Focal epilepsies associated with glioneuronal tumors: review article.

Glioneuronal tumors (GNTs) are an increasingly recognized cause of focal epilepsies, particularly in children and young adults. GNTs consist of a mixture of glial and neuronal elements and most commonly arise in the temporal lobe, particularly in the temporo-anterior-basal mesial site. They are often associated with cortical dysplasia or other neuronal migration abnormalities. Epilepsy associated with GNT is poorly controlled by antiepileptic drugs in many cases; but, it is extremely responsive to surgical treatment. However, the best management strategy of tumor-related focal epilepsies remains controversial and still remain one of the contemporary issues in epilepsy surgery. Temporo-mesial GNT are associated with a widespread epileptic network, defining, therefore, a distinct anatomo-clinico-pathological group with complex epileptogenic mechanisms. By using an epilepsy surgery oriented strategy GNT associated with focal epilepsies may have an excellent seizure outcome and, therefore, surgical treatment can be offered early to avoid both the consequences of uncontrolled seizures as well as the side effects of prolonged pharmacological therapy and the rare risk of tumor growth or malignant transformation.

MRI findings in low grade tumours associated with focal cortical dysplasia.

Magnetic resonance imaging (MRI) is mandatory to identify the epileptogenic zone in refractory temporal lobe epilepsy (TLE). The correct identification of lesions is essential to obtain good post-surgery seizure control. Low grade tumours (LGT) and focal cortical dysplasia (FCD) are common findings in symptomatic TLE, and frequently coexist. The aim of this study was to identify the MRI characteristics in the diagnosis of FCD associated with LGT. We analyzed 24 subjects with TLE who underwent tailored surgery. They all had LGTs. Two expert neuroradiologists analyzed the imaging data and compared them with histological results, hypothesizing the causes of diagnostic errors in the identification of FCD. We selected three exemplary cases to report the most important causes of errors. In the diagnosis of FCD we reported false positives and false negatives due to different causes. An incomplete MRI protocol, the large dimensions of the tumour, infiltration and related oedema were the most important factors limiting MRI accuracy. MRI can be limited by an incomplete protocol. In addition, the presence of an LGT may limit the neuroradiological diagnosis of FCD in the temporal lobe. Advanced MRI techniques could help reveal subtle lesions that eluded a previous imaging inspection.

Quantitative cervical spinal cord 3T proton MR spectroscopy in multiple sclerosis.

BACKGROUND AND PURPOSE: Brain proton MR spectroscopy ((1)H-MR spectroscopy) is a useful technique for evaluating neuronal/axonal damage and demyelization in multiple sclerosis (MS). Because MS disability is frequently related to spinal cord lesions, potential markers for MS stage differentiation and severity would require in vivo quantification of spinal integrity. However, few spectroscopy studies have investigated cervical disease due to technical difficulties. The present study used 3T (1)H-MR spectroscopy to measure the main metabolites in cervical spinal cord plaques of a group in patients with relapsing-remitting MS (RRMS) and compared them with metabolite measurements in healthy volunteers. MATERIALS AND METHODS: A (1)H-MR point-resolved spectroscopy sequence volume of interest was prescribed along the main axis of the cord between C2 and C3 levels on a plaque in a group of 15 patients with RRMS for a total acquisition time of approximately 14 minutes. MR spectroscopy data were analyzed by the user-independent fitting routine LCModel, and relative metabolite concentrations were expressed by the absolute concentration ratios. A Student t test was used to evaluate the difference compared with the healthy metabolite content previously published. RESULTS: We found a significant decrease of total N-acetylaspartate/choline and an increase in choline/creatine and myo-inositol/creatine content on MS plaques in comparison with healthy cervical spine tissue. CONCLUSIONS: In vivo (1)H-MR spectroscopy, if confirmed by other similar studies, should be as reliable for clinical studies as it is in brain imaging. Moreover, (1)H-MR spectroscopy allows examination of spinal cord integrity at a biochemical level and may be sensitive to subtle changes occurring during the course of MS disease.

Role of contrast-enhanced magnetic resonance angiography in spinal dural arteriovenous fistula.

Spinal dural arteriovenous fistulae (SDAVF) are the most common vascular malformations of the spine. Although digital subtraction angiography (DSA) remains the standard of reference to diagnose and classify vascular spinal lesions, we investigated the clinical value of contrast-enhanced MR angiography (CE-MRA), equipped with TRICKS sequences, in localizing SDAVF before selective catheter angiography and possible subsequent treatment. We studied 16 consecutive patients suspected of harbouring vascular spinal cord malformations and we tried to determine the level and the side of the arterial feeder to the arteriovenous abnormality. In 12 cases the results were compared with DSA and/or possible post-operative findings. In nine cases CE-MRA correctly depicted the origin of the fistula: in particular one patient was treated surgically only on the basis of MRA results. Thanks to its elevated spatial and temporal resolution, spinal contrast-enhanced MRA using TRICKS sequences proved reliable in detecting and localizing the SDAVF arterial feeders and can be used as a guide to subsequent selective DSA examination.

An ischaemic thalamic lesion extending to the mammillothalamic tract associated with absent ipsilateral mammillary body in a patient with temporal lobe epilepsy. A case report.

We describe a patient with right temporal lobe epilepsy with MR findings of an ischaemic thalamic lesion extending to the mammillothalamic tract and absent visualization of the mammillary body without signal changes in the hippocampus.

3T MRI in the Evaluation of Brain Aneurysms Treated with Flow-Diverting Stents: Preliminary Experience.

Deployment of stents across the neck of intracranial aneurysms to isolate the lesion from the circulation is a recently introduced endovascular treatment. These devices are known as flow-diverting stents because the stent mesh design drastically slows the blood flow within the aneurysm sac, thereby stimulating thrombus formation. Treated aneurysms require close follow-up monitoring using an effective minimally invasive method. We devised a dedicated follow-up protocol using a high field strength magnetic resonance system (MR) with gadolinium administration to monitor 11 patients treated by insertion of flow-diverting stents. Findings were compared with the results of a reference imaging procedure (CT angiography). MR accurately demonstrated patency of the stent lumen and monitored the evolution of the aneurysmal sac in all patients. Gadolinium administration proved essential in two patients to depict the complete exclusion of the flow within the aneurysmal sac.

Massive peripheral nerve hypertrophy in a patient with chronic inflammatory demyelinating polyradiculoneuropathy.

We describe a male patient with chronic inflammatory demyelinating polyradiculoneuropathy presenting extensive diffuse hypertrophy of the nerve roots of peripheral nerves. Since adolescence the patient has had a slow and progressive mainly distal loss of sensitivity and muscle weakness in all four limbs. He presented with diffuse muscle atrophy with enlarged palpable nerve trunks. Electromyography disclosed impaired sensory and motor responses in the bilateral median nerves and the right ulnar nerve. CSF examination showed elevated protein content, while MR scans depicted extensive hypertrophy of the spinal nerve roots. The patient benefitted from corticosteroid treatment.

Metabolite Changes in Normal Appearing Cervical Spinal Cord in Two Patients with Multiple Sclerosis. A Proton MR Spectroscopic Analysis.

We describe two cases of multiple sclerosis (MS) analyzed with Proton MR Spectroscopy ((1)H-MRS) with the voxel placed along the main axis of the normal appearing cervical spinal cord over three main space planes, orthogonally set. Relative concentrations expressed by the absolute concentration ratios of total NAA (tNAA), choline (Cho), myo-inositol (mI) and creatine plus phosphocreatine (Cr) were compared with the metabolites of ten healthy volunteers. We found a significant increase in mI/Cr and a small increase in Cho/Cr in the first patient, whereas the second patient had a decrease in NAA/Cr and NAA/Cho ratios. 1H-MRS will disclose biochemical changes in MS, even in normal appearing spinal cord, as already described in normal appearing cerebral tissue: these biochemical changes may provide significant information on disease prognosis.

Evolutive study of relapsing-remitting multiple sclerosis with cervical proton magnetic resonance spectroscopy. A case report.

We used quantitative proton magnetic resonance spectroscopy ((1)H-MRS) to evaluate mean relative concentrations ratios for NAA, Cr, Cho and mI during the study of cervical spinal cord plaques in a relapsing-remitting multiple sclerosis (RRMS). A cervical spine MR exam was repeated five times on the following days for two months starting from the onset of a relapse phase, using a 3T whole-body system, with the voxel placed along the demyelinazation lesion. The quantification results were compared with the healthy metabolites content. Quantitative cervical spectroscopy is a reliable tool and can offer important metabolic information as already used on the brain to evaluate the severity, progression and pathogenesis of multiple sclerosis.

CE-MR Angiography at 3.0 T Magnetic Field in the Study of Spinal Dural Arteriovenous Fistula. Preliminary Results.

SUMMARY: We report technical data and results in eight patients studied with spinal contrast-enhanced MR angiography (CE-MRA). We used a 3.0 Tesla device, dedicated phased array coil and time resolved imaging of contrast kinetics (TRICKS) sequences to visualize the feeder vessels in patients with vascular malformations. TRICKS is a method of 3D CE-MRA providing temporal information. Thanks to its high temporal and spatial resolution and high signal/noise ratio the TRICKS optimized sequence at 3.0 T yielded very encouraging results in disclosing the origin of arteriovenous malformations.

Childhood spinal glioblastoma multiforme with intracranial dissemination. A case report.

Primary spinal cord tumors in children are uncommon and account for approximately 5% of all pediatric central nervous system tumors. Intracranial metastases from primary spinal cord tumors have rarely been reported. Spinal cord glioblastoma in children mainly involves the thoracic region, whereas involvement of the medullaris conus with intracranial dissemination has been described in six cases. This paper describes a pediatric case of thoracic glioblastoma multiforme with intracranial dissemination in the early stage of the clinical course and discuss the clinical and neuroradiological manifestations, the possible patterns of dissemination and finally to consider the therapeutic implications.

Extracentral nervous system metastases from medulloblastoma. A case report.

Medulloblastoma belongs to the group of highly malignant neuroepithelial tumours and is the commonest tumour in childhood (12-25 %) (1), but is rare in adults (0.4-1%) of all primary brain tumours) (1,2). Medulloblastomas usually arise in the posterior fossa and spread readily throughout the CSF, although 10-30% of patients develop extracentral nervous system metastases (2). We describe a 30-year-old woman presenting bone metastases from medulloblastoma located predominantly in the spine.

Osseous metaplasia in a growth hormone-secreting pituitary adenoma.

A case of growth hormone-secreting adenoma of the pituitary gland showing osseous metaplasia is described in a 56-year-old acromegalic female. The tumor was composed of nests of densely granulated cells separated by and intermixed with calcifications, trabeculae of mature bone and fat. Calcifications are seldom found in pituitary adenomas. In rare instances, calcium deposits can be prominent enough to lead to the formation of pituitary stones and bone which replace the entire tumor mass. Analogously with metaplastic meningiomas, we propose using the term metaplastic adenoma to define cases with osseous metaplasia in order to distinguish between lesions containing bone from the more frequently seen calcified adenomas.

Arterial anomalies of the middle ear associated with stapes ankylosis.

An aberrant internal carotid artery in a young woman complaining of pulsatile tinnitus and conductive hearing loss was diagnosed pre-operatively by CT scan and angiographic findings. An exploratory tympanotomy was performed in order to evaluate the cause of the severe conductive hearing loss. It was possible to detect a large persistent stapedial artery associated with a stapedial fixation of unknown cause. Despite these vascular anomalies a stapedotomy was performed successfully.

Magnetic resonance imaging of hypothalamic hamartomas causing gelastic epilepsy.

Hypothalamic hamartomas may cause a peculiar epileptic syndrome characterized by seizures of laughter and precocious puberty. Four mentally handicapped patients suffering from gelastic epilepsy were referred to our institution for investigation; three of them also presented with precocious puberty. In all four cases magnetic resonance imaging (MRI) revealed a space-occupying lesion of the hypothalamus that was considered to be a hamartoma. Biopsies were not performed. Hamartomas appear isodense in plain computed tomography scans, and they do not enhance. Such lesions display an isointense signal in T1-weighted magnetic resonance images and a hyperintense signal in proton density and T2-weighted images. MRI is the procedure of choice for detecting such lesions at the base of the brain.

Fifty-five thousand cerebral angiographies.

A large series of patients submitted to cerebral angiography at the Bellaria Hospital in Bologna are presented in a preliminary report. Experience gained is discussed from the standpoints of success versus failure and of the complications. It is concluded that direct percutaneous cerebral angiography, if used selectively, still has a role to fill in a modern neuroradiology department, because of its safety. It is especially well suited for the examination of older patients. For angiography of the external carotid and the vertebral artery femoral catheterization is more suitable.

Angiographic technique in extra-intracranial arterial bypass for cerebral ischemia.

Angiography is indispensable for the selection of appropriate candidates for extra-intracranial arterial bypass (E.I.A.B.). It allows the visualization of ICA and/or MCA occlusion or inaccessible stenosis which are considered indications for E.I.A.B. Complete angiographic study also gives information about other vascular lesions and the morphology of ECA and its branches as well as collateral circulation. Moreover angiography evaluates the result of bypass. The methods of the preoperative and postoperative angiography are described.