Time dependence of serial diffusion-weighted imaging features in a case of pyogenic brain abscess.

Both signal intensity on trace images and apparent diffusion coefficient measurements on mapped images evolved rapidly on serial diffusion-weighted sequences in a case of pyogenic brain abscess that was monitored primarily by MRI before a biopsy was performed. Considering only the signal intensities on the trace images would have led to an underestimation of the intrinsic tissue changes.

Pre- and peroperative misdiagnosed sellar tumour.

We describe the case of a 76-year old woman complaining of headaches and progressive sight loss. Cerebral CT scan and MRI disclosed a large sellar tumour. Endocrine evaluation showed no evidence of pituitary hypersecretion, but a slight hyperprolactinemia related to stalk compression. A non-functioning pituitary adenoma was suspected. The pathological diagnosis was however a meningioma. In the literature, about 5% of sellar tumours are not pituitary adenomas and this is an alternate diagnosis to consider in the presence of non-secreting macroadenomas.

MR-monitored remitting-relapsing pattern of cortical involvement in Rasmussen syndrome: comparative evaluation of serial MR and PET/SPECT features.

We report the serial MR and PET/SPECT findings in a 2 1/2-year-old boy presenting with Rasmussen syndrome and highlight the close qualitative correlations between the results of the imaging modality and the functional isotopic techniques. The latter demonstrated a wider field of extension of the disease process. Routine MRI demonstrated its ability to detect brain changes matching the more sensitive PET and SPECT data and correlated well with the clinical evolution.

Whipple disease confined to the central nervous system in childhood.

In a case of pediatric Whipple disease confined to the central nervous system, white matter lesions initially appeared as areas of very low signal intensity on T1-weighted MR images and as areas of hyperintensity on proton density-weighted and T2-weighted images, and showed slight peripheral enhancement on delayed contrast-enhanced T1-weighted images. On MR studies obtained 3 and 6 months after antibiotic therapy, the lesions had decreased in size and no longer enhanced. They became progressively less hypointense on T1-weighted images and less hyperintense on T2-weighted images.

Pathogenetic factors in chronic subdural haematoma and causes of recurrence after drainage.

The radiological aspect, pathology, treatment and results of 132 subdural haematomas observed in 100 patients, are discussed. The majority of these cases were characterized by a nonhomogenous CT scan picture, resulting from repeated bleeding in a previous subdural haematoma evolving to chronicity, or in a pre-existent subdural hygroma. Taking aspirin may have constituted a predisposing factor in 16% of our patients, whilst coagulation disturbances, including anticoagulant treatment, were observed in another 6%; ethylism was present in 11%. A traumatic origin was ascertained in 80% of the patients. The treatment consisted of burr hole evacuation and drainage in 91.5% of the haematomas, corresponding to 92% of the patients; it was eventually repeated once or twice in some cases. In 6% of the patients, a subduro-peritoneal drainage had to be placed ultimately and in 2%, a membranectomy had to be performed because the haematoma had become nearly completely fibrous. The necessity for repeated evacuation and eventual subduro-peritoneal drainage seems to depend mainly on a slow brain re-expansion in some elderly people, who are actually more frequently referred. Two patients died; one was deeply comatose and another in poor general condition. Morbidity in the 96 remaining patients, 2 being lost to follow-up, was 11%: 5% related to the haematoma or to the causal trauma, and 6% from other concomitant neurological disease. The functional result was satisfactory in 85%.

[Craniostenosis and craniofacial dysmorphia]. / Craniosténoses et dysmorphies cranio-faciales.

The paper gives a brief historical survey of craniostenosis and the first operative approaches. The authors describe a classification of various types of cranio-facio-stenosis and facio-cranio-stenosis and present a detailed study of their experience in this area. Operative results are discussed in function of the selected surgical procedure, the immediate per- and post-operative complications and the short and long term morbidity. The authors present their current attitude for each dysmorphic type. They underline the heavy nature of this long-lasting and bleeding surgical procedure that concerns small children. They have recorded 31 incidents in relation with surgical procedure, 10 complications at short and long term, and 1 death. Such surgery requires an experienced and vigilant team, associating surgeons, anesthetists and intensive-care physicians.

Brain glucose utilisation in acquired childhood aphasia associated with a sylvian arachnoid cyst: recovery after shunting as demonstrated by PET.

Regional brain glucose utilisation was investigated with PET and fluorodeoxyglucose (FDG) in a case of epileptic aphasia (Landau-Kleffner syndrome) associated with a left sylvian arachnoid cyst. CT and MRI had failed to disclose any mass effect of the cyst on surrounding brain structures. Sequential metabolic measurements showed a comparable pronounced hypometabolism in cortical regions around the cyst, involving speech areas, and suggested mild but chronic compression of the developing brain. After placement of a cyst-peritoneal shunt system, significant metabolic improvement occurred in all cortical regions, especially the inferior frontal gyrus and the perisylvian area, with predominant residual deficit in the left superior temporal gyrus. These findings were correlated with a pronounced increase in word fluency and slower progress in verbal auditory comprehension. This report suggests that PET is able to evaluate the functional disturbances associated with expanding arachnoid cysts, and to follow the neurological improvement after drainage.

[Orbito-fronto-temporal approach to tumors at the base of the skull. Our experience in the creation of orbito-zygomatic-malar flap]. / Abord orbito-fronto-temporal des tumeurs basicrâniennes. Notre expérience dans la création d'un volet orbito-zygomatico-malaire.

The authors describe the technique of mobilization of the osseous orbito-zygomatico-malar complex pedicled to the masseter muscle. In some affections it is justiciable to use this approach which provides an excellent view of the lateral region of the medial cranial fossa and orbit and permits the access to the base of the tumor by a intra- and extracranial approach without traumatic injury for the brain and easy reconstruction.

Interest and necessity of combined neuroradiological and neurosurgical treatment in some cases of dural arterio-venous fistulae.

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.

Safety of the adjustable pressure ventricular valve in magnetic resonance imaging: problems and solutions.

We performed magnetic resonance imaging in 30 patients with hydrocephalus with Sophy adjustable pressure valves (PAVS). A pressure check following the MRI study showed a significant proportion with pressure valve changes, which could easily be readjusted by percutaneous manipulation. The value of the PAVS and its safety during MRI examinations are discussed.

[Juxtabulbar neurinoma of the spinal accessory nerve]. / Neurinome juxtabulbaire du nerf spinal.

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.

Intraneural ganglionic cyst of the common peroneal nerve: case report and review of the literature.

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.

Highly sensitive detection of beta-2 transferrin in rhinorrhea and otorrhea as a marker for cerebrospinal fluid (C.S.F.) leakage.

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 microliters) of rhinorrhea or otorrhea fluids. Application of this method in a series of 10 patients with CSF fistula is reported.

[Spontaneous hematoma of the cerebellum]. / L'hématome spontané du cervelet.

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.

[Tethered cord syndrome, conservative or surgical approach?]. / Syndrome du filum terminal, approche conservatrice ou chirurgicale?

The authors gave a definition of a filum terminale and discussed the symptomatology, the etiology and the pathophysiology. They stressed the importance of carrying out a full neurophysiological, orthopaedic, anal and urogenital examination. This is the only way of establishing an indication for surgical treatment that should be carried out early in order to minimize acute accidents.

Unusual complication of peritoneal drainage: migration of a shunt in the subdural space.

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.

[Papilloma of the choroid plexus of the lateral ventricle without generalized hydrocephalus]. / Papillome du plexus choroïde du ventricule latéral sans hydrocéphalie généralisée.

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.

Treatment by aspiration of brain abscesses.

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. Bacteriological examinations were positive in all our cases and a polymicrobial flora was found in half of these. One or, eventually, two aspirations within the same week were sufficient, in most cases, to promote healing. Nevertheless, in three patients, the abscesses, however sterilized, did not show any volume reduction, probably because of adhesions to the dura mater, of a large part of the abscess surface area. One patient died from concomitant cardiac disease and one patient remained seriously disabled. Epilepsy was observed as a sequela, in six patients. This study emphasizes the role of neuroradiological and bacteriological examinations, whilst surgery may be restricted, in most cases, to a simple aspiration.