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Biomedical subjects

E Volle

Publications and source records attributed to E Volle.

18 recordsLinked to original sources
PubMed2004

Specific cerebral networks for maintenance and response organization within working memory as evidenced by the 'double delay/double response' paradigm.

Most of the working memory (WM) tasks used in functional imaging studies are based on the principle of the delayed response in which both the storage and the response organization are present during the delay period. It is therefore difficult to isolate activation specific to the storage function from that specific to the organization of the response. To determine the specific neural networks associated with these two WM operations, we performed a functional MRI study in healthy subjects using a new paradigm, 'the double delay/double response' tasks. This paradigm isolates maintenance from response organization by dividing the delay into two separate parts, the first being dedicated to memory, while the second includes response organization. Activation within the dorsolateral prefrontal cortex (DLPFC) followed a relative hemispheric dissociation: activation related to maintenance was predominant in the right DLPFC but was only detected when the load exceeded three items. Activation related to response organization was predominant in the left DLPFC, regardless of whether this response was based on information held in WM ('memory guided') or was independent of WM ('visually-guided'). These results suggest that activation of the DLPFC, should be interpreted in terms of executive processing for both maintenance and response organization.

Adult↗
PubMed2002

Forced collectionism after orbitofrontal damage.

A collector is a person who collects things on purpose, either as a hobby or business, or for personal satisfaction, e.g., stamp, coin, or art collector. In such instances, the act of collecting things represents voluntary, controlled, goal-directed, selective searching. Pathologic patterns of collecting have been observed following brain damage, particularly frontal lobe damage, ranging from a tendency to grasp (prehension behavior) to an irrepressible need to seize surrounding objects and store them (hoarding behavior). These adnormal behaviors express an excessive adherence to environmental stimuli but in no way express a planned process directed toward specific items. In this article, we describe an unusual pattern of pathologic collecting behavior due to frontal lobe damage: involuntary irrepressible collecting that is goal-directed and selective. The authors report a patient who collected specifically household electrical appliances following a bilateral damage of orbito- and polar-prefrontal cortex. The patient had involuntary irrepressible collecting that was goal-directed and selective. This "forced collectionism" is different from that of the usual collectionism encountered in patients with frontal lobe lesions, as the latter is in no way a planned process directed toward specific items.

Adult↗
PubMed2001

MRI video diagnosis and surgical therapy of soft tissue trauma to the craniocervical junction.

We evaluated objective diagnostic methods for patients with possible upper cervical spine instability caused by trauma and correlated them with subsequent neurosurgical findings and outcomes. Between November 1995 and May 1998, we investigated 420 patients with functional magnetic resonance imaging (MRI) of the craniocervical junction. We evaluated the extracranial vertebral circulation by MRI angiography, with focus on the position of the dens and on the subarachnoid space during entire rotational maneuvers. We documented 72 cases (17.1%) of injuries to the alar ligaments that were accompanied by signs of instability. Twenty patients (4.8%) had a complete alar ligament rupture, and 52 (12.4%) had an incomplete rupture with coexisting instability. We referred these patients to a neurosurgeon. Surgery was eventually chosen for 42 patients (10.0%) with the intention of obtaining dorsal occipitocervical stabilization. The duration of time between the MRI evaluation and surgery ranged from 1 week to 1.5 years (mean: 3.5 mo). After the fifth postoperative day, almost all symptoms had disappeared. One year following surgery, 34 of the 42 patients (80.9%) still demonstrated successful fusion and an alleviation of their sensation of instability. Twenty-five of these patients (59.5%)--all of whom were unemployed before surgery--were able to resume a professional activity. In the eight patients (19.0%) who still had a loss of stability during the second and 14th weeks, we noticed that there were some negative effects of rehabilitation. Six of these patients developed pseudarthrosis or osteolysis of their bone grafts during the first 3 months after fusion, and three required a repeat operation. We conclude that functional MRI with lateral tilting and rotatory evaluation is a useful tool for investigating craniocervical instability. For patients who are recalcitrant to following a program of conservative therapy, surgical stabilization of the craniocervical junction appears to be justified.

Adolescent↗
PubMed2001

[Idiopathic orbital myositis].

Orbital myositis is a rare disorder considered as a subgroup of inflammatory orbital pseudotumors. The pathophysiology is still unknown. Patients typically present with orbital pain exacerbated by eye movement and diplopia. Response to steroids is dramatic. We report a case of idiopathic myositis of the right inferior muscle, which recovered after steroid therapy.

Adult↗
PubMed2000

Functional magnetic resonance imaging--video diagnosis of soft-tissue trauma to the craniocervical joints and ligaments.

Patients suffering from distortion of the cervical spine after an acceleration trauma present problems with respect to the correct diagnostic recognition of the existing injuries. To define instability of the craniocervical junction, attention should be given to the position of the dens and the dimension of its subarachnoid space during the entire rotational maneuver. Our diagnosis via functional magnetic resonance imaging (fMRI) with video did not focus on injuries to the ligamentous microstructure as visualized with high-resolution MRI. Our purpose was to demonstrate the cause of instability of the craniocervical junction by direct visualization during fMRI-video technique. Between December 1997 and March 1999, 200 patients were studied using fMRI on a 0.2-Tesla Magnetom Open. Routine evaluation of the extracranial vertebral circulation by MRI angiography as an additional preinvestigative requirement is recommended. The earliest examination time from injury to MRI evaluation was 3 months and the maximum, 5 years (average, 2.6 years). Among the 200 patients investigated, 30 showed instability of the ligamentous dens complex. Of the same 200, 8 (4%) had a complete rupture and 22 (11%) an incomplete rupture of the alar ligament, with instability signs. In another 45 patients (22.5%), fMRI-video showed evidence of instability, and all these patients had coexisting intraligamentous signal pattern variation, probably due to granulation tissue. Eighty patients of the 200 (40%) had signal indifference without demonstrable video instability signs, and 43 patients (21.5%) showed no evidence of instability and no signal variation in the alar ligaments. On the basis of recognition of instability and the malfunction of the ligaments, the fibrous capsula, and the tiny dens capsula, we now can distinguish between lesions caused by rotatory trauma to the craniocervical junction and those from classic whiplash injury.

Cervical Vertebrae↗
PubMed1998

[Functional MRT of the LS in an open magnet system--the initial results].

PURPOSE: Description of the procedure and first results with functional MRI of the lumbar spine for the investigation of discoligamentous instability. MATERIAL AND METHOD: 21 patients--11 female and 10 male--were studied with rapid True-FISP- and FLASH sequences. With the intention to document movements in maximal ante- and retroflexion a special kidney belt was used containing an inserted multi-purpose flexible coil. With this approach reproducible functional studies can be obtained. RESULTS: Movements in ante- and retroflexion could be performed manually and gradually without technical limitation of restrictions due to the equipment. The location of a patient's pain was determined by indication from the patient and correlated with the finding on the functional MR images. In 71% of patients a gain of information was obtained with regard to discoligamentous instability of the lumbar spine when compared to earlier studies (CT, MRI in neutral position). CONCLUSIONS: Functional MRI of the lumbar spine can contribute additional segmental information and contribute to further therapy planning. With this method discoligamentous instability can be documented, which is less likely with static MRI in a closed MR system.

Adolescent↗
PubMed1996

MRI examination and monitoring of pediatric patients under sedation.

From April 1992 to May 1994, 780 patients aged from 1 day to 8 years were examined. Sedation of these patients was conducted by giving chlorprothixene orally and, in some cases, chloral hydrate had to be added. The patients were monitored with a pulse oxymeter. Investigations could begin after 50 -120 min. In 710 patients (91%) the first attempt to perform the examination was successful; 70 patients required one or two further attempts. Only two of the 780 patients (0.5%) showed evidence of respiratory depression. The total number of pediatric MRI examinations performed in 1 year is almost 1000. In the hands of an experienced pediatric radiologist these examinations can be performed entirely without anesthesia.

Child↗
PubMed1996

[Osteolysis of the lateral clavicle after Tossy II injury in ice hockey players].

Injuries of the acromioclavicular joint in hockey mainly occur after trauma directly to the shoulder joint. E.g. at a fall against the border, onto the ground or in case of a body check. Tossy-III-lesions lead directly to surgery meanwhile type Tossy-II-lesions are mainly treated conservatively. Despite healing of the acromioclavicular ligaments often acromioclavicular joint pain remains despite conservative treatment because of discuss lesions or a osteolysis of the lateral end of the clavicle. The resection of the lateral end of the clavicle with certain pain relief, very good functional results and quick full level participation in hockey has been shown as the method of choice in our patients.

Acromioclavicular Joint↗
PubMed1992

Radicular avulsion resulting from spinal injury: assessment of diagnostic modalities.

The diagnostic utility of imaging techniques in injuries to the intramedullary and subarachnoid portions of the brachial plexus, with possibly complete avulsion of one or more nerve roots from the spinal cord and extramedullary meningocoele was compared in 18 patients studied by unenhanced computed tomography (CT), cervical myelography, myelographic CT (MCT) and magnetic resonance imaging (MRI). Emphasis was placed on the lesions of the subarachnoid roots. CM was the only diagnostic modality to show avulsion of 18 nerve roots and their levels in 8 patients (100% = gold standard), and to verify 2 incomplete avulsions. MCT reliably revealed 8 of 18 (45%) and MRI 1 out of 18 (6%) avulsions. Myelography with MCT showed intact subarachnoid nerve roots in 10 additional patients. MRI and MCT (16 out of 16 = 100%) were superior to myelography (14/16 = 88%) for demonstrating 16 traumatic meningocoeles in 8 patients; follow-up MRI (6-24 months) showed no increase in their size. We recommend a subsequent CT to role out fracture to the spinal column; MRI should provide significant information concerning oedema or haemorrhage in the spinal cord. Myelography with segmental MCT is performed to differentiate pre- from post-ganglionic lesions, data which are essential for deciding whether exploration of the plexus or a motor substitution operation is indicated.

Adolescent↗
PubMed1991

[Direct cervical myelography using iotrolan 300].

A prospective study of direct cervical myelography with Iotrolan 300 showed the following advantages: 1. Clear differentiation of the nerve roots. 2. Increased retention of contrast in the cervical region. 3. Improved contrast compared with conventional contrast media. 4. Optimal contrast temperature was found to be between 20 and 22 degrees C. 5. Reduction in non-specific and central nervous system complications.

Adolescent↗
PubMed1991

Selective spinal panangiography: use of a 4-F braided catheter with a soft-tip configuration.

A 4-F braided catheter with a soft radiopaque tip was used in selective spinal panangiographic procedures. Results obtained with the catheter were compared with those obtained in procedures with conventional catheters. The catheter was used in the intercostal, lumbar, and sacral arteries. Advantages of using this catheter include excellent maneuverability, reduced patient exposure to contrast medium, and reduced fluoroscopy duration.

Adolescent↗
PubMed1989

Therapeutic approach to ingested button-type batteries. Magnetic removal of ingested button-type batteries.

Button-type batteries ingested by 13 children were removed from the esophagus and the upper gastro-intestinal tract by means of the FE-EX "OGTM-technique". An initial radiogram from the nasopharynx to the anus was performed. We used the FE-EX tube magnet with a cylindric Vacomax/Vacodym magnet. In all cases the button type battery was easily detected and retracted under fluoroscopic control with the magnet. All patients tolerated the procedure without subjective complaints and were discharged soon without a need of anesthesia, surgery/endoscopy or more radiography. The FE-EX "OGTM" procedure is a relatively non-invasive approach to a potentially catastrophic pediatric problem.

Child↗
PubMed1988

CT reconstruction technique in lumbar intraneuroforaminal disc herniation.

The CT appearance of the lumbar neural foramina and contents is described in detail and compared to histopathological specimens. Direct axial scans with secondary sagittal, coronal and paraxial reconstruction series of slices of the neural foramen were derived from lumbar spine examination of fifty normal adults. These normal parameters were then used to evaluate and subdivide 20 patients with disc herniation involving the neural foramen. The new paraxial reformation was able to show an intraneuroforaminal disc involvement. CT-reformation technique and operative results in intraneuroforaminal disc herniation correspond in 80%. This improvement in preoperative diagnosis demonstrates to the neurosurgeon the full extent of disc herniation and results in an optimized operative approach.

Adult↗
PubMed1987

Pulmonary alveolar microlithiasis in pediatric patients--review of the world literature and two new observations.

Report of two new pediatric cases of pulmonary alveolar microlithiasis (PAM). PAM is a rare disease of unknown etiology; not more than 38 cases have been reported aged less than 18 years. The essential features of this disease are (1) a characteristic radiographic appearance of a sand-like opacity of both lungs and linear densities like "beads on a string" along the heart, pleura and interlobar fissures; this is best visualized by fluoroscopy in combination with magnification technique; (2) extremely few clinical signs and almost no laboratory abnormalities.

Calcinosis↗
PubMed1987

[Removal of swallowed metallic foreign bodies by orogastric magnetic intubation].

Foreign bodies with metal content ingested by 16 patients were removed from the upper gastrointestinal tract by means of a magnet inserted into the end of orogastric tube. In only one case did the foreign body uncouple from the orogastric tube-magnet arrangement during retrieval. The procedure is an alternative to endoscopic or surgical removal in some cases of metal foreign body ingestion.

Child↗
PubMed1986

Ingested foreign bodies: removal by magnet.

Metallic foreign bodies ingested by eight patients (seven children) were removed from the upper gastrointestinal tract by means of a magnet inserted into the end of an orogastric tube. No patient required hospitalization, anesthesia, surgery, or subsequent radiography, and all patients remained asymptomatic. In no case did the foreign body uncouple from the orogastric tube-magnet arrangement during retrieval. The procedure is an alternative to endoscopic or surgical removal in some cases of metallic foreign body ingestion.

Adult↗
PubMedDate not supplied

Lesions of skull base observed on high resolution computed tomography. A comparison with magnetic resonance imaging.

Forty patients with tumors involving the skull base were selected on the basis of findings at high resolution computed tomography (CT). The reliability of demonstrating bony lesions with magnetic resonance imaging (MRI) and CT were compared. CT showed osseous lesions of the skull base better than MRI but was less sensitive in evaluating an associated inflammatory reaction or in defining intracerebral infiltration. Small cortical lesions were only demonstrable with CT. MRI was superior in defining the full extent of soft tissue infiltration. Arterial encasement was observed at MRI. The special advantage of Gd-DTPA lies in the additional possibility to differentiate vessels from tumor-like lesions and in en plaque tumors.

Adolescent↗