Case report: multiple and atypical amoebic cerebral abscesses resistant to treatment

BACKGROUND

The parasite Entamoeba histolytica is the causal agent of amoebiasis, a worldwide emerging disease. Amebic brain abscess is a form of invasive amebiasis that is both rare and frequently lethal. This condition always begins with the infection of the colon by E. histolytica trophozoites, which subsequently travel through the bloodstream to extraintestinal tissues.

CASE PRESENTATION

We report a case of a 71-year-old female who reported an altered state of consciousness, disorientation, sleepiness and memory loss. She had no history of hepatic or intestinal amoebiasis. A preliminary diagnosis of colloidal vesicular phase neurocysticercosis was made based on nuclear magnetic resonance imaging (NMRI). A postsurgery immunofluorescence study was positive for the 140 kDa fibronectin receptor of E. histolytica, although a serum analysis by ELISA was negative for IgG antibodies against this parasite. A specific E. histolytica 128 bp rRNA gene was identified by PCR in biopsy tissue. The final diagnosis was cerebral amoebiasis. The patient underwent neurosurgery to eliminate amoebic abscesses and was then given a regimen of metronidazole, ceftriaxone and dexamethasone for 4 weeks after the neurosurgery. However, a rapid decline in her condition led to death.

CONCLUSIONS

The present case of an individual with a rare form of cerebral amoebiasis highlights the importance of performing immunofluorescence, NMRI and PCR if a patient has brain abscess and a poorly defined diagnosis. Moreover, the administration of corticosteroids to such patients can often lead to a rapid decline in their condition.

The Tunnel Sign Revisited: A Novel Observation of Cerebral Melioidosis Mimicking Sparganosis

The tunnel sign has been described as a specific feature of cerebral sparganosis. We present a case of a 55-year-old gentleman found to have cerebral melioidosis and with initial imaging mimicking the appearance of sparganosis. This suggests that the tunnel sign in brain abscesses may be specific for infection by Burkholderia Pseudomallei, Spirometra Mansoni or Listeria Monocytogenes.

Cutaneous Balamuthia mandrillaris infection as a precursor to Balamuthia amoebic encephalitis (BAE) in a healthy 84-year-old Californian

Soil and freshwater-dwelling amoebae may opportunistically infect the skin and evoke a granulomatous dermatitis that camouflages their underlying morphology. Amoebic infestations are incredibly rare in the U.S., predominantly occurring in the young, elderly, and immunocompromised. Sadly, because diagnosis is difficult and unsuspected, most cases are diagnosed at autopsy. The following case is of a healthy 84-year-old man with a non-healing nodulo-ulcerative cutaneous lesion on his left forearm that appeared following a gardening injury. Lesional punch biopsies repeatedly showed non-specific granulomatous inflammation with no pathogens evident histologically or by culture. Histopathologic diagnosis was made five months after initial presentation via identification of amoebic trophozoite forms in tissue from a large excisional specimen. Anti-amoebic therapy was initiated immediately. The patient experienced mental status changes three days following lesion excision, with evidence of a cystic mass in the left medial parieto-occipital lobe by CT. Both intraoperative brain biopsies and cutaneous tissue samples tested positive for Balamuthia mandrillaris by indirect immunofluorescent antibody assay performed at the Centers for Disease Control. The patient achieved a full recovery on a triple antibiotic regimen. Clinical suspicion and thorough histopathologic analysis may determine the difference between survival and death for a patient presenting with a treatment-refractory localized granulomatous lesion.

A rare case of multilocus brain abscess due to Entamoeba histolytica infection in a child

Brain abscess due to Entamoeba histolytica (E. histolytica) may pose a diagnostic problem or a therapeutic challenge, as evidenced by the paucity of papers reporting complete recovery after treatment. An 11-year-old girl presented with progressive drowsiness, diminished movements of the left upper limb, and swallowing problems. Cranial MRI showed multiple, contrast-dense masses with fluid content. She was started on meropenem. Surgical drainage was performed. No bacterial or fungal growth was observed in drainage samples. Entamoeba histolytica trophozoites were detected in the tissue sample. Intravenous metronidazole was started and continued for 6 weeks, at the end of which abscesses were found and to have shrunk considerably. Intravenous therapy was switched to oral metronidazole, which was continued for 2 weeks. She regained all her preexisting abilities. Multiple brain abscesses due to E. histolytica is a very rare occurrence, and histopathologic evaluation is important in diagnosis.

Undiagnosed amebic brain abscess

We report a case of amebic brain abscess due to Entamoeba histolytica. The patient was a 31-year-old man who presented with amebic liver abscess. His clinical course deteriorated in spite of proper drainage and treatment. He developed delirium, lethargy and then expired. With a history of heroin addiction, withdrawal syndrome from heroin was suspected. At autopsy, amebic abscesses were detected in the liver, large intestine, meninges and brain. A 19 cm amebic liver abscess was found in the right lobe of the liver. A 4 cm amebic brain abscess was found in the right occipital lobe. Microscopically, the tissue sections from the affected organs were confirmed to have degenerated E. histolytica trophozoites. Involvement of the brain in amebic liver abscess should be suspected in patients with neurological signs and symptoms.

Amebic liver abscesses: a new epidemiological trend in a non-endemic area?

BACKGROUND

Amoebic liver abscess (ALA) is the most common extraintestinal complication of colonic amebiasis. In recent decades its incidence in developed European countries has significantly increased because of travel and immigration of individuals from highly endemic areas. We report our 29-year experience in echo-guided percutaneous needle/catheter drainage (EPND/EPCD) of ALA.

PATIENTS AND METHODS

From May 1979 to November 2007, 68 ALA corresponding to 56 patients were diagnosed at our Department. All patients were treated with a metronidazole plus EPND/EPCD approach.

RESULTS

The majority of the cases did not need more than two echo-guided punctures. Two patients, both male immigrants (HIV-negative), had unmodified lesions after two EPNDs: catheter drainage was performed. A quick worsening of their clinical conditions and onset of neurological symptoms occurred; in both patients, computed tomography (CT) revealed a brain abscess. Intravenous medical therapy was started, but both died 4 and 3 days, respectively, after the onset of neurological symptoms (overall mortality rate: 3.57%).

CONCLUSION

The unfavorable outcome of two cases is a rare example of failure of percutaneous therapy of ALA. Mortality is a possible event even in a non-endemic area such as Italy. More observational data are needed to confirm the possibility of a new epidemiological trend.

A rare but fatal case of granulomatous amebic encephalitis with brain abscess: the first case reported from Turkey

The incidence of protozoal and helminthic infestations of the central nervous system (CNS) is less than 1%, but these infestations tend to follow a fatal course. They are more common among children, the elderly and immunocompromised individuals. CNS infections due to Entamoeba histolytica have been known for a long time. In recent years, especially in developing countries, there has been an increase in CNS infections due to free-living amebas (FLAs). Acute CNS infection due to Naegleria fowleri, which ends in death within 2-7 days, is termed primary amebic meningoencephalitis (PAM); subacute or chronic CNS infections due to Acanthamoeba spp, Balamuthia mandrillaris, and Sappinia diploidea, which occasionally cause cerebral abscess, are termed granulomatous amebic encephalitis (GAE). This paper presents a case of GAE with abscess formation in a 75-year-old male patient.

Amebic cerebral abscess mimicking bacterial meningitis

We report a case of an amebic brain abscess in a 2-year-old girl, with symptoms mimicking bacterial meningitis with no evidence of disease elsewhere. Histological evaluation of the abscess revealed the organisms, and the abscess regressed in response to specific medical treatment. This article reviews the rarity of these abscesses and difficulty in the diagnosis.

[Probable amebic brain abscess in a homosexual man with an Entamoeba histolytica liver abscess]

A 51-year-old Japanese-Brazilian homosexual man was admitted to a hospital because of fever, headache and right epigastralgia. He had been homosexual for 20 years. An abdominal CT revealed a liver abscess and microscopic examination of the pus of the drainage revealed cystic forms of Entamoeba histolytica. Oral administration of metronidazole 2,250 mg/day was started for amebic liver abscess. He complained of severe throbbing headache, and magnetic resonance imaging (MRI) of the brain showed a brain mass of approximately 2 cm in diameter in the right parietooccipital lobe. An amebic brain abscess was suspected and he was transferred to our hospital. Continuous oral administration of metronidazole for 49 days instead of invasive procedures gradually improved headache, fever and right epigastralgia. On the follow-up MRIs, the brain mass was gradually encapsulated, reduced its size, and finally disappeared. A diagnosis of amebic brain abscess was made on the basis of coexistent amebic liver abscess, MRI findings and a dramatic effectiveness to metronidazole. One should pay attention to E. Histolytica infection in the differential diagnosis of the abscess of the liver and brain since it has been increasing in Japan in recent years.

Role of diffusion weighted imaging in differentiation of intracranial tuberculoma and tuberculous abscess from cysticercus granulomas-a report of more than 100 lesions

Restricted diffusion is noted in a large number of non-stroke conditions including tuberculoma. The purpose of this study was to demonstrate spectrum of diffusion weighted imaging (DWI) abnormalities in tuberculomas and tuberculous abscess and to distinguish these from degenerating neurocysticercosis. Seventy tuberculomas and tuberculous abscesses in 30 patients were categorized in three groups depending on the intensity in the core of the lesion on T2 weighted images. Mean apparent diffusion coefficient (ADC) was calculated from the core as well as from the wall of the lesions. Forty-five lesions of neurocysticercosis in different stage of evolution in 12 patients were also included for comparison. The mean ADC value from the core of the T2 hypointense lesions was significantly higher compared to the wall ((1.24+/-0.32)x10(-3) and (1.06+/-0.15)x10(-3)mm(2)/s, respectively), while mean ADC value from the core of mildly T2 hyperintense lesions was significantly lower compared to the wall ((0.80+/-0.08)x10(-3) and (1.08+/-0.13)x10(-3)mm(2)/s, respectively). Truly T2 hyperintense lesions were divided into two subgroups, tuberculomas and tuberculous abscesses; ADC values from the core and the wall of these lesions were (0.74+/-0.13)x10(-3), (0.61+/-0.08)x10(-3) and (1.03+/-0.14)x10(-3), (1.08+/-0.14)x10(-3)mm(2)/s, respectively, and was significantly lower in core as compared to the wall. However, there was no significant difference between ADC values of the tuberculous abscess and the hyperintense tuberculomas. Vesicular and degenerating stages of cysticercus cysts from the core showed ADC values of (1.66+/-0.29)x10(-3) and (1.51+/-0.23)x10(-3)mm(2)/s, respectively, and were significantly higher than the core of all groups of tuberculomas and tuberculous abscess. We conclude that addition of DWI to routine imaging protocol may help in differentiation of tuberculous lesions from degenerating cysticercus granuloma.

Case report: human brain abscess due to a tetra-acetabulate plerocercoid metacestode (Cyclophyllidea)

A 38-year-old man living near Phnom Penh (Cambodia) was admitted to a hospital in Paris in June 2001 for a single episode of a generalized grand mal seizure. This episode was preceded by a 9-month history of headaches. Magnetic resonance imaging (MRI) of the head revealed a rounded lesion immediately ahead of the left central sulcus. The resected lesion was about 20 mm in diameter. Histologic examination revealed an elongated but unsegmented metacestode at the center of the lesion. Polymerase chain reaction (PCR) analysis was inconclusive due to formalin-based histologic processing of the tissue. Morphologic analysis based on the histologic sections revealed that the metacestode was a tetra-acetabulate plerocercoid of the order Cyclophyllidea, with a distinct rostellum and pseudosegmentation of the dorsoventrally flattened hindbody. This is the first report of a tetra-acetabulate plerocercoid from a human host and the first report of any cyclophyllidean plerocercoid from the human brain. After 6 weeks, the patient was asymptomatic, neurologic examination was normal, and the brain MRI showed only surgical cavitation. The patient returned to Cambodia.

Pulmonary amoebiasis presenting as superior vena cava syndrome

Pulmonary amoebiasis without liver involvement occurs sporadically as a result of haematogenous spread from a primary site, the colon. The case history is presented of a patient who developed superior vena cava syndrome due to a pulmonary amoebic abscess without liver involvement. He was initially suspected of having a neoplasm but a combination of tests including histological examination of the H&E stained excised tissue, immunofluorescence using anti-Entamoeba histolytica antibodies, and serology confirmed the diagnosis of amoebiasis. To our knowledge this is the first description of pulmonary amoebiasis presenting as superior vena cava syndrome.

Brain abscess due to Entamoeba histolytica

A patient of cerebral amoebiasis due to Entamoeba histolytica with no evidence of disease elsewhere is described. He made a complete recovery after surgical excision of the abscess along with metronidazole therapy.

Treatment of Toxoplasma brain abscess with clindamycin and sulfadiazine in an AIDS patient with concurrent atypical Pneumocystis carinii pneumonia

Toxoplasmosis is the most common opportunistic infection of the central nervous system in patients with AIDS. The standard treatment for toxoplasmic encephalitis is pyrimethamine and sulfadiazine. There have been few reports of concurrent Toxoplasma brain abscess and cavitary Pneumocystis carinii pneumonia (PCP) in Taiwan. We report the case of a 26-year-old homosexual man with coexisting infection with Toxoplasma gondii and P. carinii who was successfully treated for brain abscess with clindamycin and sulfadiazine. The cavitary lung lesions, initially diagnosed as pulmonary tuberculosis, were proved to be PCP by lung biopsy. HIV infection and syphilis had been diagnosed 1 year before admission. He presented with general weakness, ataxia, nausea, blurred vision and fever for 2 weeks. Magnetic resonance imaging of the brain revealed multiple ring-enhanced lesions over the cerebrum and cerebellum. Chest roentgenography showed a 3-cm lesion with cavitation over the right upper lung field. Diagnostic computerized tomography-guided lung biopsy revealed P. carinii cysts. Clindamycin, sulfadiazine and trimethoprim (TMP)-sulfamethoxazole (20 mg/kg/day TMP) were given with good response. His CD4 count rose from 40 to 280/microL 4 months later. All antibiotics were discontinued after 4.5 months due to the development of a skin rash. He was well at follow-up 1 year later. This case suggests that the combination of clindamycin and sulfadiazine is an effective treatment for Toxoplasma brain abscess and highlights the importance of diagnostic lung biopsy for cavitary lung lesions, particularly in a region endemic for tuberculosis.

Granulomatous amebic encephalitis in a patient with AIDS: isolation of acanthamoeba sp. Group II from brain tissue and successful treatment with sulfadiazine and fluconazole

A patient with AIDS, treated with highly active antiretroviral therapy and trimethoprim-sulfamethoxazole, presented with confusion, a hemifield defect, and a mass lesion in the right occipital lobe. A brain biopsy confirmed granulomatous amebic encephalitis (GAE) due to Acanthamoeba castellanii. The patient was treated with fluconazole and sulfadiazine, and the lesion was surgically excised. This is the first case of AIDS-associated GAE responding favorably to therapy. The existence of a solitary brain lesion, absence of other sites of infection, and intense cellular response in spite of a very low CD4 count conditioned the favorable outcome. We review and discuss the diagnostic microbiologic options for the laboratory diagnosis of infections due to free-living amebae.

Central nervous system infections following bone marrow transplantation: an autopsy report of 27 cases

The authors retrospectively assess the autopsy findings of central nervous system (CNS) infections in marrow transplant recipients. From July 1987 to June 1998, 845 patients at our institution were submitted to bone marrow transplantation (BMT). The CNS of 180 patients was studied through autopsy and these patients had their medical records reviewed. Twenty-seven (15%) patients presented brain parenchyma infection. Fungi were isolated in approximately 60% of the cases. Mean survival time was 153 days (0-1,264 days) and the majority of the patients died during the first 3 months after BMT (18 cases; 67%). Aspergillus sp. were the most prevalent fungi (approximately 30%), followed by Candida sp. infection (approximately 18%). There was one case of Fusarium sp. infection and two cases of unidentified fungus. All patients with fungal infections had documented involvement at widespread sites. Toxoplasma gondii encephalitis was demonstrated in 8 patents (approximately 30%). Bacterial abscesses were responsible for approximately 11% of the findings. Eleven (41%) of the 27 patients died secondary to cerebral causes. These results show that infectious compromise of the CNS following BMT is a highly fatal event, caused mainly by fungi and T. gondii. Furthermore, they provide a likely guide to the possible causes of brain abscesses following BMT.

Fungus-like hyphochytrids associated with human disease

We report two cases, with liver and brain abscess, respectively, where fungus-like organisms belonging to the Hyphochytriomycota were found at the site of inflammation together with Peptococcus in the first and Cysticercus cellulosae in the second case. This is the first time these groups of organisms have been reported in human material. The role of hyphochytrids in human pathology remained uncertain as they were found together with already known human pathogens.

Neuroimaging findings in patients with AIDS

An increasing number of patients are presenting with central nervous system complications of human immunodeficiency virus infection. New imaging technologies such as magnetic resonance imaging, magnetic resonance proton spectroscopy, single-photon emission computed tomography, and positron emission tomography are playing an ever-increasing role in the diagnosis of these complications. As therapeutic modes improve, imaging may assume a growing role in monitoring the responses to therapy among these patients.

[The impact of the prevention of cerebral toxoplasmosis]

In France, where 70% of adults are latently infected by toxoplasma, from 20% to 40% of patients with AIDS developed toxoplasmic encephalitis until recently. The prophylactic use of drugs which are active against pneumocystis and toxoplasma has proven to be efficient. These drugs are trimethoprim-sulfamethoxazole or dapsone-pyrimethamine. With the extent of these primary prophylaxis, there is a decrease of risk of toxoplasma encephalitis; thus the rate of toxoplasma encephalitis among opportunistic infections has fallen off from 19% of the patients in 1988 to 6% in 1994, in the department of infectious diseases of the Pitié-Salpêtrière hospital. However, toxoplasmic abscesses occurring despite the prophylaxis are frequently slow growing lesions which can become huge with a moderate mass effect, mimicking the pattern of primary cerebral lymphoma. The rule of antitoxoplasmic trial treatment must be strictly followed, even under prophylaxis.

[Diffuse toxoplasmic encephalitis in a non-immunosuppressed patient]

Diffuse encephalitic toxoplasmosis is an unusual presentation of toxoplasmosis, in which neuroradiological investigations may not show focal abcesses. Until now it was only reported in immunocompromised patients. In immunocompetent patients, cerebral toxoplasmosis is very unusual, and appears as multiple abcesses, like the classic form in immunocompromised patients. We report the case of an immunocompetent patient who presented a diffuse encephalitic toxoplasmosis; CT and MR examinations showed only nonspecific features of brain swelling and cortical infarct due to vasculitis.

Brain abscess due to infection with Entamoeba histolytica

We successfully treated a serious case of Entamoeba histolytica infection showing brain abscess, meningitis, and liver abscess by oral administration of metronidazole, intramuscular injection of dehydroemetine, and drainage of the brain abscess. The diagnosis of amebic brain abscess was based on a combination of clinical symptoms and signs, computed tomography and magnetic resonance imaging findings, a positive serologic test result for E. histolytica, a dramatic response to anti-amebic drugs after an ineffective therapeutic history with antibacterial drugs, and application of the polymerase chain reaction method.

Amoebic brain abscess: a rare but serious complication of Entamoeba histolytica infection

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Infectious lesions of the brain stem

Infectious lesions of the brain stem are rare and include primarily abscess and encephalitis. The most common etiologic agents for abscess formation are Streptococcus sp., Staphylococcus sp., and M. tuberculosis. Encephalitis is associated most often with L. monocytogenes and herpes simplex virus infection. Classical brain stem syndromes are uncommon with brain stem infections, and CSF obstruction can be seen with neurocysticercosis. The diagnosis of these lesions has been greatly aided by CT and MR imaging. Microsurgery and stereotaxis are both appropriate techniques for the treatment of brain stem abscess that establish a diagnosis, identify the causative agent, and relieve mass effect on important neural structures. Symptoms of hydrocephalus should be treated with temporary or permanent CSF diversion. Viral involvement of the brain stem is usually self-limited, and improved antimicrobial therapy has contributed to a decrease in the morbidity and mortality of bacterial and parasitic infections. Although once believed to be uniformly fatal, infections of the brain stem have now been successfully treated for more than a decade.

Amebic brain abscess and meningoencephalis

Infections caused by the free-living amebae remind us of the fine line that divides environmental and pathogenic microorganisms, and the number and complexity of the threats our natural defenses must cope with routinely. The comparative rarity of amebic brain infections, and their devastating consequences, demand utmost vigilance from the clinician. Although in many cases nothing can be done to save the lives of persons with these maladies, early diagnosis and prompt therapy can be effective in some cases. Much remains to be discovered about the pathogenesis, diagnosis, and effective therapy of amebic CNS infections.

Angiostrongylus cantonensis abscess in the brain

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Isolation of Acanthamoeba from a cerebral abscess

A 55-year-old diabetic aboriginal woman presented with a two-week history of fever, altered mental state and convulsions. On the basis of computed tomographic scanning a diagnosis of cerebral abscess was made. The pus that was drained produced no bacterial growth but, on microscopy, amoebic cysts were observed. Special cultures produced a growth of Acanthamoeba. The patient appeared to respond to drainage of the abscess and antiprotozoal therapy. Unfortunately, she developed necrotizing enteritis which led ultimately to her death. Antibiotic sensitivity and pathogenicity testing suggest that the Acanthamoeba were unusually virulent. The problems of diagnosis and management are discussed.

Acquired immunodeficiency with intestinal cryptosporidiosis: possible transmission by Haitian whole blood

A 31-year-old Frenchman had an acquired immunodeficiency syndrome (AIDS) with profound depression of cellular immunity and relative sparing of humoral immunity. The clinical picture included intractable secretory diarrhoea, vomiting, abdominal pain, and weight loss. Gastrointestinal cryptosporidiosis was present and a perfusion technique showed profuse secretion of fluid in the proximal small bowel. The patient also had recurrent Salmonella typhimurium septicaemia, cytomegalovirus infection, and cerebral toxoplasmosis and he died within 13 months. This patient did not belong to any of the groups known to be affected by this type of acquired immunodeficiency (homosexuals, drug addicts, haemophiliacs, Haitians) but had been transfused with Haitian blood 4 years before onset of symptoms. This case supports the notion that some forms of AIDS may be transmitted by blood, with a long incubation period.

Experimental amebiasis. I. Pathogenicity of axenically cultured Entamoeba histolytica in the brain of the newborn mouse

Axenically cultured Entamoeba histolytica inoculated intracerebrally into newborn Swiss mice invaded the cerebrum and produced multiple abscesses containing viable trophozoites. As few as 20 amebae of a virulent strain (HM-1:IMSS) occasionally produced fatal disease, 200 killed about 75% of animals and higher doses regularly killed all animals. In contrast, avirulent strains (HK-9 and HB-301:NIH) failed to produce acute brain disease in comparable time periods even when mice were inoculated with as many as 20,000 amebae. Two other strains (1295 and H-458:CDC) were of intermediate virulence. High doses of avirulent amebae often produced hydrocephalus as a late manifestation. In newborn, 3 week-old, and 6-week-old mice resistance to infection increased with age, and older animals often responded late to virulent strains by developing hydrocephalus.

Disseminated aspergillosis in a renal transplant patient: Diagnostic difficulties re-emphasized

An asymptomatic and radiographically occult lung abscess was the primary focus of infection in this case of fatal disseminated aspergillosis in a renal transplant recipient. Extensive neurological evaluation in response to a change in personality failed to reveal a brain abscess, which was the cause of death. This case illustrates the variability in presentations of aspergillosis and the continuing difficulties in diagnosing this infection in immunosuppressed patients.