Effects of Radiation on Spinal Dura Mater and Surrounding Tissue in Mice

PURPOSE

Spinal surgery in a previously irradiated field carries increased risk of perioperative complications, such as delayed wound healing or wound infection. In addition, adhesion around the dura mater is often observed clinically. Therefore, similar to radiation-induced fibrosis--a major late-stage radiation injury in other tissue--epidural fibrosis is anticipated to occur after spinal radiation. In this study, we performed histopathologic assessment of postirradiation changes in the spinal dura mater and peridural tissue in mice.

MATERIALS AND METHODS

The thoracolumbar transition of ddY mice was irradiated with a single dose of 10 or 20 Gy. After resection of the irradiated spine, occurrence of epidural fibrosis and expression of transforming growth factor beta 1 in the spinal dura mater were evaluated. In addition, microstructures in the spinal dura mater and peridural tissue were assessed using an electron microscope.

RESULTS

In the 20-Gy irradiated mice, epidural fibrosis first occurred around 12 weeks postirradiation, and was observed in all cases from 16 weeks postirradiation. In contrast, epidural fibrosis was not observed in the nonirradiated mice. Compared with the nonirradiated mice, the 10- and 20-Gy irradiated mice had significantly more overexpression of transforming growth factor beta 1 at 1 week postirradiation and in the late stages after irradiation. In microstructural assessment, the arachnoid barrier cell layer was thinned at 12 and 24 weeks postirradiation compared with that in the nonirradiated mice.

CONCLUSION

In mice, spinal epidural fibrosis develops in the late stages after high-dose irradiation, and overexpression of transforming growth factor beta 1 occurs in a manner similar to that seen in radiation-induced fibrosis in other tissue. Additionally, thinning of the arachnoid barrier cell layer was observed in the late stages after irradiation. Thus, consideration should be given to the possibility that these phenomena can occur as radiation-induced injuries of the spine.

Optical clearing of the dura mater using glycerol: a reversible process to aid the post-mortem investigation of infant head injury

PURPOSE

In cases of suspected abusive head trauma, a thorough and systematic study of the cranium and its contents is essential, preferably using the best available methods for observing the brain and its coverings. Building upon recent developments in skull bone removal techniques in infant autopsies, we have assessed the use of two optical clearing agents (OCAs), glycerol and mannitol, on pediatric dura mater in an attempt to increase the transparency of this tissue and thereby enhance the post-mortem assessment of infant head injuries, particularly subdural hematomas.

METHODS

Extracorporeal testing revealed glycerol to be the more effective OCA. Therefore, in situ investigations were commenced using glycerol during 33 pediatric post-mortem examinations.

RESULTS

An increase in the transparency of the dura was observed in 32 of the 33 cases, within 1 min of application of the OCA. In a 2 year old with cerebral palsy, only partial optical clearance of the dura was seen, most likely due to a significantly atrophic brain, prominent gelatinous leptomeninges, and abnormally thickened dura. This technique allowed for detection of minimal amounts of subdural bleeding over the convexities, before dissection of the dura, avoiding post-mortem blood spillage from artifactually disrupted bridging veins. Optical clearing of the dura aided in the evaluation of patterns of subdural hemorrhage in three cases of non-accidental head injury, three cases of peri-natal head injury and one case of overlaying, apparently resulting in minor crush injury to the head.

CONCLUSIONS

We have demonstrated that glycerol is an effective and easy-to-use OCA to effect the readily reversible optical clearing of human infant calvarial dura at autopsy.

Primary dural lymphoma: Complete remission after treatment with radiation therapy

Central nervous system (CNS) involvement in sarcoidosis is rare and typically occurs in 5-10% of patients. Neurological symptoms in a patient with known sarcoidosis can be attributed to neurosarcoidosis without thorough evaluation. Primary Dural Lymphoma (PDL) is an extremely rare form of non-Hodgkin lymphoma. Although PDL is technically a subtype of primary CNS lymphoma, the two entities vary markedly in their histological grade, clinical course, prognosis and treatment. The most common dural- based lesion found on CNS imaging is meningioma. It shares many imaging, clinical and epidemiologic features of PDL which often leads to misdiagnosis of PDL as meningioma. We present a case where a PDL was diagnosed after CNS symptoms failed to resolve after steroid therapy for presumed neurosarcoidosis.

Squash Cytology of a Dural-Based High-Grade Chondrosarcoma May Mimic That of Glioblastoma in the Central Nervous System

BACKGROUND

Intracranial chondrosarcoma is rare, and most cases occur in the skull base. Intradural chondrosarcoma is even rarer.

CASE

Here, we describe a case of dural chondrosarcoma with a radiation history for nasopharyngeal carcinoma and a radical prostatectomy for prostatic cancer 15 and 8 years earlier, respectively. A 67-year-old man presented with a 3-week memory disturbance and dysarthria. Computed tomography and magnetic resonance images of the brain revealed a dural-based mass in the left temporal area. Under the impression of a glioblastoma, a resection and an intraoperative squash cytology were done. A necrotic dirty background as well as bluish-to-pinkish myxoid stroma were characteristic; the nuclei of highly pleomorphic tumor cells were hyperchromatic to vesicular with an occasional ground-glass appearance. The cytoplasm was of an eosinophilic hyalinized condensed morphology with an occasional granular appearance. Histologically, the lobulated mass was composed of hypercellular lobules of well-differentiated chondrocytes intermixed with anaplastic pleomorphic cells and diagnosed as a conventional grade III chondrosarcoma. These cells were immunoreactive for D2-40, S-100 protein and vimentin. Brain invasion was also found.

CONCLUSION

Albeit rare, dural-based chondrosarcomas should be considered in the differential diagnosis for meningeal tumors, especially in the case of previous radiation therapy.

Efficacy of percutaneous epidural neuroplasty does not correlate with dural sac cross-sectional area in single level disc disease

PURPOSE

Percutaneous epidural neuroplasty (PEN) is a minimally invasive treatment. The efficacy of PEN has been relatively well investigated; however, the relationship between the clinical effectiveness of PEN and the severity of spinal canal stenosis by disc material has not yet been established. The purpose of this study was to compare clinical outcomes of PEN according to the dural sac cross-sectional area in single level disc disease.

MATERIALS AND METHODS

This study included 363 patients with back pain from single level disc disease with and without radiculopathy. Patients were categorized into groups according to spinal canal compromise by disc material: Category 1, less or more than 50%; and Category 2, three subgroups with lesser than a third, between a third and two thirds, and more than two thirds. Clinical outcomes were assessed according to the Visual Analog Scale (VAS) score for back pain and leg pain and Odom's criteria at 1, 3, 6, 12, and 24 months after treatment.

RESULTS

The demographic data showed no difference between groups according to spinal canal compromise by disc material except age (older age correlated with more spinal canal compromise). The dural sac cross-sectional area did not correlate with the VAS scores for back and leg pain after PEN in single level disc disease in Groups 1 and 2. Odom's criteria after PEN were also not different according to dural sac cross-sectional area by disc material.

CONCLUSION

PEN is an effective procedure in treating single level lumbar disc herniation without affecting dural sac cross-sectional area.

Idiopathic hypertrophic craniocervical pachymeningitis

PURPOSE

Hypertrophic craniocervical pachymeningitis (HCP) is a rare disease causing chronic inflammatory hypertrophy of the cranial and spinal dura mater. To increase awareness of this condition, we report the details of a case here.

METHODS

We reviewed the case of a 78-year-old man presenting with a rare case of HCP and summarized the clinical features, laboratory evaluations and treatment of the case.

RESULTS

In this case, the HCP involved the intracranial dura and high cervical regions, manifesting as lower cranial nerve palsies, headache, and neck pain, developing over 7 months. Magnetic resonance imaging revealed thickening of the dura in the craniocervical region with peripheral enhancement. Steroid therapy was commenced and the symptoms improved rapidly.

CONCLUSIONS

HCP can be diagnosed by MRI and laboratory investigations. In this case corticosteroid treatment was effective, although care must be taken when slowly reducing the dose. This case highlights HCP as a cause of progressive cerebellomedullar and cervical spinal cord symptoms.

Dural metastasis of nasopharyngeal carcinoma: rare, but worth considering

Metastasis of nasopharyngeal carcinoma (NPC) to the dura, an extremely rare condition, can be symptomatically silent and mistaken for a benign entity radiographically. Missed diagnosis can lead to serious consequences or prove immediately fatal. We report a woman with dural metastasis of NPC that mimicked a meningioma on radiography. Craniectomy with tumour resection was performed due to rapid progression from the onset of symptoms to disability. The patient was still alive two years after surgery. This case emphasises the need to keep in mind the possibility of dural metastasis of NPC in patients with abnormal imaging features. This would not only avoid wrong and optimistic diagnosis, but also allow for appropriate treatment in a timely manner. To our knowledge, this is the first report of metastasis of NPC to the dura. We provide detailed information on the neoplastic lesion, which masqueraded as a benign entity and caused potentially fatal consequences.

Extranodal (dural) Rosai-Dorfman disease radiologically and histologically mimicking meningioma: a case report

BACKGROUND

Rosai-Dorfman disease (sinus histiocytosis with massive lymphadenopathy) is an idiopathic nonneoplastic lymphohistiocytic proliferation with variable clinical presentations, sometimes mimicking other disorders including neoplasm. Particularly, intracranial Rosai-Dorfman disease is rare and without well-established optimal treatment modalities.

CASE

A 42-year-old man presented with gradually progressive unilateral hearing and vision loss over a two-year period. An MRI of the head showed findings consistent with meningiomatosis. He subsequently underwent a dural biopsy, and histologic examination of the lesion showed sheets of histiocytes positivefor CD68 and S-100 and negative for CD1a within a rich lymphoplasmacytic infiltrate. Some of the histiocytes showed emperipolesis of lymphocytes and plasma cells. These findings were consistent with Rosai-Dorfman disease. Interestingly, EMA-positive meningothelial whorls were seen scattered within the dominantly histiocytic-appearing process, mimicking the appearance of meningioma; these whorls were thought to be reactive in nature.

CONCLUSION

This case is important as it high-lights unusual clinical and histopathologic features of Rosai-Dorfman disease, thereby adding to the spectrum of manifestations of this entity. Awareness of such features is helpful in averting the misdiagnosis of intracranial Rosai-Dorfman disease with reactive meningothelial hyperplasia as meningiomas.

In situ forming hydrogel composed of hyaluronate and polygalacturonic acid for prevention of peridural fibrosis

Hyaluronic acid-based hydrogels can reduce postoperative adhesion. However, the long-term application of hyaluronic acid is limited by tissue mediated enzymatic degradation. To overcome this limitation, we developed a polygalacturonic acid and hyaluronate composite hydrogel by Schiff's base crosslinking reaction. The polygalacturonic acid and hyaluronate composite hydrogels had short gelation time (less than 15 s) and degraded by less than 50 % in the presence of hyaluronidase for 7 days. Cell adhesion and migration assays showed polygalacturonic acid and hyaluronate composite hydrogels prevented fibroblasts from adhesion and infiltration into the hydrogels. Compared to hyaluronate hydrogels and commercial Medishield™ gels, polygalacturonic acid and hyaluronate composite hydrogel was not totally degraded in vivo after 4 weeks. In the rat laminectomy model, polygalacturonic acid and hyaluronate composite hydrogel also had better adhesion grade and smaller mean area of fibrous tissue formation over the saline control and hyaluronate hydrogel groups. Polygalacturonic acid and hyaluronate composite hydrogel is a system that can be easy to use due to its in situ cross-linkable property and potentially promising for adhesion prevention in spine surgeries.

Idiopathic hypertrophic pachymeningitis presenting with occipital neuralgia

BACKGROUND

Although occipital neuralgia is usually caused by degenerative arthropathy, nearly 20 other aetiologies may lead to this condition.

METHODS

We present the first case report of hypertrophic pachymeningitis revealed by isolated occipital neuralgia.

RESULTS AND CONCLUSIONS

Idiopathic hypertrophic pachymeningitis is a plausible cause of occipital neuralgia and may present without cranial-nerve palsy. There is no consensus on the treatment for idiopathic hypertrophic pachymeningitis, but the usual approach is to start corticotherapy and then to add immunosuppressants. When occipital neuralgia is not clinically isolated or when a first-line treatment fails, another disease diagnosis should be considered. However, the cost effectiveness of extended investigations needs to be considered.

Subdural Effusions in the Posterior Fossa Associated with Spontaneous Intracranial Hypotension

Background:

Misdiagnosis of spontaneous intracranial hypotension remains a problem, despite increasing recognition.

Methods:

Three patients with spontaneous intracranial hypotension presented with typical findings on lumbar puncture, magnetic resonance (MR) imaging, and radioisotope cisternography. All patients showed subdural effusions in the posterior fossa on axial T2-weighted MR imaging. Axial MR images of 112 patients with other conditions were also screened for this finding.

Results:

One of three patients had typical orthostatic headache, and the other two had continuous headache. The finding of subdural effusions in the posterior fossa on axial T2-weighted MR imaging disappeared after treatment. Similar findings were found in 14 of 112 patients with other conditions. Most of the patients were over 60 years old or had dementia or previous radiation therapy.

Conclusion:

Subdural effusions in the posterior fossa can be identified by T2-weighted axial MR imaging, and are useful for the diagnosis of spontaneous intracranial hypotension and for verifying the effectiveness of treatment.

Primary spinal intradural extraskeletal Ewing sarcoma mimicking a giant nerve sheath tumor: case report and review of the literature

Primary intradural extraskeletal Ewing sarcoma is a very rare form of malignant neoplasm. Only few cases have been reported on the literature. Here, we report a case of a 14-year-old boy who had a chief complaint of pain and tingling in the right lower limb. The patient initially seemed to have a giant nerve sheath tumor but was eventually diagnosed with intradural extraskeletal Ewing sarcoma arising from the nerve roots of the cauda equine. The literature with regard to primary spinal intradural extraskeletal Ewing sarcoma is reviewed.

Esophageal squamous cell carcinoma with dural and bone marrow metastases

Patients with esophageal squamous cell carcinoma generally present at an advanced stage at the time of diagnosis. The most common sites of visceral metastasis are the lung, liver and bone, but brain and bone marrow involvement is exceedingly rare. Herein, we report a 62-year-old man with a 4-wk history of progressive low back pain with radiation to bilateral lower legs, dysphagia and body weight loss. Esophageal squamous cell carcinoma with regional lymph node, liver and bone metastases was diagnosed. He underwent concurrent chemoradiotherapy and got a partial response. Four months later, he complained of headache, diplopia and severe hearing impairment in the left ear. There was no evidence for bacterial, fungal, tuberculous infection or neoplastic infiltration. Magnetic resonance imaging of the brain demonstrated thickening and enhancement of bilateral pachymeninges and multiple enhancing masses in bilateral skull. Dural metastasis was diagnosed and he received whole brain irradiation. In addition, laboratory examination revealed severe thrombocytopenia and leucopenia, and bone marrow study confirmed the diagnosis of metastatic squamous cell carcinoma. This is the first described case of esophageal squamous cell carcinoma with dural and bone marrow metastases. We also discuss the pathogenesis of unusual metastatic diseases and differential diagnosis of pachymeningeal thickening.

Does an intraoperative finding of an intact dural sac help to prognosticate neurological recovery in cauda equinal and epiconal injuries in thoracolumbar fractures? An analysis of 31 patients

OBJECTIVE

To evaluate the effect of integrity of dural sac in determining motor neurological recovery in patients with cauda equinal and epiconal injuries in vertebral fractures at thoracolumbar junction.

METHODS

Thirty-one patients with single-level vertebra fracture over T12-L2 with cauda equinal or epiconal injuries that underwent posterior spinal decompression and stabilization were evaluated in the period between 2006 and 2012. All patients included had motor incomplete ASIA C in neurology and were either Type B or C (AO/Magerl classification) of fracture morphology. Radiologist opinion to confirm the level of conus in MRI was done preoperatively. Intraoperative findings with respect to intactness of dura was noted. All MRI images were postoperatively evaluated by an independent, blinded radiologist for evidence of dural breach caused by the trauma. All participants provided basic demographic data, ambulatory status, and current neurology and received neurologic examination at intervals. The differences in neurologic injury sites and functional walkers in patients with different levels of vertebral injury were analyzed. Receiver operating characteristic curve analysis was used to define the cut-off value of lower extremities motor score (LEMS) in functional walkers and non-walkers. All patients were seen at a postoperative follow-up of minimum 18 months.

RESULTS

Data of the 31 patients were analyzed. Seventeen patients (55%) had epiconus and lumbar roots lesions and 14 (45%) had cauda equina lesions. The injury was at the T12 vertebra in 9 patients (29%), L1 in 12 (39%) and in L2 in 10 patients (32%). Mean LEMS for patients with T12, L1, and L2 fractures were calculated. Fourteen patients had intraoperative findings of intact dura as against 17 patients with dural breach. MRI images when revisited by an independent radiologist by keeping him blind about the intraoperative surgeons findings showed statistically very good interobserver agreement (κ = 0.618) with regard to integrity of the dural sac. Postoperative neurological assessment at minimum 18 months follow-up showed that four out of the 14 patients with intact dura were walkers (28%) whereas of the 17 patients with dural breach, 13 were walkers (82%).

CONCLUSION

Neurological recovery in cauda equinal and epiconal injuries in thoracolumbar fractures is significantly less likely in an intact dural sac, probably because the dural breach prevents the roots to take as much impact as compared to an intact dural sac.

Neuroimaging of Langerhans cell histiocytosis: a radiological review

The neuroimaging of Langerhans cell histiocytosis (LCH), in most of the cases, is nonspecific and can vary depending on the location, especially as shown on magnetic resonance imaging (MRI). In the absence of a clinical history of LCH, isolated central nervous system (CNS) lesion presents a diagnostic challenge. LCH should be considered in the differential diagnosis of craniofacial tumors and neurodegenerative (ND) lesions of the brain. MRI is the modality of choice for investigating the CNS-LCH. Long-term follow-up with MRI is indicated in patients with ND-LCH. This retrospective study provides a comprehensive description of the spectrum of neuroimaging findings in patients with LCH, the underlying neuropathology, and follow-up study of the disease.

Falx chondroma with hyperostosis of the scull: a case report

INTRODUCION

Intracranial chondroma is a very rare, slow growing, benign cartilaginous tumor that arises usually from the base of the scull. Chondroma located at the falx is extremely rare. According to our best knowledge 15 cases of falx chondromas have been reported in the literature.

CASE OUTLINE

This is the first case report of falx chondroma located in the parietal area associated with hyperostosis. Magnetic resonance imaging of the brain revealed a 3x4x4 cm solid, calcified, ring-shaped, well-defined tumor at the posterior falx.The patient underwent surgery and complete resection was performed. Histological examination confirmed chondroma of the falx. Postoperative CT scan showed no residual of tumor and the patient was discharged.

CONCLUSION

The long-term prognosis is good after a total excision of the tumor. Awareness of this rare pathology in the differential diagnosis of falx mass could facilitate the diagnosis.

Bacterial cellulose membranes used as artificial substitutes for dural defection in rabbits

To improve the efficacy and safety of dural repair in neurosurgical procedures, a new dural material derived from bacterial cellulose (BC) was evaluated in a rabbit model with dural defects. We prepared artificial dura mater using bacterial cellulose which was incubated and fermented from Acetobacter xylinum. The dural defects of the rabbit model were repaired with BC membranes. All surgeries were performed under sodium pentobarbital anesthesia, and all efforts were made to minimize suffering. All animals were humanely euthanized by intravenous injection of phenobarbitone, at each time point, after the operation. Then, the histocompatibility and inflammatory effects of BC were examined by histological examination, real-time fluorescent quantitative polymerase chain reaction (PCR) and Western Blot. BC membranes evenly covered the surface of brain without adhesion. There were seldom inflammatory cells surrounding the membrane during the early postoperative period. The expression of inflammatory cytokines IL-1β, IL-6 and TNF-α as well as iNOS and COX-2 were lower in the BC group compared to the control group at 7, 14 and 21 days after implantation. BC can repair dural defects in rabbit and has a decreased inflammatory response compared to traditional materials. However, the long-term effects need to be validated in larger animals.

Hirayama disease in a 17-year-old Chinese man

Hirayama disease is an uncommon cervical myelopathy associated with neck flexion. It has been postulated to be related to the anterior shifting of the posterior dura of the lower cervical dural canal during neck flexion, resulting in lower cervical cord atrophy with asymmetric flattening. We report a case of Hirayama disease in a 17-year-old Chinese man and demonstrate the use of dynamic flexion magnetic resonance imaging of the cervical spine in the diagnosis of the disease.

Clinical approach of using Onyx via transarterial access in treating tentorial dural arteriovenous fistula

OBJECTIVE

In this study, based on clinical presentation and angiographic findings, we try to investigate the possibility to do transarterial embolization using Onyx to treat tentorial dural arteriovenous fistula (TDAVF). Particular attention will be given to the relationship between vascular anatomic characteristics and clinical management.

METHODS

We retrospectively reviewed the clinical and radiologic data of 26 patients with TDAVFs, who were treated via transarterial approach using Onyx (including three cases treating with balloon assisting) at our department from January 2005 to April 2010.

RESULTS

The total obliterated rate was 85.7, 53.8, and 66.7% in the tentorial marginal, lateral, and medial subtype, respectively. Symptoms were improved significantly in the patients whose fistulas were totally and sub-totally obliterated. The mean follow-up duration was 2.9 years. After operation, patients' symptom was dramatically improved indicated by the decrease of individual modified Rankin scale (MRS). Only one patient suffered from temporary paralysis of cranial nerve (CN) III. All 26 patients were clinically stable and without any relapsed, increased, or new symptoms. All patients had resumed their normal activities until the latest follow-up.

CONCLUSION

Treating the TDAVF via transarterial approach using Onyx maybe a feasible clinical practice. The fistula obliterated rate is highly related to the anatomic characteristic, and high complete obliterated rate can be achieved. Our preliminary results showed that Onyx injection with 'balloon assisting' technique can be helpful in some of the cases.

Effectiveness of a new gelatin sealant system for dural closure

OBJECTIVES

Watertight dural closure is imperative after neurosurgical procedures because inadequately treated leakage of cerebrospinal fluid (CSF) can have serious consequences. In this study, the authors test the use of a new gelatin glue as a dural sealant in in vitro and in vivo canine models of transdural CSF leakage.

METHODS

The in vitro model was sutured semicircles of canine dura mater and artificial dural substitute. The sutures were sealed with gelatin glue (n  =  20), fibrin glue (n  =  20), or a polyethylene glycol (PEG)-based hydrogel sealant (n  =  20). Each sample was set in a device to measure water pressure, and pressure was increased until leakage occurred. Bonding strength was subjectively evaluated. The in vivo model was dogs who underwent dural excision and received either no sealant (control group; n  =  5) or gelatin glue sealant (n  =  5) before dural closure. Twenty-eight days post-surgery, the maximum intracranial pressure was measured at the cisterna magna using Valsalva maneuver and tissue adhesion was evaluated.

RESULTS

The water pressure at which leakage occurred in the in vitro model was higher with gelatin glue (76·5 ± 39·8 mmHg) than with fibrin glue (38·3 ± 27·4 mmHg, P < 0·001) or the PEG-based hydrogel sealant (46·3 ± 20·9 mmHg, P  =  0·007). Bonding strength was higher for the gelatin glue than fibrin glue (P < 0·001) or PEG-based hydrogel sealant (P  =  0·001). The maximum intracranial pressure in the in vivo model was higher for the gelatin glue group (59·0 ± 2·2 mmHg) than the control group (13·8 ± 4·0 mmHg, P < 0·001). Tissue adhesion was lower for the gelatin glue group than the control group (P  =  0·005).

DISCUSSION

The new gelatin glue provides an effective watertight closure when used as an adjunct to sutured dural repair.