Episodic pain associated with a tumor in the parietal operculum: a case report and literature review.

We report a young woman suffering brief painful episodes in her right arm which sometimes spread to the whole right side of her body. The episodes were initially rare, but over 13 months they became increasingly frequent until occurring every 20 min. Neurological examination was normal. Magnetic resonance imaging revealed a lesion in the white matter of the parietal operculum. Lesions in the parietal operculum associated with persisting thalamic pain or loss of pain sensation have been reported, but rarely with episodic pain. Since episodic painful attacks have been described in association with various suprathalamic lesions, we conclude that paroxysmal pain attacks may be another consequence of the disturbance of the normal pattern of thalamocortical connections to the second sensory cortical area by a lesion, in our case, of the subcortical area of the parietal operculum.

Single-fraction stereotactic radiotherapy: a dose-response analysis of arteriovenous malformation obliteration.

PURPOSE: Stereotactic radiotherapy delivered in a high-dose single fraction is an effective technique to obliterate intracranial arteriovenous malformations (AVM). To attempt to analyze the relationships between dose, volume, and obliteration rates, we studied a group of patients treated using single-isocenter treatment plans. METHODS AND MATERIALS: From May 1986 to December 1989, 100 consecutive patients with angiographically proven AVM had stereotactic radiotherapy delivered as a high-dose single fraction using a single-isocenter technique. Distribution according to Spetzler-Martin grade was as follows: 79 grade 1-3, three grade 4, 0 grade 5, and 18 grade 6. The target volume was spheroid in 74 cases, ellipsoid in 11, and large and irregular in 15. The targeted volume of the nidus was estimated using two-dimensional stereotactic angiographic data and, calculated as an ovoid-shaped lesion, was 1900 +/- 230 mm3 (median 968 mm3; range 62-11, 250 mm3). The mean minimum target dose (Dmin) was 19 +/- 0.6 Gy (median 20 Gy; range: 3-31.5). The mean volume within the isodose which corresponded to the minimum target dose was 2500 +/- 300 mm3 (median 1200 mm3; range 75-14 900 mm3). The mean maximum dose (Dmax) was 34.5 +/- 0.5 Gy (median 35 Gy; range 15-45). The mean angiographic follow-up was 42 +/- 2.3 months (median 37.5; range 7-117). RESULTS: The absolute obliteration rate was 51%. The 5-year actuarial obliteration rate was 62.5 +/- 7%. After univariate analysis, AVM obliteration was influenced by previous surgery (p = 0.0007), Dmin by steps of 5 Gy (p = 0.005), targeted volume of the nidus (< or = 968 mm3 vs. >968 mm3; p = 0.015), and grade according to Spetzler-Martin (grade 1-3 vs. grade 4-6; p = 0.011). After multivariate analysis, the independent factors influencing AVM obliteration were the Dmin [relative risk (RR) 1.9; 95% confidence interval (CI) 1.4-2.5; p < 0.0001] and grade distribution according to Spetzler-Martin (RR 1.4; 95% CI 1.1-1.7; p = 0.010). Delayed complications were observed in eight patients. The 5-year actuarial rate of delayed complications was 7.4%. CONCLUSION: After stereotactic radiotherapy delivered in a single high dose using a single-isocenter technique, the success rate for complete obliteration is independently correlated to Dmin but does not seem to be influenced by Dmax and the targeted volume of the nidus.

Linac radiosurgery for cerebral arteriovenous malformations: results in 169 patients.

PURPOSE: To present the SALT group results using Linac radiosurgery (RS) for AVM in 169 evaluable patients treated from January 1990 thru December 1993. METHODS AND MATERIALS: Median age was 33 years (range 6-68 years). Irradiation was the only treatment in 55% patients. Other treatment modalities had been used prior to RS in 45%: one or more embolizations in 36%, surgery in 6%, and embolization and surgery in 3% patients. Nidus were supratentorial in 94% patients, infratentorial in 6% patients. Circular 15 MV x-ray minibeams (6-20 mm) were delivered in coronal arcs by a GE-CGR Saturne 43 Linac. Patient set-up included a Betti arm-chair, a Talairach frame. Prescribed peripheral dose was 25 Gy on the 60%-70% isodose (max dose 100%). Arteriographic results were reassessed in December 1997 at 48 to 96 months follow-up. RESULTS: The overall obliteration rate (OR) was 64% (108/169). AVM volumes ranged from 280 to 19,920 mm(3), median 2460 mm(3). OR was 70% for AVM

Inter-ictal brain SPET in frontal epilepsy: correlations with stereo-electroencephalography.

Single photon emission tomography (SPET) imaging holds promise for localization of the site of extratemporal seizures, but limited data currently exist; in particular, correlations with stereo-electroencephalography (S-EEG) have not been made. Ten patients aged 14-44 years (mean 25 years) with a proven frontal or central epilepsy by S-EEG and post-surgical follow-up were studied retrospectively: 7 patients had frontal cortectomy and one patient had a callosotomy for bifrontal epilepsy. All patients underwent clinical, inter-ictal and ictal video-EEG, computed tomography scan and/or magnetic resonance imaging, SPET and S-EEG examinations. SPET was performed inter-ictally, while on usual epileptic medications, using 99Tcm-HMPAO (n = 4) or 123I-IMP (n = 6) as the perfusion tracer. The SPET images were evaluated independently by two observers, blind to any data other than the diagnosis of frontral or central epilepsy. Localization of inter-ictal SPET hypoperfusion was compared with the epileptogenic (EZ), irritative (IZ) and lesional (LZ) zones, as defined by S-EEG. Six patients showed structural frontal abnormalities. One patient had normal SPET and one had a contralateral hypoperfusion. Therefore, concordance of sides was found in 8 of 10 patients (including one with bilateral SPET and S-EEG abnormalities). The hypoperfusion was equal to or larger than the EZ + IZ + LZ in 6 patients (5 had a frontal lesion). SPET hypoperfusion was smaller than the EZ in one patient, and different from the EZ, IZ and LZ in two patients. Although this was a retrospective study, it provides qualitative data regarding the significance of inter-ictal SPET abnormalities in frontal or central epilepsy.(ABSTRACT TRUNCATED AT 250 WORDS)

[Point of view of the radioneurologist]. / Le point de vue des neuroradiologues.

Since the 1970s, neuroradiology has benefited from significant advances and has become less and less invasive. SALT group (Saint-Anne-Lariboisière-Tenon), created in 1986, treats and follows patients presenting with arteriovenous malformation with surgery, embolization and/or radiosurgery. Treatment failures and complications are analyzed in order to better define indications and improve techniques of treatment which benefit from advances in equipment and software, as well as in radiobiology and genetics.

Methodology of "in vivo" anatomical study and stereo-electroencephalographic exploration in brain surgery for epilepsy.

Stereotactic implantation of deep SEEG electrodes performed as a prelude to surgery in some patients with drug-resistant focal epilepsy requires previous "in vivo" identification and localization of the cortical and subcortical structures to be explored, visualized "semi-directly" "or directly" by neuroradiological imaging techniques. Stereoscopic stereotactic teleangiography is a safety factor in transcutaneous electrode implantation and biopsies, but it also localizes the cortical sulci in a "semi-direct" manner by identifying vascular segments deeply buried in this sulci, which constitute their lamina vascularis. Although RMI greatly contributes to the study of the pallium, visualizing fragments of sulci and gyri does not necessarily mean that these structures can be identified with certainty, notably on the convexity of the brain. To solve this problem, RMI sections are enlarged by a photographic process, then combined with the images obtained from neuroradiological stereotaxis by means of anatomical landmarks that are common to both types of documents, using the bicommissural reference systems, bicallosal l/nl or vascular segments. This enables the angiographic laminae vascularis, which define the sulci in a "semi-direct" manner, to be used a kind of "Ariadne's clew" to identify cortical structures on RMI sections. In percutaneous stereotactic electrode implantation, the choice of the trajectories results from a compromise between the need to reach the desired anatomical structures, identified and localized within the stereotactic space, and the necessity to avoid the blood vessels displayed by stereoangiography. In some cases, the accuracy of anatomical definition can be verified during the SEEG study and/or by the evoked potential technique. Once the electrodes have been removed, their traces can be identified in a control RMI examination which constitutes a further verification.

Central sulcus patterns at MRI.

Radiologists can now use Talairach's bicommissural reference system and simple T-weighted sagittal magnetic resonance imaging (MRI) sections to recognize the central sulcus of the brain with its spatial features. In this study of 50 MRI examinations performed on normal subjects with contiguous 9 mm thick sagittal sections related to a standard proportional model that takes into account variations in the size and shape of the brain, the central sulcus could be identified on each section, despite its complexity on lateral projections and its frequent changes of course. By comparisons with the co-planar stereotaxic atlas of Talairach and Tournoux, it will be possible to localize the classical functional areas of the telencephalon.

[The rolandic line: a simple baseline for the identification of the central region. An MRI study and functional validation]. / La ligne rolandique: une ligne de base simple pour le repérage de la région centrale. Etude IRM et validation fonctionnelle.

INTRODUCTION: The identification of the central region--i.e. the central sulcus, the pre- and post-central gyri, the paracentral lobule--on MRI and angiographic images may be necessary prior to stereotactic procedures such as biopsies or resection of centrally located tumors, depth electrode recordings for presurgical evaluation of drug-resistant epilepsies, or radiosurgery of arteriovenous malformations. Stereotactic methods, such as the Talairach's proportional grid based on the bicommissural system, demonstrated the statistical position of the central sulcus according to the Ac-Pc, Vac and Vpc baselines. However, the course and the spatial position of this sulcus have remarkable individual differences that sometimes make the sulcus difficult to identify on serial sagittal MRI or lateral angiographic images. In order to facilitate this identification, the authors propose a new oblique baseline, the rolandic (R) line. MATERIAL AND METHODS: The stereotactic MRI and angiography of 22 patients were reviewed for this study. Eleven of these patients had stereotactic biopsies for a low-grade tumor located in the central region, while eleven others had multiple intracerebral electrodes implantation and depth EEG recording (SEEG: stereoelectroencephalography) in the presurgical evaluation of drug-resistant partial epilepsy, prior to epileptogenic cortex resection. The Ac-Pc, Vac, Vpc baselines and segments of the central sulcus were drawn from the mid-sagittal and lateral T1-weighted MRI images and reported on an individual graph. Surface and deep margins as well as axis of the central sulcus were also reported along with corpus callosum baselines as defined by Olivier et al.: horizontal plane, anterior and posterior callosal planes. The rolandic line was then traced from the graph:it joined the intersection point between the anterior callosal plane and an orthogonal line passing through the floor of the temporal fossa, and the intersection point between posterior callosal plane and an orthogonal line passing through the top of the hemisphere. The rolandic line was then superimposed on any sagittal MRI image or lateral stereotactic angiographic film. Finally, the spatial position of electrode contracts through which electrical stimulations elicited motor and/or sensory responses, either from central electrode implanted for motor fibers identification prior to stereotactic biopsies or from SEEG electrodes implanted for epileptogenic zone identification and cortical mapping, was reported on the individual graph. Angular and linear measurements were taken from the graph, between the rolandic line, the central sulcus axis, the Ac-Pc and callosal baselines, and the central sulcus limits (top, bottom, anterior and posterior margins). RESULTS: Graph measurements indicated that the rolandic line was significantly closer to the inferior part of the central sulcus than to its superior part (average distance between the line and the inferior point of the sulcus: 1.86 +/- 1.87 mm; average distance between the line and the superior point of the sulcus: 4.5 +/- 2.3 mm; p < 0.001-t test); similarly, the rolandic line was closer to the deep margin of the sulcus rather than to its superficial border (average distance between the line and the most anterior point of the sulcus: 11.43 +/- 3.16 mm; average distance between the line and the most posterior point of the sulcus: 7.95 +/- 4.14 mm; p < 0.01-t test). In 90% of the cases, the rolandic line followed the deep or middle part of the sulcus, with an average angle of 4.18 degrees +/- 2.53 degrees between the line and the sulcus axis. The spatial position of the electrode contacts that elicited motor/or sensory responses to stimulations correlated topographically well in all cases with the position of the motor and sensory fibers defined according to the central sulcus, baselines and reference to stereotactic atlases. (ABSTRACT TRUNCATED)

[Stereotaxic radiotherapy of cerebral arteriovenous malformations: the role of neuroradiology]. / Radiothérapie stéréotaxique des malformations artério-veineuses cérébrales: place de la neuroradiologie.

The therapeutic approach to cerebral arteriovenous malformations has been modified with the availability of stereotactic radiosurgery, initially, the main indications of radiosurgery were limited, non surgical arteriovenous malformations. Indications are now much more diverse. Imaging plays an important role in the radiosurgical management of arteriovenous malformations and its evaluation. In this review, the different roles of neuroimaging are discussed; characterization of malformations, choice of the best indications, role of embolization, delimitation of the target, evaluation of results and complications of radiosurgery.

[Contribution of radiography and gammagraphy to the monitoring of the development of psychoses]. / Apports de la radiographie et de la gammagraphie dans la surveillance de l'évolution des psychoses.

The authors emphasize the frequency of intracranial tumors in psychiatric patients. They make a distinction between the rare cases of psychiatric patients with intracranial tumors and the even most-frequent cases of tumors that express themselves through psychiatric disorders. According to the authors, the most important detection-tests are the brain scan and, more recently, the EMI scan or tomodensitometer.

[Closed injuries to the extracranial carotid artery]. / Traumatismes fermés de la carotide extra-crânienne.

A series of 26 cases of injury to the extracranial carotid artery included 3 patients with false aneurysms, 21 dissecting aneurysms, and 3 aneurysms following direct trauma. Clinical and angiographic findings, and clinical course in the 26 patients are described, together with changes observed on angiography in the 11 cases where this was repeated. Prognosis in this series appeared to be better than that usually described.

[Contribution of iodinated cisternography to craniocerebral computed tomography]. / Apport de la cisternographie iodée à la tomodensitométrie cranio-cérébrale.

Computerized tomography is usually adequate to explore supratentorial lesions of the skull and brain. However, it is often inadequate for a detailed analysis of lesions of the base of the skull and their anatomical rapports. Opacification of the subarachnoid spaces by means of a contrast medium (computerized cisternography) has proved extremely useful in such cases. The contrast media utilized are tri-iodized, water-soluble compounds which are well tolerated. The technique and anatomical data of the method are described, and its applications in different fields of tumoral and non-tumoral pathology are discussed.

[Reliability of a simplified method of localization of CT images. Correlation with stereotaxic results in 30 cases]. / Fiabilité d'une méthode simplifiée de transposition des images TDM. Corrélations au repérage stéréotaxique dans 30 cas.

A simplified method of localization of cerebral lesions by reference to CT Scan images was compared systematically in 30 cases, with localization obtained under stereotaxic conditions. The comparison was made in reference to the pineal gland and certain ventricular landmarks. The uncertainty of the method in an angular plane is less than or equal to 2,5 degrees; it is less than or equal to 3 mm in a linear plane in more than 90% of the cases.

[Diagnostic imaging of brain arteriovenous malformations]. / Imagerie diagnostique des malformations artério-veineuses cérébrales.

The goals of the imaging work-up of cerebral arteriovenous malformations are not only the diagnosis of malformations but also their radioanatomic characterization in order to define an appropriate treatment plan for a given lesion, to evaluate and to compare results of treatment modalities, to look for parameters correlated with a high risk of bleeding and to identify indications of radiosurgery. In this review, the diagnostic value of imaging techniques is discussed: CT scan, MR imaging, vascular explorations. Radioanatomic parameters most useful for therapeutic discussion are defined: feeding arteries, associated aneurysms, size and topography of nidus, draining veins.

[Stereotaxic diagnosis and treatment of colloid cysts of the 3d ventricle. Apropos of 7 cases]. / Diagnostic et traitement stéréotaxique des kystes colloïdes du troisième ventricule. A propos de 7 cas.

The clinical and anatomical results of the treatment of 7 colloid cysts of third ventricle by stereotaxic aspiration are reported. A history of increased intracranial pressure was reported in all patients (4 females aged of 12, 16, 28, 38 years; 3 males aged of 36, 54, 59 years). A ventricular shunting device has been inserted in 4 patients. Pre-operative clinical findings were: signs of increased intracranial pressure (1 case), isolated memory disturbances (3 cases); motor weakness, memory disturbances and psychomotor slowness (2 cases); 1 of the 2 last cases had also thymic disturbances. Clinical examination was normal in 1 patient. CT-Scan revealed 5 hyperdense lesions, 3 with slight enhancement; 1 hypodensity encircled by an hyperdense ring without enhancement, 1 not enhancing isohypodensity. 6 colloid cysts were between the Foramens of Monro, 1 in the posterior third ventricle. Cyst volume ranged from 1.8 to 6.3 cc. (m: 3.4). Biventricular hydrocephalus was present in all but 1 patient. Stereotaxic aspiration of the cyst performed according to Talairach's system resulted in a release of C.S.F. circulation in all cases. 3 colloid cysts were aspirated completely, 4 were reduced to 3%, 11%, 12%, 33% of the initial volume. Post-operatively 2 patients presented with a transient meningeal reaction, 1 with a transient "myoclonic" syndrome. In 1 "completely aspirated" case a control CT-Scan showed, 5 years later, a small hyperdensity corresponding to 4% of the initial cyst volume. All patients lead a normal and useful life (Follow-up: 8-78 months, m: 45). Neurological examination is normal in 6 cases and shows a pre-existent facial asymmetry in 1. Ours results suggest that stereotaxic investigation should be the first safe procedure in order to achieve both diagnosis and treatment of colloid cysts of third ventricle.

[Parenchymal changes after radiosurgery of cerebral arteriovenous malformations. Clinical and MRI data]. / Réactions parenchymateuses après radiochirurgie des malformations artério-veineuses cérébrales. Données cliniques et IRM.

BACKGROUND AND PURPOSE: Purposes of this study are to describe different parenchymal changes seen after radiosurgery of cerebral arteriovenous malformations and the clinical symptoms which can be associated, and risk factors correlated with them. PATIENTS: and method. From the whole population of 705 patients with a cerebral arteriovenous malformations treated by radiosurgery between 1984 and 1998, clinical from 615 patients and post radiosurgery MRI data from 367 patients were reviewed. Neurological deficit occurred in 5.37% of cases and was still persistant in 1.46% of cases. Delay of occurrence of deficits ranged from 6 to 83 months (mean: 27 months, median: 15 months). Parenchymal changes seen in MRI were classified in 4 grades: 1 without parenchymal changes, 2 hypersignal in sp T2, 3=2 with homogenous enhancement with gadolinium, 4 with hyposignal in spT1 and annular irregular enhancement. Several parameters (size, volume, angioarchitecture of the cerebral arteriovenous malformation, dosimetric parameters) were studied and correlations were searched by uni and multivariate analysis with occurrence and delay of occurrence of deficits or parenchymal changes. RESULTS: In multivariate analysis, only size was significantly correlated with occurrence of parenchymal changes (p=0.0016); only size of the malformation was significantly correlated with delay of occurrence of parenchymal changes (p=0.0082); only grade 4 was correlated with occurrence of neurological deficit (p<0.00001). However, when only "a priori" parameters (known before radiosurgery) are introducted in logistic model, size taille (p=0.02) and hypoplasy of a sinus (p=0.0049) are significantly correlated with occurrence of neurological deficit. Only parenchymal changes grade 4 was significantly correlated with delay of occurrence of a neurological deficit (p<0.00001). However, when only a priori parameters (known before radiosurgery) are introducted in logistic model, only arterial steal (p=0.054) was significantly correlated with delay of occurrence of a neurological deficit. CONCLUSION: Parenchymal changes are various in expression, signification and clinical symptoms associated with them. They must be known and recognized for better prevention and symptomatic treatment as well.