Felix Umansky

Radiation-induced meningioma.

The long-term or delayed side effects of irradiation on neural tissue are now known to include the induction of new central nervous system neoplasms. However, during the first half of the 20th century, human neural tissue was generally considered relatively resistant to the carcinogenic and other ill effects of ionizing radiation. As a result, exposure to relatively high doses of x-rays from diagnostic examinations and therapeutic treatment was common. In the present article the authors review the literature relating to radiation-induced meningiomas (RIMs). Emphasis is placed on meningiomas resulting from childhood treatment for primary brain tumor or tinea capitis, exposure to dental x-rays, and exposure to atomic explosions in Hiroshima and Nagasaki. The incidence and natural history of RIMs following exposure to high- and low-dose radiation is presented, including latency, multiplicity, histopathological features, and recurrence rates. The authors review the typical presentation of patients with RIMs and discuss unique aspects of the surgical management of these tumors compared with sporadic meningioma, based on their clinical experience in treating these lesions.

Olfactory Groove Meningiomas from Neurosurgical and Ear, Nose, and Throat Perspectives: Approaches, Techniques, and Outcomes

OBJECTIVE: To review the surgical approaches, techniques, outcomes, and recurrence rates in a series of 80 olfactory groove meningioma (OGM) patients operated on between 1990 and 2003. METHODS: Eighty patients underwent 81 OGM surgeries. Tumor diameter varied from 2 to 9 cm (average, 4.6 cm). In 35 surgeries (43.2%), the tumor was removed through bifrontal craniotomy; nine operations (11.1%) were performed through a unilateral subfrontal approach; 18 surgeries (22.2%) were performed through a pterional approach; seven surgeries (8.6%) were carried out using a fronto-orbital craniotomy; and 12 procedures (14.8%) were accomplished via a subcranial approach. Nine patients (11.3%) had undergone surgery previously and had recurrent tumor. RESULTS: Total removal was obtained in 72 patients (90.0%); subtotal removal was achieved in 8 patients (10.0%). Two patients, one with total and one with subtotal removal, had atypical (World Health Organization Grade II) meningiomas, whereas 78 patients had World Health Organization Grade I tumors. There was no operative mortality and no new permanent focal neurological deficit besides anosmia. Twenty-five patients (31.3%) experienced surgery-related complications. There were no recurrences in 75 patients (93.8%) 6 to 164 months (mean, 70.8 mo) after surgery. Three patients (3.8%) were lost to follow-up. In two patients (2.5%) with subtotal removal, the residual evidenced growth on computed tomography and/or magnetic resonance imaging 1 year after surgery. One of them had an atypical meningioma. The second, a multiple meningiomata patient, was operated on twice in this series. CONCLUSION: A variety of surgical approaches are used for OGM resection. An approach tailored to the tumor’s size, location, and extension, combined with modern microsurgical cranial base techniques, allows full OGM removal with minimal permanent morbidity, excellent neurological outcome, and very low recurrence rates.

Endovascular Stent-Assisted Angioplasty in the Management of Traumatic Internal Carotid Artery Dissections

Background and Purpose— The prognosis of traumatic dissection of the internal carotid artery is worse than for spontaneous dissections. Rapid stenting followed by antiplatelet therapy may prevent complications when anticoagulation therapy is not applicable. Methods— Patients with angiographically proven traumatic carotid artery dissection and hemodynamic significant hemispheric hypoperfusion, or in whom anticoagulant therapy was either contraindicated or failed clinically, were regarded as being at high risk for stroke and were selected for stenting. Results— Ten patients with traumatic dissection underwent stenting. Endovascular treatment reduced mean dissection stenosis from 69% to 8%. During a mean clinical follow-up time of 16 months, none had additional transient ischemic attacks or stroke. Doppler ultrasound studies did not detect any signs of de novo in-stent stenosis. Conclusion— In selected cases of traumatic carotid artery dissections, endovascular stent-assisted angioplasty immediately restored the integrity of the vessel lumen and prevented efficiently the occurrence of new ischemic events, without additional anticoagulation.

Percutaneous vertebroplasty: Technique and results in 192 procedures

Abstract Percutaneous vertebroplasty with acrylic cement (usually polymethylmethacrylate) consists of injecting cement into vertebral bodies weakened by osseous lesions. The objective of this procedure is to obtain an analgesic effect by mechanical stabilization in destructive lesions of the spine. The three major indications are aggressive vertebral hemangiomas, severe or refractory pain related to osteoporotic vertebral fractures, and malignant vertebral tumors. Complications are infrequent, but occur essentially in patients with vertebral malignant tumors. We present our experience with 148 patients that underwent 192 percutaneous PMMA vertebroplasties for the treatment of painful osteoporotic compression fractures (76 patients, 105 vertebral levels), hemangiomas (31 patients, 43 vertebral levels) and neoplasms (31 patients, 43 vertebral levels). In a vast majority of appropriately selected cases and especially in osteoporotic cases, vertebroplasty constitutes a relatively simple procedure with a very high rate of success.

Meningovenous Structures of the Petroclival Region: Clinical Importance for Surgery and Intravascular Surgery

OBJECTIVE The goals of this investigation were to perform a detailed analysis of petroclival microanatomic features, to investigate the course of the abducens nerve in the petroclival region, and to identify potential causes of injury to neurovascular structures when anterior transpetrosal or transvenous endovascular approaches are used to treat pathological lesions in the petroclival region. METHODS Petroclival microanatomic features were studied bilaterally in seven cadaveric head specimens, which were injected with colored silicone before microdissection. Another cadaveric head was used for histological section analyses. RESULTS A lateral or medial location of the abducens nerve dural entrance porus, relative to the midline, was correlated with the course and angulation of the abducens nerve in the petroclival region. The angulation of the abducens nerve was greater and the nerve was closer to the petrous ridge in the lateral type, compared with the medial type. The abducens nerve exhibited three changes in direction, which represented the angulations in the petroclival region, at the dural entrance porus, the petrous apex, and the lateral wall of the internal carotid artery. The abducens nerve was covered by the dural sleeve and the arachnoid membrane, which became attenuated between the second and third angulation points. The abducens nerve was anastomosed with the sympathetic plexus and fixed by connective tissue extensions to the lateral wall of the internal carotid artery and the medial wall of Meckel’s cave at the third angulation point. There were two types of trabeculations inside the sinuses around the petroclival region (tough and delicate). CONCLUSION The petroclival part of the abducens nerve was protected in a dural sleeve accompanied by the arachnoid membrane. Therefore, the risk of abducens nerve injury during petrous apex resection via the anterior transpetrosal approach, with the use of the transvenous route through the inferior petrosal sinus to the cavernous sinus, should be lower than expected. The presence of two anatomic variations in the course of the abducens nerve, in addition to findings regarding nerve angulation and tethering points, may explain the relationships between adjacent structures and the susceptibility to nerve injury with either surgical or endovascular approaches. Venous anatomic variations may account for previously reported cases of subarachnoid hemorrhage with the endovascular approach.

Diagnosis and management of Rosai-Dorfman disease involving the central nervous system

Abstract Introduction: Rosai–Dorfman disease is a benign non-neoplastic proliferative disorder of histiocytes originally described in the cervical lymph nodes. Extranodal sites were later recognized, and by 1990, they were shown to represent over 40% of cases; however, central nervous system involvement is still considered rare. We review the literature, which shows a steady increase in reports of Rosai–Dorfman disease involving the brain and/or spine. Methods: A literature search was performed for the period 1969–2008, using multiple search engines, with keywords Rosai–Dorfman disease, central nervous system Rosai–Dorfman disease and sinus histiocytosis with massive lymphadenopathy. Results: By December 2008, 111 cases of Rosai–Dorfman disease involving the central nervous system had been reported in the literature, including our cases. In the central nervous system, Rosai–Dorfman disease is ubiquitous. Although it is characterized by unique, indeed pathognomonic, histopathological cytoarchitecture, it may be mistaken for many other neoplastic and inflammatory histioproliferative diseases. Surgical resection with post-operative corticosteroids remains the treatment of choice. Conclusions: Rosai–Dorfman disease involving the central nervous system appears to be more common than previously thought and may well assume a more prominent place in the differential diagnoses of dural-based lesions. Expert awareness of the characteristic histopathology and immunohistochemistry of the disease is required for accurate diagnosis.

Hypertrophic spinal pachymeningitis: report of two cases and review of the literature

The cases of two patients with idiopathic pachymeningitis hypertrophica that caused progressive paraparesis are presented. Gadolinium-enhanced magnetic resonance imaging was used to demonstrate this pathological entity in one patient, and myelography was used in the other. Decompressive surgery led to significant neurological improvement. The etiology, diagnosis, and management of this disease is discussed, and the literature is reviewed. To our knowledge, this is the first report to describe the features of this rare pathological entity on magnetic resonance imaging.

The microsurgical anatomy of the abducens nerve in its intracranial course

The microsurgical anatomy of the abducens nerve through its intracranial course was studied in 20 specimens obtained from 10 cadaver heads fixed in formalin. Another 20 specimens were used to study the pattern of branching of the nerve trunk. The following intracranial segments were studied: subarachnoid or intracisternal, petroclival, and intracavernous. Angulations, neurovascular relationships, and branching patterns of the nerve are described. The long intracranial course of the abducens nerve, its tortuosity, and its tight attachment to the skull base at the level of the petrous apex may influence its vulnerability in some pathological conditions.

Endovascular management of symptomatic vertebral artery dissection achieved using stent angioplasty and emboli protection device.

Abstract Extracranial vertebral artery (VA) dissection may lead to significant arterial stenosis, occlusion, or pseudoaneurysm formation with subsequent hemodynamic and embolic infarcts. To prevent thromboembolic complications, anticoagulation with intravenous heparin followed by oral warfarin has been recommended for all patients with acute dissections, regardless of the type of symptoms, unless there are contra-indications. Nevertheless, anticoagulation is not innocuous, may be contra-indicated or may be ineffective to prevent symptoms or dissection progression. Because it is effective and less invasive than other surgical procedures, endovascular treatment of VA dissection has recently attracted interest. We present a case of a traumatic VA dissection, presenting with multiple embolic infarctions that was managed with protected stent-assisted angioplasty. Protected stent-assisted VA angioplasty has not been previously reported and appears to be a safe, effective and immediate method of restoring vessel lumen integrity and should be considered in the therapy of selected cases of VA dissection.

Giant Cavernous Sinus Teratoma: A Clinical Example of a Rare Entity: Case Report

OBJECTIVE AND IMPORTANCE Teratomas represent 0.5% of all intracranial tumors. These benign tumors have tissue representative of the three germinal layers: ectoderm, mesoderm, and endoderm. Most teratomas are midline tumors located predominantly in the sellar and pineal regions. Cavernous sinus location is very rare; only two purely intracavernous teratomas have been reported. CLINICAL PRESENTATION A 14-year-old boy presented with a history of progressive right eye proptosis and visual acuity impairment, headaches, and a neuralgia-like facial pain in the right V1 distribution. A head computed tomographic scan and magnetic resonance imaging disclosed a large tumor filling the right cavernous sinus and extending into the ipsilateral middle fossa. These scans also demonstrated mixed signals derived from different tissues conforming to the tumor (fat, cartilage, muscle strands, bone, and a primordial tooth). Heterogeneous enhancement was seen after infusion of contrast medium. Significant bone erosion and remodeling was evident in the middle fossa floor and right orbit, with secondary proptosis. A presumptive diagnosis of mature teratoma was made. INTERVENTIONWith the use of a right frontotemporal interfascial approach, a combined extra- and intradural dissection of the tumor was performed. The lesion entirely occupied the cavernous sinus, laterally displacing the Gasserian ganglion and trigeminal branches (predominantly V1 and V2). The internal carotid artery and Cranial Nerve VI were medially displaced by the tumor mass. The lesion was composed of different tissues, including hair, fat, cartilage, muscle, nerve-like tissue, bone, and a primordial tooth. The tumor was removed completely, and the pathological report confirmed the diagnosis of a mature teratoma. There was no evidence of recurrence at the 8-month follow-up examination. CONCLUSIONBecause of the lesion’s location in the lateral wall of the cavernous sinus, a total removal was achieved with the use of standard microsurgical techniques. Knowledge of the microanatomy is essential in treating intracavernous pathology. We present the third reported case of a giant mature teratoma of the cavernous sinus.