Subdural and epidural empyemas: MR imaging

Fatal case of subdural empyema caused by Campylobacter rectus and Slackia exigua

We report a fatal subdural empyema caused by Campylobacter rectus in a 66-year-old female who developed acute onset of confusion, dysarthria, and paresis in her left extremities. A CT scan showed hypodensity in a crescentic formation with a mild mid-line shift. She had a bruise on her forehead caused by a fall several days before admission, which initially raised subdural hematoma (SDH) diagnosis, and a burr hole procedure was planned. However, her condition deteriorated on the admission night, and she died before dawn. An autopsy revealed that she had subdural empyema (SDE) caused by Campylobacter rectus and Slackia exigua. Both microorganisms are oral microorganisms that rarely cause extra-oral infection. In our case, head trauma caused a skull bone fracture, and sinus infection might have expanded to the subdural space causing SDE. CT/MRI findings were not typical for either SDH or SDE. Early recognition of subdural empyema and prompt initiation of treatment with antibiotics and surgical drainage is essential for cases of SDE. We present our case and a review of four reported cases.

Concomitant extradural, subdural, and intraparenchymal abscesses of the brain in a patient with cerebral melioidosis - A case report

Background

Extra axial abscess of the brain is a rare entity, moreover, extra-axial abscess concomitant with intraparenchymal purulent collections are scarcely reported in the literature. Etiology includes penetrating trauma, paranasal sinusitis, mastoiditis, craniospinal surgeries, and the rare spread of infectious agents through the hematogenous route.

Case description

We present a case of a young male with Burkholderia pseudomallei Central Nervous System (CNS) melioidosis, forming abscesses in extra-axial and intraparenchymal planes without contiguity.

Conclusion

This is to emphasize the importance of MR spectroscopy and other convenient methods in differentiating the etiology in cranial infections.

Non-contrast-enhancing subdural empyema: illustrative case

BACKGROUND

Subdural empyema (SDE) is a life-threatening intracranial infection that, without timely surgical intervention and appropriate antibiotic treatment, is inevitably fatal. SDE is classically recognized on brain imaging as a subdural collection surrounded by a contrast-enhancing ring.

OBSERVATIONS

The authors describe the case of a 41-year-old male with clinical features consistent with SDE but without any contrast enhancement on multiple computed tomography scans obtained more than 48 hours apart. Given the high clinical suspicion for SDE, a craniotomy was performed that demonstrated frank pus that eventually grew Streptococcus pyogenes.

LESSONS

This case demonstrates that SDE may present without ring enhancement on contrast-enhanced imaging. In critically ill patients with a high clinical suspicion for SDE despite lack of contrast enhancement, we demonstrate that exploratory burr holes or craniotomy can provide diagnostic confirmation and source control.

Subdural empyema due to mixed infections successfully treated medically: A case report with review literature

Subdural empyema is a rare intracranial infection with an accumulation of purulent material between the dura and arachnoid matter. We report a case of 17 years old presented with an altered conscious level. CSF analysis showed increased WBCs. His situation has improved after treating by acyclovir, ceftriaxone, vancomycin, and dexamethasone.

Subdural empyema is a rare intracranial infection with an accumulation of purulent material between the dura and arachnoid matter. We report a case of 17 years old presented with an altered conscious level. CSF analysis showed increased WBCs. His situation has improved after treating by acyclovir, ceftriaxone, vancomycin, and dexamethasone. Bacterial infection medical treatment meningeal irritation subdural empyema viral infection.

Unusual intracranial suppuration: illustrative cases

BACKGROUND

Intracranial suppuration (ICS) is a rare complication that can arise from various disease processes and is composed of brain abscess, extradural empyema, and subdural empyema. Although significant progress has been achieved with antibiotics, neuroimaging, and neurosurgical technique, ICS remains a serious neurosurgical emergency. An uncommon presentation of ICS is sterile ICS, which has yet to be fully elucidated by clinicians. The authors present 2 cases of unusual sterile ICS: a sterile subdural empyema and a sterile brain abscess.

OBSERVATIONS

Both patients underwent surgical treatment consisting of craniotomy to evacuate the pus collection. The blood cultures from both the patients, the collected empyema, and the thick capsule from the brain abscess were sterile. However, the necrotic brain tissue surrounding the abscess contained inflammatory cells. The authors’ review of the literature emphasizes the rarity of sterile ICS and substantiates the necessity for additional studies to explore this field.

LESSONS

Sterile ICS is a disease entity that warrants further investigation to determine appropriate treatment to improve patient outcomes. This study highlights the paucity of data available regarding sterile ICS and supports the need for future studies to uncover the etiology of sterile ICS to better guide management of this condition.

Intracranial Manifestation of Melioidosis: A Case Report and Long-Term Follow-Up

Primary neurological melioidosis is rare with fewer than 50 cases reported world-wide. We report the first documented case of primary neurological melioidosis in Sweden, a 32-year old male who previously lived in Thailand for six years and recently moved to Sweden. He presented with headache, irritability and lack of concentration. Investigation with computerized tomography (CT) and subsequent magnetic resonance imaging (MRI) showed epidural fluid that was interpreted as a chronic epidural hematoma. He underwent surgical evacuation of the epidural collection that was found to be a white collection mixed with pus and bacterial culture results were positive for Burkholderia pseudomallei.

Detection of Coalescent Acute Mastoiditis on MRI in Comparison with CT

Purpose

Current imaging standard for acute mastoiditis (AM) is contrast-enhanced computed tomography (CT), revealing inflammation-induced bone destruction, whereas magnetic resonance imaging (MRI) outperforms CT in detecting intracranial infection. Our aim was to compare the diagnostic performance of MRI with CT in detecting coalescent AM and see to which extent MRI alone would suffice to diagnose or rule out this condition.

Methods

The MR images of 32 patients with AM were retrospectively analyzed. Bone destruction was evaluated from T2 turbo spin echo (TSE) and T1 Gd magnetization-prepared rapid acquisition with gradient echo (MPRAGE) images. Intramastoid enhancement and diffusion restriction were evaluated subjectively and intramastoid apparent diffusion coefficient (ADC) values were measured. The MRI findings were compared with contrast-enhanced CT findings of the same patients within 48 h of the MR scan.

Results

Depending on the anatomical subsite, MRI detected definite bone defects with a sensitivity of 100% and a specificity of 54–82%. Exception was the inner cortical table where sensitivity was only 14% and specificity was 76%. Sensitivity for general coalescent mastoiditis remained 100% due to multiple coexisting lesions. The absence of intense enhancement and non-restricted diffusion had a high negative predictive value for coalescent mastoiditis: an intramastoid ADC above 1.2 × 10⁻³ mm²/s excluded coalescent mastoiditis with a negative predictive value of 92%.

Conclusion

The MRI did not miss coalescent mastoiditis but was inferior to CT in direct estimation of bone defects. When enhancement and diffusion characteristics are also considered, MRI enables dividing patients into low, intermediate and high-risk categories with respect to coalescent mastoiditis, where only the intermediate risk group is likely to benefit from additional CT.

Subdural empyema complicated after trepanation and drainage of chronic subdural hematoma: A case report

RATIONALE

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical diseases. However, complicated subdural empyema rarely occurs after trepanation and drainage of chronic subdural hematoma.

PATIENT CONCERNS

A male patient (77 years old) was admitted to the hospital on the 2nd day of fever after an undergoing a "trepanation and drainage of chronic subdural hematoma" operation at a local hospital. After admission, the patient was treated with an emergency operation in which a subdural abscess was diagnosed and then administered antibiotics after the operation.

DIAGNOSIS

According to the clinical manifestations, intraoperative findings of imaging examination and the results of pus culture, the diagnosis was subdural empyema.

INTERVENTION

We surgically removed the subdural empyema. Postoperative antibiotics were administered according to the results of bacterial culture.

OUTCOMES

At 3 months after the operation, the patient returned to the hospital for reexamination and was found to have achieved a good recovery and good self-care.

LESSONS

Subdural empyema after trepanation and drainage of chronic subdural hematoma is a very rare and severe disease. Early diagnosis and operative intervention as well as the intravenous administration of antibiotics can improve the prognosis of patients and enhance their quality of life.

A New Classification System is Helpful in Diagnosing Intracranial Complications of Acute Mastoiditis in CT

PURPOSE

To assess the usefulness of the new computed tomography (CT) classification criteria proposed by Horowitz et al. and their effect on inter-observer agreement when estimating intracranial complications of acute mastoiditis.

METHODS

In this study 53 contrast-enhanced CT scans of patients with acute mastoiditis were each retrospectively reviewed by two radiologists, using two different assessment criteria for intracranial complications. According to the new criteria, intracranial CT findings in the perisinuous area were graded into four classes (I normal, II linear halo, III nodular halo ≤4 mm thick and IV nodular halo >4 mm thick), where classes III and IV indicate a high risk for epidural abscesses. Inter-reader agreement was estimated by weighted kappa analysis for both methods.

RESULTS

With the old method, epidural abscesses were suspected in six and venous sinus thrombosis in five patients. With the new method, high-risk perisinuous lesions (classes III or IV) were detected in 11 patients, and sinus thrombosis outside the perisinuous area in 3 patients. All epidural abscesses were in the perisinuous area. Of the patients four, in whom intracranial pathology was not suspected with the old method, fell into the high-risk group (class III) according to the new method. All class IV lesions were also determined to be pathological with the old method. The inter-observer agreement (weighted kappa) rose from 0.21 (old method) to 0.80 (new method) when assessing epidural abscesses and from 0.44 (old method) to 0.85 (new method) when assessing sinus thrombosis.

CONCLUSION

The new assessment method raised the inter-observer agreement for detection of intracranial acute mastoiditis complications, namely epidural abscesses and venous sinus thrombosis.

Multiple Brain Abscesses due to Streptococcus anginosus: Prediction of Mortality by an Imaging Severity Index Score

An elderly patient with altered mental status, brain abscesses, ventriculitis, and empyemas died of septic shock and brain abscesses secondary to Streptococcus anginosus despite aggressive treatment. An imaging severity index score with a better prognostic value than the Glasgow coma scale predicted mortality in this patient.

Bacterial, Fungal, and Parasitic Infections of the Central Nervous System: Radiologic-Pathologic Correlation and Historical Perspectives

Despite remarkable progress in prevention and treatment, infectious diseases affecting the central nervous system remain an important source of morbidity and mortality, particularly in less-developed countries and in immunocompromised persons. Bacterial, fungal, and parasitic pathogens are derived from living organisms and affect the brain, spinal cord, or meninges. Infections due to these pathogens are associated with a variety of neuroimaging patterns that can be appreciated at magnetic resonance imaging in most cases. Bacterial infections, most often due to Streptococcus, Haemophilus, and Neisseria species, cause significant meningitis, whereas the less common cerebritis and subsequent abscess formation have well-documented progression, with increasingly prominent altered signal intensity and corresponding contrast enhancement. Atypical bacterial infections are characterized by the development of a granulomatous response, classically seen in tuberculosis, in which the tuberculoma is the most common parenchymal form of the disease; spirochetal and rickettsial diseases are less common. Fungal infections predominate in immunocompromised hosts and are caused by yeasts, molds, and dimorphic fungi. Cryptococcal meningitis is the most common fungal infection, whereas candidiasis is the most common nosocomial infection. Mucormycosis and aspergillosis are characterized by angioinvasiveness and are associated with high morbidity and mortality among immunocompromised patients. In terms of potential exposure in the worldwide population, parasitic infections, including neurocysticercosis, toxoplasmosis, echinococcosis, malaria, and schistosomiasis, are the greatest threat. Rare amebic infections are noteworthy for their extreme virulence and high mortality. The objective of this article is to highlight the characteristic neuroimaging manifestations of bacterial, fungal, and parasitic diseases, with emphasis on radiologic-pathologic correlation and historical perspectives.

Presumptive Subdural Empyema in a Dog

A 13 mo old mixed-breed dog was referred for acute lateralized forebrain signs. MRI of the brain demonstrated abnormalities consistent with severe meningitis and subdural empyema secondary to a retrobulbar abscess. The dog’s clinical signs improved with antibiotic therapy, and repeat imaging showed resolution of subdural fluid accumulation presumed to be empyema with mild residual meningeal enhancement. Subdural empyema is an infrequent cause of encephalopathy in small animals and usually develops through direct extension of a pericranial infection. This report presents a case of presumptive subdural empyema in a dog that was successfully treated without surgical intervention. MRI is the preferred imaging modality for diagnosis of subdural empyema, and the characteristic imaging features are described.

Pediatric parafalcine empyemas

Subdural intracranial empyemas and brain abscesses are a rare complication of bacterial sinusitis. Pediatric parafalcine abscesses are a rare entity with different treatment compared with other brain abscesses. We present two pediatric cases with falcine abscess as a sinusitis complication and introduce our department’s treatment management. In addition a review of literature is performed. Surgical cases of our department and their management are compared with the current literature. In our cases, both of the children showed a recurrent empyema after the first surgical treatment and antibiotic therapy. A second surgical evacuation was necessary. The antibiotic therapy was given for 3 months. Short-time follow-up imaging is necessary irrespective of infection parameters in blood and patient's clinical condition. Especially in parafalcine abscesses a second look may be an option and surgical treatment with evacuation of pus is the treatment of choice if abscess remnants are visualized.

Neonatal bacterial meningitis

Neonatal meningitis contributes substantially to neurological disability worldwide. Its incidence remains low but is significantly higher in neonates with documented sepsis, preterm infants, and when meningitis is nosocomial. Neonates are at higher risk of meningitis because of immaturity in humoral and cellular immunity, and the absence of specific clinical signs makes diagnosis of meningitis more difficult in neonates than in older children. Neonatal meningitis remains, therefore, a public health challenge for pediatricians. Mortality and long-term complications in survivors are observed in 10-15% and 20-50%, respectively, depending on term at diagnosis, type of identified organisms, and delay before treatment. Neurological deficits range from moderate-to-severe disabilities to more subtle problems including visual deficits, middle-ear disease, and cognitive and behavioral impairments. Intracerebral complications should be documented using magnetic resonance imaging. Treatment should be initiated once the diagnosis is suspected using a parenteral combination of bactericidal antibiotics adapted to pathogen sensitivity.

Emergent neuroimaging of intracranial infection/inflammation

Infectious and inflammatory processes of the intracranial compartment often result in acute clinical presentations. The possible causes are legion. Clues to the diagnosis involve clinical presentation, laboratory analysis, and neuroimaging. This article reviews some of the salient factors in understanding intracranial infection/ inflammation, including pathophysiology and neuroimaging protocols/findings, and provides some examples and a few "pearls and pitfalls."

Bilateral chronic subdural hematoma contaminated with Klebsiella pneumoniae : an unusual case

This article presents the case of a bilateral chronic subdural hematoma which was contaminated with Klebsiella pneumoniae and resulted in a life-threatening central nervous system infection. After repeated of bilateral burr-hole drainage, the patient became hyperpyrexic and drowsy. Suppuration within the subdural space was suspected and then the patient underwent bilateral fronto-temporo-parietal craniotomies, and pus was evacuated. Its cultures revealed Klebsiella pneumoniae. Intravenous meropenem was given for 6 weeks. He recovered completely. Microorganisms like Klebsiella pneumoniae may directly infect the subdural space with iatrogenic contamination.

Subdural empyema secondary to sinus infection in children

OBJECTIVE

To evaluate the impact, on morbidity and mortality, of aggressive surgical management of subdural empyema of sinus origin in children.

METHOD

The authors conducted a retrospective review of 20 children admitted between 2000-2007 to Alder Hay Children Hospital and The Walton centre for Neurology and Neurosurgery for subdural empyema secondary to sinus infection. Clinical presentation, duration of symptoms, radiological investigations, surgical treatment and post-operative outcome were evaluated.

RESULTS

Outcome was favourable in 19 cases. In four cases, there were re-accumulation requiring surgical evacuation, four patients experienced post-operative seizures but were seizure-free at follow-up. There was only one mortality in the series.

CONCLUSION

Subdural empyema secondary to sinus infection, although uncommon, it could be associated with a relative high morbidity and mortality rate. Early aggressive surgical and medical management with drainage of intracranial or sinus collections and antibiotics therapy lead to a low mortality or morbidity rate and good clinical outcome.

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.

ACR Appropriateness Criteria on headache-child

In a pediatric patient with an isolated headache or a classic migraine unaccompanied by neurologic signs, presence of a seizure, or supporting historical data, an imaging workup is usually not indicated. For a sudden severe headache or a headache with positive neurologic signs or symptoms or supporting historical data, MRI or CT should be considered. For the acute severe (thunderclap) headache, CTA, MRA, or catheter angiography may be appropriate.

Recognizing neurosurgical conditions in the pediatrician's office

Clinical problems with potential neurosurgical ramifications, such as headache and abnormalities of head size and shape, arise often in general pediatric practice. Other neurosurgical issues may manifest themselves less frequently and more insidiously. In either case the pediatrician who is alert to spectrum of the presentations of neurosurgical conditions will direct investigations and referrals efficiently and inspire the confidence of the patient and the family.

Epidural hematoma as a complication of sphenoid sinusitis and epidural abscess: a case report and literature review

Imaging is of paramount importance in early diagnosis of epidural abscess and its intracranial complications. Typical CT imaging features of an epidural abscess include a hypodense lentiform extra-axial collection with rim enhancement. We present a case of epidural abscess that was hyperdense on CT scan due to the presence of associated epidural hematoma. The literature is reviewed regarding this unusual complication of epidural abscess.

An unusual presentation of neurotuberculosis: subdural empyema. Case report

Tuberculosis continues to be a major public health concern, especially in developing countries. Many types of neurotuberculosis have been described, but there is only one previously reported case of subdural empyema caused by tuberculous bacilli. A 1-year-old boy who had been treated for pulmonary tuberculosis was referred to the authors' institution with a diagnosis of right frontoparietal extraaxial abscess formation. Computerized tomography and magnetic resonance imaging revealed an extraaxial abscess with no evidence of calvarial infection. A craniotomy was performed to drain the pus, which was located subdurally. A polymerase chain reaction test yielded positive results, and histopathological examination revealed caseation. Antituberculous treatment was started after a diagnosis of subdural empyema with related neurotuberculosis had been made. At the end of a 12-month course of medical therapy, the patient was well with no evidence of tuberculosis.

Complications of Acute Otitis Media and Sinusitis

Otitis media and sinusitis are clinically identifiable infections of the middle ear and sinuses. Both conditions should be regarded as dynamic processes with a clinical spectrum, which may extend from a self-limiting condition to a prolonged and sometimes complicated disease. With the advent of antibiotics, the natural course of these diseases has changed significantly. Severe complications once characterized by high mortality and morbidity have become rare. This has led to a generation of general practitioners, otolaryngologists, and pediatricians trained in an atmosphere of complacency in the treatment of otitis media and sinusitis. However, several recent publications report an increasing incidence of serious complications associated with otitis and sinusitis, probably due to rising antibiotic resistance. A high index of suspicion, based on clinical grounds, is therefore warranted. The ultimate goal in the approach of these conditions is pharmacotherapeutic management, resorting to surgery for the restoration of function rather than for the eradication of the infectious disease. As new information becomes available on the etiology, pathogenesis, and bacteriology of these conditions, new strategies are being used to improve treatment and to prevent complications. These measures should include a more appropriate choice of antibiotics, the determination of the role of adjuvant therapy and surgical procedures, and the development of new vaccines.

Intracranial complications of sinusitis in childhood

Complications of sinusitis in children, such as intracranial abscess formation, are uncommon and are often clinically unremarkable in comparison to similar disease processes in adults. Between 1983 and 1991, 443 children were admitted to Children's National Medical Center in Washington, DC, for treatment of sinusitis. Fourteen of these children presented with intracranial extension of the infection and abscess formation. A retrospective review of these patients revealed that the risk of developing an intracranial abscess secondary to sinusitis was 3%. The management of these patients included surgical drainage of the infected sinuses and intracranial surgical exploration. Cranialization and exenteration of the frontal sinus proved to be effective single-stage procedures. While not indicated in all patients, these procedures eliminated the sinus as a source of continued or potential infection and obviated the need for a second obliterative procedure. Combined antimicrobial therapy and surgical drainage should be the management protocol.

Neuroimaging of meningeal disease

In the past two decades, the advent of CT and MRI has made a considerable impact on the evaluation of meningeal diseases, conditions once regulated to cytological, histopathological, or postmortem analyses alone. This article reviews the imaging findings in various meningeal processes with particular attention to the anatomic definition of the meningeal layers and their relationship to the development of meningeal pathology and consequent imaging characteristics.

Bilateral epidural empyemas in an adolescent

Epidural empyema is an unusual cause of headache that may be encountered in the emergency department. The collection of suppurative fluid usually results from local spread of sinusitis, although many other predisposing factors have also been described. Patients with epidural empyema usually present with nonspecific cephalalgia that may be accompanied by fever and leukocytosis but is unlikely to be associated with focal neurological findings. The case of an adolescent who presented to our emergency department twice in 6 days with persistent headache is reported; cranial computed tomography performed on the second visit demonstrated bilateral epidural empyema. This entity is uncommon, but may certainly be encountered by the emergency physician.

The efficacy of MR imaging in subdural empyema

MRI findings of a 14-year-old boy with subdural empyema (SE) are reported and compared with those of serial CT-scan. He was admitted with fever, headache, right hemiplegia and facial palsy. Initial enhanced CT-scan revealed a slit left lateral ventricle and a shift in the mid-line structures, but failed to detect any SE. MRI at 10 days after admission clearly demonstrated SE as an area of low intensity on T1-weight (T1WI) and very high intensity on T2-weight (T2WI). Post-contrast enhanced MRI (CE-MRI), using Gd-DTPA, showed a contrast enhancement in the wall of SE. However, no definite parenchymal abnormal intensity areas were detected, suggesting that the diagnosis was made sufficiently early for timely treatment and good neurological outcome. CE-MRI proved to be a more powerful and better diagnostic procedure than enhanced CT-scan, and was very useful in determining the state and development of the disease.