CT and MRI of ruptured intracranial dermoids

Dermoid cyst of the infratemporal fossa: a case report of surgical resection by infratemporal fossa type B approach

OBJECTIVE

This is a case report of a dermoid cyst located in the infratemporal fossa and its surgical removal using infratemporal fossa type B approach.

CASE REPORT

A 15-year-old male was referred from a local clinic after an incidental finding of a mass lesion in the skull base area on computed tomography (CT). Pre-operative magnetic resonance imaging showed a large cystic mass lesion, expanding to the foramen ovale with fat component in the right infratemporal fossa region. The lesion was completely excised using an infratemporal fossa type B approach.

CONCLUSION

An extremely rare case of dermoid cysts of the infratemporal fossa was managed with infratemporal fossa type B approach without severe complication.

An Intracranial Extradural Dermoid Cyst Presenting with Two Dermal Sinuses and an Abscess in a Child

Dermoid cysts account for only a small fraction of intracranial masses, with extradural dermoid cysts being considered a much rarer entity than those located intradurally. Intracranial dermoid cysts vary in clinical presentations: some maybe asymptomatic whilst others harbor features of raised intracranial pressure, neurological deficits, or even aseptic meningitis. Dermoid cysts may also present with cutaneous lesions. Herein, we report a rare case of a 1-year-old female presenting with a midline, scalp abscess. Brain MRI revealed an intracranial, extradural tumor, with features suggestive of a dermoid cyst, unusually located in the crista galli, and complicated by the formation of two cutaneous sinus tracts. After identification and characterization by MRI, bitemporal craniotomy was performed with complete excision of the mass and sinus tracts. Histological analysis confirmed dermoid cyst as the final diagnosis. Postoperatively, the patient recovered fully and had no evidence of recurrence in subsequent visits. The case mentioned above highlights the rarity of such a presentation for an intracranial extradural dermoid cyst and the vitality of early imaging for midline cutaneous lesions for identification of intracranial extensions and avoidance of detrimental consequences.

The incidence and risk factors for adjacent vertebral fractures in community-dwelling people with prevalent vertebral fracture: the 3rd and 4th survey of the ROAD study

In this 3-year follow-up study of 66 community-dwelling adults with severely deformed vertebral fractures, the annual incidence of adjacent vertebral fracture (AVF) was 6.1%/year. Lower bone mineral density at the femoral neck and spinopelvic malalignment were risk factors for AVF.

PURPOSE

This study aimed to clarify the incidence and risk factors of adjacent vertebral fractures (AVFs)-fractures adjacent to a prevalent vertebral fracture (VF)-using an established population-based cohort from the ROAD study.

METHODS

Among the 1213 participants who underwent whole-spine radiography in ROAD's third (2012-2013, the baseline) and fourth surveys (2015-2016, the follow-up), 66 (12 men, 54 women) had at least one VF at the baseline. VF and AVF were determined radiographically using Genant's semi-quantitative (SQ) method, where VF was SQ ≥ 2 and AVF was a one-level cranial or caudal vertebra with an SQ grade one or more higher at the follow-up. An interviewer-administered questionnaire was applied, and anthropometric measurements and bone mineral density (BMD) measurements at the lumbar spine and femoral neck were performed. Sagittal imbalance of the spine was defined as a mismatch between pelvic incidence and lumbar lordosis (PI-LL) of > 20°. Multivariate logistic regression analyses were performed to identify risk factors for AVF.

RESULTS

AVF occurred in 12 participants (1 man, 11 women). The annual incidence of AVF was estimated at 6.1%/year. Logistic regression analyses revealed that lower BMD at the femoral neck and PI-LL > 20° were risk factors for AVF.

CONCLUSIONS

The annual incidence of AVF in a general population with prevalent VF was 6.1%/year. In addition, lower BMD at the femoral neck and PI-LL > 20° were risk factors for AVF.

Patient with Epilepsy Caused by the Spontaneous Rupture of an Intracerebral Dermoid Cyst

BACKGROUND

This is a rare case of a patient presenting with epileptic seizures and headaches who was diagnosed with spontaneous intracerebral dermoid cyst rupture via radiographic imagery, and rupture was confirmed via a pathology report.

CASE DESCRIPTION

We report the case of a woman aged 26 years who presented with a history of chronic headache for 9 years without other symptoms, and progressive worsening of her headache had occurred for 1 month prior to admission. Radiologic examination showed a large mass located in the left temporal fossa and a large amount of homogeneous matter in the subarachnoid space of the ipsilateral cerebral hemisphere, then the tumor was completely excised. A left pterional craniotomy was conducted under general anesthesia for removal of the tumor, and pathological examination showed a dermoid cyst.

CONCLUSIONS

We discuss the clinical and radiologic features, as well as the treatment of this patient.

Ruptured Central Nervous System Dermoid Cyst of Suprasellar Region Manifesting as Unusual Epileptic Seizure

BACKGROUND

Central nervous system dermoid cysts are rare lesions derived from ectopic epithelial cells. They are slow-growing benign tumors but may cause significant morbidity through compression of neurologic and vascular structures and, rarely, rupture into the subarachnoid space.

CASE DESCRIPTION

We present a rare case of a spontaneously ruptured intracranial dermoid cyst in a 32-year-old man presenting as new-onset epileptic seizures due to chemical meningitis caused by dissemination of fat or lipid droplets.

CONCLUSIONS

The dermoid cyst is a rare entity, the rupture of which is exceptional and often spontaneous. It is manifested by a polymorphic and nonspecific clinical picture requiring the use of imaging. This is based on CT and especially MRI, which make it possible to positively diagnose the nature of the cyst and the rupture, specify the extent of the dissemination of the lipid content in the subarachnoid spaces, and detect possible complications such as hydrocephalus. It also makes it possible to carry out a precise topographic assessment to plan the therapeutic conduct and guide a possible surgical intervention.

Diagnostic Dilemma: Cerebellopontine Angle Lipoma Versus Dermoid Cyst

Both lipomas and dermoid cysts of the cerebellopontine angle are rare tumors. These tumors differ in their embryological origin but share similar features on imaging. Both of these congenital lesions can be found in the cerebellopontine angle (CPA), and symptomatic clinical presentation is dictated by the location of the lesion. This paper demonstrates a unique case in which a CPA lipoma was misidentified as a dermoid cyst, leading to surgical intervention. Further, the paper provides a literature review of CPA lipomas and dermoid cysts to aid readers in further differentiating between these two unique tumors.

Interdural cavernous sinus dermoid cyst in a child: case report

Interdural dermoid cysts (DCs) of the cavernous sinus (CS), located between the outer (dural) and inner layer (membranous) of the CS lateral wall, are rare lesions in children. The authors report on a 5-year-old boy with third cranial nerve palsy and exophthalmos who underwent gross-total removal of an interdural DC of the right CS via a frontotemporal approach. The patient had a good outcome and no recurrence at the 12-month follow-up. To the best of the authors' knowledge this is the second pediatric case of interdural DC described in the literature.

Preparation and characterisation of an innovative injectable calcium sulphate based bone cement for vertebroplasty application

Spine-Ghost: a novel injectable resorbable cement containing mesoporous bioactive glass and a radiopaque glass-ceramic phase in a calcium sulphate matrix.

Ruptured dermoid cyst of the lateral cavernous sinus wall with temporary symptoms: a case report

BACKGROUND

Dermoid cysts are non-neoplastic tumors that arise from defects in the separation of the neuroectoderm. Cyst rupture rarely occurs spontaneously and the most common symptom is headache, followed by seizure. Although many cases of ruptured dermoid cysts present with symptoms, reports of cases that are asymptomatic, or where symptoms disappear, are rare.

CASE PRESENTATION

We report the case of a 66-year-old Asian man with a history of sudden onset headache who was found to have high amounts of fat material in the subarachnoid space and a fat suppression mass in the left cavernous sinus. He underwent oral steroid therapy. Five days after starting medication his headache symptoms disappeared. Routine neurological imaging was then performed without surgical procedure. Magnetic resonance imaging revealed evidence of the remains of a static lesion 6 months after his first visit. He has remained headache free for 10 months since the initial event.

CONCLUSIONS

Although cases of ruptured dermoid cysts presenting with consistent symptoms have been commonly reported, until now there were few reports on asymptomatic cases or cases where symptoms disappeared. We believe that surgical intervention is unnecessary for ruptured dermoid cysts with minimal symptoms.

A Middle Cranial Fossa Dermoid Cyst Treated by an Endonasal Endoscopic Approach

Dermoid cysts are rare, benign, congenital ectodermal inclusion cysts in the skull base, comprising skin supplements surrounded by squamous epithelium. In the period of embryological development, the cysts originate from ectodermal cells left behind in the cranial region by the closure of the neural tube and are primarily located at the midline, especially in the subarachnoid spaces. These lesions are usually asymptomatic and diagnosed incidentally. When the cysts reach large sizes, they can be symptomatic due to infection, rupture, or mass effect around neurovascular tissue. The cysts typically demonstrate accurate radiological diagnostic features. In this case report, we present a rare dermoid cyst in the middle cranial fossa, treated by an endonasal endoscopic approach. The endonasal endoscopic management of appropriate middle cranial fossa is discussed as a recent advance in the extended applications of endoscopic sinus surgery.

A Ruptured Dermoid Cyst of the Cavernous Sinus Extending into the Posterior Fossa

Supratentorial dermoid cysts are uncommon to develop in the cavernous sinus. We present a ruptured dermoid cyst of the cavernous sinus extending into the posterior fossa. The patient was a 32-year-old female who complained occipital headache, blurred vision, and tinnitus over 4 years. Brain magnetic resonance (MR) imaging revealed an enhanced tumor in the right cavernous sinus extending into the right temporal base and the posterior fossa with findings of ruptured cyst. Surgical resection was performed, and pathological findings were confirmed to be a dermoid cyst. We report a second case with ruptured dermoid cyst of the cavernous sinus extending into the posterior fossa.

Giant middle fossa epidermoid presenting as holmes' tremor syndrome

Intracranial dermoids may gradually reach an enormous size before the onset of symptoms. Common clinical presentations of intracranial epidermoid include headache and seizures. We present a case of a 35-year female patient with giant middle fossa epidermoid that presented with Holmes’ tremor syndrome, and we review the relevant literature. To the best of our knowledge, such a presentation has not previously been described in the literature.

Ruptured conus medullaris dermoid cyst with fat droplets in the central canal [corrected]

Spinal dermoid tumors are rare, benign, slow growing tumors. These tumors may become acutely symptomatic after rupture or infection. Excision of the lesion with long term close follow-up studies is required for the management of these lesions. We present a very rare case of ruptured conus medullaris dermoid cyst in a 22-year-old male presented with urinary retention and low back pain. Magnetic resonance imaging scan with contrast reveals a lesion in the cauda equina inseparable from conus medullaris with fat droplets within the central spinal canal extending up to the medulla. Patient was operated with laminectomy and near complete excision of the lesion was done. Patient's low back pain was relieved following surgery. However patient had persistent urinary incontinence and on clean intermittent self-catheterization. Histopathology was suggestive of dermoid cyst.

Randomized controlled trial of percutaneous vertebroplasty versus optimal medical management for the relief of pain and disability in acute osteoporotic vertebral compression fractures

OBJECT

Osteoporotic vertebral compression fractures (VCFs) are a major cause of increased morbidity in older patients. This randomized controlled trial compared the efficacy of percutaneous vertebroplasty (PV) versus optimal medical therapy (OMT) in controlling pain and improving the quality of life (QOL) in patients with VCFs. Efficacy was measured as the incidence of new vertebral fractures after PV, restoration of vertebral body height (VBH), and correction of deformity.

METHODS

Of 105 patients with acute osteoporotic VCFs, 82 were eligible for participation: 40 patients underwent PV and 42 received OMT. Primary outcomes were control of pain and improvement in QOL before treatment, and these were measured at 1 week and at 2, 6, 12, 24, and 36 months after the beginning of the treatment. Radiological evaluation to measure VBH and sagittal index was performed before and after treatment in both groups and after 36 months of follow-up.

RESULTS

The authors found a statistically significant improvement in pain in the PV group compared with the OMT group at 1 week (difference -3.1, 95% CI -3.72 to -2.28; p < 0.001). The QOL improved significantly in the PV group (difference -14, 95% CI -15 to -12.82; p < 0.028). One week after PV, the average VBH restoration was 8 mm and the correction of deformity was 8°. The incidence of new fractures in the OMT group (13.3%) was higher than in the PV group (2.2%; p < 0.01).

CONCLUSIONS

The PV group had statistically significant improvements in visual analog scale and QOL scores maintained over 24 months, improved VBH maintained over 36 months, and fewer adjacent-level fractures compared with the OMT group.

Ruptured intradiploic dermoid cyst overlying the torcular herophili

We present a 22-month-old boy with a ruptured dermoid cyst overlying the torcular herophili. The cyst had caused scalp erosion and a lytic bone lesion and was successfully excised surgically. The general features of these cysts are discussed, along with the surgical procedure and implications of cyst rupture.

Intracranial dermoid cysts: variations of radiological and clinical features

BACKGROUND

Intracranial dermoid cysts are uncommon, and their clinical features as well as surgical management differ from patient to patient. Dermoids are generally benign lesions, but may cause spontaneous complications such as meningitis and/or hydrocephalus due to rupture and epileptic seizures depending on their location. Little has been reported about characteristic imaging findings with resulting therapeutic considerations, and only a few reports exist about associated hydrocephalus. Imaging modalities have changed and can facilitate differential diagnosis and follow-up if applied correctly. In this paper, we attempt to contribute our clinical experience with the management of dermoid cysts.

PATIENTS AND METHODS

The charts of five men and two women with intracranial dermoid cysts were retrospectively reviewed. The patients were treated between September 1993 and September 2006. Selected patients are presented in detail.

RESULTS

Tumour location, size and radiographic characteristics varied in each patient. Clinical presentations comprised focal neurological deficits as well as epileptic seizures, persistent headache, mental changes and psycho-organic syndromes. One patient underwent delayed ventriculo-peritoneal shunting after ruptured fatty particles caused obstructive hydrocephalus. Despite dermoid rupture into the subarachnoid space, three patients never developed hydrocephalus. Diffuse vascular supra-tentorial lesions were seen in one patient as a result of aseptic meningitis. Diffusion-weighted imaging (DWI) hyperintensity in dermoids is related to decrease of water proton diffusion and should be used for both the diagnosis and follow-up of this lesion.

CONCLUSION

Although dermoid cysts are known to be benign entities per se, their rupture can cause a wide range of symptoms including aseptic meningitis and/or hydrocephalus. This may be due to intraventricular obstruction and/or paraventricular compression. While rupture does not necessarily bring about hydrocephalus, radical removal of the tumour and close monitoring of ventricular size is required. Although not widely recognised as such, DWI is considered to be a useful imaging modality in the diagnosis and follow-up of dermoids.

Intraventricular and subarachnoid fat after spinal injury

The authors report an extremely rare case with intraventricular and subarachnoid fat developed after trauma to spine and soft tissue in a 54-year-old male. The initial computed tomography (CT) showed multiple low attenuation lesions, which were thought to be pneumocephalus. Cerebral magnetic resonance imaging (MRI) showed lesions with high signal intensity on T1-weighted magnetic resonance images and high signal intensity on T2-weighted images, indicating fat globules within the CSF. In this report, the clinical presentation, radiological findings, and a review of the literature are presented.

Ruptured intracranial dermoid cysts: clinical, radiographic, and surgical features

OBJECTIVE

Intracranial dermoid cysts are pathologically characterized by a thick, stratified squamous epithelium cyst wall containing dermal elements. Rupture into the subarachnoid spaces and ventricles is extremely rare. We review the clinical, radiographic, and surgical features of eight ruptured dermoid cysts.

METHODS

We retrospectively evaluated five surgically treated patients with pathologically proven ruptured dermoid cysts. Clinic notes, operative reports, and neuroimaging, including initial computed tomographic and magnetic resonance imaging scans, were reviewed. Imaging was also available on three outside patients reviewed by members of our radiology department.

RESULTS

The most common presentations were headaches (57%) and seizures (42%), followed by hydrocephalus (29%) from intraventricular rupture. These lesions were consistently hypodense on computed tomographic scans and hyperintense on T1-weighted images with minimal to no enhancement after gadolinium administration. Disseminated fat droplets were present in the subarachnoid space in both cerebral hemispheres in all patients, and five patients had intraventricular rupture with fat-fluid levels in the ventricles. Gross to near-total resection of the primary lesion was achieved in all five surgically treated patients treated at our institution. Four patients had remnant tumor capsules adherent to neurovascular structures that were unresectable. Repeat resection was performed for one recurrence; there were no further recurrences during a follow-up period of 2 to 134 months (mean, 65.6 mo). Two patients with preoperative hydrocephalus eventually required ventriculoperitoneal shunting.

CONCLUSION

Ruptured intracranial dermoid cysts represent 0.18% of all central nervous system tumors surgically treated in our institution during a 12-year period. The presence of disseminated fat droplets in the subarachnoid space or ventricles on neuroimaging is diagnostic for a ruptured dermoid cyst. Gross total removal is achievable; however, residual tumor capsules adherent to neurovascular structures should be left behind to minimize complications.

Early histologic changes following polymethylmethacrylate injection (vertebroplasty) in rabbit lumbar vertebrae

STUDY DESIGN

An ex vivo histologic study in rabbits.

OBJECTIVE

To evaluate the early histologic effects of polymethylmethacrylate (PMMA) injection on bone and intraosseous neural tissue following vertebroplasty in rabbit lumbar vertebrae.

SUMMARY OF BACKGROUND DATA

Vertebroplasty with PMMA is performed to treat painful osteoporotic vertebral fractures. Early pain relief has been consistently documented, but its mechanism has not been elucidated. Among the mechanisms of pain relief may be the immediate stabilizing effects of the cement, and the exothermic reaction during curing, which may lead to intraosseous neural ablation. It has been well established that PMMA can induce thermal osteonecrosis after arthroplasty, but the potential for osteonecrosis after vertebroplasty has not been established. Previous studies have suggested that temperature elevations during cement curing may induce thermal bone necrosis. However, this cause-and-effect relationship has not yet been histologically studied in an animal model.

METHODS

Vertebroplasty with PMMA was performed at 2 levels in 12 New Zealand rabbits (24 levels); trochar insertion without PMMA injection was performed at 3 levels each of 2 control animals (6 levels). Sacrifice was performed 24 hours after the procedure. Histologic examination was performed to evaluate the presence of bone or intraosseous neural tissue necrosis.

RESULTS

Half of the levels with PMMA showed evidence of necrosis at the bone-cement interface. Almost all (11 of 12) showed only focal necrosis, with only 1 specimen showing necrosis along the entire periphery of the PMMA. The other 12 specimens and all control levels displayed no bone necrosis. There was no evidence of intraosseous neural tissue necrosis in control or PMMA-injected specimens.

CONCLUSION

Injection of PMMA in rabbit lumbar vertebral bodies produces early, focal bone necrosis in only half of cases, suggesting that competency of the cement-bone interface is reasonable in most cases. No evidence of intraosseous neural tissue damage was found.

Efficacy of percutaneous cementoplasty for bone metastasis from hepatocellular carcinoma

OBJECTIVE

To assess the efficacy of percutaneous cementoplasty for painful bone metastasis from hepatocellular carcinoma (HCC).

METHODS

Cementoplasty was performed for 22 metastatic bone tumors in 13 patients. All patients had intractable pain and were diagnosed as metastatic bone tumor from HCC. The ostyneedle was inserted in the center of the site of bone metastasis under CT guidance. VAS score, Tokuhashi score and Frankel score were used for assessment of the efficacy of cementoplasty. We also assessed the response to treatment, adverse events and prognosis.

RESULTS

Only the VAS score, but not Tokuhashi and Frankel scores, improved after cementoplasty. Cementoplasty for painful bone metastasis provided relief of severe pain but did not improve prognosis, neurological function or survival. Eleven of 13 (85%) patients showed CR or PR and the mean pain-free period was 5 months, including a 10-month pain-free period in one case. No major complications were encountered.

CONCLUSIONS

Percutaneous cementoplasty can provide pain relief and improvement of quality of life, though without survival benefits, for HCC patients with painful bone metastasis.

Ruptured intracranial dermoid: an unusual cause of headache in an older patient

A 76-year-old woman with a history of migraine presented with worsening headache. Computerized tomography brain scan and magnetic resonance imaging brain scan showed the presence of fat globules in the cerebrospinal fluid space. This appearance was suggestive of ruptured intracranial dermoid. She recovered spontaneously. While headache is a known presentation of ruptured intracranial dermoid, the condition is unusual to present in older people.

Ruptured intracranial dermoid cysts

Rupture of intracranial dermoid cysts (RICDC) is a rare phenomenon. The mechanism of rupture, pathophysiology of fat in the ventricles and subarachnoid spaces, possible complications, and proper management of such conditions are proposed on the basis of a review of the literature and experience with two cases of ruptured intracranial dermoid cysts (One was in the pineal region, while another was in the fourth ventricle). It is concluded that rupture of intracranial dermoid cysts is usually spontaneous and non-fatal. Persistence of fat in the subarachnoid spaces postoperatively may last asymptomatically for years. Surgery is the only way to deal with these benign lesions. If the capsule is adherent to vital areas, incomplete removal is advised as recurrence and malignant transformation are unlikely to occur.

Coexisting intracranial meningeal melanocytoma, dermoid tumor, and Dandy–Walker cyst in a patient with neurocutaneous melanosis

✓ Neurocutaneous melanosis (NCM) associated with Dandy–Walker malformation is a very rare congenital neurodysplasia with the same origin. Primary intracranial melanocytic and dermoid tumors are also benign congenital lesions that usually arise from the leptomeninges and are formed by the inclusion of cutaneous ectoderm at the time of neural tube closure. The authors describe a patient with coexisting intracranial meningeal melanocytoma, NCM with Dandy–Walker malformation, and intraventricular dermoid tumor.

Temporal Lobe Epilepsy Caused by Dermoid Cyst

A 15-year-old boy presented with a dermoid cyst in the left temporal lobe manifesting as complex partial seizures. Magnetic resonance imaging demonstrated a tumor with mixed signal intensity in the left anterior temporal subdural area, but no evidence of rupture. Intraoperatively, the tumor was located mainly in the deep sylvian fissure, adjacent to the amygdala, and had compressed the hippocampus. Intraoperative electrocorticography (ECoG) showed sporadic interictal spikes in both the adjacent areas of the tumor and over the anterior segment of the hippocampus. Total removal of the tumor and gliotic area of the surrounding tissue including the amygdala was performed. The hippocampal epileptic region was treated by transection of the pyramidal layer to preserve verbal memory function. Histological examination showed the dermoid tumor was closely attached to the brain parenchyma. The complex partial seizures ceased completely after surgery. Intraoperative recording of ECoG from the hippocampus and other limbic structures was very important to determine the epileptogenic area even if the tumor did not directly invade the hippocampus.

Radiation exposure to the surgeon during fluoroscopically assisted percutaneous vertebroplasty: a prospective study

STUDY DESIGN

A prospective case control study design was conducted.

OBJECTIVES

The purpose of the current study was to determine the intraoperative radiation hazard to spine surgeons by occupational radiation exposure during percutaneous vertebroplasty and possible consequences with respect to radiation protection.

SUMMARY OF BACKGROUND DATA

The development of minimally invasive surgery techniques has led to an increasing number of fluoroscopically guided procedures being done percutaneously such as vertebroplasty, which is the percutaneous cement augmentation of vertebral bodies.

METHODS

Three months of occupational dose data for two spine surgeons was evaluated measuring the radiation doses to the thyroid gland, the upper extremities, and the eyes during vertebroplasty.

RESULTS

The annual risk of developing a fatal cancer of the thyroid is 0.0025%, which means a very small to small risk. The annual morbidity (the risk of developing a cancer including nonfatal ones) is 0.025%, which already means a small to medium risk. The dose for the eye lens was about 8% of the threshold dose to develop a radiation induced cataract (150 mSv); therefore, the risk is very low but not negligible. The doses measured for the skin are 10% of the annual effective dose limit (500 mSv) recommended by the ICRP (International Commission on Radiologic Protection); therefore, the annual risk for developing a fatal skin cancer is very low.

CONCLUSION

While performing percutaneous vertebroplasty, the surgeon is exposed to a significant amount of radiation. Proper surgical technique and shielding devices to decrease potentially high morbidity are mandatory. Training in radiation protection should be an integral part of the education for all surgeons using minimally invasive radiologic-guided interventional techniques.

Intradural dermoid tumor of the posterior fossa in a child with diastematobulbia

Dermoid tumors (DTs) are rare lesions and represent 0.3% of all intracranial tumors. More than 50% of these tumors are diagnosed in childhood or early adolescence. Authors report an intradural DT of the posterior fossa in a child aged 4 years, possibly originating in the brainstem in which the diastematobulbia was detected postoperatively. Magnetic resonance imaging investigations are mandatory to diagnose these cases. The only curative treatment in DT is the total removal of the lesion. The reported case presents good recovery in the follow-up period of 3 years. The surgical intervention is particularly related to the DT type. Diastematobulbia associated with DT and the origin of the DT in the brainstem is discussed based on the literature.

Efficacy of percutaneous vertebroplasty combined with radiotherapy in osteolytic metastatic spinal tumors

OBJECT

Vertebroplasty involves the percutaneous injection of polymethylmethacrylate into collapsed vertebral bodies due to hemangioma, osteoporosis, or malignant tumor. The purpose of this study was to evaluate the merits and efficacy of percutaneous vertebroplasty (PVP) combined with radiotherapy in treating patients with osteolytic metastatic spinal tumors (OMSTs).

METHODS

Twenty-eight patients with OMSTs underwent PVP for the treatment of 72 vertebrae after administration of a local anesthetic or induction of general anesthesia for pain relief and spinal stabilization. Radiotherapy for suppressing tumor or inducing pain relief was performed immediately after PVP in 22 patients. Pain levels were assessed before and after the procedure by using a visual analog scale (VAS), and follow-up assessment was conducted at 1, 3, 6, and 9 months. On postoperative Day 3, marked-to-complete VAS score-based pain relief was achieved in 13 patients (48%) and moderate relief was demonstrated in 11 (41%). The mean VAS pain score was reduced from 8.2 to 3, and major complications were absent in all cases. Follow-up plain radiography was performed to assess vertebral column stability. Neither additional vertebral collapse in the treated vertebrae nor neurological deterioration was observed.

CONCLUSIONS

Percutaneous vertebroplasty is a minimally invasive procedure and, when combined with radiotherapy, seems to be effective in providing pain relief and stabilization in patients with OMSTs.

Ruptured “giant” supratentorial dermoid cyst

Intracranial dermoid and epidermoid cysts are rare lesions formed from the inclusion of ectodermal elements during neural tube closure. Although not entirely consistent, imaging characteristics on CT and MRI can aid differentiation of dermoids and epidermoids, as can age at presentation, location and tendency to rupture. The distinction between dermoid and epidermoid lesions is important prognostically and may impact on surgical management as a subtotally resected dermoid is less likely to recur than its epidermoid counterpart. The distinction of large dermoid lesions as "giant" adds little to information regarding the natural history or prognosis of these lesions and should be abandoned.

Extra-axial brain tumors

Meningiomas, schwannomas, metastases, maldevelopmental cysts, epidermoids, dermoids and bone tumors represent the vast majority of extra-axial brain tumors. The location of extra-axial brain tumors affects treatment planning and predicts their prognosis. Computed tomography and particularly magnetic resonance imaging are used for diagnosis and localization. In this article, the imaging findings of the extra-axial brain tumors are discussed.

Osteoporotic vertebral collapse: percutaneous vertebroplasty and local kyphosis correction

Forty-six cases of osteoporotic vertebral collapse (27 thoracic, 19 lumbar) were treated by means of percutaneous vertebroplasty in a hyperlordosis position. Institutional review board approval and informed consent were obtained. Kyphosis reducibility was preprocedurally estimated from the angular difference between neutral and hyperlordosis positions. Effective reduction was the angular difference in neutral positions before and after vertebroplasty. Reduction (< or =14 degrees ; mean, 6.43 degrees) was obtained in cases with estimated reducibility greater than 5 degrees (31 cases, 67%), which is a 34% (6.5 degrees of 19.1 degrees ) mean reduction. A significantly greater level of kyphosis reduction was observed in cases with intravertebral clefts (20 cases, 43%) at hyperlordosis than in those without (7.2 degrees vs 4.9 degrees ; P < .01). Vertebroplasty may reduce kyphosis due to localized collapsed vertebrae; intravertebral mobility and cleft suggest this possibility.

Dermoid lesion of the cavernous sinus: case report and review of the literature

Intracranial dermoids are rare congenital tumors. Supratentorial dermoid cysts were more frequently reported in the last decade, and they are known to have a predilection for the cavernous sinus. Interdurally localized dermoids presenting with ophthalmoplegia is uncommon. Previously, the association of dermoid lesions with the cavernous sinus and the complexity of the operative procedure were emphasized only by a few authors. We report a case of a dermoid cyst that was embedded fully in the cavernous sinus and review the related cavernous dermoid lesions in the literature. Fronto-orbitozygomatic craniotomy was performed, and despite adherence of the tough capsule to the cranial nerves, the lesion was grossly removed in total. The patient was doing well 1 year after the operation, and there was no recurrence of signs and symptoms. Interdural growth of cavernous dermoid tumors must be considered, and careful evaluation of preoperative computed tomography and magnetic resonance images aids in making the decision concerning the operative approach. Upon review of the literature, we detected only eight similar cases concerning cavernous dermoid cysts. Although total excision of these cavernous lesions has been reported previously, we believe that total excision can sometimes be hazardous and not feasible.

Ex vivo measurement of intravertebral pressure during vertebroplasty

STUDY DESIGN

Ex vivo biomechanical study using cadaver vertebral bodies. OBJECTIVE.: To measure the increase in internal vertebral body pressure from cement injection during vertebroplasty.

SUMMARY OF BACKGROUND DATA

Theoretically, the increased force required to inject polymerizing (viscous) cement into a vertebral body during vertebroplasty could produce a concomitant increase in intravertebral pressure and cause additional damage to the vertebral body. An alternative means of reducing intravertebral pressure during injection may be needed.

METHODS

We placed 11-gauge cannulas bipedicularly in six vertebral bodies from each of two fresh female cadaver spines (one osteoporotic, one normal). One cannula served as the injection route; a manometer was connected to the other. After immersion of the spines in a saline bath, the vertebral bodies were injected with 10 mL of Simplex P cement by depressing the syringe plunger at a rate of 7 mm/sec using a materials testing machine. Static pressure was measured before and after injection. Peak pressure was measured during injection. Maximum pressure elevation was calculated as peak pressure minus initial static pressure.

RESULTS

Maximum pressure elevation averaged (+/-SD) 9.4 +/- 8.5 mm Hg and 6.4 +/- 5.0 mm Hg in the osteoporotic and normal spines, respectively. In all cases (9 of 12) in which the pressure measurement system remained patent (i.e., not occluded by cement), postinjection pressure returned to the initial static pressure.

CONCLUSION

The increase in intravertebral body pressure from cement injection during vertebroplasty is minimal. Alternative means of reducing intervertebral pressure before injection may not be needed.

The effect of vertebral body percentage fill on mechanical behavior during percutaneous vertebroplasty

STUDY DESIGN

An ex vivo biomechanical study was conducted using osteoporotic cadaveric vertebral bodies.

OBJECTIVE

To determine the relationship between the percentage of osteoporotic vertebral body volume filled with polymethylmethacrylate cement during percutaneous vertebroplasty and the percentage restoration of strength and stiffness.

SUMMARY OF BACKGROUND DATA

A previous biomechanical study reported a weak relationship between the volume of cement injected and restoration of vertebral body strength and stiffness. Vertebral bodies vary considerably in size among regions and among spines, and the weak correlation may be attributed to the fact that the volume of vertebral bodies was not explicitly considered.

METHODS

The volume of 120 vertebral bodies (T6-L5) harvested from 10 osteoporotic female cadaver spines was determined by Archimedean displacement. Compression fractures were experimentally created, and initial strength and stiffness were determined. The vertebral bodies were stabilized using bipedicular injections of 2-8 mL of cement and then recompressed, after which posttreatment strength and stiffness were measured. Linear regression was used to analyze the relationship between percentage of volume fill and percentage of restored stiffness and strength.

RESULTS

The correlations between percentage of fill and restored strength and stiffness were weak: r2 = 0.21 and r2 = 0.27, respectively. On average, restoration of strength and stiffness required vertebral body cement fills of 16.2% and 29.8%, respectively.

CONCLUSION

Strength and stiffness are weakly correlated with the percentage fill volume of cement injected during vertebroplasty.

Differential diagnosis of intracranial lesions with high signal on T1 or low signal on T2-weighted MRI

Magnetic resonance imaging (MRI) is the preferred technique for examining intracranial pathology in the non-acute setting in most cases. The aim of this review is to demonstrate the imaging appearances on unenhanced spin-echo MRI of lesions that show characteristic, unusual signal changes, which occur due to the presence of fat, cholesterol, paramagnetic substances, rapidly flowing fluids, air, cortical bone or calcification. The nature of the MRI signal, together with the anatomical location of the lesion should allow the provision of a narrow differential diagnosis, before the use of intravenous contrast medium or additional imaging sequences.

The effect of the monomer-to-powder ratio on the material properties of acrylic bone cement

The procedure percutaneous vertebroplasty consists of injecting polymethylmethacrylate cement into vertebral bodies for the treatment of osteoporotic compression fractures and tumors of the spine. Clinicians practicing vertebroplasty commonly alter the mixture of monomer-to-powder recommended by the manufacturer in an effort to decrease viscosity and increase the working time. The purpose of the current study was to measure the effect of varying the monomer-to-powder ratio on the compressive material properties (compressive modulus, yield stress, and ultimate compressive strength) of the cement Simplex P (Stryker-Howmedica-Osteonics, Rutherford, NJ). Cylindrical specimens were prepared using monomer-to-powder ratios of 0.45 to 1.00 mL/g and tested in compression. Peak compressive material properties occurred at the mixture ratio recommended by the manufacturer (0.5 mL/g) but decreased as the ratio of monomer to powder was increased. The material properties of specimens cured for 1 hour were significantly less than those for specimens cured for 24 hours. The monomer-to-powder ratio affects the compressive material properties of cement. The clinical significance of these results with respect to vertebroplasty is yet to be determined.

Isolated central canal rupture of spinal dermoid: report of two cases

We report two cases of lumbar spinal dermoid cysts with asymptomatic rupture and migration of free fat droplets into the central canal. No fatty droplets were seen within the lumbar subarachnoid space. The presence of fat droplets within the central canal is unusual because the central canal is rudimentary in adults. We suggest that hydromyelia secondary to tumour and specific tumour morphology might facilitate the selective rupture of dermoids into the central canal. We recommend a follow up of these patients to detect any possible intracranial migration of fat droplets and resultant complications.

Percutaneous vertebroplasty: treatment of painful vertebral compression fractures with intraosseous vacuum phenomena

OBJECTIVE

This study was undertaken to determine the efficacy of percutaneous vertebroplasty in treating patients with painful compression fractures of the thoracic and lumbar vertebrae that contain intraosseous vacuum phenomena.

MATERIALS AND METHODS

Nineteen cases of painful vertebral compression fractures with intraosseous phenomena occurring in 18 patients (six men, 12 women; age range, 59-88 years; mean age, 75.5 years) were identified from 393 percutaneous vertebroplasties performed in 199 patients during 32 and a half months. All patients had osteoporosis, with severe vertebral compression to less than one third of the vertebral body height in 13 of 19 cases. Affected levels were T6 (n = 1), T8 (n = 2), T9 (n = 1), T11 (n = 1), T12 (n = 4), L1 (n = 5), L2 (n = 2), L3 (n = 1), L4 (n = 1), and L5 (n = 1). All cases had the typical intravertebral body vacuum cleft appearance on radiographs. Imaging and clinical features were analyzed.

RESULTS

The mean volume of polymethyl methacrylate injected was 7.43 mL (range, 4.0-15.0 mL). Typically, the polymethyl methacrylate filled the intravertebral vacuum cleft. Complications during radiography consisted of minimal polymethyl methacrylate leakage into the adjacent disk (15/19 cases) and the paravertebral soft tissues (8/19 cases). No complications required surgical intervention. At clinical follow-up, pain relief was complete in eight patients (44.4%), partial in six patients (33.3%), and unchanged in four patients (22.2%).

CONCLUSION

Percutaneous vertebroplasty is effective in the treatment of patients with painful vertebral compression fractures with intraosseous vacuum phenomena.

Vertebral compression fractures: pain reduction and improvement in functional mobility after percutaneous polymethylmethacrylate vertebroplasty retrospective report of 245 cases

PURPOSE

To describe the immediate outcome of a large cohort of patients who underwent percutaneous polymethylmethacrylate (PMMA) vertebroplasty for treatment of one or more vertebral fractures.

MATERIALS AND METHODS

This retrospective cohort study included seven university-based and private hospitals in the United States. Of 488 consecutive patients (mean age, 76 years) who underwent percutaneous PMMA vertebroplasty between 1996 and 1999, 245 were successfully interviewed retrospectively after vertebroplasty (median time, 7 months). Through telephone interview, patients completed our self-developed questionnaire designed to measure pain (10-point scale), ambulation (five-point scale), and ability to perform activities of daily living (ADL) (five-point scale) before and after vertebroplasty. Differences in reported pain, ambulation, and ability to perform ADL before and after vertebroplasty were evaluated with paired t tests. Differences in proportions were compared with the McNemar test. Subgroup analyses were performed to assess the consistency of differences in pre- and postprocedural pain and functional status by patient age, number of fractures, time from fracture to vertebroplasty, and time from vertebroplasty to questionnaire completion.

RESULTS

On a 10-point scale, mean pain decreased from 8.9 before vertebroplasty to 3.4 afterward (P <.001). Seventy-two percent of patients had substantially impaired ambulation before vertebroplasty compared with 28% afterward (P <.001). Ability to perform ADL was also significantly improved following vertebroplasty (P <.001). Twelve patients (4.9%) experienced symptomatic complications (none major or life threatening).

CONCLUSION

Treatment of vertebral fractures with percutaneous PMMA vertebroplasty appears to be safe and results in substantial immediate pain reduction and improved functional status. A randomized controlled trial appears warranted to assess the efficacy and safety of vertebroplasty.

An ex vivo evaluation of an inflatable bone tamp used to reduce fractures within vertebral bodies under load

STUDY DESIGN

Ex vivo biomechanical study using osteoporotic cadaveric vertebral bodies.

OBJECTIVE

To determine if fracture reduction could be achieved by the inflatable bone tamp (tamp) in vertebral bodies under simulated physiologic loads.

SUMMARY OF BACKGROUND DATA

Previous ex vivo biomechanical studies showed that kyphoplasty restored vertebral body height with vertebral body endplates under stress-free conditions.

METHODS

Simulated compression fractures were experimentally created in 18 osteoporotic vertebral bodies alternatingly assigned to one of two treatment (tamp inflation) groups: low axial load (111 N) or high axial load (222 N). Each vertebral body was then placed between two platens in a special radiolucent loading fixture and subjected to the preassigned load to simulate in vivo physiologic loading. The tamps were inflated and postreduction heights were measured fluoroscopically. The effect of applied load and condition on vertebral body height was checked for significance (P < 0.05).

RESULTS

Comparing the experimental conditions (initial, postcompression, postinflation), there were no significant vertebral body height differences between the load groups (low load vs. high load). However, vertebral body height differences between conditions within each load group were all significant. For the low-load and high-load groups, mean postinflation heights (24.4 and 24.4 mm) were significantly greater than mean postcompression heights (21.6 and 22.5 mm) but significantly less than initial vertebral body heights (26.6 and 26.3 mm), respectively. Initial heights were fully restored in 22% (two of nine) of vertebral bodies in both groups.

CONCLUSION

The inflatable bone tamp restored some of the height lost to compression fractures in vertebral bodies under simulated physiologic loads.

Expanding experience with spontaneous dermoid rupture in the MRI era: diagnosis and follow-up

With widespread use of CT and MR imaging, experience with spontaneous dermoid rupture has significantly increased. What was previously believed to be a generally severe or even fatal accident, being the diagnosis made either at surgery or autopsy, or in patients with such consequent conditions as chemical meningitis or obstructive hydrocephalus, now appears to be more frequent than previously thought, and there is some evidence that it may also cause only a slight symptomatology or even be quite asymptomatic. We reviewed the clinical and imaging data of our series of five patients with spontaneously ruptured dermoids, spinal in one case, and intracranial supratentorial in four. These had their diagnosis following mild symptoms (number two cases) or incidentally (number two cases); the spinal tumor caused acute bladder dysfunction, possibly while undergoing rupture, and was associated with indolent intracranial fat spread. Three of the patients also had MR demonstration of asymptomatic persistence of fat spread in the subarachnoid spaces, respectively, 3, 4, and 5 years after rupture. One of the five cases, concerning a parasellar dermoid followed up over 6 years, provides the first demonstration of MR signal intensity change of the tumor prior to rupture.

Ruptured intracranial dermoid cysts

BACKGROUND

Intracranial dermoid cysts are rare congenital neoplasms that are believed to arise from ectopic cell rests incorporated in the closing neural tube. The rupture of an intracranial dermoid cyst is a relatively rare event that typically occurs spontaneously. In the past it was believed that rupture is always fatal, a hypothesis that is not supported by more recently reported cases. The symptoms associated with rupture vary from no symptoms to sudden death.

METHODS

The present paper analyzes published cases of ruptured intracranial dermoid cysts in terms of their age profile and their clinical presentation and describes an additional case.

RESULTS

Analysis of published cases revealed headache (14 out of 44 patients; 31.8%) and seizures (13 out of 44 patients; 29.5%), to be the most common signs of rupture followed by, often temporary, sensory or motor hemisyndrome (7 out of 44 patients; 15.9%), and chemical meningitis (3 out of 44 patients; 6.9%).

CONCLUSION

Headache occurred primarily in younger patients (mean age 23.5 +/- 9.3 years), whereas seizures primarily occurred in older patients (mean age 42.8 +/- 11.3 years). The patients with sensory or motor hemisyndrome associated with rupture of an intracranial dermoid cyst showed a more homogeneous age distribution (mean age 38.4 +/- 23.5 years).