Listening with one or two hemispheres: verbal dichotic testing after intracarotid barbiturate injection.

A verbal dichotic test was given to 16 patients during right or left hemisphere narcosis induced by intracarotid barbiturate injection (Wada's procedure). During right hemisphere narcosis patients did not repeat left ear words. This demonstrates an intrahemispheric competition within the left hemisphere at the detriment of left ipsilateral ear words. After left dominant hemisphere narcosis, when aphasia had apparently disappeared, patients temporarily did not repeat right ear words. This suggests that, during this critical time period, two competitive processes took place. First the right hemisphere selected the left ear words by an intrahemispheric competition. Second it imposed them on the recovering left hemisphere at the detriment of right ear words, because of an interhemispheric competition.

Treatment of experimental carotid aneurysms by endoprosthesis implantation: preliminary report.

Four experimental aneurysms were treated by implantation of an endoprosthetic stent. The aneurysms were surgically created by grafting a venous pouch on the carotid artery of mongrel dogs. Aneurysm patency was assessed angiographically. Under systemic heparinization and via a transfemoral approach, the stent measuring 20 mm in length and 5 mm in diameter, was implanted in the lumen of the parent artery at the level of the aneurysmal neck. Good angiographic results were obtained immediately following implantation, showing exclusion of the aneurysm from the circulation. Patency of the parent vessel was preserved in all the experimental aneurysms treated. In one case an angiogram performed 30 days later showed the same findings with excellent tolerance of the device. The technique of endovascular treatment of experimental aneurysms by stent implantation appears feasible and safe in vivo. Further investigations are still necessary before clinical applications.

CT-guided needle biopsy of intracranial tumours: results in 118 consecutive patients.

The purpose of this paper is to evaluate the efficacy and safety of CT-guided needle biopsies and to determine the optimal indications for this technique. The case histories of 118 patients who underwent a CT-guided biopsy for brain lesions during a six-year period, from November 1986 to September 1992, were reviewed. During a preliminary CT-scan, the entry site was determined and localized using a radio opaque marker and the safest route to the lesion was chosen. One hundred and thirty four procedures were performed in 118 patients. A positive diagnosis of tumour was obtained in 106 patients (89.8%). Repeat procedures were required in 18 patients. High-grade gliomas were the more common lesions (55.1%). Morbidity and mortality was assessed over the 30-day period after the procedure. Nine patients died during this time. Eight patients from day 3 to day 30 in the expected course of their disease and one within 48 first hours from neurological deterioration following the procedure. We found that CT-scan guided biopsies are a safe and accurate way to obtain brain tissue specimens for pathological diagnosis in selected cases. For superficial and large tumours it is a simple, fast and effective procedure.

[Clinical and electroencephalographic manifestations during the Wada test using intracarotid injection of methohexital (Brietal)]. / Manifestations cliniques et électro-encéphalographiques lors du test de Wada par injection intra-carotidienne de méthohexital (Brietal).

In this retrospective study we report our 12 years' experience of the Wada test (intra-carotid injection of short half-life barbiturates) using Methohexital. The clinical manifestations induced by Methohexital were similar to those observed with Amobarbital. The inocuity of the test is attested by the finding that no incident or accident has been reported in 126 injections, the risk being the same as for arteriography. The two main advantages of Methohexital over Amobarbital are: 1) short hemispheric narcosis, which makes it possible to explore the two carotid arteries territories during the same session and limits the risk of drug diffusion to the two hemispheres; 2) the rare occurrence of vigilance troubles such as drowsiness or falling-asleep, which are frequently observed during Amytal Wada test. Intracarotid Methohexital injections are effective to determine the hemispheric lateralization of language and useful to evaluate the role of each hemisphere in memory, especially before the surgical treatment of drug-resistant focal epilepsies.

Dural fistulae of the cavernous sinus treated by embolization. Ten cases.

We report ten cases of dural fistulae of the cavernous sinus treated by the endovascular route. The fistulae were fed by the internal and external carotid arteries. All patients presented with ophthalmic symptoms and/or headache and/or intracranial murmur. Embolization was decided on the ground of all in visual acuity, exophthalmos, ophthalmoplegia or sudden exacerbation of clinical symptoms. It was performed after selective catheterization of external carotid feeders with non-resorbable particles. The shunt was totally occluded in 7 cases, and local signs were improved in all patients: the intracranial murmur disappeared in 2 out of 4 cases and headache was relieved in 2 out of 3 cases. No permanent complication was observed. Among the various possible treatments of these dural fistulae, embolization of branches of the external carotid artery is a simple, effective and safe method, provided its principles and indications are respected.

Spontaneous calcific cerebral emboli from calcified aortic valve stenosis.

Calcific cerebral emboli (CE) are a rare complication of calcified aortic valve stenosis (CAS). These emboli usually result from diagnostic manoeuvres (e.g. left heart catheterization) or from therapeutic procedures (e.g. heart valve surgery). Spontaneous calcific emboli are exceptional. We present the cases of two subjects known to have CAS who presented with acute neurological disorders suggesting strokes. In both subjects CT scans of the skull and brain provided a diagnosis of spontaneous CE by showing calcium-dense dots located on vessels or within the cerebral parenchyma. Additional examinations enabled us to determine the origin (heart or carotid artery) of these emboli. The finding of spontaneous cerebral CE is a very strong argument in favour of surgical valve replacement in these patients.

[Percutaneous injection of methyl-metacrylate in osteoporosis and severe vertebral osteolysis (Galibert's technic)]. / Injection percutanée de méthyl-métacrylate dans le traitement de l'ostéoporose et ostéolyse vertébrale grave (technique de P. Galibert).

The authors present their preliminary experiences using methyl-metacrylate by percutaneous injection for the treatment of osteoporosis and osteolysis of the vertebral body and for vertebral angiomas. The injection of cement strengthens the vertebral body and prevents its collapse. The mixture used consist of 4.80 g of powder with 5 cm3 of monomer liquid. The technique is performed with radiological control under neuroleptanalgesia and a local anesthesia before insertion of the needle. This technique gives good results for the treatment of vertebral pain caused by osteoporosis or osteolysis.

[Bilateral and severe segmental stenosis of intracranial carotids and their branches in a 10 1/2 month old girl with a pneumococcal meningitis (author's transl)]. / Sténoses segmentaires sévères des aratères de la base du cerveau, au cours d'une méningite à pneumocoque chez un nourrisson de 10 mois et demi.

Segmental arterial stenosis on intracranial carotid, horizontal parts of the middle cerebral and anterior cerebral arteries are possible complications in purulent meningitis in infants. From a case of these stenosis in a 10 1/2 month old girl with a pneumococcal meningitis, the authors point out the angiographic signs of these stenosis, their pronostic value and the place of carotid angiography in the diagnosis of these stenosis.

[Neurinoma of the trigeminal nerve. Excision by combined suboccipital and pteriono-temporal approach]. / Neurinome du trijumeau. Exérèse par abord mixte sous-occipital et ptériono-temporal.

The authors report a recent personal case of trigeminal neurinoma with a topographical extension both in the cerebello pontine angle and the middle cerebral fossa. This 33 year-old female suffered from progressive sensory disturbances of her right hemiface associated with a right fifth nerve motor deficit, a right VI nerve palsy and a tinnitus. CT scan and angiogram were evocative of a right hourglass trigeminal neurinoma. Two successive operative stage through suboccipital route and a pteriono-temporal extra and intradural approach allowed a complete removal of the tumour. A post-operative rhinorrhea dried up with 10 days. The patient complained with a right hemiface anesthesia and a palsy of the masseter muscles; the VI nerve palsy recovered within 3 months. From the review of the literature (118 cases) the authors summarize the anatomical, clinical and radiological features of these tumours and point out. The difficulty of their surgical removal that was only complete in half of cases. The high frequency of hourglass neurinomas explains that a single suboccipital or subtemporal approach--even with opening of the tentorium--only allowed 23 complete removal among the 58 published or quoted interventions. This justifies that in a majority of cases a combined approach must be preferred, using successively a suboccipital and an intradural subtemporal route, the latted giving access to the cavernous sinus in case of its invasion.

[Extra-intracranial anastomosis: radio-clinical correlations]. / L'anastomose extra-intracrânienne: corrélations radio-cliniques

25 patients have been operated on by means of extra-intracranial anastomosis (22 with STA-MCA anastomosis, 3 with occipital-MCA anastomosis). 23 patients underwent an angiographic study early after surgery (two weeks). The patency rate is 14 out of 23 (13 STA, 1 occipital anastomosis). In comparison of its pre-operative size, the afferent artery has enlarged in the most cases, particularly in patients with complete obliteration, either of the carotid artery, or of the middle cerebral artery. In every case, only a limited part of the MCA territory is visualized through the anastomosis. In no case was the complete MCA field visualized; the frontal branches, particularly, are not supplied through a temporal anastomosis. In the case of occipital anastomosis, both upper and lower branches of MCA are supplied through the new channel. 11 patients underwent a second angiographic study, from one year through 28 months after the first one. In three patients with no patency on the first angiography the anastomosis remained non patent. So, in this series, no anastomosis was seen to became patent secondarily. In 8 patients with patency on the first control, the anastomosis remained patent on the second angiography. In patients with a pre-operative stenosis, no increasing of the size of the vessel could be noticed. The filling of the MCA branches is difficult to be discussed, for in these cases, the angiographies were not performed selectively through the external carotid artery. In patients with a pre-operative thrombosis, an enlarging of the vessels was seen, as well as an extension of the intra-cranial filling through the anastomosis. Clinical correlations are the following ones: the most patients with TIA's had a stenosis. They presented no increasing of the size of the vessels. They were doing well after operation, as if a little more of blood supply was sufficient to improve the general blood perfusion. Every patient with stroke had a pre-operative thrombosis and presented an enlarging of the vessels with a better filling on the second angiography, as if a great deal of additional blood supply was required; the clinical improvement is slow (3 out of 5) and remains often incomplete.

[Developmental ophthalmic ischemia. Regression after emergency extra-intracranial anastomosis]. / Ischémie ophtalmique en évolution. Régression après anastomose extra-intracrânienne en urgence.

Recently several publications have insisted on the ability of E.I.C.B. in reversing ocular manifestations due to chronic ophthalmic ischemia, when surgical carotid desobstruction is considered impossible or hazardous. Revascularization with E.I.C.B. can also be useful--on emergency --in case of "in evolution" ophthalmic ischemia, due to low pressure perfusion in the carotid-ophthalmic territory, to save vision. The authors report the case of a patient, presenting an optico-pyramidal syndrome "in evolution", secondary to occlusion of the left carotid artery associated with stenotic lesions in the ophthalmic artery, reversed by E.I.C.B. performed on emergency. Left visual acuity and diastolic retinian arterial pressure --respectively inferior to 1/10 and unmeasurable, before operation--raised up to 6/10 and 18 mmHg within the first twelve post-operative days and reached 8/10 and 38 mmHg after eleven weeks. This case report aims at pointing out the capacity of E.I.C.B. performed on emergency in reversing ophthalmic ischemia--"in evolution"--before constitution of irreversible lesions.