Subdural empyema of the cervical spine: clinicopathological correlates and magnetic resonance imaging. Report of three cases

Streptococcus intermedius: From a Normal Oral Commensal to a Life-Threatening Organism

Subdural empyema is a collection of pus in the subdural space between the dura mater and the arachnoid. It carries very high morbidity and mortality as it can spread anywhere in the brain; however, the risk can be mitigated with appropriate surgical and medical intervention. Being protected by the skull, cranial infections are usually preceded by a significant risk factor, either an external invader such as skull fractures secondary to trauma, penetrating injury, prior surgery, or, more commonly, in more than 50% of cases, due to spread of an internal infection such as ear or sinus infections. Anaerobic and aerobic bacteria can cause subdural empyema. Both gram-positive and gram-negative bacteria are notorious for developing this kind of infection; for example, different groups of gram-positive streptococci and staphylococci, gram-negative Haemophilus influenza, and other gram-negative bacilli can cause subdural empyema. While streptococci are more frequent with sinus infection causing subdural empyema, staphylococci are associated with skin invasion secondary to either head trauma or cranial surgery. Streptococcus intermedius is a gram-positive alpha-hemolytic pathogen belonging to the larger Streptococcus anginosus group that itself is a subgroup from viridans streptococci, aka Streptococcus milleri. Streptococcus intermedius is an oral commensal flora and is considered to be a low-virulence bacteria in immunocompetent patients but can be associated with significant morbidity and mortality. Subdural empyema tends to occur more often in immunocompromised patients such as diabetic patients, those with human immunodeficiency virus infection, and those using immunosuppressive medications. The clinical course ranges from indolent to fulminant. The size and location of the abscess play a role in clinical presentation. Headache is the most common presenting symptom, but patients can also present with fever, nausea, seizure, or altered mental status. Diagnosis can be obtained with CT and MRI scans of the brain. Prompt drainage of the abscess and lengthy antibiotics improve the prognosis significantly. Our case highlights a rare origin of subdural empyema from the direct spread of a skin abscess.

Mixed pyogenic and tuberculous spinal epidural abscesses perforating the dura and extending into the subdural space: A case report and review of the literature

Background

Spinal infections are associated with a wide variety of clinical conditions, including osteomyelitis, spondylitis, diskitis, septic facet joints, and abscesses. Based on its anatomical relationship with the dura mater, the abscess can be epidural (extradural) or subdural (intrathecal). Subdural intramedullary abscesses of the lumbar spinal canal are more common than subdural extramedullary abscesses. Here, we present a rare case of a patient with a mixed pyogenic and tuberculous epidural abscess in the lumbar spine, which perforated the dura and extended to the subdural space.

Case Description

A 29-year-old male presented with progressively worsening back pain and lower-limb weakness over a period of 3 months, with an associated inability to walk, intermittent radicular pain primarily on the left side, intermittent incontinence, and a history of low-grade fever and night sweats. The patient had a history of intravenous (IV) drug abuse and reported practicing unprotected sexual intercourse. Furthermore, the patient had recently came into contact with a person diagnosed with tuberculosis (TB). The patient was administered empirical broad-spectrum antibiotics and underwent emergent L4-L5 laminectomy and spinal abscess decompression. IV antibiotics were selected based on culture results, and anti-TB medications were started. Postoperatively, the patient demonstrated a remarkable lower-limb power improvement and radicular pain alleviation.

Conclusion

Spinal epidural abscess perforation of the dura and extension into the subdural space is extremely rare. Distinguishing between epidural and subdural abscesses radiologically is challenging. Multiple risk factors, such as unprotected sexual contact and IV drug misuse, may be associated with the development of polymicrobial abscesses in the lumbar spine. Careful anticipation, identification, and isolation of the causative micro-organisms can ensure effective antibacterial treatment. Early diagnosis, expeditious surgical decompression, and antibiotic treatment are associated with promising outcomes.

Spontaneous lumbar intraspinal subdural abscess: a case report

BACKGROUND

Subdural spinous abscess is a rare pathology that carries significant morbidity if not diagnosed and treated early; of the cases reported in the literature, very few are genuinely spontaneous in nature.

CASE PRESENTATION

Here we demonstrate the case of an otherwise entirely fit and well 56-year-old White, British female presenting with low back pain, bilateral sciatica and sensate urinary retention; lumbar subdural spinous abscess was diagnosed on urgent magnetic resonance imaging and the patient was successfully managed with surgical evacuation and prolonged antibiotic therapy. The patient made a full neurological recovery and was followed-up in the outpatient setting 12 weeks following her initial surgery; she was pain free with normal inflammatory markers and a normal neurological examination. There have been no further consultations and a telephone call at 20 weeks confirmed that she remains well.

CONCLUSIONS

This is the second case reported in the literature of a genuinely spontaneous subdural spinous abscess, which was successfully managed with surgical evacuation following prompt diagnosis. This highlights the need to ensure infective pathologies are kept at the back of one's mind even in the most unlikely circumstances, and that excellent outcomes can be achieved with early surgical intervention.

Spinal Subdural Abscess Mimicking an Extradural Tumor: A Case Report

Spinal subdural abscesses (SSAs) are rare pathologies presenting as encapsulated pus located intradurally and extramedullary. Although there is no uniform opinion on the cause of this pathology, approximately 50% of cases are attributed to Staphylococcus aureus infection. Here, we present a rare case of a female patient who presented to N.N. Burdenko Neurosurgical Center for treatment of an extradural tumor in the lower lumbar spine. She complained of acute lower back pain, lower limb muscle spasms, progressive lower limb weakness, numbness in toes, and increased frequency of defecation (five to six times per day). Intraoperatively, we discovered that the epidural space was clear and a subdural abscess was located and removed. The patient was started on antibiotics and recovered 29 days later. This case report illustrates an atypical SSA mimicking an extramedullary tumor on MRI.

Spinal Subdural Abscess Following Food Intoxication: A Case Report

Introduction

Spinal subdural abscess (SSA) or empyema is a rare pathology and its exact incidence is unknown. Staphylococcus aureus (S aureus) is the most frequently responsible organism. The patients with SSA may have one or more predisposing immunosuppressive conditions. However, here we report a rare case of SSA following food intoxication without any significant comorbidities.

Case Report

A 42-year-old healthy man presenting with fever, severe low back pain (LBP), and trunk motion restriction was transferred to our hospital. He had been treated for an unknown fever after food intoxication in another hospital. Eighteen days earlier, he and his colleagues together ate raw horse meat and briefly boiled chicken breast. They all had food intoxication on the following day. Subsequently, our patient began to have a high fever and severe LBP. Laboratory data showed leukocytosis of 16,000/mm³. Also, the C-reactive protein was elevated to 26 mg/dL. The blood culture result was consistent with S aureus. Magnetic resonance imaging (MRI) showed focal epidural fluid collection that appeared contiguous with the subdural fluid collection through a dural defect in the axial plane on T2-weighted (T2W) images. An emergent surgery was performed. Frank pus was expressed from the epidural space as well as from the subdural space through the defect. The pus later grew S aureus. The patient was started on antibiotic therapy postoperatively. The patient completely recovered 1 month after surgery.

Conclusions

SSA following food intoxication is a very rare case. SSA can be identified with a small dural defect and the intrathecal fluid collection compressing the cauda equina in the axial plane on T2W magnetic resonance images. Having suspicion of epidural abscess and likewise subdural abscess and making an early diagnosis using MRI and an emergent surgery are important when the clinician notices a febrile patient with severe LBP and trunk motion stiffness.

Intradural Staphylococcus aureus Abscess of the Cauda Equina in an Otherwise Healthy Patient

Abscesses involving the spine are usually located in the epidural space. In rare circumstances, intradural spinal abscesses can occur, typically in the setting of tuberculosis or other predisposing systemic conditions. In this illustrated case report, we discuss the imaging and intraoperative findings of an otherwise healthy patient with an intradural abscess of the cauda equina caused by Staphylococcus aureus. Although rare, intradural spinal abscesses can occur in the absence of typical “red flags” for infection, and a bacterial abscess should be considered in the differential diagnosis of intradural spinal cystic enhancing lesions.

Spinal Subdural Abscess Following Laminectomy for Symptomatic Stenosis: A Report of 2 Cases and Review of the Literature

BACKGROUND Spinal subdural abscesses, also known as empyemas, are rare infectious lesions, the exact incidence of which is unknown. Presentation is typically dramatic, with back pain, fever, motor, and sensory deficits. Rapid identification and surgical intervention with laminectomy, durotomy, and washout provides the best outcomes. While hematogenous spread of an extra-spinal infection is the most common cause of this condition, a significant number of cases result from iatrogenic mechanisms, including lumbar punctures, epidural injections, and surgery. CASE REPORT Here we present 2 cases: 1) an 87-year-old man with type 2 diabetes, schizophrenia, mild cognitive impairment, and symptomatic lumbar spinal stenosis and 2) a 62-year-old man with a prior L3-4 spinal fusion with symptomatic lumbar spinal stenosis. In both cases, patients underwent laminectomy for spinal stenosis and developed epidural abscess. Following successful drainage of the epidural abscess, they continued to be symptomatic, and repeat imaging revealed the presence of a subdural abscess that was subsequently evacuated. Case 1 had significant improvement with residual lower-extremity weakness, while Case 2 made a complete neurological recovery. CONCLUSIONS These cases illustrate patients at increased risk for developing this rare spinal infection, and demonstrate that rapid recognition and surgical treatment is key to cure and recovery. Review of the literature highlights pertinent risk factors and demonstrates nearly one-third of reported cases have an iatrogenic etiology. The cases presented here demonstrate that a subdural process should be suspected in any patient with intractable pain following treatment of an epidural abscess.

Intradural Extension of a Pyogenic Epidural Abscess: A Case Report

CASE

Few cases of spinal epidural abscess involving an extradural abscess with an intradural extension have been reported. A unique complication with extension of pus from the epidural space through multiple perforations into the dura is described. Due to a proximal meningeal inflammatory reaction, which served as a proximal plug, no cerebrospinal fluid leak was encountered.

CONCLUSION

Intradural extension of pus through multiple dural perforations is a rare complication of spinal epidural abscess and a treatment challenge. Early diagnosis enabling prompt surgical decompression, along with subsequent aggressive debridements and prolonged intravenous antibiotic treatment, can lead to a favorable outcome.

Pyogenic Intradural Abscess of Lumbar Spine: A Case Report

We report a case of spinal intradural abscess which shows serial changes on magnetic resonance imaging (MRI). Well-encapsulated, rim-enhancing lesion with mass effect was visualized at ventral side of lumbar spinal canal on 17 days after initial negative MRI, which was thought to be epidural abscess. It was revealed to be intradural in location on operation and successfully treated by drainage and antibiotics. Follow-up MRI showed resolution of abscess. Clinical significance and pathogenesis of this case was briefly discussed.

Infections of the spinal subdural space in children: a series of 11 contemporary cases and review of all published reports. A multinational collaborative effort

INTRODUCTION

Positioned anatomically between the spinal epidural space and the intramedullary compartment, the spinal subdural space remains the least common area of localized infection in the central nervous system. Infectious processes of the subdural spinal space include subdural spinal empyema, subdural spinal abscess, infected spinal subdural cyst, and infectious spinal subdural cyst. To date, there has been no systematic review of these entities in children, with the cumulative knowledge of the pathophysiologic, microbiologic, and demographic characteristics of these infections relegated solely to few small series and case reports.

METHODS

A series of 11 recent cases culled from the collaboration of international authors are presented. In addition, an exhaustive MEDLINE search and manual review of the international literature was performed, identifying a total of 73 cases of spinal subdural infections in patients under the age of 21. Data of interest include the age, sex, signs, and symptoms at presentation, spinal location of infection, presence of spinal dysraphism, and other comorbidities, offending organism, treatment, outcome, and follow-up.

RESULTS

Patients ages ranged from 4 weeks to 20 years (mean, 6.5 years). Males outnumbered females by a ratio of 2:1. Over half (53 %) of spinal subdural infections in children were associated with spinal dysraphism or other congenital abnormalities of the spine. The commonest organism to infect the spinal subdural space in children is mycobacterium tuberculosis and the thoracic spinal region was most commonly infected.

CONCLUSIONS

The disease is usually treated surgically, although a more expectant approach consisting of antibiotics and observation has also been proposed.

Incidence of Unintended Durotomy in Spine Surgery Based on 108 478 Cases

BACKGROUND:

Unintended durotomy is a common complication of spinal surgery. However, the incidences reported in the literature vary widely and are based primarily on relatively small case numbers from a single surgeon or institution.

OBJECTIVE:

To provide spine surgeons with a reliable incidence of unintended durotomy in spinal surgery and to assess various factors that may influence the risk of durotomy.

METHODS:

We assessed 108 478 surgical cases prospectively submitted by members of the Scoliosis Research Society to a deidentified database from 2004 to 2007.

RESULTS:

Unintended durotomy occurred in 1.6% (1745 of 108 478) of all cases. The incidence of unintended durotomy ranged from 1.1% to 1.9% on the basis of preoperative diagnosis, with the highest incidence among patients treated for kyphosis (1.9%) or spondylolisthesis (1.9%) and the lowest incidence among patients treated for scoliosis (1.1%). The most common indication for spine surgery was degenerative spinal disorder, and among these patients, there was a lower incidence of durotomy for cervical (1.0%) vs thoracic (2.2%; P = .01) or lumbar (2.1%, P < .001) cases. Scoliosis procedures were further characterized by etiology, with the highest incidence of durotomy in the degenerative subgroup (2.2% vs 1.1%; P < .001). Durotomy was more common in revision compared with primary surgery (2.2% vs 1.5%; P < .001) and was significantly more common among elderly (> 80 years of age) patients (2.2% vs 1.6%; P = .006). There was a significant association between unintended durotomy and development of a new neurological deficit (P < .001).

CONCLUSION:

Unintended durotomy occurred in at least 1.6% of spinal surgeries, even among experienced surgeons. Our data provide general benchmarks of durotomy rates and serve as a basis for ongoing efforts to improve safety of care.

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.

Spinal subdural abscess: A rare cause of low back pain

Spinal subdural abscess (SSA) is a rare but well-described entity. It may occur secondary to a systemic infectious focus or following a surgical procedure. There are only two SSA cases in the literature that are unrelated to such conditions and without any well-documented etiology. SSA is a neurosurgical emergency and diagnosis may be difficult. Progressive neurological deficits and severe pain with fever suggest the diagnosis. Surgical drainage and subsequent prompt antimicrobial therapy should be performed without delay. We report a patient with SSA unrelated to any predisposing condition and discuss underlying mechanisms of this disease.

Cranio-Spinal Subdural Empyema due toS. Intermedius: a Case Report

BACKGROUND AND PURPOSE

Subdural empyema represents a loculated infection between the dura and the arachnoid. It has been described either intracranially or in the spinal canal, the latter localization being quite rare. While treatment guidelines for a single (either brain or spinal) localization of a subdural empyema are more or less established, its management when a massive involvement of CNS is evident represents a challenge.

METHODS

The authors describe a unique case of a 65-year-old woman having a massive involvement of the entire CNS with multiple localizations, both intracranial and spinal. Early diagnosis was obtained through brain CT scans followed by cranio-spinal contrast enhanced MRI scans. Patient was treated with external ventricular drainage and suboccipital craniectomy, while on antibiotic therapy.

RESULTS

Patient's neurological condition gradually improved. By the end of the eighth hospital week, she was discharged without any neurological deficit.

CONCLUSIONS

Spinal subdural empyema and brain subdural empyema are not always, as in our case, two different entities. Prompt diagnosis and treatment constitute the major variables affecting outcome.

Clinical assessment and medical treatment of spine infections

Spinal infections affect the vertebral bodies, the intervertebral disks, the spinal canal, and the paravertebral soft tissues and structures. A delay in diagnosis can result in spine deformity, substantial neurologic complications, and even death. Because of this, a high level of awareness is required by physicians in order to diagnose infections of the spine promptly. Advances in medical microbiologic testing and newer imaging methods have contributed considerably to the medical treatment of these infections. Through careful followup, less invasive approaches orchestrated by a multidisciplinary team that includes a spine surgeon, an infectious diseases specialist, and a neuroradiologist may be sufficient to treat patients with these infections. Research done through multidisciplinary collaborations will further advance our knowledge for the successful treatment of spinal infections.

LEVEL OF EVIDENCE

Level V (expert opinion). Please see the Guidelines for Authors for a complete description of levels of evidence.

Benign intradural extramedullary masses in children of northern India

Twenty-five children with benign intradural extramedullary tumors/lesions were retrospectively analyzed to see the frequency of different histotypes in this location and their variation from the Western world. The duration of symptoms, clinical profile and surgical outcome of these cases were evaluated. The age of children ranged from 1.5 to 18 years, with a mean age of 7.5 years. Thirteen amongst them were male. Follow-up ranged from 3 months to 5 years with a mean of 19 months. McCormick functional grading was used retrospectively to find out the functional outcome in these children. Sixty-eight percent of these cases presented with functional grade IV or V. The mean duration from the appearance of the first symptoms to admission to our hospital in these children was 13 months. Improvement in the functional grade following surgical excision was noted amongst all, except one, who presented with schwannoma, and did not improve from grade III even after a 14-month follow-up. Reoperation/two-staged operation was required in 3 children. The following conclusions were drawn from this study: (1) approximately half (48%) of intradural extramedullary benign tumors are nerve sheath tumors, i.e. neurofibromas, neurilemomas and schwannomas. Giant neurofibromas with giant extraforaminal extension may rarely manifest with a large extraspinal mass; (2) meningioma is an infrequent tumor in this location; (3) developmental cystic dysraphic lesions (neurenteric cyst, arachnoid cysts), unassociated with the stigmata of spinal dysraphism, are significantly more frequent (28%) than reported in the literature; (4) the possibility of infective lesions (granuloma, abscess) causing compressive features cannot be denied even in intradural extramedullary tumors; (5) long-standing lesions, with a long segment involvement, also have a good outcome following a good microsurgical excision, and (6) more than half of the children (68%) present with a severe neurological compromise, either because of ignorance and poor education or due to the scanty diagnostic facilities available at the peripheral hospitals of the developing milieu.

General principles in the medical and surgical management of spinal infections: a multidisciplinary approach

OBJECT

Infections along the spinal axis are characterized by an insidious onset, and the resulting delays in diagnosis are associated with serious neurological consequences and even death. Infections of the spine can affect the vertebral bodies, intervertebral discs, spinal canal, and surrounding soft tissues. Neurological dysfunction occurs when the spinal cord becomes compressed, edematous, or ischemic due to compression by abscess or vascular compromise. The aim of this paper was to detail general diagnostic and management principles for this disease.

METHODS

Recent progress in medical technologies, including the development of potent antimicrobial drugs, advanced imaging, and improved surgical methods, have dramatically reduced morbidity and mortality rates for spinal infections; however, debate still exists on the proper management of this disease. In this paper, the authors review the current management protocols for spinal infections at their institution, focusing on medical and surgical treatments for vertebral osteomyelitis, intervertebral disc space infections, and spinal canal and soft-tissue abscesses.

CONCLUSIONS

Technological advances in imaging modalities, pharmaceutics, and surgery have resulted in excellent outcomes and have greatly reduced the morbidity and mortality rates associated with spinal infections. Currently, treatment of spinal infections requires a multidisciplinary team that includes infectious diseases experts, neuroradiologists, and spine surgeons. The key to successful management of spinal infections is early detection.

Spinal subdural empyema after a dural tear

Spinal subdural empyema is an exceptionally rare and serious condition. Immediate surgery with complete exposure and drainage of the abscess is generally recommended. The authors present a patient in whom a Staphylococcus aureus septicemia related to nosocomial pneumonia developed after a thoracic laminectomy. The surgery was further complicated by an unintended durotomy (dural tear). Ten days postoperatively, the patient experienced back pain and lower-extremity symptoms caused by a subdural empyema. Cultures from the wound also grew S. aureus. This represents the first case of spinal subdural empyema in which the spread of infection into the subdural space is believed to have been facilitated by a dural tear. The patient had a favorable outcome despite an initial delay in surgical intervention because of a pulmonary embolus.

Cervical subdural empyema following acupuncture

A review of the literature reveals only a few cases of spinal subdural empyema. Etiologies of spinal subdural empyema include hematogenous spread from skin lesions, systemic sepsis, direct spread from spinal osteomyelitis and complications of discography. However, in this report, we describe a patient who developed spinal subdural empyema following several cervical acupuncture sessions. Operative treatment with adequate laminectomy, removal of abscess, and copious irrigation resulted in good recovery. Microbiologic culture study of pus obtained at surgery was positive for Staphylococcus aureus. The need for sterilization procedures for acupuncture is emphasized and a brief review of the relevant literature is presented.

Spinal subdural abscess: successful treatment with limited drainage and antibiotics in a patient with AIDS

The authors present a case of Staphylococcus aureus spinal subdural abscess in a patient with AIDS. Although complete surgical drainage has been strongly advocated in the literature, this patient made a complete neurologic and symptomatic recovery and radiographically demonstrated resolution of the abscess with only limited surgical drainage and parenteral antibiotics. Magnetic resonance imaging findings of this unusual lesion are discussed. Relevant literature in the management of spinal subdural abscesses is reviewed.