Cholesterol granuloma and cholesteatoma are the two most common destructive lesions of the petrous apex. Arachnoid cyst is much less common. These three expansile lesions are often indistinguishable ...on clinical grounds. Accurate pre-operative radiological diagnosis on computed tomography scan and magnetic resonance imaging is important in order to plan the appropriate treatment. Pre-operative radiological differential diagnosis between primary cholesteatoma of petrous apex and a intrapetrous arachnoid cyst remains a significant problem. The following aspects need evaluation for recognition of intrapetrous arachnoid cysts: 1) an awareness of their existence, 2) homogeneous signal on T1 and T2 weighted images, closely resembling cerebro-spinal fluid signal, 3) special heavily weighted T2 images on magnetic resonance imaging: fluid-attenuated inversion recovery imaging, 4) careful correlation of clinical-radiological data. Symptomatic arachnoid cysts are best treated with conservative drainage surgery through middle cranial fossa. A case of a petrous apex arachnoid cyst is reported which has been radiologically mistaken for a primary cholesteatoma and operated through an infratemporal fossa approach type B. The patient (40-year-old female) came to our attention with right trigeminal pain which had been present for one year and dizziness. Neurotologist and skull-base surgeons should include arachnoid cyst as a rare possibility in the evaluation and treatment of petrous apex cystic lesions.
Objective– We have investigated recurrence of stroke in a consecutive series of young adults, aged 16 to 45 years, after a first cerebral infarction. Methods– From January 1, 1988 to December 31, ...1996 we submitted those patients to a diagnostic protocol including angiographic, cardiological, and haematological investigations. The patients were followed at 6 month intervals up to December 31, 1998. Results– We have evaluated and followed‐up 135 patients, 71 men and 64 women, who were 3.99% of all the admitted stroke patients. At 12 months after stroke, 83 patients had returned to work, 40 patients were mildly to moderately handicapped, 4 were using a wheel‐chair, and 8 had died. Follow‐up was 26 to 123 months (mean 68.8). Recurrence of stroke, always of ischaemic nature, was seen in 15 patients (11.1%), 3 to 76 months after the first stroke (mean 27.4), for an annual incidence of 2.26%. Recurrence was significantly associated with Partial Anterior Circulation Syndrome and Haematological subtype of first stroke (respectively, P=0.0209 and P=0.0135, ξ2 test), but not with age (≤ or >35 years) or risk factors. Repetition of stroke was never fatal, but it caused heavy disability in 13 patients, 8 of whom had completely or nearly completely recovered after the first event. Conclusions– Our data suggest that recurrence of stroke is a major clinical problem also for the patients aged less than 45 years and that it might be more frequent with specific clinical syndromes and etiologic subtypes of first stroke.
Objectives– To evaluate the presence of microembolic signals (MES) in the middle cerebral artery distal to a stented carotid artery late after stent deployment. MES may be a signal of thrombus ...formation at the stent level. Patients and methods– Two patient groups were studied with transcranial Doppler at different intervals after deployment of Palmaz stents or Wallstents for stenosis of the internal or common carotid artery. Group 1: from 6 to 12 months after stent deployment; Group 2: >12 months after stenting. Results– One out of 19 patients in Group 1 showed MES (5.0%); however, this patient also had two mechanical heart valves. None out of 17 patients in Group 2 had MES. Conclusions– Carotid stents seem to have a very low emboligenic potential after the early post‐deployment period. This is a reassuring message for present and future patients harboring such stents.
A methodology for patient-specific model reconstruction and computational mesh generation of arterial bifurcations from angio-CT scans is presented. Three-dimensional models were reconstructed with a ...level set technique, analyzed with a skeletoning algorithm and automatically decomposed into branches. Cooper scheme was then employed to generate high quality hexahedral mesh. We successfully applied our technique to the carotid bifurcations of two patients affected by severe atherosclerotic plaques. The proposed technique is fast, accurate and reproducible, and can be a useful tool for the evaluation of arterial fluid dynamics within conventional computed tomography investigations.
The clinical-CT scan correlation was studied in 37 stroke patients with global aphasia. The time between stroke and language examination was between 21 and 60 days; the time between stroke and CT ...scan was equal to or longer than 21 days. It was found that while 22 patients harboured the expected large lesions including Broca's and Wernicke's areas, 8 had anterior lesions sparing Wernicke's area, 3 had posterior lesions sparing Broca's area, and 4 had deep lesions centered on the insula and lenticular nucleus. These findings suggest that global aphasia, albeit apparently simple from the semeiological viewpoint (also due to its severity), does in fact include different clinical entities. However, no clear-cut correlation was found between either subtype of speech production or severity, and locus of the lesion (except that deep lesions were associated with somewhat milder forms). An interesting finding, i.e. that all 8 patients with anterior lesions were females, while the 3 posterior ones were male, is briefly discussed in terms of possible differential organization of language functions in the two sexes.
Since 1989 we performed stereotactic radiotherapy treatments of cerebral arterovenous malformations (AVM), estimating three-dimensional (3-D) localization and shape of target volumes by the Leksell ...stereotactic helmet on two orthogonal radiographic projections. Due to the limitations of this method, we developed a new technique for the localization of the target volume using digital subtraction angiography (DSA) and digital image processing. To achieve this result we first developed a method to correct nonlinear distortion of DSA images using spatial relocation of image pixels based on a calibration grid. We then developed an algorithm for localization of the target volume using two independent DSA projections. Target volume coordinates in the helmet system are calculated using two DSA acquisitions taken with a free angle (∼90°), one in the AP and the other in the LL direction. The helmet can be freely positioned between the x-ray source and the image plane. The projections of eight reference points inserted in the helmet at a known location, are used to calculate the transformation matrix between the two coordinate systems. We performed numerical and experimental validation of the system. A hypothetical random error (up to 2 mm) on image coordinates of the reference points allowed to determine that the error in target localization was less than 0.2 mm. Using DSA images of target points with a known location within a phantom, the error between calculated and actual location was, on average, 0.30±0.13 mm (mean±SD), with a maximum error of 0.49 mm. The results of numerical and experimental validations show that the system we have developed allows fast and accurate localization of the center of the target volume and it is suitable for efficient guiding during stereotactic radiosurgery of AVM.
OBJECTIVES--To report experience of intra-arterial thrombolysis for acute stroke, performed with a microcatheter navigated into the intracranial circulation to impale the clot. METHODS--Patients were ...selected on the following criteria: (1) clinical examination suggesting a large vessel occlusion in stroke patients between 18 and 75 years; (2) no radiographic signs of large actual ischaemia on CT at admission; (3) angiographically documented occlusion of the middle cerebral artery (MCA) stem or of the basilar artery (BA), without occlusion of the ipsilateral extracranial internal carotid artery or of both the vertebral arteries; (4) end of the entire procedure within six hours of stroke. 12 patients with acute stroke were recruited, eight of whom had occlusion of the MCA stem and four of the BA. Urokinase was used as the thrombolytic agent. RESULTS--Complete recanalisation in six MCA stem and in two BA occurred, and partial recanalisation in two MCA stem and one BA. There was no recanalisation in one BA. A clinically silent haemorrhage occurred in two patients, and a parenchymal haematoma in one patient, all in MCA occlusions. At four months five patients achieved self sufficiency (four with MCA and one with BA occlusion). Six patients were dependent (three totally), and one died. CONCLUSIONS--The strict criteria of eligibility allowing the enrollment of very few patients and the procedure itself, requiring particular neuroradiological expertise, make this procedure not routine. Nevertheless, the approach can be considered a possible option for patients with acute ischaemic stroke.
We present the clinical and neuroradiological features of tethered cord syndrome in a young woman and discuss the diagnostic role of CT scanning, performed before and after myelography.
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