Intracranial suppuration: a modern decade of postoperative subdural empyema and epidural abscess

Case report: Diagnosis and treatment of delayed epidural pyogenic abscess after brain tumor operation: a report of 5 cases and review of the literature

Objective

To explore the clinical manifestations and treatment of delayed epidural pyogenic abscess after brain tumor surgery.

Method

To retrospectively analyze the medical records of 5 patients with delayed epidural pyogenic abscess after brain tumor surgery in our hospital from January 2010 to December 2020, including clinical manifestations, laboratory results, imaging findings, treatment measures, prognosis, etc. The causes of epidural abscesses were analyzed, and the treatment methods and prognosis were evaluated.

Result

Among the 5 cases, there were 4 male and 1 female patient, aged 52-75 years. Three cases were gliomas and 2 cases were meningiomas. Four cases received postoperative radiotherapy, and 1 case had open frontal sinus during operation. None of the surgical incisions were infected. The time between the tumor surgery and the discovery of an epidural abscess was 1.5 to 24 months. All 5 patients had headaches, 1 case had a fever, and 2 cases had limb dysfunction. Three cases had elevated blood inflammatory markers. MRI- DWI showed restricted diffusion. All 5 patients underwent surgery, 4 patients had bone flap removed, and 1 patient had bone flap retained. Bacterial culture was positive in 3 cases and negative in 2 cases. All 5 cases were cured, followed up for 1.5-9 years, and no epidural abscess recurred.

Conclusion

The clinical manifestations and laboratory results of delayed epidural pyogenic abscess after brain tumor surgery are not specific, but MRI-DWI has specificity. Postoperative radiotherapy for brain tumors and intraoperative opening of the frontal sinus may be associated with delayed epidural pyogenic abscess. For patients with normal skin flap and no serious inflammation of the bone flap, clinicians can attempt to preserve the bone flap.

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.

Surgical Antimicrobial Prophylaxis in Neonates and Children Undergoing Neurosurgery: A RAND/UCLA Appropriateness Method Consensus Study

Pediatric neurosurgery is a highly specialized branch of surgery in which surgical site infections (SSIs) are potentially serious complications that can also adversely affect a good surgical outcome, compromising functional recovery and, in some cases, even putting the patient’s life at risk. The main aim of this consensus document is to provide clinicians with a series of recommendations on antimicrobial prophylaxis for neonates and children undergoing neurosurgery. The following scenarios were considered: (1) craniotomy or cranial/cranio-facial approach to craniosynostosis; (2) neurosurgery with a trans-nasal-trans-sphenoidal approach; (3) non-penetrating head injuries; (4) penetrating head fracture; (5) spinal surgery (extradural and intradural); (6) shunt surgery or neuroendoscopy; (7) neuroendovascular procedures. Patients undergoing neurosurgery often undergo peri-operative antibiotic prophylaxis, with different schedules, not always supported by scientific evidence. This consensus provides clear and shared indications, based on the most updated literature. This work has been made possible by the multidisciplinary contribution of experts belonging to the most important Italian scientific societies, and represents, in our opinion, the most complete and up-to-date collection of recommendations on the behavior to be held in the peri-operative setting in this type of intervention, in order to guide physicians in the management of the patient, standardize approaches and avoid abuse and misuse of antibiotics.

Check the Ear. The Importance of Ear Examinations in Assessment of Intracranial Subdural Empyema

Intracranial subdural empyema (ISE) is an uncommon condition previously associated with almost 100% morbidity and mortality. Since the introduction of antibiotics and advancements in diagnosis the complication rates have significantly improved. We report an unusual case of a 32-year-old Aboriginal male diagnosed with ISE. On closer inspection the ISE was found to be a complication of otitis media with a cotton bud lodged in the external acoustic meatus. The report provides a literature review on the relationships of ISE, otitis media and foreign bodies. We conclude that although rare, all patients with suspected ISE should undergo an ear examination as it is at no cost to the patient or health service but may be the difference between life and death.

Neurosurgical complications: what the radiologist needs to know

Visits to the emergency department by patients who have recently undergone neurosurgery are a common occurrence, and these patients frequently receive emergent cross-sectional head imaging in order to evaluate for complications. Different neurosurgical approaches may have typical postoperative imaging findings that can be confused with pathology. Furthermore, particular abnormal postoperative imaging findings may signal an evolving complication. It is essential for the radiologist to understand common neurosurgical procedures and their potential complications in order to provide proper diagnostic evaluation of the postoperative neurosurgical patient. The purpose of this review is to assist radiologists in the evaluation of the postoperative neurosurgical patient and educate them on associated complications. Familiarity with common neurosurgical techniques and postoperative complications will help radiologists make the correct diagnosis, communicate effectively with the neurosurgeon, and expedite patient care.

Post-operative complications of craniotomy and craniectomy

Craniotomy and craniectomy are widely performed emergent neurosurgical procedures and are the prescribed treatment for a variety of conditions from trauma to cancer. It is vital for the emergency radiologist to be aware of expected neuroimaging findings in post-craniotomy and craniectomy patients in order to avoid false positives. It is just as necessary to be familiar with postsurgical complications in these patients to avoid delay in lifesaving treatment. This article will review the commonly encountered normal and abnormal findings in post-craniotomy and craniectomy patients. The expected postoperative CT and MRI appearance of these procedures are discussed, followed by complications. These include hemorrhage, tension pneumocephalus, wound/soft tissue infection, bone flap infection and extradural abscesses. Complications specifically related to craniectomies include extracranial herniation, external brain tamponade, paradoxical herniation, and trephine syndrome.

Epidural abscess presenting as severe depression with suicidal ideations: Case report

Background

Epidural abscess (EDA) is an uncommon form of intracranial infection that generally presents with fever, headache, and focal neurologic deficit. Imaging generally reveals a lentiform collection with diffusion restriction on diffusion weighted image. We present an interesting case in which a patient with EDA presented with three weeks of depression with suicidal ideations. The patient displayed no notable infectious signs and the imaging was suggestive of chronic subdural hematoma (SDH) rather than EDA.

Case Description

The patient is a 57-year-old man with past medical history significant for epilepsy and left hemiplegia secondary to remote traumatic brain injury who presented with a three-week history of depression, anxiety, and active suicidal ideation, resulting in psychiatric admission to an outside hospital. He had undergone three previous craniotomies for SDH many years ago and had no significant psychiatric history. Magnetic resonance imaging was consistent with subacute right SDH. On presentation, patient was at neurologic baseline and was afebrile with unremarkable labs. Operative findings demonstrated frank purulence in the epidural space. The patient was treated with antibiotics and both depression and suicidal ideations resolved postoperative day 5.

Conclusions

EDA can present in atypical ways, especially in patients who have undergone previous cranial procedures. Depression is one possible atypical presentation.

Delayed intracranial subdural empyema following burr hole drainage: Case series and literature review

RATIONALE

A subdural empyema (SDE) following burr hole drainage of a chronic subdural hematoma (CSDH) can be difficult to distinguish from a recurrence of the CSDH, especially when imaging data is limited to a computed tomography (CT) scan.

PATIENTS CONCERNS

All patients underwent burr hole drainage of the CSDH at first, and the appearance of the SDE occurred within one month.

DIAGNOSES

A contrast-enhanced magnetic resonance imaging (MRI) scan, with diffusion-weighted imaging (DWI), revealed both the SDE and diffuse meningitis in all patients.

INTERVENTIONS

In Case 1, because the patient was very young, burr hole drainage of the SDE, rather than craniotomy, was performed. However, subsequent craniotomy was required due to recurrence of the SDE. In Cases 2 and 3, an initial craniotomy was performed without burr hole drainage.

OUTCOMES

Symptoms improved for all patients, and each was discharged without any neurologic deficits or subsequent recurrence.

LESSONS

Neurosurgeons should consider the possibility of infection if recurrence of CSDH occurs within 1 month following drainage of a subdural hematoma. A contrast-enhanced MRI with DWI should be performed to differentiate SDE from CSDH. In addition, surgical evacuation of the empyema via wide craniotomy is preferred to burr hole drainage.

Risk factors for surgical site infections and assessment of vancomycin powder as a preventive measure in patients undergoing first-time cranioplasty

OBJECTIVE Craniectomy is often performed to decrease intracranial pressure following trauma and vascular injuries. The subsequent cranioplasty procedures may be complicated by surgical site infections (SSIs) due to prior trauma, foreign implants, and multiple surgeries through a common incision. Several studies have found that intrawound vancomycin powder (VP) is associated with decreased risk of SSIs after spine operations. However, no previously published study has evaluated the effectiveness of VP in cranioplasty procedures. The purpose of this study was to determine whether intrawound VP is associated with decreased risk of SSIs, to evaluate VP's safety, and to identify risk factors for SSIs after cranioplasty among patients undergoing first-time cranioplasty. METHODS The authors conducted a retrospective cohort study of adult patients undergoing first-time cranioplasty for indications other than infections from January 1, 2008, to July 31, 2014, at an academic health center. Data on demographics, possible risk factors for SSIs, and treatment with VP were collected from the patients' electronic health records. RESULTS During the study period, 258 patients underwent first-time cranioplasties, and 15 (5.8%) of these patients acquired SSIs. Ninety-two patients (35.7%) received intrawound VP (VP group) and 166 (64.3%) did not (no-VP group). Patients in the VP group and the no-VP group were similar with respect to age, sex, smoking history, body mass index, and SSI rates (VP group 6.5%, no-VP group 5.4%, p = 0.72). Patients in the VP group were less likely than those in the no-VP group to have undergone craniectomy for tumors and were more likely to have an American Society of Anesthesiologists physical status score > 2. Intrawound VP was not associated with other postoperative complications. Risk factors for SSI from the bivariable analyses were diabetes (odds ratio [OR] 3.65, 95% CI 1.07-12.44), multiple craniotomy procedures before the cranioplasty (OR 4.39, 95% CI 1.47-13.18), prior same-side craniotomy (OR 4.73, 95% CI 1.57-14.24), and prosthetic implants (OR 4.51, 95% CI 1.40-14.59). The multivariable analysis identified prior same-side craniotomy (OR 3.37, 95% CI 1.06-10.79) and prosthetic implants (OR 3.93, 95% CI 1.15-13.40) as significant risk factors for SSIs. After adjusting for potential confounders, patients with SSIs were more likely than those without SSIs to be readmitted (OR 7.28, 95% CI 2.07-25.60). CONCLUSIONS In this study, intrawound VP was not associated with a decreased risk of SSIs or with an increased risk of complications. Prior same-side craniotomy and prosthetic implants were risk factors for SSI after first-time cranioplasty.

Intracranial subdural empyema mimicking a recurrent chronic subdural hematoma

Intracranial subdural empyema (ISDE) is a life-threatening condition. The risk for ISDE increases in patients that have undergone prior intracranial procedures. The non-specificity in its clinical presentation often makes ISDE difficult to diagnose. Here, we present a rare case of ISDE mimicking a recurrent chronic subdural hematoma, emphasizing the significance of obtaining early magnetic resonance images of the brain for early diagnosis and treatment to achieve the optimal outcome.

Relationship between demography, etiology, level of consciousness, and outcome of surgical intracranial suppurations of bacterial origin in a tropical tertiary center

Introduction:

Intracranial suppurations (ICS) of bacterial origin are associated with significant mortality and morbidity. This study aimed to review demography, etiology, level of consciousness, and outcome of surgical ICS in a tropical tertiary hospital.

Materials and Methods:

All patients admitted to the neurosurgical unit within the study period of 7 years that had a surgical intervention for their ICS were prospectively included in the study. In accordance with the unit protocol, all patients in whom there was clinical suspicion of ICS had a preoperative computed tomography scan and/or magnetic resonance imaging done. The following data among others were documented and recorded electronically: demography, clinical and radiological diagnosis, etiology of ICS, admission Glasgow Coma Scale (GCS) score, type of neurosurgical intervention, mode of anesthesia, and outcome.

Results:

Forty-nine patients were included in the study. There were 33 males with a male-to-female ratio of 2.1:1. All patients presented at least a week after the use of antibiotics. The most common type of ICS was cerebral abscess (33 patients, 67.3%). There was no statistical significant association between outcome and age group (P = 0.630), gender (P = 0.999), diagnosis (P = 0.464), etiology of ICS (P = 0.169), solitary or multiplicity of ICS (P = 0.485), or type of offending organism (P = 0.278).

Conclusions:

ICS usually follows otorhinological infections in our center. The surgical outcome is dependent on the admission GCS score.

Management of infections complicating the orbitocranial approaches: Report of two cases and review of literature

BACKGROUND

The orbitocranial approaches are now indispensible for treating lesions of the skull base, providing access to lesions in the anterior and middle cranial fossae, as well as the upper clivus and anterior brainstem. The management of infectious complications of the orbitocranial approaches, however, has evaded the literature.

CASE DESCRIPTION

We present two cases of patients who underwent orbitocranial approach whose clinical course was complicated by wound infection and osteomyelitis. One patient was treated with antibiotics and then had a custom implant placed for cranioplasty. The other case was managed with removal of bone and wire-mesh cranioplasty.

CONCLUSION

Management of orbitocraniotomy infections can be difficult due to the complex geometry of the flap and to cosmetic considerations. Once the infection involves the bone, the bone can be replaced after cleaning or discarded and a cranioplasty performed. Cranioplasty can be performed with wire-mesh or a custom implant made by computer-assisted modeling.

Pediatric intracranial abscesses

Intracranial infections in children are a relatively rare, but potentially severe condition. Because of the potential for rapid deterioration, timely diagnosis and treatment are necessary. These infections are categorized based on their intracranial location: epidural abscess, subdural empyema, and brain abscess. They largely arise from direct extension of adjacent infection, hematogenous seeding, or trauma. Clinical presentations of intracranial infections also vary. However, common signs and symptoms include headache, fever, nausea and vomiting, altered mental status, focal neurologic deficits, and seizures. In general, MRI demonstrates a peripherally enhancing lesion with high signal on diffusion weighted imaging (DWI). Bacterial isolates vary, but most commonly are a single pathogen. Successful treatment requires a multidisciplinary team approach including such modalities as antibiotic therapy and surgical drainage. When possible, open surgical evacuation of the abscess is preferred, however, in cases of deep-seated lesions, or in unstable patients, aspiration has also been performed with good results.

Demography, types, outcome and relationship of surgically treated intracranial suppuration complicating chronic suppurative otitis media and bacterial rhinosinusitis

Introduction:

Surgically treated intracranial suppurations (ICS) are uncommon, life-threatening neurosurgical emergencies. They can result from complication of chronic suppurative otitis media (CSOM) and bacterial rhinosinusitis (BRS). The objective of this study was to know the frequency of BRS and CSOM and relate it to its rare complication of surgically treated ICS while also describing the demography, type and outcome of ICS that resulted from BRS and CSOM.

Materials and Methods:

All patients that presented to the Otorhinolaryngological department and Neurosurgical unit of the same institution with clinical and radiological features of CSOM, BRS, and ICS were prospectively studied over a 5-year period. Patients were followed up for a minimum of 3 months.

Results:

Two thousand, two hundred and seventy-nine patients presented during the 5-year study period. Of all these patients, 1511 had CSOM (66.3%) and 768 (33.7%) presented with features of BRS. Eleven (0.73%) had ICS complicating their CSOM while 8 (1.04%) cases of surgically treated ICS followed BRS. Bacterial rhinosinusitis was not more likely to lead to ICS (P = 0.4348). The Odds ratio (OR) of a child ≤ 18 years of age with CSOM developing ICS was 5.24 (95% Confidence interval 1.13-24.34; P = 0.0345), while it was 7.60 (95% Confidence interval 1.52-37.97; P = 0.0134) for children with BRS.

Conclusions:

The most common type of ICS complicating CSOM and BRS was brain abscess and subdural empyema, respectively. Children are more prone to develop surgical ICS following CSOM and BRS. The proportion of males that had ICS was higher in both CSOM and BRS patients. Optimal outcome is achieved in patients that presented with GCS of 13 and above.

Immediate postoperative imaging after uncomplicated endoscopic approach to the anterior skull base: is it necessary?

BACKGROUND

Postoperative imaging is frequently performed to assess for intracranial complications following anterior skull base (ASB) surgery. However, there is little data to suggest that radiologic studies change the management of complications. In this study, the utility of postoperative imaging within 72 hours after uncomplicated ASB surgery was examined.

METHODS

A retrospective review was conducted of 143 patients who underwent endoscopic ASB surgery between 2007 and 2013 at Loyola University Medical Center. The main outcomes measures included the ability of head computed tomography (CT) scan to identify postoperative complications and hallmark symptoms associated with complications.

RESULTS

Seventy-nine patients underwent postoperative imaging within 72 hours of the initial surgery. The most common finding was pneumocephalus (35/79; 44%). Expanding pneumocephalus requiring surgical intervention developed in 3 cases. Cerebrospinal fluid (CSF) leak was the most common complication, occurring in 22 of 143 (15%) of the patients. Of the 24 patients who developed a postoperative complication, all had clinical signs or symptoms indicative of the need for surgical or medical intervention. The positive predictive value for a head CT scan to detect a complication was 12%, negative predictive value was 92%, and sensitivity and specificity were 63% and 48%, respectively.

CONCLUSION

Routine postoperative imaging may be unnecessary after uncomplicated endoscopic ASB surgery because (1) it may not alter patient management; (2) it may not detect the most common complication (CSF leak); and (3) when imaging is positive, the patient has clinical symptoms suggesting a need for intervention.

Betadine irrigation and post-craniotomy wound infection

OBJECT

The purpose of this study is to evaluate the efficacy of betadine irrigation in preventing postoperative wound infection in cranial neurosurgical procedures.

METHODS

A total of 473 consecutive cranial neurosurgical procedures, including craniotomies and burr hole procedures were retrospectively reviewed. Patients had either antibiotic irrigation or dilute betadine plus antibiotic irrigation prior to skin closure. Infection was determined by purulence noted on reoperation and confirmed with bacterial growth culture. One and three month postoperative infection rates were calculated. Statistical analysis was performed using Chi-squared tests.

RESULTS

This study included 404 patients. Betadine was used in 117 (29.0%). At 1 month after surgery, there was no difference in the rate of wound infection between the two groups (1.7% each). However, at 90 days, the betadine group had a 2.6% infection rate compared with 3.8% in the antibiotic group, indicating a 33% decrease in infection rates with the addition of betadine (p=.527). The small sample size of the study produced a low power and high beta error.

CONCLUSIONS

In this small preliminary study, betadine decreased postoperative infection rates compared with antibiotic prophylaxis alone at 90 days but not 30 days. This was not statistically significant, but a larger sample size would lower the beta error and decrease confounding bias associated with group heterogeneity. The potential for betadine, a cheap, low toxicity antimicrobial, to decrease infection rates and reoperations for infection warrants a larger multicenter trial.

An unusual presentation of subdural empyema caused by Porphyromonas gingivalis

Subdural empyema is an uncommon clinical entity. The first case of Porphyromonas gingivalis subdural empyema is reported. We report a case of 34-year-old male who presented with subdural empyema and sinusitis. Through the utilization of polymerase chain reaction (PCR) tests on subdural pus, we were able to confirm the diagnosis and institute appropriate treatment. Early surgical intervention and intravenous antibiotics meant that the patient recovered fully. Infections caused by P. gingivalis should be considered in differential diagnoses of central nervous system (CNS) abscesses or subdural empyema especially in patients with precedent periodontal diseases and sinusitis.

Intracranial suppuration complicating sinusitis among children: an epidemiological and clinical study

OBJECT

Intracranial abscess is a very infrequent complication of sinusitis among children. Case series, mostly small and focusing on surgical treatment, have appeared in the literature, but there has been no study on the epidemiology of this condition, nor has there been any large-scale study on the intensity of therapy or outcomes.

METHODS

Data were drawn from the Kids' Inpatient Databases for 1997, 2000, 2003, and 2006 and the National Inpatient Sample for 2001. Cases were defined by the conjunction between the diagnostic codes for intracranial abscess and those for acute or chronic sinusitis or mastoiditis.

RESULTS

Eight hundred forty-seven hospital admissions were captured. Over the 10 years of the study, admission rates ranged between 2.74 and 4.38 per million children per year. Boys were affected much more commonly than girls. Black children were affected out of proportion to their presence in the population. The overall incidence seemed to peak in early adolescence. Sinogenic cases had a marked seasonal pattern peaking in winter, but no seasonal variation was seen for otogenic cases. Asthma comorbidity was more prevalent among sinogenic cases. The mortality rate was 2%, and death occurred only among sinogenic cases. Moreover, sinogenic cases tended to require more intensive therapy, as measured by the number of procedures, and there was a trend toward less favorable discharge dispositions. Older patients and black patients were less likely to be discharged directly to home. At least a quarter of the cases were managed without neurosurgical intervention. White patients were treated without neurosurgery more often than others.

CONCLUSIONS

Analysis of administrative data sets has yielded a descriptive picture of intracranial abscess complicating sinusitis among children, but the very low incidence of this condition impedes prospective clinical research directed at practical management issues.

Imaging of the post-operative cranium

Imaging plays an essential role in the evaluation of patients after cranial surgery. It is important to be familiar with the normal anatomy of the cranium; the indications for different surgical techniques such as burr holes, craniotomy, craniectomy, and cranioplasty; their normal postoperative appearances; and complications such as tension pneumocephalus, infection, abscess, empyema, hemorrhage, hematoma, herniation, hygroma, and trephine syndrome. Postoperative infection and hemorrhage are common to all neurosurgical procedures, where-as other complications are peculiar to certain procedures (eg, drill "plunging" during burr hole creation and sinking skin flap after craniec-tomy). Recognizing life-threatening complications such as tension pneumocephalus and paradoxical herniation, which require urgent intervention, is important for a better clinical outcome. Computed tomography is fast, cost effective, and easily accessible for first-line imaging. Magnetic resonance imaging has higher sensitivity for detecting postoperative infection and ischemia, but diffusion-weighted imaging may be less reliable for detecting postoperative infections.

Cranial and spinal subdural empyema

Subdural empyema represents a loculated suppuration between the dura and the arachnoid. It has been described either intracranially or in the spinal canal, the latter localization being quite rare. It is a rare but serious illness with a declining mortality rate but rather frequent neurological sequelae. Morbidity and mortality in intracranial and spinal subdural empyema directly relate to the delay in diagnosis and therapy. The epidemiology, etiology, pathophysiology and symptoms of spinal subdural empyema and cranial subdural empyema are somewhat different, but brain and spinal subdural empyema are not always two different entities. An adequate treatment strategy should be selected on a case-by-case basis, especially for patients with a massive CNS involvement, where management represents a challenge.

Pus and free bone flaps

OBJECT

The goal of this investigation is to describe the results of a vigorous attempt to preserve contaminated free bone flaps and avoid the problems associated with the traditional and common practice of discarding the flap, administering a course of antibiotics, and after several months, performing a cranioplasty.

METHODS

Patients with clearly contaminated, free cranial bone flaps, including so-called high risk cases, were treated by meticulous debridement of the surgical bed, scrubbing, soaking, and then replacing the bone flap in its normal position, and administering a course of intravenous antibiotics.

RESULTS

Fourteen patients with contaminated avascular cranial bone flaps were treated using this technique. All bone flaps were able to be preserved. Conclusions Patients with bacteriologically contaminated, free bone flaps can be treated successfully without discarding the flaps. Success is dependent upon aggressive surgical debridement and persistence.

Operative intracranial infection following craniotomy

OBJECT

Postoperative infection after cranial surgery is a serious complication that requires immediate recognition and treatment. In certain cases such as postoperative meningitis, the patient can be treated with antibiotics only. In cases that involve a bone flap infection, subdural empyema, or cerebral abscess, however, reoperation is often needed. There has been significant disagreement regarding the incidence of postoperative central nervous system (CNS) infections following cranial surgery. In this paper the authors' goal was to perform a retrospective review of the incidence of CNS infection after cranial surgery at their institution. They focused their review on those patients who required repeated surgery to treat the infection.

METHODS

The authors reviewed the medical records and imaging studies in all patients who underwent a craniotomy or stereotactic drainage for CNS infection over the past 10 years. Subgroup analysis was then performed in patients whose infection was a result of a previous cranial operation to determine the incidence, factors associated with infection, and the type of infectious organism. Patients treated nonoperatively (that is, those who received intravenous antibiotics for postoperative meningitis or cellulitis) were not included. Patients treated for wound infection without intracranial pus were also not included.

RESULTS

During the study period from January 1997 through December 2007, approximately 16,540 cranial surgeries were performed by 25 neurosurgeons. These included elective as well as emergency and trauma cases. Of these cases 82 (0.5%) were performed to treat postoperative infection in 50 patients. All 50 patients underwent their original surgery at the authors' institution. The median age was 51 years (range 2-74 years). There were 26 male and 24 female patients. The most common offending organism was methicillin-sensitive Staphylococcus aureus, which was found in 10 of 50 patients. Gram-negative rods were found in 15 patients. Multiple organisms were identified in specimens obtained in 5 patients. Six patients had negative cultures. Most craniotomies leading to subsequent infection were performed for tumors or other mass lesions (23 of 50 patients), followed by craniotomies for hemorrhage and vascular lesions. Almost half of the patients underwent > 1 cranial operation before presenting with infection.

CONCLUSIONS

Postoperative infection after cranial surgery is an important phenomenon that needs immediate recognition. Even with strict adherence to sterile techniques and administration of antibiotic prophylaxis, a small percentage of these patients will develop an infection severe enough to require reoperation.

Subdural empyema and other suppurative complications of paranasal sinusitis

Suppurative intracranial infection, including meningitis, intracranial abscess, subdural empyema, epidural abscess, cavernous sinus thrombosis, and thrombosis of other dural sinuses, are uncommon sequelae of paranasal sinusitis. A high index of suspicion is necessary to identify these serious complications. We present a patient with subdural empyema in whom the diagnosis was delayed, followed by a discussion of suppurative complications of sinusitis. The case shows the rapid progression of subdural empyema, which represents a true neurosurgical emergency requiring prompt diagnosis and management.

Salvage of infected craniotomy bone flaps with the wash-in, wash-out indwelling antibiotic irrigation system. Technical note and case series of 12 patients

OBJECT

When complicated by infection, craniotomy bone flaps are commonly removed, discarded, and delayed cranioplasty is performed. This treatment paradigm is costly, carries the risks associated with additional surgery, and may cause cosmetic deformities. The authors present their experience with an indwelling antibiotic irrigation system used for the sterilization and salvage of infected bone flaps as an alternative to their removal and replacement.

METHODS

The authors retrospectively reviewed the medical records for 12 patients with bone flap infections following craniotomy who received treatment with the wash-in, wash-out indwelling antibiotic irrigation system. Infected flaps were removed and scrubbed with povidone-iodine solution and soaked in 1.5% hydrogen peroxide while the wound was debrided. The bone flaps were returned to the skull and the irrigation system was installed. Antibiotic medication was infused through the system for a mean of 5 days. Intravenous antibiotic therapy was continued for 2 weeks and oral antibiotics for 3 months postoperatively. Wound checks were performed at clinic follow-up visits, and there was a mean follow-up period of 13 months. Eleven of the 12 patients who had undergone placement of the bone flap irrigation system experienced complete resolution of the infection. In five patients there was involvement of the nasal sinus cavities, and in four there was a history of radiation treatment. In the one patient whose infection recurred, there was both involvement of the nasal sinuses and a history of extensive radiation treatment.

CONCLUSIONS

Infected bone flaps can be salvaged, thus avoiding the cost, risk, and possible disfigurement associated with flap removal and delayed cranioplasty. Although prior radiation treatment and involvement of the nasal sinuses may interfere with wound healing and clearance of the infection, these factors should not preclude the use of irrigation with antibiotic agents for bone flap salvage.

Empyèmes sous-duraux de l’enfant : stratégie thérapeutique

We report a series of five subdural empyema (SDE) in children and young adults treated in the same neurosurgical department. These five cases were reviewed retrospectively. There were four boys and one girl, aged from three months to 18 years at time of diagnosis (median age: 7 years). SDE following intracranial surgery were excluded from the study. All patients were treated surgically (burr hole evacuation or craniotomy, repeated in some cases), followed by intravenous antibiotic therapy (mean time: 52 days) adapted to the micro-organism. Only the two patients treated by large craniotomy at first had a single surgical procedure. Involved micro-organisms are as follow: Streptococcus intermedius (n=2), Streptococcus pneumoniae (n=1), Escherichia coli (n=1), absence of any identified micro-organism (n=1). The five patients are alive (median follow-up: 22 month) without any sequelae. We advocate an aggressive surgical treatment of SDE in children with a large bone flap to allow the surgeon to remove pus and membranes as much as possible, even in the interhemispheric fissure, followed by intravenous appropriate antibiotherapy and eradication of the source of infection. Even this "aggressive" treatment may sometimes not avoid re-operation. A careful follow-up is mandatory, because of the high risk of recurrence.

Preservation of bone flaps in patients with postcraniotomy infections

OBJECT

Management of postcraniotomy wound infections has traditionally consisted of operative debridement and removal of devitalized bone flaps followed by delayed cranioplasty. The authors report the highly favorable results of a prospective study in which postcraniotomy wound infections were managed with surgical debridement to preserve the bone flaps and avoid cranioplasty.

METHODS

Since 1990, 13 patients with postcraniotomy wound infections have been prospectively treated with open surgical debridement and replacement of the bone flap. All patients received a full course of systemic antibiotic agents based on the determination of the bacterial culture and antibiotic sensitivity. Notable risk factors for infection included prior craniotomies, radiotherapy, and skull base procedures. The mean long-term follow-up period was 35 +/- 20 months. In all five patients who underwent craniotomies without complications, bone flap preservation was possible with full resolution of the infection and without the need for additional surgery. Among the eight patients with risk factors, bone preservation was possible in six patients, although two required minor wound revisions (without bone flap removal). Both patients who underwent craniofacial procedures required an additional procedure in which the bone flap was removed for recurrent infection (one after 2 months and the other after 29 months).

CONCLUSIONS

In patients with uncomplicated postcraniotomy infections, simple operative debridement is sufficient and it is not necessary to discard the bone flaps and perform cranioplasties. Even patients with risk factors such as prior surgery or radiotherapy can usually be treated using this strategy. Patients who undergo craniofacial surgeries involving the nasal sinuses are at higher risk and may require bone flap removal.

Diffusion-weighted MRI of subdural and epidural empyemas

We reviewed diffusion-weighted images (DWI) from eight patients with subdural and four with epidural empyemas to assess the possibility of differentiating between these lesions by DWI. The signal intensities of the empyemas on DWI, and maps of the apparent diffusion coefficient (ADC) were analysed in seven patients. In seven of the eight patients with subdural empyema, the lesions appeared as areas of high signal. The ADC maps confirmed that these areas were the result of restricted diffusion. (In the remaining patient, the lesion showed a mixture of high and low signal.) The epidural empyemas contained areas of low signal in all four patients; part of the empyema was isointense or gave high signal in two. DWI may be an adjunct to conventional sequences for differentiating between subdural and epidural empyemas.

Intracranial suppuration: a clinical comparison of subdural empyemas and epidural abscesses

BACKGROUND

We compared the clinical features and therapeutic outcomes of intracranial suppurations (IEs) caused by sub-dural empyema (SDEs) and epidural abscesses (EAs).

METHODS

Twenty-four patients with IE were retrospectively identified at our institution over a period of 14 years. Therapeutic outcomes at 6 months were determined using the Glasgow Outcome Scale.

RESULTS

Among them, 15 had SDE and nine had EA with or without SDE. The three most frequently encountered clinical features Included fever (79%), disturbed consciousness(58%), and seizures (54%). Postneurosurgical or posttraumatic states (42%) and complication after meningitis (38%) were the two most common modes of infection. The overall mortality rate was 8% (2/24). However, if mortality and severe neurologic sequelae were included in the poor outcome group, then 29% (7/24) of our patients would be considered treatment failures.

CONCLUSION

In this study, SDE commonly arose following bacterial meningitis with a more fulminant course, but no deaths occurred. In contrast, EA commonly has a more Indolent course and is postoperatively or post-traumatically related, and therefore may have a higher mortality rate based on primary brain pathophysiology alone. Inpatients with meningitis or who undergo postneurosurgical procedures and develop fever, progressive disturbed consciousness, seizures, and focal neurologic signs, immediate neuroimaging studies should be per-formed to determine whether IE is present. Early surgical drainage and aggressive antimicrobial therapy are necessary.

[Intracranial epidural abscess in a newborn secondary to skin catheter]

Intracranial epidural abscesses are uncommon lesions, being more frequents in older children and adults. They commonly arise as a result of direct extension of a preexisting infection and rarely present with focal deficit. We present a case of a 11-days old preterm infant who developed an intracranial epidural abscess as a result of an infected scalp vein catheter. The diagnosis was made on the basis of the cranial ultrasound and CT scan images. An identified strain of Enterococcus faecium was cultured from all the samples. The patient underwent a right frontal craniotomy with drainage of the abscess and a 2-week total course of intravenous antibiotics was administrated. CT scan imaging 3 week after the procedure demonstrated no evidence of residual lesion. When present, a scalp vein catheter, in absence of others predisponing factors, must be considered as an etiologic agent for an intracranial epidural abscess in this age-group.

Disorders that mimic central nervous system infections

Many noninfectious diseases can cause signs, symptoms, and cerebrospinal fluid (CSF) abnormalities simulating central nervous system (CNS) infection. Infection usually can be excluded in these cases by the judicious use of serologic tests and CSF stains and cultures. Then, the correct diagnosis is typically suggested by the history and the concomitant presence of clinical and laboratory evidence of disease in other organ systems. Occasionally, particularly when such evidence is absent, the distinction requires meningeal or brain biopsy.

[Intracranial abscess and empyema: neurosurgical management]

Brain abscesses and empyemas are severe infections with lethal outcomes in the case of inappropriate treatment. The files of 34 patients with brain abscesses, and nine with intracranial empyemas treated over eight years (1990-1997) were analyzed retrospectively. Cases were evaluated for treatment and compared with data from the literature. Patients with brain abscess underwent either aspiration of the lesion through a burr hole (79.5% of the cases), or craniotomy and excision (8.8% of the cases); 11.7% were treated only with antibiotics. The operative mortality was 2.9% and the outcome was satisfactory in 85% of patients. These results are in agreement with data from the literature. Prognosis is strongly related to the initial clinical status. Current methods of treatment include surgical aspiration of large abscesses with a mass effect, and are usually associated with a poor clinical status. Excision is suggested whenever aspiration procedures have failed, or in the presence of foreign material or fungal abscess. Medical treatment is indicated for small and deeply located abscesses in patients with satisfactory clinical states. Empyemas in our series were treated with burr hole and pus aspiration. The mortality rate was 11%, and 62.5% of the patients made a good recovery. In agreement with other reported studies, the method of treating subdural empyema is much less significant than an aggressive early drainage of the infection. Although brain abscesses and empyema remain a significant neurosurgical concern, aggressive treatment can result in an excellent outcome in the majority of patients.

Intracranial subdural empyemas in the era of computed tomography: a review of 699 cases

OBJECTIVE

Intracranial empyemas are the most common form of intracranial suppuration seen in our unit and, despite modern antibiotic therapy and advanced neurosurgical and imaging facilities, these pus collections remain a formidable challenge, often resulting in significant morbidity and death. We present an analysis of our 15-year experience with this condition in the era of computed tomography.

METHODS

A retrospective analysis of 4623 patients admitted with intracranial sepsis during a 15-year period (1983-1997) identified 699 patients with intracranial subdural empyemas. The inpatient notes for these patients were analyzed with respect to clinical, radiological, bacteriological, surgical, and outcome data. Statistical analyses were performed.

RESULTS

The 699 intracranial subdural empyemas accounted for 15% of all admissions for intracranial sepsis during the study period. Young male patients in the second or third decade of life were most commonly affected (62%), and the mean age was 14.65+/-12.2 years. Almost all patients (96%) underwent surgery. Eighty-two percent of patients experienced good outcomes (Glasgow Outcome Scale scores of 4 or 5). A morbidity rate of 25.9% (including postoperative seizures) was noted, and 85 patients died (mortality rate, 12.2%).

CONCLUSION

Intracranial subdural empyema, which is a neurosurgical emergency, is rapidly fatal if not recognized early and managed promptly. Early surgical drainage, simultaneous eradication of the primary source of sepsis, and intravenous administration of high doses of appropriate antibiotic agents represent the mainstays of treatment.

Infections of the nervous system

Epidemiologic trends causing infections of the nervous system remain a significant source of morbidity and mortality one half-century after the introduction of penicillin. This article outlines common causes of bacterial meningitis, aseptic meningitis syndrome, encephalitis, abscess, spinal cord syndromes, and cranial and peripheral nerve problems. Recommendations for diagnostic evaluation and both empiric and definitive antimicrobial therapy are offered; controversial management issues are also discussed. The protean manifestations of varicella-zoster virus and Lyme diseases are outlined. In addition, special considerations in the immunocompromised host, including organ transplant recipients, cancer patients, and HIV-positive persons are explained, and antimicrobial therapy is discussed.

Focal intracranial infections

Focal intracranial infections are relatively rare, but the consequences of a missed or delayed diagnosis are significant. The clinician is urged to consider these diagnoses in patients with headaches or focal neurologic examinations, particularly in the setting of known or suspected otorhinologic disease. For diagnosis, gadolinium-enhanced MR imaging or MR imaging with angiography are the procedures of choice; CT is far less sensitive and specific. Lumbar puncture is contraindicated in most of these infections. Management of suspected elevation of intracranial pressure and broad empiric antibiotic therapy should be instituted emergently. Early involvement of surgical services is recommended.