Atypical MELAS syndrome associated with a new mitochondrial tRNA glutamine point mutation.

The authors studied a 47-year-old patient who presented with an association of deafness, acute cerebral stroke-like episode, leukoencephalopathy, and extensive basal ganglia calcifications. Late onset and neuroradiologic findings were atypical for MELAS syndrome (Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Strokelike episodes). A heteroplasmic G to A transition at nucleotide 4332 in the tRNA glutamine gene was identified in the patient's muscle mitochondrial DNA. The pathogenicity of the mutation was shown in single muscle fibers by the correlation between high mutation load and cytochrome c oxidase defect.

Advances in the endovascular treatment of intracranial arteriovenous malformations.

The three treatment options for intracranial arteriovenous malformation are resection, endovascular embolization, and stereotactic radioneurosurgery, in rare cases, the malformation can be eradicated using only one of these options; most cases require a combination of the options, even all three. The most recent advances have been in interventional neuroradiology with the introduction of highdefinition 3D imaging and hyperselective intranidal endovascular embolization using rnicrocatheters and microguidewires, giving marked advantages in terms of rapidity, efficacy, and safety, Nidal devascularization is now much improved, as shown by the increased interval between embolization sessions, while high-field functional magnetic resonance imaging plays a valuable role in the preembolization work-up and postembolization follow-up.

[Efficacy of lumbar chemonucleolysis in the treatment of foraminal and extra-foraminal hernias]. / Efficacité de la chimionucléolyse lombaire dans le traitement des hernies foraminales et extra-foraminales.

A retrospective review of 1,200 nucleolyses performed over a three year period from January 1995 to December 1997 showed 116 discal treatments for foraminal and extra-foraminal localizations. The anatomic localization through the foramen and the intense clinical signs typify these anatomoclinical forms of lumbar hernia. In contrast with complex and disruptive surgical cure, percutaneous nucleolysis offers a precise and rapid method which can be performed in a very short time in outpatients with a success rate of 80%. Most localizations concern L3-L4 and L4-L5 hernias which give the best clinical outcomes.

[Dural fistula of the cavernous sinus. Treatment through an intravenous approach apropos of 4 cases]. / Fistules durales de la loge caverneuse. Traitement par voie endoveineuse à propos de 4 cas.

The authors report 4 cases of symptomatic dural fistula of the carotid cavernous sinus treated by transvenous coils. The objectives of dural fistula treatment are now clearly established and several methods are available. Abstention is the rule for asymptomatic forms, whereas symptomatic forms with ophthalmological complications may respond to manual compression of the jugular vein and the carotid artery, arterial embolization, radiotherapy or venous embolization. Arterial embolization results in complete cure in 72% to 78% of the cases, but it is limited by the meningeal supply of the internal carotid artery, with the microcatheter the transvenous route make it possible to treat the meningeal supply from the internal and external carotids without affecting the arterial system, but this technique is restricted by the anatomy of each patient.

Chemonucleolysis of lumbar disc herniation with ethanol.

PURPOSE: To demonstrate the efficiency of the treatment of the lumbar disk herniation (LDH) with absolute alcohol. MATERIALS/METHODS: From June 1997 to September 2000, 118 patients with 126 LDH, 69 males and 49 females, aged 19 to 77 (mean age: 51.1 years) were treated with absolute alcohol nucleolysis. In 75 cases, the LDH were parasagittal, in 30 foraminal, in 17 medial and in 4 extraforaminal. In most cases, the sensitive symptoms and motor or reflex abnormalities corresponded to the lumbar disc herniation level. Nucleolysis was made in ambulatory condition and each patient underwent general anesthesia. All procedures were performed in surgical conditions and controlled under digital fluoroscopy. The disc puncture was laterally made at the junction of middle and posterior thirds of the disc, under strict lateral fluoroscopic control. A discogram was obtained before ethanol injection. Injection dose of absolute alcohol was 0.4 ml. The realization time was about 15 minutes. RESULT: Total improvement of symptoms was obtained in 97.55% of cases. Two patients remained with low-back pain and the failure treatment rate was 0.84% (1 case). CONCLUSION: Nucleolysis with ethanol is a very effective, safe and low cost treatment for any kind of LDH, that allows to treat several levels during the same procedure, and can be repeated several times. Nucleolysis with ethanol can be made in ambulatory condition and be proposed to patients who refuse surgical treatment and have allergic background.

Posterior cervical haemangiopericytoma with intracranial and skull base extension. Diagnostic and therapeutic challenge of a rare hypervascular neoplasm.

Haemangiopericytomas are rare hypervascular tumors arising from pericytes. They may occur anywhere in the body, but posterior cervical location is rather uncommon. A case of posterior cervical haemangiopericytoma with posterior fossa and temporal bone extension is reported. Although the patient had undergone preoperative endovascular embolization and surgical resection on three separate occasions, control of the skull base extension was not successful. Following endovascular embolization combined with radiotherapy, the patient has been asymptomatic for 48 months. Angiographic features may help in differentiating haemangiopericytomas from other hypervascular lesions. Preoperative endovascular embolization is recommended due to the pronounced tendency for haemorrhage throughout biopsy and surgical procedures.

Contribution of discography to the diagnosis and treatment of lumbar disc herniation.

In this study, based on 600 cases of lumbar disc herniation treated by chemonucleolysis, the authors underline the importance of performing good discography and interpreting its results. A discographic classification of intervertebral disc deterioration is suggested. A CT-discographic study is reported and its results are compared with those of standard discography. On the basis of these studies, the authors have established methodological data concerning the efficacy of chemonucleolysis and its evaluation.

[The role of magnetic resonance angiography in the follow-up of intracranial arteriovenous malformations treated by an intravascular approach]. / Rôle de l'Angio-IRM dans la surveillance des malformations artério-veineuses intra-crâniennes traitées par abord endo-vasculaire.

The purpose of our work was to measure the accuracy and reliability of MR-Angiography in the study and follow-up of intracranial arteriovenous malformations, and in particular to evaluate the results of endovascular treatment. Over an 18-month period 4 patients with such malformations were examined by MR-Angiography. There was an angioma of the corpus callosum, a left parieto-rolandic angioma, a posterior thalamic angioma and a cerebellar angioma. All examinations were performed with a Magneton-Impact 1 Tesla machine (Siemens, Erlangen, Germany), using a head coil, MR-Angiography with time-of-flight sequences and differential arterial and venous saturations. Each patient was examined by MR-Angiography first at the beginning of treatment, then when ambulatory after embolization. The morphological study applied to the afferent vessels, the nidus and the efferent veins. MR-Angiography proved to be very good in identifying the arteries feeding the malformation, and this made it easier to evaluate the reduction of their input after treatment, without having recourse to any arteriography. Beside, analysis of the nidus was facilitated by the judicious arrangement of arterial and venous saturations. In fact, the systematic use of MR-Angiography in the follow-up of intracranial arteriovenous malformations makes it possible to measure, with full reliability, the efficacy of the endovascular treatment under conditions of comfort unequalled in these out-patients, and selective angiography sequences need to be performed only during therapeutic phases.

[Superselective angiography of the circumflex arteries in preoperative evaluation of femoral neck fractures]. / L'angiographie supersélective des artéres circonflexes dans l'evaluation pré-opératoire des fractures du col fémoral.

The study of arterial vascularity in the head and neck of the femur is performed as an emergency exploration of femoral neck fractures by means of selective catheterization. The systematization of vascular lesions thus obtained is compared with the anatomical types of fractures. The posteromedial circumflex artery is not injured definitively as a rule, so that conservative osteosynthesis can be preferred to arthroplasty.

[Post-traumatic intrasplenic arteriovenous fistula in a child. Spontaneous regression]. / Fistule artério-veineuse intrasplénique post-traumatique chez un enfant. Régression spontanée.

We report on an 11-year-old boy who developed splenic arteriovenous fistula resulting from blunt abdominal trauma. This fistula disappeared spontaneously after 8 months of follow-up without any complication.

[Surgical and pathological study of the approach to the superior choroid plexus of the 3 rd ventricle. One case of posterior choroid arteriovenous aneurysm (author's transl)]. / Etude anatomo-chirurgicale de la voie d'abord de la toile choroïdienne supérieure du 3e ventricule. A propos d'un anévrysme artério-veineux choroïdien postérieur.

The authors describe a case of an arterio venous malformation of the tela choroidea of the third ventricle which was feeding by the postero medial choroidal artery and draining by the internal cerebral vein. This A-V malformation was microsurgically excluded in sitting position by an occipital interhemispheric, transtentorial and transversal transcallosal approach without any postsurgical clinical signs. An anatomical study of this region shows an easy recognition of the choroidal postero medial artery by the regular presence of an arterial loop which concavity is crossed by the terminal segment of the basilar vein of Rosenthal. The knowledge of the occipital internal veins drained in the callosal posterior vein to form a common trunk, the cuneo limbic vein drained itself into the vein of Galen is important to know. This venous system is to preserve at the time of retraction of the occipital lobe to not give rise to infarction and therefore hemianopsia. At least the transverse section of the posterior part of corpus callosum permits a good approach of the roof of the third ventricle and is clinically very harmless if the protection of the cuneo limbic vein is assumed.