of the head revealed right frontal hypodense lesion with mass effect and focal contrast enhancement. A small left occipital lesion was also present. HIV-associated brain toxoplasmosis was considered and phenytoin, pyrimethamine, clindamycin and antiretrovirals were administered. Hemiparesis improved but, 3 weeks prior to admission, he developed progressive headache and bilateral visual defects. Upon admission to our center, he was found with left homonymous hemianopsia, right hemiparesis and a large hypodense left occipital lesion on a head CT scan. Proton MR spectroscopy showed lactate at 1.3ppm, amino acids at 0.9ppm, and diffusion-weighted imaging (DWI) revealed hyperintensity at the lesion, suggesting a pyogenic abscess. Aspiration yielded purulent material and Nocardia asteroides grew in culture. The patient was treated with trimethoprim-sulfametoxazole and recovered with a mild visual field residual defect.

Primary central nervous system lymphomas in immunocompetent patients

OBJECTIVES

Primary central nervous system lymphoma (PCNSL) is a rare pathology and is most often seen in immunodeficient patients. This article presents our casuistic of PCNSL in immunocompetent patients and make a literature review on this issue with focus on recent advances, investigations, and controversies in diagnosis and management of this pathology.

MATERIAL AND METHODS

Nine patients operated in the last years in our clinics are analysed in relation to sex, age, time of symptoms, procedures and adjuvant treatment. Posteriorly the results are compared with those in the preview literature.

RESULTS

The age ranged from 44-68 years (middle of 66 years); 62.5% of the patients were female. The mean time of symptoms, when the diagnostic was made, was 3.2 months (range 1-6 months). The most common symptoms were hemiparesis (present in 75% of the patients) headache (37.5%) seizures (25%) and ataxia (25%). The most common localization was the parietal, frontal and temporal lobe surface with 25% of the patients for each localization. Five patients (50%) were treated with stereotactic biopsy, three with surgery (37.5%) and one (12.5%) with both of them. Five patients (62.5%) were submitted to pos-operative radiotherapy as adjuvant treatment. In relation to the histology, the most common cell type was Diffuse B Cells.

CONCLUSIONS

This study demonstrated that complete surgical resection followed by radiotherapy have shown good results. In opposition to the literature, the authors regard chemotherapy as a secondary line treatment and recommend its use only in some selected cases.

AIDS-Related Primary Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) can develop in the setting of profound immunosuppression, including late-stage infection with HIV. The management of such patients has yet to be defined optimally and differs substantially from that of immunocompetent patients who have PCNSL. The clinical features, diagnosis, and management of AIDS-related PCNSL are reviewed. The authors focus on commonly encountered diagnostic and therapeutic dilemmas and explore some promises and pitfalls of Epstein-Barr virus-directed therapies.

The Birth of Stereotactic Surgery: A Personal Retrospective

The field of human stereotactic surgery was born at Temple Medical School in Philadelphia in 1947, with Ernst A. Spiegel and Henry T. Wycis its parents. I had the great fortune of walking into Dr. Spiegel's laboratory as a freshman medical student looking for a summer research project in 1956, when the field was just emerging from its infancy, and worked with Spiegel and Wycis for most of the next 13 years and Rolf Hassler the following year. The perspective of the early growth of the field of stereotactic surgery from this unique position and my wanderings through the field as it grew, contracted, and then blossomed are presented.

CNS cryptococcoma in an HIV-positive patient

This is the first case of brain cryptococcoma in an AIDS patient reported in Argentina. The patient was a 28-year-old white heterosexual man with AIDS who presented with altered mental status, seizures, visual hallucinations, headache, and fever without significant focal neurological deficit. He had a lumbar puncture, and was treated for cryptococcal meningitis. Subsequent brain CT scanning and MRI disclosed a mass lesion in the occipital lobe. Histopathological examination of biopsy was compatible with cryptococcoma, and tissue culture revealed Cryptococcus neoformans. Resolution of the mass and edema resulted after treatment with intravenous amphotericin B for six weeks, which was followed with maintenance oral fluconazole. Intracranial mass is an uncommon complication in AIDS patients with cryptococcosis, and cryptococcoma should be considered as differential diagnosis of brain mass lesion in these patients. The etiologic diagnosis is necessary because central nervous system (CNS) toxoplasmosis, lymphoma, and tuberculoma can produce similar clinical syndromes and MRI or CT findings to cryptococcoma. Also, these pathologies may coexist with meningeal cryptococcosis.

Neoplastic masquerade syndromes

Masquerade syndromes are classically defined as entities which emulate inflammatory conditions but which are in fact due to a neoplastic process. Careful history and examination in concert with appropriate ancillary investigations and histopathologic evaluation of tissue specimens are required in order to make the correct diagnosis. Many conditions may result in an appearance mimicking an inflammatory condition. The authors review neoplastic conditions which may be considered masquerades. The most common of these is primary intraocular lymphoma or primary central nervous system lymphoma, occurring predominately in older individuals. Diagnostic strategies, therapy, and prognosis are reviewed in detail. Other conditions that can be considered masquerade syndromes are reviewed as well, including lymphomatous and nonlymphomatous conditions, such as melanoma, retinoblastoma, juvenile xanthogranuloma, metastatic lesions, and paraneoplastic syndromes, among others.

Central nervous system infection during immunosuppression

Suppression of the immune system by human immunodeficiency virus (HIV) infection or immunosuppressive therapy following transplantation increases susceptibility to CNS infection. Examination of the level and type of immunosuppression, in addition to the clinical and radiologic findings at the time of diagnosis can aid the clinician in determining the most likely etiology of infection. This article discusses how suppression of the host immune status modifies the presentation and diagnosis of selected CNS infections and the recommended treatment for these infections.

Focal neurological disease in patients with acquired immunodeficiency syndrome

Focal neurological disease in patients with acquired immunodeficiency syndrome may be caused by various opportunistic pathogens and malignancies, including Toxoplasma gondii, progressive multifocal leukoencephalopathy (PML), cytomegalovirus (CMV), and Epstein-Barr virus-related primary central nervous system (CNS) lymphoma. Diagnosis may be difficult, because the findings of lumbar puncture, computed tomography (CT), and magnetic resonance imaging are relatively nonspecific. Newer techniques have led to improved diagnostic accuracy of these conditions. Polymerase chain reaction (PCR) of cerebrospinal fluid specimens is useful for diagnosis of PML, CNS lymphoma, and CMV encephalitis. Recent studies have indicated the diagnostic utility of new neuroimaging techniques, such as single-photon emission CT and positron emission tomography. The combination of PCR and neuroimaging techniques may obviate the need for brain biopsy in selected cases. However, stereotactic brain biopsy, which is associated with relatively low morbidity rates, remains the reference standard for diagnosis. Highly active antiretroviral therapy has improved the prognosis of several focal CNS processes, most notably toxoplasmosis, PML, and CMV encephalitis.

Stereotactic biopsy aided by a computer graphics workstation: experience with 200 consecutive cases

BACKGROUND

The advent of modern computer technology has made it possible to examine not just the target point, but the entire trajectory in planning for stereotactic biopsies.

METHODS

Two hundred consecutive biopsies were performed by one surgeon, utilizing a computer graphics workstation. The target point, entry point, and complete trajectory were carefully scrutinized and adjusted to minimize potential complications.

RESULTS

Pathologically abnormal tissue was obtained in 197 cases (98.5%). There was no mortality in this series. Symptomatic hemorrhages occurred in 4 cases (2%).

CONCLUSIONS

Computer graphics workstations facilitate safe and effective biopsies in virtually any brain area.

Opportunistic infections in HIV disease: down but not out

Despite the marked improvement in patient survival and reduction in the incidence of HIV-related opportunistic infections with the introduction of potent, combination antiretroviral therapy, these infections remain a significant challenge in the management of HIV-infected patients. Ongoing issues that will require further study include a better characterization of immune reconstitution illnesses, other potential alterations in the natural history of opportunistic infections with antiretroviral therapy, and to what degree patients who experience failure of antiviral treatment become susceptible to various opportunistic processes.