Technical Aspects of Intra-Arterial Electroencephalogram Recording

The purpose of this prospective study is to show a technique for recording electroencephalographic activity via an endovascular approach in presurgical evaluation of epileptic patients. Technical aspects and insertion strategy are outlined. Advantages of intra-arterial electroencephalography have been demonstrated. It is a semi-invasive procedure that provides information in temporal lobe and extratemporal epilepsy. It allows a dynamic electroencephalographic recording and patient tolerance is excellent. Risks are practically absent. Disadvantages are: in comparison to ovale electrodes, chronic and multicontact recording is not possible and the recording is only intercritical.

Helical CT cholangiography in the evaluation of the biliary tract: application to the diagnosis of choledocholithiasis

BACKGROUND

We evaluated the role of helical computed tomographic (HCT) cholangiography in the study of the biliary tract, especially in the detection of choledocholithiasis, and compared it with direct cholangiography.

METHODS

One hundred one patients with biliary lithiasic pathology undergoing direct cholangiography to rule out choledocholithiasis were included in this study. HCT was performed before and after slow infusion of cholangiographic contrast. Three-dimensional reconstructions and axial images were reviewed by two independent observers. Ultrasonography also was performed on all patients.

RESULTS

The success rate of HCT cholangiography was 99%, with only a slight reaction to the contrast. The density values were significantly higher in the distal region of the tract and showed a significant correlation with serum bilirubin levels. Anatomic evaluation of the biliary tract with CT was similar to that with direct cholangiography. Anatomic variants were found on 23 studies. Twenty-two patients had choledocholithiasis, and 21 cases were detected with HCT cholangiography. The sensitivity of this technique (95.5%) was greater than that with unenhanced CT (60%) and ultrasonography (27.3%). Maximum intensity projection reconstructions were the most valuable for detecting choledocholithiasis.

CONCLUSION

HCT cholangiography is a reliable technique that is similar to direct cholangiography in visualizing biliary anatomy, anatomic variants, and choledocholithiasis.

Optic nerve aspergillosis: report of a case diagnosed by fine-needle aspiration biopsy

The aim of this study was to describe the fine-needle aspiration biopsy (FNAB) procedure in patient with a optic nerve lesion. A case of optic nerve and brain aspergillosis, an infrequent condition that can mimic tumor or tumor-like lesions, is reported. The patient was studied by CT and MRI and definite diagnosis was established by means of an ultrasound-guided FNAB. Specimen preparation revealed the presence of multiple hyphae of Aspergillus fumigatus in the optic nerve lesion. The FNAB procedure is a safe and reliable diagnostic method for suspected intraorbitary tumors and tumor-like conditions especially when other less-invasive modalities have failed to establish the diagnosis and when cytologic confirmation is needed to implement aggressive therapy.

[The contribution of an intraarterial electroencephalographic study in patients with deep epileptogenic foci]

OBJECTIVES

To evaluate the diagnostic efficacy of an intra-arterial electroencephalographic recording and determine which patients obtain most benefit from this technique, to compare the results obtained using other recording techniques and to establish a standard for recording.

PATIENTS AND METHODS

We made 64 intra-arterial recordings in 30 patients from one of three groups: persons with drug-resistant temporal epilepsy; patients with epileptic seizures of any type who required cerebral arteriography and patients whose illness required selective anteriography for any reason. We used a Seeker 10 guide-wire, the end of which acted as an electrode and a 2 minute recording was made. The position of the electrode varied depending on the site of the patients disorder. Activity was simultaneously measured with surface electrodes. Using the chi squared non-parametric test, we analysed the efficacy of the test. The paired t test was used to establish the concordance between observers. We compared the results obtained from the intra-arterial EEG with the simultaneous surface recording.

RESULTS

We found three types of electroencephalographic patterns. The commonest was defined by the presence of high-voltage multi-spiked acute waves. The sensitivity of the test was 93.33%, the specificity was 80% and the overall value of the test was 86.66%. The chi squared test showed its reliability in the diagnosis of deep epileptogenic foci. There was high concordance between the observers in the study. No complications were seen in the patients in this study.

CONCLUSION

The intra-arterial EEG recording is a semiinvasive test which may be useful in a selected group of patients and has high sensitivity and specificity.

[Preoperative percutaneous++ vertebroplasty in hemangioma compression]

INTRODUCTION

Vertebroplasty is a new procedure used in interventional neuroradiology, involving percutaneous introduction of acrylic cement.

CLINICAL CASE

We present the case of a D10 vertebral hemangioma, which had progressed so as to cause compression of the spinal cord. We used combined treatment. Vertebroplasty was done with acrylic cement, using transpedicular percutaneous puncture, with subsequent bilateral laminectomy to decompress the spinal cord. One year later the clinical condition is completely satisfactory. The signs of paraparesia and dorsalgia have disappeared. Posterior fixation was not necessary.

CONCLUSIONS

Vertebroplasty is effective since the vertebral body is consolidated and pain avoided. We give details of the methodology, indications and possible complications of the technique of percutaneous vertebroplasty.

[Wegener's granulomatosis with meningeal involvement: clinic-radiological correlations]

INTRODUCTION

Wegener's granulomatosis is a systemic vasculitis which, in its classical form, is characterized by involvement of the superior and inferior respiratory tract and the kidneys. The vasculitis may be multisystemic. Ophthalmic and neurological involvement are common (22% and 54% of those affected respectively). When considering involvement of the nervous system, the commonest finding is peripheral neuropathy, particularly in the form of multiple mononeuritis. Meningeal involvement is exceptional.

CLINICAL CASE AND CONCLUSIONS

We present a case of Wegener's granulomatosis with meningeal involvement, studied using CT and MR. The findings using imaging techniques are described, and conditions which should be considered in the differential diagnosis are discussed.

[Idiopathic hypophyseal hyperplasia: diagnosis by magnetic resonance]

INTRODUCTION

Hypophyseal hyperplasia is an uncommon disorder in which the gland increase in size due to excessive proliferation of strings of normal cells, which usually secrete prolactin. Different aetiologies may cause this disorder of the hypophyseal gland. However, in a small number of cases the hyperplasia is not due to any of these aetiologies and is therefore known as idiopathic hypophyseal hyperplasia. There are few references in the literature to idiopathic hypophyseal hyperplasia with hyperprolactinaemia. Usually diagnosis is reached after treatment for a hypophyseal adenoma, since the clinical features are similar.

CLINICAL CASES

We present three cases seen in our department, in which hormone and endocrine studies were done to exclude known causes of hyperplasia, together with CT and MR scans. We analyzed the behaviour of hypophyseal hyperplasia by using imaging techniques, and the differential aspects with regard to hypophyseal adenomas. Firm diagnosis is only made on anatomopathological study of the hypophysis. However, we consider that sound knowledge of the characteristics of this condition may help to establish the correct diagnosis and thus avoid unnecessary surgery.

CONCLUSIONS

We review the information published in the literature on this subject, emphasizing the importance of differential diagnosis by means of imaging techniques.

[Epilepsy as the first sign of multiple sclerosis]

INTRODUCTION

Epileptic crises are uncommon in patients with multiple sclerosis. However, epilepsy is commoner in these patients than in the general population. An epileptic crisis as the presenting feature of multiple sclerosis is even rarer. The lesions involved in the pathogenesis of these crises are plaques of demyelinization which affect the cortical or subcortical areas. Other factors, some of which are still not clearly understood, such as the fibre, electrolytic changes, size of the plaque, reactive gliosis and the enzyme (Na(+)-K+)ATPase, seem also to play a part in the production mechanism. Magnetic resonance is a very sensitive technique used in the detection of demyelinating lesions during the acute phase. The sensitivity is further increased by the use of gadolinium.

CLINICAL CASES AND CONCLUSIONS

We present two cases of multiple sclerosis which presented as epileptic crises. In one there were generalized tonic-clonic crises and in the other partial sensitive crises. We mention the EEG findings, CSF analysis and neuroimaging diagnostic techniques.

[Magnetic resonance imaging usefulness in the diagnosis of intratumor bleeding in hypophyseal adenomas]

Hypophyseal adenomas are the most frequent intrasella tumours. They are classified as macroadenomas or as microadenomas depending on whether their size is greater or less than 1 cm. Hypophyseal tumours may undergo ischaemic necrosis and haemorrhage when the blood supply is reduced. Intratumoural bleeding is found in varying percentages, between 9.9% and 26%. We review our series of 122 patients with hypophyseal adenomas in whom MR was done. Signs of bleeding were found in 12 patients (9%). In five cases, bleeding had presented as hypophyseal apoplexy, in five cases with subacute symptoms and in two cases was asymptomatic and diagnosis fortuitous. Of the adenomas with intratumoural bleeding, 9 were functioning tumours (4 secreted PRL, 4 ACTH and 1 GH) and 3 non-functioning. The risk factors considered in the pathogenesis of intratumoural bleeding are numerous. The increased incidence of bleeding in large and in invasisve adenomas, especially when treated with bromocriptin, is well established. MR is the ideal technique to detect intratumoural bleeding, T2 weighted sequences being very useful in the diagnosis of bleeding in the acute phase. In the subacute phase, focal areas of hyperintensity are seen in T1 and of hypo/hyperintensity in T2. In the chronic phase, areas of hypodensity are seen both in T1 and in T2. In our study we analyze the clinico-radiological correlation in patients with signs of intratumoural bleeding.