Intracranial phycomycosis: a clinicopathological and radiological study

Ruptured Mycotic Aneurysm of the Distal Circulation in a Patient with Mucormycosis Without Direct Skull Base Extension: Case Report

BACKGROUND AND IMPORTANCE

Infectious intracranial aneurysms are a rare subset of intracranial aneurysms caused by bacterial, fungal, or viral sources. Intracranial aneurysms of fungal etiology carry a high mortality risk and typically occur in immunocompromised patients via direct extension of skull base infections, or more rarely, after intracranial surgery.

CLINICAL PRESENTATION

We present the case of a 27-yr-old female with systemic lupus erythematous and primary pulmonary mucormycosis, who suffered a subarachnoid hemorrhage from a ruptured fusiform distal middle cerebral artery aneurysm. Despite undergoing a successful extracranial-to-intracranial bypass and aneurysm excision, the patient ultimately died following progressive disseminated infection and a secondary intracranial hemorrhage of unknown etiology. Pathological examination of the excised artery confirmed Mucor infection.

CONCLUSION

To the best of our knowledge, this case represents one of the first mycotic cerebral aneurysms from mucormycosis in a patient without an underlying skull base infection or previous intracranial surgery. Despite optimal surgical management, clinical outcomes for mycotic cerebral aneurysms are largely dependent on the success of medical therapies at controlling systemic disease.

Diagnosis and Treatment of Isolated Cerebral Mucormycosis: Patient-Level Data Meta-Analysis and Mayo Clinic Experience

BACKGROUND

Isolated cerebral mucormycosis is a rare and serious infection associated with intravenous drug abuse.

METHODS

We performed a comprehensive meta-analysis of cases reported in studies and have included an unreported case from our institution. We searched PubMed/Medline, EMBASE, Scopus, Cochrane Databases, and our institution's electronic medical health records from inception through March 31, 2018. The cases were considered isolated (only affecting the cerebrum, cerebellum, or brainstem) if the absence of other primary sources of infection had been documented. Continuous variables were summarized using the median and interquartile range and categorical variables using frequencies and proportions. The relationships between variables were tested using the Wilcoxon rank sum and Pearson χ² tests.

RESULTS

A total of 130 studies (141 patients) met the eligibility requirements and were screened; 68 patients were included. The median age was 28 years (interquartile range, 24-38); 57% were men. Most patients had a history of intravenous drug abuse (82%), and 20% had positive human immunodeficiency virus findings. The lesion location was mostly supratentorial (91%), especially in the basal ganglia (71.2%). The cultures were positive in 38%, with Rhizopus the most common organism (59%). The mortality rate was 65%. The survivors were significantly more likely to have received amphotericin B (92% vs. 43%; P < 0.001) or to have undergone stereotactic aspiration (58% vs. 25%; P < 0.01).

CONCLUSIONS

Isolated cerebral mucormycosis has a pooled mortality rate of 65%. The presence of lesions in the basal ganglia, rapidly progressive symptoms, and a history of intravenous drug abuse should raise suspicion for the early initiation of amphotericin B and stereotactic aspiration.

Epidemiology and outcome of zygomycosis: a review of 929 reported cases

BACKGROUND

Zygomycosis is an increasingly emerging life-threatening infection. There is no single comprehensive literature review that describes the epidemiology and outcome of this disease.

METHODS

We reviewed reports of zygomycosis in the English-language literature since 1885 and analyzed 929 eligible cases. We included in the database only those cases for which the underlying condition, the pattern of infection, the surgical and antifungal treatments, and survival were described.

RESULTS

The mean age of patients was 38.8 years; 65% were male. The prevalence and overall mortality were 36% and 44%, respectively, for diabetes; 19% and 35%, respectively, for no underlying condition; and 17% and 66%, respectively, for malignancy. The most common types of infection were sinus (39%), pulmonary (24%), and cutaneous (19%). Dissemination developed in 23% of cases. Mortality varied with the site of infection: 96% of patients with disseminated disease died, 85% with gastrointestinal infection died, and 76% with pulmonary infection died. The majority of patients with malignancy (92 [60%] of 154) had pulmonary disease, whereas the majority of patients with diabetes (222 [66%] of 337) had sinus disease. Rhinocerebral disease was seen more frequently in patients with diabetes (145 [33%] of 337), compared with patients with malignancy (6 [4%] of 154). Hematogenous dissemination to skin was rare; however, 78 (44%) of 176 cutaneous infections were complicated by deep extension or dissemination. Survival was 3% (8 of 241 patients) for cases that were not treated, 61% (324 of 532) for cases treated with amphotericin B deoxycholate, 57% (51 of 90) for cases treated with surgery alone, and 70% (328 of 470) for cases treated with antifungal therapy and surgery. By multivariate analysis, infection due to Cunninghamella species and disseminated disease were independently associated with increased rates of death (odds ratios, 2.78 and 11.2, respectively).

CONCLUSIONS

Outcome from zygomycosis varies as a function of the underlying condition, site of infection, and use of antifungal therapy.

Extracranial internal carotid artery Salmonella mycotic aneurysm complicated by occlusion of the internal carotid artery: depiction by color Doppler sonography, CT and DSA

Mycotic aneurysms of the extracranial carotid artery are rare. Seventy-four cases have been described in the medical literature and only eight secondary to Salmonella infection. To our knowledge, color Doppler sonography, computed tomography (CT), and digital subtraction angiography (DSA) findings relating to the diagnosis and follow-up of extracranial internal carotid artery mycotic aneurysm complicated by occlusion have not previously been described in the literature. We present a report of color Doppler sonography, CT, and DSA findings of a mycotic aneurysm of the right extracranial internal carotid artery due to Salmonella associated with occlusion of the internal carotid artery, promptly diagnosed and followed up using these imaging modalities.

Pseudomonas aeruginosa causing a right carotid artery mycotic aneurysm after a dental extraction procedure

Mycotic aneurysms of the carotid arteries are rare. We describe a right carotid artery mycotic aneurysm in a 70-year-old man. His symptoms began immediately after a complicated molar extraction and persisted until the diagnosis was made and surgical resection and repair were undertaken. Pseudomonas aeruginosa was isolated from multiple blood cultures and excised tissues. We review another 73 cases uncovered by an extensive literature search. Bacteremia, recent surgery, head and neck infections, dental infections, and endocarditis are the most common predisposing conditions. Computed tomography and magnetic resonance imaging are techniques for accurately confirming the suspicion of any aneurysm, but angiography is the gold standard. Primary resection of the aneurysm with native vein interposition, in conjunction with prolonged antibiotic therapy, is the preferred strategy. A total of 6 cases thus far, including ours, have been clearly associated with dental surgical procedures. These cases are characterized by rapidly enlarging neck masses in the presence of fever. Microorganisms, particularly gram-negative rods, in contrast to normal oral flora, eg, streptococci and anaerobes, are often isolated. With prompt diagnosis and treatment, outcome is often satisfactory.

Central nervous system infection in the compromised host

The possible causes of central nervous system infection in the compromised host are many. Careful consideration of the underlying defects in host defenses, the epidemiology of infection, and the clinical findings, however, can narrow these possibilities and focus diagnostic testing. Aggressive attempts at early diagnosis and therapy offer the potential for meaningful survival.

Survival from sino-orbital mucormycosis due to Rhizopus rhizopodiformis

We report the first case of sino-orbital mucormycosis caused by Rhizopus rhizopodiformis. Therapy consisted of conservative surgical drainage and intravenous amphotericin B. The patient, an insulin-dependent diabetic, survived her infection with minimal residual deformity. This case and a literature review suggest that infection due to R. rhizopodiformis in diabetics might be more amenable to treatment than mucormycosis caused by other species of fungi. Speciation of such fungi would permit the determination of species specific mortality rates, and may be of therapeutic and prognostic value.

Disseminated mucormycosis with renal involvement

A case of fatal disseminated mucormycosis causing bilateral renal artery thrombosis, parenchymal and collecting system invasion and destruction, and extrinsic perirenal and proximal ureteral compression is presented. In addition to acute renal failure meningoencephalitis, cerebral hemorrhagic infarction and septic enterocolitis were contributing causes of death.

Cranial zygomycosis caused by Saksenaea vasiformis. Case report

A previously healthy youth who had sustained severe head trauma and had received steroids and broad-spectrum antimicrobial agents developed a cranial zygomycotic infection with Saksenaea vasiformis. This is the first time this zygomycete has been implicated as a disease agent. Early identification of the fungal infection and subsequent vigorous medical and surgical therapy led to recovery.