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Biomedical subjects

J R Bentson

Publications and source records attributed to J R Bentson.

At least 19 recordsLinked to original sources
PubMed1998

Pentoxifylline is not a promising treatment for multiple sclerosis in progression phase.

Fourteen MS patients took pentoxifylline at varying doses for up to 24 months. In vitro production of tumor necrosis factor alpha was reduced in patients taking 2,400 to 3,200 mg/day of pentoxifylline for 12 weeks or more. Twelve of the 14 patients experienced worsening of the disease during the study according to clinical, MRI, or visual evoked potential criteria. These results provide no hint of efficacy for pentoxifylline as a treatment for MS in progression phase.

Adult↗
PubMed1997

Assessment of intraaxial and extraaxial brain lesions with digitized computed tomographic images versus film: ROC analysis.

RATIONALE AND OBJECTIVES: The authors evaluated the diagnostic accuracy of viewing computed tomographic (CT) scans as film versus soft-copy images at a workstation. METHODS: Receiver operating characteristic analysis of the interpretation of 202 CT scans (103 were normal, 99 were abnormal) by five neuroradiologists was performed. Abnormal images contained high- or low-attenuation intraaxial lesions or extraaxial fluid (subdural, subarachnoid, or epidural hemorrhage). Hard copies were read on a standard light box, and digital images were examined at a 1,024 x 1,250 workstation. Lesion location and type and confidence ratings were recorded on a worksheet. RESULTS: There were no statistically significant differences in diagnostic accuracy between the two display modes. Reader performance was slightly better with the workstation in the assessment of low-attenuation lesions. CONCLUSION: Diagnostic accuracy is similar for CT scans displayed at a workstation and those displayed as hard copy in the assessment of subtle intra- and extraaxial brain lesions.

Brain↗
PubMed1991

Meckel cave lesions: percutaneous fine-needle-aspiration biopsy cytology.

The authors describe the novel combination of two traditional methods to facilitate diagnosis of Meckel cave lesions, which may otherwise require craniotomy to obtain adequate tissue samples. Fine-needle-aspiration biopsy cytology was performed on tissue obtained with a percutaneous approach via the foramen ovale with use of fluoroscopic guidance and intravenous analgesia during an outpatient procedure. This new application of fine-needle-aspiration biopsy cytology results in decreased patient morbidity and significant cost reduction.

Adult↗
PubMed1988

Embolization: an adjunctive measure for removal of carotid body tumors.

Small carotid body tumors that do not encircle the internal carotid artery are excised with relative ease and minimal risk by the conventional subadventicial approach. Large carotid body tumors frequently encircle the internal and external carotid arteries, and extensive bleeding often complicates the resection, increasing the risk of carotid artery rupture and damage to major cranial nerves. Recent improvements in surgical techniques and selective embolization have lessened the risks of surgical excision, decreased the blood loss, and diminished the time required for resection. Experiences in the resection of carotid tumors with and without embolization are compared. Early resection of carotid body tumors, before involvement of the internal carotid artery and carotid bulb, is advocated.

Adult↗
PubMed1987

Asymptomatic degenerative disk disease and spondylosis of the cervical spine: MR imaging.

Evidence on magnetic resonance (MR) images of disk degeneration and herniation, as well as of cord and root impingement, may be regarded either as normal, age-related changes or as causative of symptoms. Individuals referred for MR examinations of the larynx without symptoms referable to the cervical spine were studied retrospectively (35 patients) or prospectively (65 patients) over a 2-year period. With a solenoid surface coil, 5-mm-thick sections were acquired in sagittal, axial, and coronal planes with T1-weighted spin-echo pulsing sequences. Disk protrusion (herniation/bulge) was seen in five of 25 (20%) patients aged 45-54 and 24 of 42 (57%) patients older than 64 years of age. Posterolateral protrusions were seen in only nine of 100 patients and occurred with greatest frequency in patients over 64 years of age. In no patient was obliteration of the intraforaminal fat seen. Spinal cord impingement was observed in nine of 58 (16%) patients under 64 years of age, and in 11 of 42 (26%) patients over 64 years of age. Cord compression was observed in seven of 100 patients and occurred solely secondary to disk protrusion in all cases. The percentage of cord area reduction never exceeded 16% and averaged approximately 7%.

Aged↗
PubMed1987

MR imaging of the nasopharynx and floor of the middle cranial fossa. Part I. Normal anatomy.

The normal anatomy of the nasopharynx and floor of the middle cranial fossa was analyzed with magnetic resonance (MR) imaging. MR images from five healthy volunteers were correlated with whole-organ cryomicrotome sections from three cadavers. Anatomic connections exist between the paranasopharyngeal spaces and the surface structures of the skull base. These anatomic connections include the intimate relationship between the eustachian tube and the pharyngobasilar fascia, the attachment of the muscles of mastication and deglutition to the skull base, and vascular and nervous structures in the foramina. The inherent contrast between the soft tissues of the nasopharynx and related structures and the bone of the floor of the middle cranial fossa allowed excellent visualization of these anatomic connections.

Cadaver↗
PubMed1987

MR imaging of the nasopharynx and floor of the middle cranial fossa. Part II. Malignant tumors.

The intracranial extension of tumors of the nasopharynx and related spaces presents a difficult imaging problem. Unlike computed tomography (CT) scans, magnetic resonance (MR) images are not limited by beam-hardening artifacts from bone or dental amalgam. Forty-six patients with malignant tumors of the nasopharynx and related spaces affecting the skull base underwent MR imaging. MR images were obtained with a 0.3-T permanent-magnet imaging system in axial, sagittal, and coronal planes. MR findings were compared with clinical records, plain radiographs, CT scans, and pathologic correlates when available. MR imaging could demonstrate neoplastic invasion of the bone of the floor of the middle cranial fossa and the vital soft-tissue structures related to it as well as or better than CT. Tumor extension was viewed directly as a continuous mass or indirectly by marrow replacement or displacement of normal structures. Specific anatomic routes through which tumors extend from the nasopharynx to the middle cranial fossa were inferred from MR findings.

Eustachian Tube↗
PubMed1987

Intravascular balloon embolization of a large mid-basilar artery aneurysm. Case report.

A patient who presented with multiple episodes of subarachnoid hemorrhage was diagnosed as having a large mid-basilar artery aneurysm that had no definable surgical neck. Balloon embolization was performed utilizing two detachable silicone balloons to occlude the mid-basilar artery and the aneurysm. The procedure was carried out with the patient fully awake and alert. One day after the procedure, the patient developed pontine and cerebellar ischemia which completely resolved after 5 days on heparin therapy. A follow-up angiogram performed immediately after the procedure and at 3 months demonstrated complete occlusion of the mid-basilar artery and the aneurysm. The patient was intact neurologically upon discharge 5 days after the embolization procedure and has since resumed his normal activities. Balloon embolization therapy may offer some advantages over surgical methods for the treatment of such therapeutically challenging aneurysms.

Adult↗
PubMed1986

Magnetic resonance imaging of the brainstem and cranial nerves.

Ten normal human volunteers and 44 patients with pathology of the brainstem or cranial nerves were scanned using a. 3 Tesla permanent MR imaging system. MR images were obtained of the cranial nerves and brainstem using various spin-echo pulse sequences and scanning planes. 4 mm thick sections with .75 mm pixels on a 256 display matrix were used whenever possible. The normal MR images were correlated with thin section cryodissection specimens of fresh human cadavers. Brainstem structures including major nuclei and tracts were then identified. The cranial nerves were followed through the subarachnoid cisterns and the base of the skull. Pathological involvement of the brainstem by tumors, infarcts, and demyelinating disease was well shown and correlated with clinical findings. Examples of optic glioma, fifth, eighth, and twelfth nerve schwannomas as well as other cranial nerve pathology were also demonstrated. Magnetic resonance produces excellent images of cranial nerves and brainstem with high contrast resolution. Unlike CT, there is no beam hardening artifact from bone. T1 weighted images maximize brainstem-CSF contrast and are useful for demonstrating the external anatomy of the brainstem and cranial nerves. The T2 weighted images show internal brainstem anatomy, CSF within neural foramina, and highlight many pathological conditions.

Adult↗
PubMed1986

Spontaneous arteriovenous fistulas of cerebral vessels in association with fibromuscular dysplasia.

Four cases of spontaneous arteriovenous fistula seen in association with fibromuscular dysplasia of the parent artery are presented. In two patients, the fistula was between the carotid artery and cavernous sinus; in two others, the fistula involved the vertebral artery and paravertebral veins. It is postulated that the angiopathy was responsible for the fistula. Treatment by detachable balloon embolization was successful in each case; however, the presence of the fibromuscular dysplasia made treatment more difficult.

Adult↗
PubMed1986

Balloon embolization of a large distal basilar artery aneurysm. Case report.

Interventional neurovascular techniques have advanced to a level where treatment of intracranial aneurysms by intravascular detachable balloon embolization therapy is now possible. A patient is presented who had a spontaneous subarachnoid hemorrhage from a large aneurysm of the distal basilar artery. The aneurysm arose at the bifurcation of the posterior cerebral arteries and measured 15 X 9 X 9 mm. With the patient fully awake, a detachable silicone balloon was passed into the basilar artery by a transfemoral arterial approach. Stenosis (greater than 60%) of the mid-section of the basilar artery, secondary to arterial vasospasm from the recent hemorrhage, was present. The stenosis was treated by transluminal angioplasty, after which the balloon was passed into the aneurysm and detached. A follow-up angiogram 3 months later demonstrated complete occlusion of the aneurysm and a widely patent basilar artery at the angioplasty site.

Adult↗
PubMed1986

Treatment of direct carotid cavernous sinus fistulae. Various therapeutic approaches and results in 148 cases.

From 1974 to 1986, 148 patients with carotid cavernous fistula (CCF) were evaluated for intravascular therapy. Four patients died from hemorrhage before treatment could be instituted and the CCF closed spontaneously in 5. Therapeutic approaches which resulted in complete occlusion in the remaining 139 cases were transarterial in 118, transvenous in 15 and external compression of the carotid artery and jugular vein in 6. The current treatment of choice of the direct CCF is intravascular embolization using detachable balloons, particulate emboli or liquid adhesive agents to occlude the CCF while attempting to preserve the carotid artery. In 15 patients it was technically too difficult to use the transarterial approach. The patients were therefore treated from a transvenous approach including access via the femoral vein, superior ophthalmic vein, intraoperatively from the inferior petrosal sinus or direct puncture of the cavernous sinus. Embolic agents used included detachable silicone balloons, steel minicoils, particulate emboli and isobutyl-2-cyanoacrylate. In 14 of these 15 patients total obliteration was achieved with marked improvement in symptoms. Complications occurred in 3 patients including perforation of the cavernous sinus resulting in subarachnoid hemorrhage, delayed pontine hemorrhage from subtotal occlusion of the fistula and transient increased proptosis.

Arteriovenous Fistula↗
PubMed1986

Closure of carotid cavernous sinus fistulae by external compression of the carotid artery and jugular vein.

From 1974-1986, 152 patients with carotid cavernous sinus fistulae (CCF) have been evaluated. Progressive closure of both dural and direct types of CCF have been noted utilizing intermittent external manual compression of the cervical carotid artery and jugular vein. In a group of 71 patients in whom this treatment was attempted, we have observed that 7 of 23 patients (30%) with dural CCF, and 8 of 48 patients (17%) with direct CCF had complete closure of their fistulae with no recurrence either clinically or at angiography done one year later. Closure occurred at varying times, from several minutes to 6 months (mean 41 days) following compression therapy. In those patients with CCF without rapidly progressive visual deterioration, cerebral ischemia, or other complicating factors, we recommend this technique with serial clinical follow-up and angiography before more definitive therapy is employed.

Adolescent↗
PubMed1986

Intravascular detachable balloon embolization of intracranial aneurysms. Indications and techniques.

The treatment of intracranial aneurysms from a transvascular approach, with preservation of the parent vessel is now being performed in selected cases. From a transfemoral approach, a silicone detachable balloon is flow-directed up the carotid or vertebral-basilar artery, guided directly into the aneurysm and detached. The aneurysm is thus excluded from the circulation and the parent artery is preserved. Thus far, this technique has been successful in treating aneurysms in the cavernous carotid, carotid ophthalmic, posterior communicating, distal basilar, and posterior cerebral artery distributions. The indications and techniques of detachable balloon embolization therapy are presented.

Embolization, Therapeutic↗
PubMed1986

Percutaneous transluminal angioplasty of the subclavian and vertebral arteries.

Percutaneous transluminal angioplasty (PTA) for atherosclerotic lesions of the subclavian, vertebral, and brachiocephalic vessels is being performed in selected cases. Clinically patients presented with symptoms of vertebral basilar insufficiency, multiple transient ischemic attacks, subclavian steal syndrome, and motor weakness of the upper extremity. Thus far, 22 procedures have been performed with good results. This included 16 subclavian, 4 vertebral, and 2 innominate arteries. Follow-up has ranged from 8 to 26 months (mean 17 months). No permanent neurologic complications have occurred with this technique, and all patients had significant clinical and radiographic improvement following this procedure.

Aged↗
PubMed1985

Magnetic resonance imaging of the brainstem: normal structure and basic functional anatomy.

Normal structure and basic functional anatomy of the brainstem were studied using anatomic sections obtained with a cryomicrotome whole-organ sectioning technique. Major tracts and nuclei were identified and their function summarized. Magnetic resonance imaging of the brainstem was performed on 10 normal volunteers. By comparing these images with the corresponding anatomic sections, normal structures, including major tracts and nuclei, were identified. Knowledge of location and function of clinically important brainstem nuclei and tracts is necessary for optimal magnetic resonance image interpretation.

Brain Stem↗
PubMed1984

Carotid-cavernous fistula following nasopharyngeal biopsy.

A middle-aged man with a cervical lymph node metastasis underwent nasopharyngeal biopsy in search of the primary tumor. Following biopsy his eye became swollen and painful with unilateral loss of vision. A carotid-cavernous fistula was demonstrated, as was deficient ossification at the base of the skull. The fistula was successfully treated with balloon embolization.

Arteriovenous Fistula↗