Demonstration of purulent bacterial intracranial infections by computed tomography

Infantile subdural empyema: The role of brain sonography and percutaneous subdural tapping in a resource-challenged region

Background:

This study explored the outcome of children with patent anterior fontanelles who were treated with trans-fontanelle ultrasound scan (TFUSS), which is more affordable and available than CT scan and MRI in the diagnosis of childhood intracranial pathologies and treatment of subdural empyema, in developing countries.

Patients and Methods:

Seventeen infants with post-meningitic subdural empyema, diagnosed using trans-fontanelle ultrasound alone and treated with subdural tapping over a 31-months period, were studied.

Results:

Eleven patients presented with grades II and III Bannister and William grading for level of consciousness in intracranial subdural empyema. Aspirate from 7 (41.2%) patients were sterile. The most common organisms isolated were Streptococcus faecalis 3 (17.6%), Haemophilus Influenza 2 (11.8) and Staphylococcus aureus 2 (11.8), multiple organisms were isolated in three of the patients. Ninety-four percent (94%) of the patients had good outcome. Five subjects developed hydrocephalus, one patient had a recurrence of subdural empyema, four patients had residual hemiparesis, two of the four patients had speech difficulties, while one patient (~6%) died.

Conclusion:

While CT and MRI remain the gold standard for investigating intracranial lesions, transfontanelle ultrasonography is adequate for diagnosis of infantile subdural empyema in resource-challenged areas. Percutaneous subdural tap is an affordable and effective therapy in such patients with financial challenges.

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."

Disproportionate correlation between imaging and outcome in an infant with cerebral abscess

Brain abscesses represent organized foci of suppuration within the parenchyma. In this paper, we describe the case of a 3-month old girl with a large, complicated cerebral abscess. In addition, the course of treatment is presented. The patient’s recovery was excellent. The follow-up MRI showed only subtle porencephalic changes as the only parenchymal sequels, which may have been due to central nervous system (CNS) plasticity in infants.

Imaging aspects of pyogenic infections of the central nervous system

Although pyogenic infections of the central nervous system are not a frequent group of diseases, their morbidity and mortally are very high. For this reason they require prompt diagnosis and treatment to avoid several complications that can lead to an undesired outcome. In this article, we review the imaging findings of these infections according to the anatomic site, their complications, and their differential diagnosis. Special attention is given to the different techniques of magnetic resonance imaging like perfusion, spectroscopy, and diffusion, for each specific situation such as meningitis, abscess, ventriculitis, purulent extra axial collections, and vascular complications.

Radiologic study of injection drug use complications

The complications of injection drug use (IDU) can lead to a wide variety of clinical problems that range from complications localized to the injection site to more disseminated disease. The radiologic workup of these problems uses multiple modalities, depending on the location and type of problem to be investigated. This article discusses and illustrates some of the local and disseminated complications that can occur after IDU.

CT findings of intracranial blastomycosis in a dog

Computed tomography (CT) findings in a dog with intracranial blastomycosis were marked periventricular contrast enhancement of the lateral ventricles, the 3rd ventricle, and the mesencephalic aqueduct. The CT appearance correlated with the histopathologic findings, where severe ependymitis was present throughout the ventricular system and there was stenosis of the mesencephalic aqueduct due to an inflammatory infiltrate. CT is therefore recommended as a screening test for intracranial blastomycosis in dogs and also as an imaging modality for follow-up evaluation after treatment. This is particularly true in dogs with systemic or ocular blastomycosis, which appear to be at higher risk of developing CNS involvement.

Neuroradiologic review of intracranial infection

The detection of intracranial infection continues to be a common reason for neuroradiologic examination. This review covers the neuroradiologic findings of the variety of common infections. It includes meningitis and its complications, as well as bacterial, viral, tuberculous, fungal, and parasitic diseases. Finally, a review of the common infections associated with AIDS is presented. With an increased ability to recognize such infections, radiologists should be able to supply their clinical colleagues with more specific diagnoses.

CT scanning in meningitis

Twelve paediatric cases of acute meningitis were reviewed retrospectively. Findings on CT scan were compared with the clinical course and resulting neurological sequelae. Complications detected by CT scanning include subdural effusion, empyema, hydrocephalus, cerebral atrophy, oedema and infarction. The CT scan results adequately correlated with neurological signs in most cases. Infarction was a reliable indicator of neurological sequelae. Cerebral atrophy alone, however, did not correlate well with the clinical sequelae.

Haemophilus influenzae meningitis with prolonged hospital course

A retrospective evaluation of Haemophilus influenzae type b meningitis observed over a 2-year period documented 86 cases. Eight of these patients demonstrated an unusual clinical course characterized by persistent fever (duration: greater than 10 days), cerebrospinal fluid pleocytosis, profound meningeal enhancement on computed tomography, significant morbidity, and a prolonged hospital course. The mean age of these 8 patients was 6 months, in contrast to a mean age of 14 months for the entire group. Two patients had clinical evidence of relapse. Four of the 8 patients tested for latex particle agglutination in the cerebrospinal fluid remained positive after 10 days. All patients received antimicrobial therapy until they were afebrile for a minimum of 5 days. Subsequent neurologic examination revealed a persistent seizure disorder in 5 patients (62.5%), moderate-to-profound hearing loss in 2 (25%), mild ataxia in 1 (12.5%), and developmental delay with hydrocephalus which required shunting in 1 (12.5%). One patient had no sequelae.

Value of contrast enhanced CT scanning in the non-trauma emergency room patient

To determine the value of performing contrast CT in addition to non-contrast CT in the evaluation of acute non-traumatic central nervous system disorders, we retrospectively reviewed 322 cases originating from the emergency room at our institution. The most common indication for scanning was seizure activity (34% of total), followed by headache (30%), focal neurological deficit (10%), and altered mental status (8%). 75% of the non-contrast scans were normal. The contrast-enhanced scan revealed abnormalities not evident on the non-contrast scan in only three of these cases, and the information did not alter patient management. We conclude that in the acute setting, if a non-contrast CT is normal, a contrast study is usually unnecessary. Therefore, given the additional risks of contrast infusion, the contrast study, if needed, is generally best obtained at a later date, after more careful evaluation of the patient's history and medical records. If the non-contrast CT scan is abnormal, a contrast enhanced CT scan may be beneficial, but, again, is often not needed to direct acute patient management.

[Cerebral abscess. Analysis of 41 cases over a 10-year period]

Although treatment with antibiotics and computerized tomography (CT) of the brain have considerably improved the prognosis of intracranial purulent collections, brain abscess remains a lethal disease in about one out of ten cases. We present a series of 41 brain abscesses diagnosed between 1976 and 1986 and treated surgically. The clinical signs were more often neurological than infectious. Among the exploratory methods, only CT has a real diagnostic value. Treatment is both medical and surgical. Simple aspiration seems to have the triple advantage of producing prompt and effective decompression of brain tissue, enabling the pathogen(s) to be isolated so that the appropriate antibiotic can be chosen, and being a repeatable and little traumatic procedure with less sequelae than surgical excision.

Leucocyte scanning--a valuable tool in diagnosing cerebral abscess--a survey

Intracerebral abscess is a diagnosis which occasionally can be difficult to establish by using CT scan only. This survey describes the usefulness of a supplementary indium-111 autologous granulocyte scan which may increase the diagnostic specificity in the differential diagnosis between neoplasm and intracranial abscess. Judging from the literature and our own investigations the application of the granulocyte scan is discussed with special reference to the possible pitfalls which can give both false negative and false positive results.

Development of paranasal and mastoid sinuses: a computed tomographic pilot study

Paranasal sinus and mastoid disease in children is an important potential source of intracranial sepsis. Cranial computed tomographic (CT) scans are a primary imaging modality for assessment of the paranasal sinuses and mastoids. Radiographic assessment of paranasal sinus development has largely been confined to plain radiographs and polytomographic examination. We report a pilot, quantitative analysis of 30 CT scans obtained from patients without known ear, nose, or throat disease, and aged from 3 weeks to 13.8 years. Ethmoid, sphenoid, and mastoid sinus development was assessed by a "pneumatization index" (PI) derived from each CT scan. At all ages, the rank order of sinus development was ethmoid greater than mastoid greater than sphenoid. Individual developmental rates showed considerable variation. In the newborn, mastoid and sphenoid sinus development was minimal, whereas ethmoid sinuses showed substantial aeration. The data suggest that, for children older than 5 years of age, an ethmoid sinus PI less than or equal to 0.714 is highly suspicious of paranasal sinus disease.

Subdural empyema and cranial epidural abscess

Subdural empyema and cranial epidural abscess are life-threatening infections that require a combined medical and surgical approach for proper management. The pathophysiology, clinical presentation, diagnosis, and treatment of these conditions are discussed.

Brain abscess in childhood

The author review 10 years' experience in managing brain abscess in childhood: 19 cases were treated in children from 1 to 18 years old. The etiology was rhinogenic in 5 cases, congenital heart disease in 5, hematogenous in 3, traumatic in 3, postoperative in 1, and unknown in 3 cases. Brain abscesses that developed by direct spread were located nearby the source, whereas metastatic abscesses (such as cardiogenic or hematogenous) in most cases spread via the vertebral-basilar system, usually developing in the parieto-occipital regions. Four of the 5 cases with multiple abscesses were cardiogenic and one hematogenous. The most important neurological signs were paresis (10 cases) and cranial nerve involvement (10 cases). Six abscesses were sterile and 6 grew aerobic and 6 anaerobic bacteria. In one case, aerobic as well as anaerobic bacteria were found. Fifteen patients were treated preoperatively with antibiotics. The treatment was operative in 17 cases. In two cases, gravely ill on admission, no surgical treatment was given. The etiology, localization, bacteriology, surgical methods, and results in those cases are discussed.

Radiology of intracranial empyemas, with special reference to computed tomography

Intracranial empyemas are collections of pus, which usually develop in the subdural or extradural space; the former is more frequent. They are not common lesions, forming about one fifth to one third of reported series of intracranial abscesses [1, 2]. In the preantibiotic era, they were commonly fatal [3], but a review of series reported since widespread use of antibiotics indicated a continuing mortality rate of 25% [4]. Their radiological interest resides not only in their importance, but also in the problems of early diagnosis. Negative results have been reported with a number of techniques, including radionuclide imaging [5], computed tomography (CT) [2, 4, 6, 7] and cerebral angiography [8, 9]. A recent neurosurgical review concluded balefully that "no reassurance can be obtained from negative investigations". The present study is an examination of the possible ways in which such negative studies, particularly CT, can be avoided.

Atypical CT findings in bacterial meningoencephalitis

Computed tomography has become a valuable imaging modality in the evaluation and management of most intracerebral infections. We report two cases of intracranial infections with atypical CT findings, and attempt to correlate these findings with the pathophysiology.

Clinical stages of human brain abscesses on serial CT scans after contrast infusion. Computerized tomographic, neuropathological, and clinical correlations

The authors describe a classification of human brain abscesses into stages of development as demonstrated on computerized tomography (CT) scans. The results of CT staging of 14 human brain abscesses are compared with the previously published findings in an experimental brain abscess model developed by the same authors. The CT criteria for categorizing brain abscesses into cerebritis and capsule stages were based on the pattern of contrast enhancement and the time-density curve of enhancement obtained from sequential CT scans after contrast infusion. Using these CT criteria, it was possible to accurately categorize all 14 brain abscesses into cerebritis and capsule stages. Histological examination of surgical and autopsy specimens provided immediate confirmation of the abscess stage in six patients. Indirect staging, based on surgical findings and/or subsequent autopsy findings, was possible in eight patients. Corticosteroid administration greatly reduced contrast enhancement in the cerebritis stage, but had little effect in the capsule stage. A systematic approach utilizing CT for establishing the diagnosis, staging, and treatment planning of brain abscess is proposed.

[Neurological and cerebrospinal fluid evaluation in children with serogroup A meningococcal meningitis]

Our aim is to present the results obtained from the evaluation of the neurological examination as well as chemical and cytologic data from the CSF obtained at the admission and discharge of 255 children aged between zero and 12 years with a diagnosis of serogroup A meningococcal meningitis made at the Hospital Emilio Ribas in São Paulo, Brasil, in the years of 1976 and 1977. By the time of their admission, 27 patients (10,59%) showed positive neurologic findings besides meningeal signs. Seizures were the most common ones, with higher incidence in children under 13 months; ataxia, deafness, motor deficits, neuro-psychomotor involution, subdural effusions and disturbed behavior followed in that order. Subdural effusions were found only in those under 13 months. A fatal outcome was registered in eleven (4,31%) patients, of which nine died in the first 24 hours after admission. By the time of hospital discharge 14 patients (5,49%) had neurological abnormalities, deafness and ataxia being the most common ones, in the older patients. Under 13 months, developmental involution predominated. There is no need of CSF evaluation for antibiotic therapy interruption in patients with meningococcal meningitis.

CT evaluation of Haemophilus influenzae meningitis with clinical and pathologic correlation

Ten proven cases of Haemophilus influenzae meningitis have been reviewed, in which all had CT scans during their first 3 weeks of illness. An attempt was made to correlate the neuropathologic basis of the disease with the CT findings. Progression of the CT changes with the course of illness and treatment is emphasized. Usual indications for CT imaging of the brain in patients with meningitis are: detection of subdural empyema or effusion, hydrocephalus, infarct, cerebritis and abscess. Widespread cerebral damage can be more fully evaluated with iodine contrast infusion if clinically indicated. CT scanning has proven to be a valuable indicator of such complications and useful predictor of clinical recovery or residual neurologic sequelae.

Bilateral intracranial granulomas as a complication of infected subdural peritoneal shunt

Intracranial granuloma in childhood is considered to be a very rare disorder. A three-year-old child is described who had bilateral intracranial granulomas originating from the ends of bilateral subdural-peritoneal shunts. Serial computerized tomographic examinations revealed variable and peculiar findings. Since subdural-peritoneal shunt is used in neonate, intracranial granuloma must be considered as a potential complication of unremoved subdural-peritoneal shunt.

Serial CT scans in Haemophilus influenzae meningitis of childhood

Eleven children admitted to hospital with H. influenzae meningitis had computerized tomographic head scans during the acute stage of the illness. 10 of the 11 had at least one other scan between two weeks and 30 months later. This study evaluated the changes seen in the scans in relation to the evolution of the illness, especially with reference to subdural effusions and communicating hydrocephalus. The early scans were found to have no significance in predicting clinical outcome. However, a temporary developmental lag occurred in those children with subdural effusions, transient communicating hydrocephalus, and without permanent neurological deficit.

CT studies of brain abscesses in cats

Cerebral abscesses were produced in 56 cats by introducing staphylococcus aureus into the white matter of one cerebral hemisphere, using a stereotaxic apparatus. The cats were treated with antibiotics and/or steroids. The size and density of the inflammatory process and the abscess ring were measured on postcontrast CT scans. Differences were found depending on the stage of the abscess, but the deviation of values were too great for determining the age of the abscess from one measurement, to be able to apply proper treatment. The size and density of the abscesses were the same on CT whether the animals were treated or not. This was contrary to the clinical picture, the measurements of edema, and the histopathological studies.

Neuropathological and computerized tomographic findings in experimental brain abscess

The neuropathological progression of brain abscess formation was studied experimentally at sequential stages in dogs, and the findings correlated with the appearance on computerized tomographic (CT) brain scans. The evolution of brain-abscess formation was divided into four stages based on histological criteria: early cerebritis (Days 1 to 3); late cerebritis (Days 4 to 9); early capsule (Days 10 to 13); and late capsule (Days 14 and later). The cerebritis stage was characterized by prominent perivascular cuffing by inflammatory cells in the area adjacent to the developing necrotic center. However, the early elements of capsule formation appeared with the presence of fibroblasts by Day 5. The CT scans showed ring-shaped contrast enhancement by Day 3. Delayed scans at 30 minutes revealed diffusion of the contrast material into the developing necrotic center, forming a solid lesion. In lesions that were well encapsulated (14 days and older), five distinct histological zones were apparent: 1) a well formed necrotic center; 2) a peripheral zone of inflammatory cells, macrophages, and fibroblasts; 3) the dense collagenous capsule; 4) a layer of neovascularity associated with continuing cerebritis; and 5) reactive astrocytes, gliosis, and cerebral edema external to the capsule. The CT appearance of well encapsulated abscesses showed a typical ring-shaped contrast-enhancing lesion. On the delayed scans, the "ring" did not fill in with contrast enhancement. The diameter of the ring correlated best with the presence of cerebritis (perivascular infiltrates in the adventitial sheaths of vessels surrounding the abscess). The discussion focuses on the relevance of this study to the current management of patients with brain abscess.

Recent diagnostic experience with subdural empyema

The authors review the Neurological Institute experience of six cases of subdural empyema in the 4 years since the introduction there of computerized tomography (CT) scanning. Four patients had no known prior neurological disease, and presented with the classical clinical syndrome of fever, depressed sensorium, and focal seizures; three of these patients had histories or radiographic evidence of sinus disease. The two remaining patients had undergone earlier drainage procedures for chronic subdural hematomas, and presented without neurological symptoms but with low-grade fever and signs of local wound infection. All of the patients of the former (primary) empyema group had technically satisfactory contrasted CT scans at a time when the clinical syndrome was fully developed, and none revealed the subdural collection. Angiograms were performed in three of these cases and were uniformly successful in demonstrating the collections and suggesting their inflammatory natures. Both secondary empyemas were readily visualized by CT, and showed characteristic brightly enhancing membranes. It is concluded that primary and secondary subdural empyemas differ both in clinical presentation and in accuracy of CT diagnosis. In the former group, evidence of sinus disease is suggestive but does not by its absence exclude a purulent subdural collection. In patients with the typical clinical syndrome, reliance on CT is hazardous, and angiography is the diagnostic procedure of choice.

Electroencephalographic cranial computerized tomographic correlations in brain abscess

The authors studied 19 cases of brain abscess. The investigation included one or more EEG records from 13 patients and one or more cranial computerized tomograms in all cases. In this work the two techniques were associated to establish the diagnosis of cerebral abscess. The EEG is almost always abnormal and pronounced EEG disturbances are, in most cases, sufficient for indicating a diagnosis of a space-occupying process. On the other hand, EEG patterns suggestive of brain abscess were detected in only 38% of the patients. In brain abscess, CCT is of considerable value since the existence of 'suppurative' images was demonstrated in all cases and of these, 70% were characteristic. The association of these two techniques is thus extremely useful in the diagnosis of cerebral abscess, to follow its evolution and to detect postoperative relapse or to evaluate the efficiency of medical management alone.

Cerebral abscesses produced by bacterial implantation and septic embolisation in primates

The degree of brain abscess encapsulation is positively related to surgical mortality and methods to enhance capsule wall formation, therefore, have therapeutic relevance. Two primate models are described which may be useful in the investigation of encapsulation of traumatic and metastatic brain abscesses. Direct intracerebral inoculation induces abscesses displaying more prominent inflammatory responses and encapsulation than does septic embolisation, despite similar abscess age and size. Cerebral ischaemia surrounding metastatic suppurative foci may retard capsule wall formation.

Computed tomographic presentation of granulomatous reaction from intraventricular shunt

A case is presented in which the patient was diagnosed as having a large mass lesion arising in the region of the quadrigeminal plate. The patient had been shunted in the past for hydrocephalus. The computed tomographic picture was that of a primary brain neoplasm. At surgery extensive granulation tissue was found. The similarity between the CT presentation of this inflammatory mass and a neoplasm is emphasized.

Experience with multiloculated brain abscesses

The author reports his experience with 10 consecutive multiloculated brain abscesses diagnosed by computerized tomography and successfully treated by excision (primary or early secondary) or repeated aspiration.

Computer reconstructed sagittal and coronal CT scans. Applications in neurological disorders of infants and children

Recent technical advances in computed tomography (CT) allow sagittal and coronal image reconstruction by computer manipulation of data from thin-section transverse scans. Three cases are presented to illustrate this new supplementary modality in the pediatric patient. The technique, diagnostic implications and value of orthogonal plane image reconstruction are discussed.

Role of vascular proliferation on angiographic appearance and encapsulation of experimental traumatic and metastatic brain abscesses

Experimental traumatic abscesses were produced in rhesus monkeys by intracerebral injection of nutrient agar contaminated with Staphylococcus epidermidis, and metastatic abscesses were induced by intracarotid embolization of silicone cylinders contaminated with Staphylococcus epidermidis. All monkeys underwent preoperative and serial postoperative carotid angiography. Traumatic abscesses produced early capsular blushes and progressive anterior cerebral artery displacements. Metastatic abscesses induced transient midline shifts but no capsular stains. Postmortem studies on the monkeys showed that mean capsular thickness and segmental wall vascularity of the traumatic and metastatic abscesses were significantly different (p less than 0.001), despite equal abscess ages and similar abscess volumes. In comparison to traumatic abscesses, metastatic abscesses demonstrated reduced inflammatory cell infiltration and retarded collagen formation around proliferating capsular vessels. Brain surrounding the metastatic abscesses demonstrated ischemic changes. The results suggest that 1) capsular blushes during cerebral angiography are secondary to vascular proliferation within the capsule and not to compression of surrounding brain, 2) vascular staining reflects capsular thickness, 3) capsular vascularity contributes to collagen formation, 4) encapsulation is dependent upon the integrity of surrounding brain, and 5) adjacent cerebral ischemia may impede inflammatory responses involved in capsule formation.

Craniocerebral computed tomography in the neonate

Craniocerebral computed tomography (CT) is an extremely important component of the armanentarium for diagnosis of neurological disorders in the neonate. The indications, techniques, normal anatomy, and pathologic abnormalities of CT scans in newborn infants are presented. Hydrocephalus and intracranial hemorrhage are discussed in depth.

CT diagnosis of intracranial cystic abnormalities in children

The introduction of computed axial tomography has been of tremendous importance in the evaluation of intracranial pathology in children. The broad spectrum of cystic intracranial lesions of congenital, infectious, traumatic, vascular and neoplastic origin are discussed. Their CT findings, pathology and pathogenesis are emphasized.

Computed tomography in meningitis

Computed tomography in 34 cases of meningitis has revealed a spectrum of findings. In acute cases these include enlargement of the subarachnoid spaces, generalized contrast enhancement of the meninges and ependyma, sterile and pyogenic subdural collections, cortical infarction, and cerebral necrosis.

Computerised axial tomography and acute neurological problems of childhood

The results of computerised axial tomography (CAT) in 80 children with neurological symptoms and/or signs of less than 3 months' duration are discussed in relation firstly to intracranial pathology and secondly to clinical presentation. 26 children had intracranial space-occupying lesions (tumour, abscess, haemorrhage, infarct). CAT was abnormal in 25 of these and diagnostic in 18. A further 20 children had meningitis or encephalitis, and CAT was abnormal in 12. In contrast with this high rate of scans showing pathology, CAT was abnormal in only 4 of the remaining 34 children who had less definite or no intracranial disease. Analysis of clinical presentation showed that 42 of 69 children presented with persisting neurological signs and of these, 25 had an intracranial space-occupying lesion and 29 had abnormal CAT. Only 5 of 27 children who had symptoms alone or signs lasting less than 24 hours had abnormal CAT, and no intracranial lesion requiring specific treatment was missed. CAT is useful for demonstrating the site, size, and nature of many lesions. The scan may not initially be abnormal in brain stem gliomas and in small subdural collections of fluid.

Computed tomography for neurological intensive care patients. Report on one hundred CT examinations

The first 100 computed tomographic (CT) examinations of the patients on the neurological intensive care ward are discussed and reported on the basis of selected typical findings. Characteristic patterns of the CT findings in determined cerebral diseases are explained. The possibility and necessity of CT observations of the development, of inflammatory and cerebrovascular processes in particular are emphasized. A comparison of our experience with CT and other neuroradiological methods, is made. The clinical diagnoses, including the respective number of cases and the pertinent CT findings, are presented in a Table.