Extra-axial cranial nerve enhancement: a pattern-based approach.

Cranial nerve enhancement is a common and challenging MRI finding that requires a meticulous and systematic evaluation to identify the correct diagnosis. Literature mainly describes the various pathologies with the associated clinic-radiological characteristics, while the radiologist often needs a reverse approach that starts from the radiological findings to reach the diagnosis. Therefore, our aim is to provide a new and practical pattern-based approach to cranial nerve enhancement, which starts from the radiological findings and follows pattern-driven pipelines to navigate through multiple differential diagnoses, guiding the radiologist to reach the proper diagnosis. Firstly, we reviewed the literature and identified four patterns to categorize the main pathologies presenting with cranial nerve enhancement: unilateral linear pattern, bilateral linear pattern, unilateral thickened pattern, and bilateral thickened pattern. For each pattern, we describe the underlying pathogenic origin, and the main radiological features are displayed through high-quality MRI images and illustrative panels. A suggested MRI protocol for studying cranial nerve enhancement is also provided. In conclusion, our approach for cranial nerve enhancement aims to be an easy tool immediately applicable to clinical practice for converting challenging findings into specific pathological patterns.

Epidural bleeding secondary to a synovial cyst rupture: a case report and review of literature.

Hemorrhage into a juxtafacet cyst is rare and cyst rupture with hemorrhagic extension into the epidural space is even less commonly seen. We describe the case of a patient with a hemorrhagic synovial cyst with rupture associated to abundant bleeding in the epidural space. A 61-year-old man had a 5-month history of worsening low back pain radiating into the right leg with associated weakness and numbness. A magnetic resonance imaging scan showed the presence of a mild anterior spondylolisthesis of L5 on S1 with increased synovial fluid into both facet joints. A suspected synovial cyst of the right facet joint at level L5-S1, with signal characteristics consistent with hemorrhage was seen. Caudally, epidural blood was evident from S1 to S2 that involved spinal canal and right S1 and S2 foramens. These findings were confirmed at surgery.

Dermoid Cysts of the Asterion: An Unusual Location for Unusual Dermoids, Radiological Findings and Neurosurgical Implications.

Asterion is an uncommon site for lesions, especially dermoid cysts. We report a case series of three asterional intracranial dermoid cysts, which, to the best of our knowledge, have never been described before. Patients presented with non-specific symptoms and underwent surgical excision of the lesions. It is crucial to correctly diagnose intracranial masses and to identify their relationships with surrounding anatomical structures, especially if the location is unusual as the asterion, to plan surgery. The challenge of this tumor location is to preserve the venous drainage system during surgical procedures, because of the contiguity between the asterion and the transverse-sigmoid junction. Rupturing or damaging of the venous drainage system have been proven to be catastrophic because they lengthen surgical time and present dire consequences for patients. In conclusion, it is crucial to familiarize with atypical dermoid presentation to ensure proper diagnoses and to perform adequate imaging for optimal surgical planning.

Evaluation of Skull Base Tumors with Dynamic TurboFLASH MRI during Gadolinium Injection.

Background and Purpose This study was aimed to investigate the role of dynamic TurboFLASH gadolinium (Gd) magnetic resonance (MR) imaging in improving the differential diagnosis of skull base tumors. Methods Eleven patients with skull base tumors underwent standard MR and ultrafast TurboFLASH sequence during gadolinium injection. Results The characterization of tumor vascularity was performed. Different patterns of gadolinium uptake for each tumor type were observed. This is particularly important to identify tumors at high risk of intraoperative bleeding. All glomus tumors, typically highly vascularized, showed an enhancement at the arterial phase, reflecting the arterialization of these tumors which is not detectable on conventional MR. No signal increase at the arterial phase was instead observed in other cases in which the ruling out of a glomus tumor was important because of the location of the lesion. Moreover TurboFLASH identified the pathognomonic "filling-in" profile of cavernous sinus cavernous hemangiomas (CSCH), that is, the progressive centripetal enhancement of the lesion at the beginning of the venous phase. Conclusion The dynamic analysis of tumor contrast enhancement with the TurboFLASH sequence provides useful additional information to that obtained with conventional MR, improving the differential diagnosis of skull base tumors, particularly in the distinction between glomus and nonglomus tumors and in diagnosing CSCH.

Chondromyxoid Fibroma of the Skull Base: Our Experience with an Elusive Disease.

Chondromyxoid fibroma (CMF) is an extremely rare lesion of the skull base. This histologic type typically predilects metaphysis of the long bones. It is locally invasive/infiltrative, and this tendency is more concerning in the skull base, where a radical resection is often technically impossible because of the presence of vital neurovascular structures. We present a case of a 19-year-old woman who presented with a sudden onset of right facial weakness, progressively worsening to a severe disfiguring motor weakness. Gadolinium-enhanced brain magnetic resonance imaging showed an osteolytic lesion located in the right mastoid involving the stylomastoid foramen and the right seventh cranial nerve. A partial mastoidectomy was performed, with an excellent rate of tumor resection and complete local control of the disease at follow-up. The analysis of current literature indicates that a radiologic diagnosis is rarely strictly convincing of CMF. Histologic diagnosis is often difficult due to the lack of a specific immunohistochemical pattern of chondrosarcoma. Surgery is currently recognized as the mainstay to manage this lesion, although a trend toward adjuvant radiation therapy (RT) currently is seen. Although a tendency of local recurrence is well recognized in the literature, the very slow and indolent behavior of this lesion plus the trend to enhance local control of the disease with high-dose RT pushed us to a reappraise the role of radical skull base surgeries burdened by the risks of major complications, cosmetic deformities, and additional neurologic deficits.

Morphometric anatomical and CT study of the human adult sacroiliac region.

PURPOSE: To identify and describe the morphometry and CT features of the articular and extra-articular portions of the sacroiliac region. The resulting knowledge might help to avoid complications in sacroiliac joint (SIJ) fusion. METHODS: We analyzed 102 dry hemi-sacra, 80 ilia, and 10 intact pelves and assessed the pelvic computerized tomography (CT) scans of 90 patients, who underwent the examination for conditions not involving the pelvis. We assessed both the posterior aspect of sacrum with regard to the depressions located externally to the lateral sacral crest at the level of the proximal three sacral vertebrae and the posteroinferior aspect of ilium. Coronal and axial CT scans of the SIJ of patients were obtained and the joint space was measured. RESULTS: On each side, the sacrum exhibits three bone depressions, not described in anatomic textbooks or studies, facing the medial aspect of the posteroinferior ilium, not yet described in detail. Both structures are extra-articular portions situated posteriorly to the SIJ. Coronal CT scans of patients showing the first three sacral foramens and the interval between sacrum and ilium as a continuous space display only the S1 and S3 portions of SIJ, the intermediate portion being extra-articular. The S2 portion is visible on the most anterior coronal scan. Axial scans show articular and extra-articular portions and features improperly described as anatomic variations. CONCLUSIONS: Extra-articular portions of the sacroiliac region, not yet described exhaustively, have often been confused with SIJ. Coronal CT scans through the middle part of sacrum, the most used to evaluate degenerative and inflammatory conditions of SIJ, show articular and extra-articular portions of the region.

Simultaneous Contralateral Vestibular Schwannoma and Middle Ear Paraganglioma Tumor.

To the best of our knowledge, only 2 cases of a simultaneous contralateral vestibular schwannoma (VS) and middle ear paraganglioma (MEP) have previously been reported in literature. We report the third case observed in a 43-year-old male, who presented with an 11-year history of right-sided hearing loss and a 1-year history of left-sided pulsatile tinnitus. A magnetic resonance imaging (MRI) showed a VS on the right side and computer tomography (CT) identified a Fisch type A1 paraganglioma on the left side. The VS was treated using a translabyrinthine approach and the MEP was kept under radiological observation for 1 year. Due to the growth of the MEP (Fisch type A2), it was treated with excision via a retroauricular approach. Our case was very challenging because there was a different and important pathology on each side, both carrying a risk of deafness as a consequence of the disease and/or the treatments.

Gelastic epilepsy without hypothalamic hamartoma: three additional cases.

We describe three children with gelastic seizures without hypothalamic hamartoma whose seizures were characterized by typical laughing attacks associated or not with other seizure types. Ictal/interictal EEG and magnetic resonance imaging were performed. All three subjects showed a good response to carbamazepine therapy with complete seizure control in addition to a benign clinical and cognitive outcome. These three cases confirm that gelastic epilepsy without hypothalamic hamartoma, both in cryptogenic or symptomatic patients (one child showed a dysplastic right parietotemporal lesion), usually has a more benign natural history, and carbamazepine seems to be the most efficacious therapy to obtain both immediate and long-term seizure control. These findings need to be confirmed in a larger sample of children affected by gelastic epilepsy without hypothalamic hamartoma.

Stereotactic radiosurgery for brain metastases: analysis of outcome and risk of brain radionecrosis.

PURPOSE: to investigate the factors affecting survival and toxicity in patients treated with stereotactic radiosurgery (SRS), with special attention to volumes of brain receiving a specific dose (V10 - V16 Gy) as predictors for brain radionecrosis. PATIENTS AND METHODS: Two hundred six consecutive patients with 310 cerebral metastases less than 3.5 cm were treated with SRS as primary treatment and followed prospectively at University of Rome La Sapienza Sant'Andrea Hospital. Overall survival, brain control, and local control were estimated using the Kaplan-Meier method calculated from the time of SRS. Univariate and multivariate analysis using a Cox proportional hazards regression model were performed to determine the predictive value of prognostic factors for treatment outcome and SRS-related complications. RESULTS: Median overall survival and brain control were 14.1 months and 10 months, respectively. The 1-year and 2-year survival rates were 58% and 24%, and respective brain control were 43% and 22%. Sixteen patients recurred locally after SRS, with 1-year and 2-year local control rates of 92% and 84%, respectively. On multivariate analysis, stable extracranial disease and KPS >70 were associated with the most significant survival benefit. Neurological complications were recorded in 27 (13%) patients. Severe neurological complications (RTOG Grade 3 and 4) occurred in 5.8% of patients. Brain radionecrosis occurred in 24% of treated lesions, being symptomatic in 10% and asymptomatic in 14%. On multivariate analysis, V10 through V16 Gy were independent risk factors for radionecrosis, with V10 Gy and V12 Gy being the most predictive (p = 0.0001). For V10 Gy >12.6 cm3 and V12 Gy >10.9 cm3 the risk of radionecrosis was 47%. CONCLUSIONS: SRS alone represents a feasible option as initial treatment for patients with brain metastases, however a significant subset of patients may develop neurological complications. Lesions with V12 Gy >8.5 cm3 carries a risk of radionecrosis >10% and should be considered for hypofractionated stereotactic radiotherapy especially when located in/near eloquent areas.

Geniculate ganglion meningioma.

The geniculate ganglion is an unusual location for an intratemporal/intracranial meningioma. We present a case of meningioma intrinsic to the geniculate ganglion that presented peculiar features on high-resolution computed tomography (HRCT) and magnetic resonance imaging. On HRCT, we found erosion of the geniculate ganglion with enlargement of the facial canal associated with the appearance of some calcifications within the lesion. These latter findings were confirmed at histological examination. In our patient, the T1- and T2-weighted magnetic resonance images had an intermediate signal and a mild hyperintensity, respectively. Although intracranial meningiomas can have calcifications within the mass, none of the cases of geniculate ganglion meningiomas described in the literature presented with calcifications. To our knowledge, our case is the first with this combination. The presence of calcifications led us to suspect a meningioma of the geniculate segment, which was confirmed at histological examination.

Midline medulloblastoma versus astrocytoma: the position of the superior medullary velum as a sign for diagnosis.

PURPOSE: We wish to describe the position of the superior medullary velum (SMV) in midline posterior fossa tumours as a sign in helping to distinguish between midline medulloblastoma and midline astrocytoma. MATERIAL AND METHODS: Sagittal T1-weighted MRI images of 21 consecutive patients with histologically documented posterior fossa midline astrocytomas (nine cases) and medulloblastomas (12 cases) were reviewed, with respect to the position of the velum medullare superius. RESULTS: In all medulloblastomas the SMV was superiorly dislocated; in eight astrocytomas it was anteriorly and/or inferiorly disclocated; only in one astrocytoma the SMV presented upward dislocation. CONCLUSION: In the differential diagnosis between medulloblastoma and astrocytoma the upward dislocation of the SMV is strongly suggestive of medulloblastoma.

Intrathecal anti-CD20 antibody: an effective and safe treatment for leptomeningeal lymphoma.

A patient with relapsed B cell non-Hodgkin lymphoma (NHL) infiltrating the Central nervous system (CNS) and resistant to chemotherapy was treated with intrathecal Rituximab (IT RTX), administered weekly for eight weeks at increasing doses, from 10 to 40 mg. After the second administration the patient showed significant clinical improvement and Cerebro spinal fluid (CSF) clearance of lymphomatous cells. A MRI scan performed after 30 days from the start of therapy showed full regression of lymphomatous infiltration. This report confirms the efficacy and safety of IT RTX in the treatment of CNS B-cell NHL.

Spontaneous regression of optic pathways gliomas in three patients with neurofibromatosis type I and critical review of the literature.

CASE REPORTS: The authors report their experience about three children (two girls, one boy; average age 1.6 years) with a spontaneous regression of optic gliomas. All of them had a previous diagnosis of neurofibromatosis type 1 (NF 1). None of them underwent surgery or biopsy nor received chemotherapy or radiotherapy. The complete regression was documented by MRI scans performed during a mean follow-up of 6.3 years. LITERATURE REVIEW: Moreover, the authors analyze the features of the 16 cases previously reported in English literature of spontaneously regressed optic gliomas with an overview of the different therapeutic strategies. The knowledge that this kind of tumor, particularly in young patients, may regress is important in the decision of the best therapeutic approach.

Complete remission of brain metastases in three patients with stage IV melanoma treated with BOLD and G-CSF.

BACKGROUND: Brain metastases are the most life-threatening among the secondary localizations of melanoma for their unresponsiveness to the surgical, radiotherapeutic and/or chemotherapeutic treatments. METHODS: Accidentally, we observed a complete response (CR) in a patient undergoing chemotherapy with bleomycin, vincristine or Oncovin, CCNU or lomustine, dacarbazine (BOLD) regimen for metastatic melanoma including brain metastases, who was also treated with G-CSF to manage a concomitant leukopenia. After this observation, seven more patients with stage IV melanoma with brain metastases were treated with BOLD regimen repeated every 6 weeks with administration of G-CSF in the intervals. RESULTS: Three patients presented CR (37.5%). Two patients stopped the treatment after two courses for evident progressive disease (25%). The other three patients showed stable disease (SD: 37.5%). Median duration of SD was 24 weeks. Among the eight patients, six (75%) achieved clinical benefit. Median time to progression was 8.5 months (range 0-74+ months). Median survival was 12.5 months (range 4-74+ months). Two patients are still alive and disease-free after 74 and 57 months, respectively. CONCLUSION: We believe that the brilliant CR, the long duration of the disease-free intervals and the long survival in at least three of eight patients should encourage further research on BOLD with G-CSF for the treatment of advanced melanoma.

Degenerative changes of porcine intervertebral disc induced by vertebral endplate injuries.

STUDY DESIGN: Graded endplate injuries were performed in porcine lumbar discs. The effects of such injuries were compared to control animals in which a sham operation was performed. OBJECTIVES: To investigate the effects of endplate injuries on disc tissue. SUMMARY OF BACKGROUND DATA: Studies have shown that injuries of vertebral endplates are frequently found at autopsy. However, little is known on the effects of acute injuries of vertebral endplates in vivo. METHODS: Ten domestic pigs were included in the study group. Under general anesthesia, the lower three discs of the lumbar spine were exposed and randomly submitted to multiple endplate injuries, isolated endplate injury, and no treatment. A sham operation was performed in 5 pigs used as control group. Animals were killed 7 months after surgery and the harvested lumbar spine submitted to MRI investigations, histologic, and biochemical analysis. RESULTS: MRI showed that all but one discs treated with multiple endplate injuries were markedly degenerated while, of the discs treated with an isolated injury, one was markedly degenerated, five slightly degenerated and two were normal (P = 0.01). Histologic analysis showed severe changes in discs treated with multiple injuries. In those who had an isolated injury, changes were less severe and essentially limited to the posterior anulus or the inner anterior anulus. Biochemical analysis showed an inverse correlation between uronate content in the nucleus pulposus and severity of endplate injuries. CONCLUSIONS: Injuries of vertebral endplates in porcine discs were found to cause degenerative changes in the disc tissue on MRI, histologic, and biochemical investigations. The severity of such degenerative changes was related to the severity of endplate injuries. Injuries of vertebral endplate may be one of the pathomechanisms leading to early changes in the disc matrix and eventually to abnormal biomechanical behavior of the whole disc. The present animal model seems to be a suitable experimental model for disc degeneration.