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Biomedical subjects

J Delavelle

Publications and source records attributed to J Delavelle.

At least 37 records · Page 2Linked to original sources
PubMed2000

Facial palsy in cerebral venous thrombosis : transcranial stimulation and pathophysiological considerations.

BACKGROUND: Cranial nerve palsy in cerebral sinovenous thrombosis (CVT) is rare, its pathophysiology remains unclear, and data from electrophysiological examinations in such patients are missing. CASE DESCRIPTION: We report the case of a 17-year-old woman with familial protein S deficiency who was admitted with extensive multiple CVT. Two weeks after onset of symptoms, she developed isolated right peripheral facial palsy, and MR venography showed segmental occlusion of the ipsilateral transverse sinus. Complete recovery of facial palsy occurred concomitant with recanalization of the transverse sinus. Facial neurography, including transcranial magnetic stimulation of the facial nerve and related motor cortex, ruled out a coincidental idiopathic palsy and revealed conduction block proximal to the facial canal. CONCLUSIONS: Facial palsy in our patient was caused by transient neurapraxia in the intracranial segment of the nerve. We suggest that elevated venous transmural pressure in the nerve's satellite vein, which belongs to the affected drainage territory of the transverse sinus, might have caused venous blood-brain barrier dysfunction in the intrinsic vascular system of the nerve, with leakage of fluids and ions into the endoneurial space and thus an increase in interstitial resistance.

Adolescent↗
PubMed1999

The various MRI patterns of pituitary apoplexy.

The aim of this study was to describe the various MRI features, in correlation to surgical and pathological findings, in patients who presented with pituitary apoplexy (PA). Eleven patients presenting with PA, were evaluated with various MR protocols including spin-echo (SE) T1-weighted sequences in 9 of 11 patients, post gadolinium SE T1-weighted sequences in only 8 of 11 patients, and with T2-weighted SE sequences in 2 of 11 patients. All patients had transsphenoidal pituitary surgery after MR studies. The severity of presenting symptoms ranged from headaches to coma. Ten patients had pituitary macroadenoma; one had a non-hemorrhagic metastatic lesion into a non-adenomatous pituitary gland. Of the 11 patients, one was studied at the acute stage of PA (1 day after onset), 9 at the subacute period (3-15 days after onset), and one at the late stage (5 months after onset). Images compatible with intratumoral hemorrhage were found in all macroadenomas, whereas the metastatic pituitary lesion did not show evidence of bleeding. All gadolinium-enhanced studies showed partial tumoral enhancement. The SE T2-weighted studies demonstrated areas of low and high signal intensities in keeping with the presence of blood degradation contents. Pituitary apoplexy present with different MR features, including hemorrhagic and non-hemorrhagic characteristics on T1-weighted images. Gadolinium-enhanced images do not provide complementary diagnostic information when the presence of blood is assessed on plain images.

Adult↗
PubMed1999

A pure case of Gerstmann syndrome with a subangular lesion.

The four symptoms composing Gerstmann's syndrome were postulated to result from a common cognitive denominator (Grundstörung) by Gerstmann himself. He suggested that it is a disorder of the body schema restricted to the hand and fingers. The existence of a Grundstörung has since been contested. Here we suggest that a common psychoneurological factor does exist, but should be related to transformations of mental images rather than to the body schema. A patient (H.P.) was studied, who presented the four symptoms of Gerstmann's syndrome in the absence of any other neuropsychological disorders. MRI showed a focal ischaemic lesion, situated subcortically in the inferior part of the left angular gyrus and reaching the superior posterior region of T1. The cortical layers were spared and the lesion was seen to extend to the callosal fibres. On the basis of an extensive cognitive investigation, language, praxis, memory and intelligence disorders were excluded. The four remaining symptoms (finger agnosia, agraphia, right-left disorientation and dyscalculia) were investigated thoroughly with the aim of determining any characteristics that they might share. Detailed analyses of the tetrad showed that the impairment was consistently attributable to disorders of a spatial nature. Furthermore, cognitive tests necessitating mental rotation were equally shown to be impaired, confirming the essentially visuospatial origin of the disturbance. In the light of this report, the common cognitive denominator is hypothesized to be an impairment in mental manipulation of images and not in body schema.

Brain↗
PubMed1999

Brain magnetic resonance imaging (MRI) and neurological changes after a single high altitude climb.

PURPOSE: Neurological impairment, mental dysfunction, and brain imaging changes caused by severe hypoxia have been described by several authors. However, the occurrence of transitory, long lasting, or permanent brain damage has been debated. Although climbing to 8000 m is reserved to a small number of climbers, there are hundreds of lowlanders spending relatively short holidays climbing peaks up to 6000 m in the Andes or in the Himalayas. They are usually not well acclimated and often suffer from acute mountain sickness (AMS). The aim of this study was to examine the effect of a single high altitude exposure on the changes in brain MRI and neuropsychological testing in climbers. METHODS: Brain MRI, medical history, and a battery of neuropsychological tests were obtained in eight male climbers between 31 and 48 yr of age a few days before and between 5 and 10 d after returning to sea level following ascent to altitudes of over 6000 m without oxygen. RESULTS: The mean AMS symptom score recorded at 5500 m was three in all climbers, headache being the predominant symptom. CONCLUSION: We did not observe the changes in brain imaging and in neuropsychological testing observed by other authors. The residual central nervous system impairment following return from high altitude was not observed in our study, and the good results in neuropsychological testing were well correlated with the unchanged brain MRI imaging.

Adult↗
PubMed1999

Psychosocial functioning in chronic epilepsy: relation to hippocampal volume and histopathological findings.

MRI volumetric measurements of the ipsi- and contralateral hippocampal volume (HV) were performed in a group of 37 patients with lesional and non-lesional temporal (TLE), and extratemporal lobe (ETLE) lobe epilepsy. Twenty-six patients underwent surgery and the resected tissues subjected to histopathological examination. Psychosocial scores were calculated on the basis of employment, partnership/family status and presence of a positive psychiatric history. Poorest values were obtained for the group with right lesional and non-lesional TLE (RTLE, p < 0.001). In this group, significant positive correlations between psychosocial functioning and the left hippocampal volume or age of onset were observed. We found that the left hippocampal volume in RTLE was smaller with increasing epilepsy duration. We conclude that patients with RTLE represent a particular group with regard to the structural and psychosocial consequences of chronic epilepsy. With regard to histopathological analysis, no particular type of lesion was identified as the major determinant of the results described above.

Adult↗
PubMed1998

Non-invasive epileptic focus localization using EEG-triggered functional MRI and electromagnetic tomography.

We present a new approach for non-invasive localization of focal epileptogenic discharges in patients considered for surgical treatment. EEG-triggered functional MR imaging (fMRI) and 3D EEG source localization were combined to map the primary electrical source with high spatial resolution. The method is illustrated by the case of a patient with medically intractable frontal lobe epilepsy. EEG obtained in the MRI system allowed triggering of the fMRI acquisition by the patient's habitual epileptogenic discharges. fMRI revealed multiple areas of signal enhancement. Three-dimensional EEG source localization identified the same active areas and provided evidence of onset in the left frontal lobe. Subsequent electrocorticography from subdural electrodes confirmed spike and seizure onset over this region. This approach, i.e. the combination of EEG-triggered fMRI and 3D EEG source analysis, represents a promising additional tool for presurgical epilepsy evaluation allowing precise non-invasive identification of the epileptic foci.

Adolescent↗
PubMed1997

Neoplastic invasion of the laryngeal cartilage: reassessment of criteria for diagnosis at CT.

PURPOSE: To evaluate eight different diagnostic criteria to help detect neoplastic invasion of laryngeal cartilage at computed tomography (CT). MATERIALS AND METHODS: In a prospective series, 111 patients with carcinoma of the larynx or hypopharynx underwent thin-section, contrast material-enhanced CT before total or partial laryngectomy. The following CT criteria were evaluated: extralaryngeal tumor, sclerosis, tumor adjacent to nonossified cartilage, serpiginous contour, erosion or lysis, obliteration of marrow space, cartilaginous blowout, and bowing. Histologic findings were correlated with findings on CT scans obtained at each level. RESULTS: Histologically, 122 of 412 cartilages were invaded. Depending on the diagnostic criteria and each specific cartilage, there was great variation in sensitivity (7%-83%) and specificity (40%-100%). Sclerosis was the most sensitive criteria in all cartilages but often corresponded to reactive inflammation in the thyroid cartilage. Extralaryngeal tumor and erosion or lysis yielded the highest specificity. Tumor adjacent to nonossified cartilage, serpiginous contour, and obliteration of marrow space were specific although not sensitive signs of invasion in the arytenoid and cricoid cartilage and were nonspecific in the thyroid cartilage. Blowout and bowing were not useful. Selection of the appropriate combination of criteria enabled an overall sensitivity of 91% (associated specificity, 68%) or an overall specificity of 79% (associated sensitivity, 82%). CONCLUSION: Detection of neoplastic cartilage invasion with CT greatly depended on the appropriate use of individual and combined CT criteria.

Adult↗
PubMed1997

Early high-dose intravenous methylprednisolone in acute disseminated encephalomyelitis: a successful recovery.

We describe a patient with acute disseminated encephalomyelitis (ADEM) who was treated with high-dose intravenous methylprednisolone 2 days after onset of neurologic symptoms. Despite poor prognostic factors and extensive white matter lesions, the patient recovered dramatically with no need for maintenance steroid therapy. This case report of fulminant ADEM treated successfully with early high-dose intravenous methylprednisolone, although uncontrolled, suggests that this agent should be studied in other cases.

Adult↗
PubMed1997

Discrepancies between HMPAO and ECD SPECT imaging in brain tumors.

Among several brain radiopharmaceuticals for SPECT imaging, 99mTc complexes of HMPAO and ECD are the most widely used. They are considered to be equal in their capacity to reflect regional cerebral blood flow; but discrepancies between HMPAO and ECD brain uptake have been reported in stroke patients. This paper reports our observations regarding discrepancies between HMPAO and ECD SPECT in 14 of 23 patients with suspected brain tumors or presumed metabolic cerebral abnormalities. We obtained similar conflicting results, namely focal HMPAO hyperactivities and isoactive ECD SPECT. The majority of these discrepancies were found in patients with brain tumors (10 of 13 patients), while only 4 of the 10 remaining patients with nontumoral process showed similar discrepant results. The physiopathology behind these observations is discussed here, and it is likely to be related to the specific response to cellular metabolic disorders rather than to perfusion disturbances.

Adult↗
PubMed1996

Leptomeningeal cyst in newborns due to vacuum extraction: report of two cases.

Two new cases of leptomeningeal cysts subsequent to vacuum extraction are reported. Both children presented with a huge, nonpulsating, transilluminating subgaleal collection over the anterior fontanel that appeared soon after instrument delivery. Plain X-rays, computed tomography, and magnetic resonance imaging confirmed that the subgaleal collection was cerebrospinal fluid and showed the presence of a diastatic coronal suture in both cases. Treatment consisted of duraplasty with periosteal flaps and application of fibrin glue. In one case, an associated porencephalic cyst was treated with a cystoperitoneal shunt. Surgical treatment of leptomeningeal cyst due to vacuum extraction is simple and should not be postponed, despite the tendency for the extracranial cyst to regress, because of the potential risk of continuous growth of an underlying porencephalic cyst and risk of neurological damage.

Arachnoid Cysts↗
PubMed1996

Three- to five-dimensional biomedical multisensor imaging for the assessment of neurological (dys) function.

This report describes techniques and protocols implemented at the Geneva Canton University Hospitals (HUG) for the combination of various biomedical imaging modalities and sensors including electromagnetic tomography, to study, assess, and localize neurological (dys) function. The interest for this combination stems from the broad variety of information brought out by (functional) magnetic resonance imaging, magnetic resonance spectroscopy, computed tomography, single-photon emission tomography, positron emission tomography, and electromagnetic tomography. Combining these data allows morphology, metabolism, and function to be studied simultaneously, the complementary nature of the information from these modalities becoming evident when studying pathologies reflected by metabolic or electrophysiologic dysfunctions. Compared with other current multimodality approaches, the one at the HUG is totally compatible with both clinical and research protocols, and efficiently addresses the multidimensional registration and visualization issues. It also smoothly integrates electrophysiology and related data as fully featured modalities.

Computer Graphics↗
PubMed1992

Toxoplasma encephalitis in patients with the acquired immunodeficiency syndrome.

Among 504 cases of AIDS diagnosed between 1983 and 1990, there were 86 patients (17%) with toxoplasma encephalitis (TE). All were symptomatic at the time of diagnosis. General signs such as fever, neck stiffness, or headache were present in 87.2%, and 75.6% had focal signs. The primary means of diagnosis was computerized tomographic scanning, revealing 169 lesions of which 80% were immediately contrast-enhancing. All patients had IgG antibodies against Toxoplasma gondii either before (74 of 75 evaluable patients) or at the time of diagnosis of TE (73 of 75). Elevated antibody titers were present in 44% of evaluable patients, compared to 11% of patients with AIDS and other opportunistic infections. Initial treatment was pyrimethamine plus sulfonamides in 65 patients, and pyrimethamine plus clindamycin in 12 patients, with other combinations or no treatment accounting for the remainder. Life-table analysis of the time to discontinuation of treatment because of suspected side effects suggested that sulfadiazine was significantly more toxic, with 48% of patients experiencing an interruption in treatment after 30 days, than pyrimethamine (12%) or clindamycin (24%). The 30-day mortality rate was 12%, and median survival was 310 days after diagnosis, 530 in patients treated with zidovudine and 190 days in those not so treated. Of 82 evaluable patients, 16 relapsed once and 4 of these more than once. The risk of relapse was 27% 1 year after diagnosis of a first episode of TE.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Empty sella syndrome associated with diabetes insipidus: case report and review of the literature.

Alteration of posterior pituitary function in the empty sella syndrome is rare. A case of central diabetes insipidus and clear-cut deficiency of gonadotropins associated with an empty sella is described. Although computed tomographic scan revealed a defect of the diaphragma sellae, other pathogenic mechanisms are considered. Previously documented cases of empty sella syndrome associated with diabetes insipidus are reviewed.

Adult↗
PubMedDate not supplied

Long-term changes induced by high-dose irradiation of the head and neck region: imaging findings.

High-dose irradiation is an effective treatment for tumors in the head and neck. Radiation-induced complications are uncommon but may result in chronic, progressive symptoms months or years after therapy. In 19 (1%) of 1,950 patients who underwent successful high-dose irradiation of head and neck tumors over a 5-year period, delayed radiation-induced changes were documented with imaging. These changes can be categorized as soft-tissue, bone, and cartilage necrosis; fibrosis leading to functional disorders; arteriopathy; central nervous system reactions, delayed myelopathy, and cranial nerve palsies; and the development of meningiomas. Radiologic features of radiation-induced soft-tissue, bone, and cartilage necrosis include inflammatory swelling adjacent to the area of involvement; deep gas-containing ulcerations; sclerotic appearance of the involved cartilages; fragmentation and sloughing of necrotic bone or cartilage; and abscess and fistula formation. Masticator muscle fibrosis appears as an area of diffusely increased signal intensity on T2-weighted images and of enhancement on postcontrast T1-weighted images. Radiation arteriopathy may manifest as occlusion, subocclusive sclerotic or atheromatous plaque, localized mural thrombus, aneurysm, or, rarely, spontaneous rupture. In central nervous system reactions, imaging findings include demyelination foci in the white matter, focal radiation necrosis, and severe brain atrophy. Radiation-induced meningiomas display the same imaging features as non-radiation-induced meningiomas at computed tomography, magnetic resonance imaging, and angiography, although follow-up examinations may reveal their more aggressive biologic behavior. Knowledge of the radiologic appearance of radiation-induced changes may prevent misinterpretations and facilitate treatment.

Aged↗