In four large, 15–25 mm, internal carotid artery aneurysms (3 intracavernous and 1 carotid ophtalmic), treatment by common carotid ligation was preferred. Pre- and postoperative MRI were obtained, at a delay between 5 to 9 years. Recovery of the ocular and visual symptomatology was a function of the role played by mechanical and/or ischaemic factors. No early or late consequences, ascribable to the common carotid ligation, were observed. Aneurysmal thrombosis occurred in the first postoperative week, but retraction of the thrombosed aneurysms was only obvious and maximal after several months. For this reason, rapid clinical recovery could be due, in the first instance, to the loss of aneurysmal pulsatility. Complete disappearance of the aneurysm was observed in two cases. In the other two, a small remnant of the initial lesion, without any unfavourable consequences, was revealed, respectively 6 and 9 years after the intervention, by current, modern-days, MRA.

In the scope of a late intervention policy on ruptured intracranial aneurysms, on D.+12 on an average, we first used tranexamic acid, at moderate doses: 3 g orally or 1.5 g intravenously per day. We, subsequently, added nimodipine, usually 240 mg orally per day or 2 mg intravenously per hour. The medical treatment consisted of amply sufficient hydration, and in systematic and regular administration of analgesics and sedatives. Hypotension was absolutely avoided; if necessary, an antihypertensive treatment was prescribed very cautiously. Phenytoin was regularly given.

PURPOSE: Our goal was to determine the accuracy of MR angiography at 0.5 T for the diagnosis of intracranial aneurysms. METHODS: We retrospectively studied 140 patients, 70 with acute subarachnoid hemorrhage, who were either at high or low risk for intracranial aneurysm. Three-dimensional time-of-flight MR angiography was typically performed to cover the circle of Willis, with a volume thickness of 30 mm. Conventional spin-echo MR images and MR angiograms were reviewed together, and the results were compared with those obtained at intraarterial cerebral angiography to determine the sensitivity and specificity of MR angiography. RESULTS: Eighty-nine aneurysms (size range, 2 to 27 mm; 25 aneurysms < 5 mm) were identified at intraarterial cerebral angiography. Six aneurysms were missed by MR angiography and two were doubtful (sensitivity, 91% to 93%; specificity, 100%). Missed aneurysms were located outside the MR angiographic acquisition volume (n = 3) or on the carotid siphon (n = 3; size = 2, 3, and 5 mm). CONCLUSION: Even if MR angiography presents some restrictions in acquisition volume and spatial resolution, the detection rate of intracranial aneurysms is excellent at 0.5 T in both asymptomatic patients and in those with subarachnoid hemorrhage. A midfield system is not a restriction to the detection of intracranial aneurysms by MR examination.

Spinal dural arterio-venous fistula (AVF) is a well defined entity that seems to be paradoxically underdiagnosed since the advent of new imaging techniques, especially magnetic resonance (MR) imaging. Recent cases of misdiagnosis have led us to review the clinical context and the imaging features of spinal dural AVF.

The radiological aspect, pathology, treatment and results of 132 subdural haematomas observed in 100 patients, are discussed.

Methods: To assess the potential of thymidine for imaging brain tumors, 20 patients with untreated (n = 14) and recurrent (n = 6) supratentorial intracranial tumors were studied with PET by using 2-[C-11]thymidine (Tdr), and the results were compared with [F-18]fluorodeoxyglucose (FDG) PET data. Results: Blood analysis consistently revealed a rapid clearance of the intact Tdr together with the appearance of CO2/HCO3- that, with time, accounted for approximately 70% of the total blood activity. As soon as 10 min after tracer injection, brain images showed a low and homogeneous Tdr distribution over the normal brain structures (cortex-to-blood ratio approximately 1). Visual and quantitative analysis revealed increased Tdr uptake (tumor-to-cortex ratio greater than or equal to 1.2) in 11 of 14 untreated tumors and in 5 of 6 recurrent tumors. No correlation was found between Tdr uptake and tumor grade. In 12 of the 14 untreated tumors, FDG uptake was low (tumor-to-cortex ratio: 0.83 +/- 0.79), but a FDG hot spot was visualized in 8 of 10 high-grade and in none of the 4 low-grade tumors. FDG uptake was consistently low in recurrent tumors (tumor-to-cortex ratio: 0.49 +/- 0.19), and PET-FDG was negative in 3 of the 6 cases. Conclusion: These data indicate the feasibility of brain tumor imaging with Tdr and suggest the potential clinical usefulness of the method in the detection of tumor recurrences. The specificity of the method remains, however, to be investigated.

The authors report 3 observations of dural arterio-venous fistula cured by combined neuroradiological and neurosurgical intervention. In the first case, the shunt affected the left lateral sinus. Repeated embolizations failed whilst intracranial hypertension developed, as a consequence of flux in the opposite lateral sinus and in the sagittal sinus. Surgical intervention, consisting in isolation of the transverse sinus, led to complete cure, after a one month delay. In the second case, the shunt was adjacent to the sagittal sinus, right parietal, and had led to an intracerebral haematoma, by rupture of an arterialized cortical vein. Embolizations alone could not cure the fistula which therefore had to be excised. In the third case, the shunt was located in the falx, at the parieto-occipital junction, and was responsible for arterialization of cerebral veins in the right parieto-occipital region. For this reason, after failure of endovascular treatment, the fistula was coagulated, with subsequent complete cure. These three cases illustrate the different types of drainage of such arterio-venous fistula, and their corresponding neurological symptoms and signs, complications and risks, that required a radical-not only clinical, but also anatomical-cure. This aim was achieved when embolizations were accompanied by direct surgical attack.

A 27-year-old woman presented with right spinal accessory juxtabulbar schwannoma, associated with hydrocephalus. The only specific clinical symptom was long-standing weakness of the right trapezius. C.T. scan evoked a cerebellar tumor, whilst the jugular foramen appeared normal. Vertebral angiography was not decisive. M.R.I. suggested an extra-axial tumor. Post-operative evolution was entirely favourable. Schwannomas of the 9th, 10th and 11th cranial nerves are generally located at the level of the jugular foramen but can also be observed along the extracranial path of these nerves. An intracranial paramedial, or so-called "intracisternal" localization is rare and is best diagnosed by magnetic resonance imaging.

The authors report a case of compression of the peroneal nerve by an intraneural ganglionic cyst. The chief complaint is generally a lateral upper leg pain occasionally associated with foot drop and swelling of the upper tibiofibular joint. In our case, the disease was revealed by a tentative intraarticular injection of betamethasone. Early microsurgical treatment remains the only way to avoid permanent motor sequellae.

As beta-2 transferrin is almost specific to the cerebrospinal fluid, its detection in rhinorrhea or otorrhea fluids demonstrates the occurrence of CSF fistula. We describe a highly sensitive method based on immunoaffinity-mediated capillary blotting for the detection of this cathodic isoform of transferrin in minute amounts (3 μl) of rhinorrhea or otorrhea fluids. Application of this method in a series of 10 patients with CSF fistula is reported.

Paragangliomas of the cauda equina are not so rare as said in the literature. Two additional cases are presented with a global analysis of the 59 cases from the literature. The diagnosis of this pathology greatly benefit of the use of immunostainings as the cells are often neuron-specific enolase, neurofilament proteine and somatostatine positive so that electron microscopy is thus no longer mandatory for establishing the diagnosis. In addition, we report the first magnetic resonance images of this tumor at this location.

Forty spontaneous cerebellar hematomas have been observed in 39 patients whose age ranged from 13 to 82 years. Arterial hypertension is the most frequent aetiological factor. Amongst the other causes, vascular malformations, anticoagulant therapy, metastatic tumor, sepsis were found. Diagnosis is no longer a challenge since the introduction of C.T. scan, whilst M.R.I. may give most valuable informations concerning aetiology, especially when a vascular malformation is present. In this study, the influence of the hematoma size and of hydrocephalus on consciousness was demonstrated. The purpose of surgical treatment is twofold: alleviating brainstem compression and correcting hydrocephalus

Forty spontaneous cerebellar hematomas have been observed in 39 patients whose age ranged from 13 to 82 years, 26 being older than 60. Arterial hypertension is the most frequent aetiological factor. Amongst the other causes, vascular malformations, which may also be present in older people, anticoagulant therapy, metastatic tumor, sepsis were found; one case remained unsolved. Diagnosis is no longer a challenge since the introduction of C.T. scan, whilst M.R.I. may give most valuable informations concerning aetiology, especially when a vascular malformation is present. In this study, the influence of the hematoma size and of hydrocephalus on consciousness was demonstrated; development of hydrocephalus is favoured by the size and by a rather median location of the hematoma. In the future, M.R.I. should give better precisions concerning an eventual extension of the hemorrhage to the brainstem. The purpose of surgical treatment is twofold: alleviating brainstem compression and correcting hydrocephalus; yet, divergent opinions have been put forward in retrospective studies, concerning evacuation of the hematoma and drainage of hydrocephalus. In this series, direct attack doesn't seem to be indicated in hematomas less than 3.5 cm diameter, unless a causal lesion has to be removed. The ideal moment for hematoma evacuation is, finally, dictated by the clinical status and its evolution; however, the authors prefer, if possible, to delay it for at least 48 hours. Amongst the 39 patients, 14 deceased; of the 25 survivors, 19 were autonomous, 7 being nearly asymptomatic, 6 patients remained handicapped. Consciousness is a main prognostic factor, whilst coma in the first hours has a clearly unfavourable significance.

Quite a number of cases of upward shunt migration have already been reported in the literature. The authors report the case of a newborn boy who presented a sequential alternate change of pressure gradients based, according to their opinion, on fields of pressures exerted by fluids in different compartments of the patient's body. The authors propose a physicoanatomical explanation on the basis of the surgical findings.

A benign papilloma of the choroid plexus of the left lateral ventricle is found in a five-month old infant. An important dilatation of the isolated occipital horn is observed, without generalized enlargement of the ventricles. The clinical signs are limited to a moderate macrocephaly with deviation of head and eyes to the left. The absence of global hydrocephalus is rather exceptional in such cases, where overproduction of cerebrospinal fluid, in an amount proportional to the tumoral mass, is generally admitted. Nevertheless, the literature offers no absolute proof of the role of oversecretion alone in the origin of hydrocephalus, whilst an eventual obstruction of the circulatory pathways and resorption areas of the C.S.F. must be kept in mind. The absence of hydrocephalus, in the present case, suggests that the subarachnoid spaces and arachnoid villi remained patent.

A benign papilloma of the choroid plexus of the left lateral ventricle is found in a five-month old infant. An important dilatation of the isolated occipital horn is observed, without generalized enlargement of the ventricles. The clinical signs are limited to a moderate macrocephaly with deviation of head and eyes to the left. The absence of global hydrocephalus is rather exceptional in such cases, where overproduction of cerebrospinal fluid, in an amount proportional to the tumoral mass, is generally admitted. Nevertheless, the literature offers no absolute proof of the role of oversecretion alone in the origin of hydrocephalus, whilst an eventual obstruction of the circulatory pathways and resorption areas of the C.S.F. must be kept in mind. The absence of hydrocephalus, in the present case, suggests that the subarachnoid spaces and arachnoid villi remained patent.

Sixteen patients, with a total of 18 abscesses, were treated by aspiration and systemic antibiotic therapy, to which antiepileptic prophylaxis and corticosteroids were added. Diagnosis of the abscesses and monitoring of their evolution relied principally upon computed tomography; this technique was also used per-operatively when aspirating small abscesses.

After a lapse of not less than two years the authors study the functional and clinical evolution of 62 patients presenting myelopathy in cervical arthrosis treated by surgery. A scoring system for evaluating the functional deficit of the patients is used for quantitative assessment of the disorders. Surgery brought a frank improvement in 38 patients: it left the sensorimotor deficits of 19 patients unchanged. The handicap continued to deteriorate in three patients. Two patients died from non-neurological disorders. The data are compared with those in the literature which indicate an improvement rate of the same order of magnitude. Within certain limits, age and the degree of initial handicap do not seem to influence the long-term result of surgery. However, the time lapse between the appearance of the first signs of deficiency and surgery seem to constitute an important prognostic factor. The shorter the time lapse, the better the result.

In a 9 month-old infant, who displayed an epileptic seizure, the Brain CT-Scan shows a ventricular enlargement and a bilateral pericerebral effusion, associated with a left parieto-temporal arterio-venous malformation. Angiogram reveals a small angioma shunting the blood flow from the left middle cerebral artery into the lateral sinus. Intracranial pressure, recorded with a fontanellar transducer, is borderline. The angioma is excised and the operation, during which the subarachnoid location of the pericerebral effusion is confirmed, is followed by gradual subsiding of the internal and external hydrocephalus, that was caused by enhancement of the pressure in the venous sinuses. This case belongs to an infantile form of Benign Intracranial Hypertension, in which CT-Scan has to be interpreted cautiously, to avoid the pitfall of a wrong diagnosis of brain atrophy.