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Biomedical subjects

S Bien

Publications and source records attributed to S Bien.

At least 19 recordsLinked to original sources
PubMed2006

CNS involvement in hereditary neuropathy with pressure palsies (HNPP).

We assessed seven patients with hereditary neuropathy with liability to pressure palsies (HNPP) with 16 electrophysiological tests and cranial MRI for CNS abnormalities. Mean latencies differed between patients with HNPP and controls for the blink reflex, the jaw-opening reflex, and acoustic evoked potentials. MRI abnormalities were observed in four patients. Our study suggests subclinical but functionally relevant CNS myelin damage in HNPP.

Adult↗
PubMed2006

Surgical management of dural arteriovenous fistulas with transosseous arterial feeders involving the jugular bulb.

Dural arteriovenous fistulas located in the vicinity of the jugular foramen are complex vascular malformations and belong to the most challenging skull base lesions to treat. The authors comprehensively analyze multiple features in a series of dural arteriovenous fistulas with transosseous arterial feeders involving the jugular bulb. Four patients who underwent surgery via the transcondylar approach to treat dural arteriovenous fistulas around the jugular foramen were retrospectively reviewed. Previously, endovascular treatment was attempted in all patients. The success of the surgical treatment was examined with postoperative angiography. Complete obliteration of the dural arteriovenous fistulas (DAVFs) was achieved in three patients, and significant flow reduction in one individual. All patients had a good postoperative outcome, and only one experienced mild hypoglossal nerve palsy. Despite extensive bone drilling, an occipitocervical fusion was necessary in only one patient with bilateral lesions. The use of an individually tailored transcondylar approach to treat dural arteriovenous fistulas at the region of the jugular foramen is most effective. This approach allows for complete obliteration of the connecting arterial feeders, and removal of bony structures containing pathological vessels.

Aged↗
PubMed2005

Value of digital volume tomography in patients with conductive hearing loss.

Digital volume tomography (DVT) is an extension of panoramic tomography. With this diagnostic technique, characterized by high resolution, a narrow section width (0.125 mm) and three-dimensional display, small pathological processes can be well visualized. Twenty-five patients with the history of a progressive hearing loss were examined with DVT (Accu-I-tomo, Morita, Japan). The results were compared with pre- and intraoperative findings to evaluate the diagnostic value of DVT in cases of erosion of the ossicular chain. With high resolution and artifact-free demonstration of the middle ear and the ossicular chain, it was possible to define its continuity preoperatively by DVT in all 25 cases. An intact ossicular chain was found by DVT in 13 cases and was later confirmed by surgery. The predicted erosion of the ossicles was verified in 12 patients, and a tympanoplasty type III was performed. Digital volume tomography is an excellent technique to examine the middle ear cleft and inner ear, and expands the application of diagnostic possibilities in the lateral skull base. Therefore, improvement in preoperative diagnosis is achieved along with more accurate planning of the surgical procedure. Digital volume tomography delivers a small radiation dose with a high resolution and a low purchase price for the equipment.

Adult↗
PubMed2004

Selective high-dose intra-arterial cisplatin as palliative treatment for incurable head and neck cancer.

OBJECTIVE: The purpose of the present study was to evaluate the palliative effect of selective intra-arterial chemotherapy in progressive unresectable head and neck cancer previously treated with radiochemotherapy. PATIENTS AND METHODS: 8 patients with advanced residual or recurrent squamous cell carcinoma of the head and neck were evaluated. These patients were included in the present study particularly because of progredient pain and recurrent bleedings due to tumor progression. In addition 6/8 patients suffered from unpleasant tumor-related smell. All patients received simultaneous infusions of cisplatin (150 mg/m2) intra-arterially to the tumor and sodium thiosulfate intravenously (9 g/m2) for systemic neutralization of cisplatin. The patients were treated by at most 4 cycles of selective intra-arterial chemotherapy via femoral approach. RESULTS: Tumor-associated pain, occurrence of tumor bleeding and tumor-related smell were reduced after at least 2 cycles of intra-arterial chemotherapy in all patients. Clinical and radiological assessment of the primary tumor site revealed a partial response in 4 patients while 4 patients were classified as nonresponders. Intra-arterial cisplatin treatment was well tolerated. CONCLUSION: Selective intra-arterial cisplatin therapy can be delivered safely for palliation of tumor-related symptoms of incurable head and neck cancer.

Antineoplastic Agents↗
PubMed2003

The Doppler-guided transfalcine venous approach in selected cases of vein of Galen malformations.

OBJECTIVE: This investigation was performed to evaluate the specific procedural issues and indications of a surgically assisted Doppler-guided endovascular transfalcine venous approach for the treatment of vein of Galen aneurysmal malformations (VGAM) in critically ill neonates. PATIENTS AND METHODS: Two neonates out of a clinical series of 15 children (8 males and 7 females) with vein of Galen malformations were treated by our neurovascular team, using a combined surgically assisted endovascular transfalcine approach. In the biplanar angiography room a radiographically guided craniotomy (1.5 cm) was placed over the cranial projection of the falciforme sinus. After craniotomy the orthograd flow of the falciforme sinus was identified by Doppler ultrasonography. The sinus was punctured by an i. v. cannula with injection port and was sutured to the skin. A microcatheter was maneuvered over a guide into the malformation under fluoroscopic control. For embolization Guglielmi electrolytically detachable platinum coils were placed into the malformation as an embolic agent. Neurological examination records, available MR images, computed tomographic scans, pre- and postembolization angiograms and follow-up data were analyzed. RESULTS: In both individuals the malformation was classified as VGAM. The follow-up was 6 and 7 months, respectively. No technique associated morbidity or mortality occurred in the present series. At discharge both selected neonates were in stable condition and the flow in the VGAMs could be significantly reduced by a combination of approaches including the venous transfalcine approach. Meanwhile, 6 months after birth one neonate died due to a deterioration of the pulmonary hypertension. CONCLUSIONS: Endovascular treatment is presently the most efficient strategy to allow neonates and infants survive the early manifestation of vein of Galen malformations and probably render a normal neurological development. Consequently, a combination of approaches in selected cases including the Doppler guided venous transfalcine route should be regarded as a preferential treatment modality, especially in patients with arterial vasospasms and venous stenosis.

Cerebral Angiography↗
PubMed2001

Current concepts in the classification, diagnosis and treatment of hemangiomas and vascular malformations of the head and neck.

There are many different classifications of vascular anomalies. As the correct classification of the vascular lesion has a direct influence on therapy it is difficult to decide which treatment should be considered as the treatment of choice. Based on an extensive review of the literature and personal experience of the treatment of more than 200 patients with hemangiomas or vascular malformations of the head and neck, a clinical classification is described that allows vascular lesions to be categorized in order to plan purposeful treatment. In general, hemangiomas represent the main group of vascular lesions in infancy and childhood. They are usually apparent a few weeks after birth and are characterized by an initially rapid growth of epithelial cells, followed by spontaneous involution. Hemangiomas should be differentiated from vascular malformations that are present at birth but may not be evident clinically. Spontaneous involution of vascular malformations has never been reported, whereas laser therapy can induce involution of hemangiomas at an early stage in a majority of cases. In certain situations steroids or surgical removal may seem to be the appropriate therapy of choice. In contrast, vascular malformations have to be treated according to their histopathology and location, as well as their hemodynamic features as shown radiographically with angiography. The accurate diagnosis of vascular anomalies is essential for further treatment, as shown by clinical experience at the University of Marburg.

Arteriovenous Malformations↗
PubMed2001

Treatment-induced neoangiogenesis in cerebral arteriovenous malformations.

We investigated the angiogenetic and proliferative activity of the endothelium of 30 consecutive surgical cases of AVM treated at our institution by immunohistochemical detection of the PCNA, MIB-1, Flk-1 and VEGF antibodies. Endothelial positive immunostaining was observed in 87% of the cases for PCNA, in 20% for MIB-1, and in 80% for Flk-1. Of 22 individuals treated with incomplete embolization prior to surgery, 17 showed an expression of VEGF (77%), but only two of the eight patients (25%) who were treated without prior embolization exhibited such an immunoreaction (P=0.0086). The proliferation and growth of cerebral AVMs is documented by endothelial expression of PCNA and MIB-1. The statistically significantly higher expression of VEGF in partially obliterated (embolized) AVMs is most likely caused by transient regional hypoxia within the AVM nidus that mediates neoangiogensis. It points out the clinical relevance of a complete occlusion in order to avoid neovascularization associated with subsequent morbidity and mortality.

Antigens, Nuclear↗
PubMed2001

Standard variant venous dysplasia of the cerebellum in a patient suffering from Muenke's syndrome and tinnitus.

BACKGROUND: Muenke's syndrome is a rarely seen craniosynostosis syndrome. Bilateral or unilateral coronal craniosynostosis, brachydactyly, tarsal and carpal coalitions are the typical clinical findings. Sensorineural hearing loss is reported in more than 30% of the affected patients. In patients with Muenke's syndrome intracranial vascular dysplasia has not been reported yet. PATIENT AND METHODS: A 13-year-old boy suffering from Muenke's syndrome reported a pulsating left-sided light tinnitus. Clinically a bluish formation was found at the lower part of the left-sided ear drum. In order to clarify the cause of the tinnitus and the bluish formation, extensive diagnostics (e.g. audiometry, magnet resonance tomography, magnet resonance phlebography, angiography) were carried out. RESULTS: Audiometry found a left sensorineural hearing loss with a conductive component. Radiological investigations found a standard variant venous dysplasia of the left petrous bone to be the reason for the tinnitus. CONCLUSION: Awareness of intracranial vascular dysplasia should be noted in individuals with Muenke's syndrome especially in cases of clinically suggestive symptoms like pulsating tinnitus.

Adolescent↗
PubMed2001

Endothelial proliferation, neoangiogenesis, and potential de novo generation of cerebrovascular malformations.

OBJECT: To date, both arteriovenous malformations (AVMs) and cavernomas have been considered to be congenital malformations. A recent survey of the literature has shown the potential for de novo generation of both familial and sporadic cavernomas as well as AVMs. Therefore, it was of interest to determine the biological behavior of these lesions in detail. METHODS: The proliferative and angiogenic capacities of the endothelium of 13 cavernomas and 25 AVMs obtained in patients recently treated (1997-1998) at one institution were studied. Immunohistochemical staining for proliferating cell nuclear antigen (PCNA), MIB-1, and vascular endothelial growth factor (VEGF) and its receptor Flk-1 was performed using standard staining procedures. Positive immunostaining of the nuclei of endothelial cells was observed in specimens of both AVMs and cavernomas for PCNA (80% of AVMs and 85% of cavernomas), and Flk-1 (80% of AVMs and 31% of cavernomas). Endothelial expression of VEGF in the 18 incompletely embolized AVMs was found in 72% of cases but only in 28% of the seven cases in which patients did not undergo endovascular treatment: it was found in 38% of cavernomas. Endothelial expression of MIB-1 was found in 12% of AVMs but in no cavernomas. CONCLUSIONS: These results indicate that there is endothelial proliferation as well as neoangiogenesis in cerebral cavernomas and AVMs. The increased level of angiogenesis in only partially obliterated AVMs underscores the need for radical and complete occlusion of cerebral AVMs to avoid recurrences and further risks of morbidity.

Adult↗
PubMed2000

Spinal type IV arteriovenous malformations (perimedullary fistulas) in children.

OBJECTS: Intradural perimedullary spinal arteriovenous fistula (AVF) is a synonym for type IV spinal arteriovenous malformation (AVM). It is an important clinical differential diagnosis in all patients with slowly progressive or acute spinal symptoms. Perimedullary AVFs are rare in the paediatric age group. We report the treatment regimen and the clinico-radiological findings for these malformations at our institution. METHODS: Of four paediatric patients, three individuals with persistent fistulas after endovascular treatment were operated on. The malformations were obliterated completely in all patients without any morbidity. In three patients previously documented neurological symptoms resolved during follow-up. CONCLUSIONS: If slowly progressive or acute radicular or medullary symptoms arise in children, a spinal arteriovenous malformation should be ruled out by MRI. A combined endovascular and surgical treatment of paediatric spinal AVM type IV (perimedullary AVFs) carries a low risk of morbidity and is reasonably effective.

Adolescent↗
PubMed2000

Individual cortical current density reconstructions of the semantic N400 effect: using a generalized minimum norm model with different constraints (L1 and L2 norm).

Event-related brain potentials were recorded to study whether verbs and nouns activate topographically distinct cortical generators. Fifteen subjects performed a primed lexical decision task with verb/verb and noun/noun pairs. The relatedness between prime and target items was varied in three steps (unrelated, moderately, and strongly related) and the EEG was recorded from 124 scalp electrodes. The topography of cortical sources of the N400 effect was evaluated by standardized differences scores and by cortical current source estimates which were constrained by the individual MRI-determined cortex anatomy. A behavioral priming effect and a substantial N400 effect was found for both word categories. However, the topography of the grand average N400 effect of verbs and nouns did not differ, neither for raw nor for standardized amplitudes. Cortical current source estimates of the N400 effect revealed a very broad and scattered distribution of active locations with pronounced interindividual differences. Cortical current source estimates obtained with the L1-norm and L2-norm model, respectively, differed in the distribution of sources over the cortex but converged on the same "hot spots." The data give no indication that the N400 effect is generated by word category-specific networks which have a different topography. The marked individual differences are discussed with respect to the involved processes and the current source estimation procedures.

Adult↗
PubMed1999

[Motor evoked potentials during embolization of arteriovenous malformations for the detection of ischemic complications].

Motor evoked potentials (MEP) recorded from the distal extremity muscles in response to transcranial magnetoelectrical stimulation were analyzed in a total of 10 patients during embolization of arteriovenous malformations (AVM) localized in frontal and parietal lobe (N = 5), in the temporal lobe (N = 2), in the the brain stem (N = 1), in the medulla oblongata (N = 1), and in the cerebellum (N = 1). The objective of this study was to clarify whether MEP allow reliable detection of ischemic complications during these procedures. Stable potentials as observed in 8 of 10 patients coincided in every case with an uneventful neurological outcome. Temporary significant prolongation of the central motor conduction time (CMCT) was observed in 2 patients. Both patients demonstrated a transient hemiparesis after the procedure, probably caused by ischemia. Our results clearly indicate that MEP are able to detect ischemic events during embolization of AVMs. Therefore, the use of MEP as a monitor of pyramidal function during endovascular therapeutic procedures seems to be promising.

Adolescent↗